Gray Matter

Non-perioperative

Opioid-naive patient with uncontrolled pain on IV PCA after open hemicolectomy

A 58 y.o., 82 kg, 5'4" woman is on the surgical floor on postoperative day 1 after an open right hemicolectomy. The acute pain service is consulted first thing in the morning for poorly controlled pain.

HPIA planned laparoscopic right hemicolectomy for cecal adenocarcinoma was converted to open through an upper-to-lower midline incision because of dense adhesions. Preoperatively she declined an epidural should the case be converted. Four-hour general anesthetic: fentanyl 250 mcg and hydromorphone 1.5 mg; acetaminophen 1 g IV, dexamethasone 4 mg, ondansetron 4 mg; no NSAID. The surgeon infiltrated the incision with 20 mL of bupivacaine 0.25% at closure. EBL 350 mL; 2.5 L crystalloid. In PACU she received hydromorphone 1.2 mg IV and an IV PCA was started.

PMHHypertension. GERD. Depression, well controlled. Prior cesarean delivery. No alcohol or recreational drug use. Has never taken an opioid outside of the hospital.

MEDSHome: lisinopril 20 mg daily, sertraline 100 mg daily, omeprazole 20 mg daily. Current orders: hydromorphone PCA, 0.2 mg demand dose, 10-minute lockout, no basal infusion; acetaminophen 650 mg PO q6h prn; ondansetron 4 mg IV q6h prn; diphenhydramine 25 mg IV q6h prn itching, given twice overnight; lisinopril given this morning. Clear liquid diet.

PHYS EXAMAwake, tearful, holding a pillow against the incision. HR 108; BP 156/92; RR 22 and shallow; SpO2 93% on 2 L nasal cannula; T 37.9 C. Diminished breath sounds at both bases. Abdomen mildly distended, hypoactive bowel sounds, midline dressing dry.

LABSThis morning: Hgb 10.8 g/dL (preop 12.6); WBC 11.8 K/uL; platelets 238 K/uL; Na 137; K 4.4; creatinine 1.3 mg/dL (preop 0.8); glucose 168. Urine output 20 mL/h over the last 6 hours.

CURRENT STATEPain 7/10 at rest and 10/10 with coughing or turning. She has not been out of bed and will not use the incentive spirometer. Her husband has stayed at the bedside overnight.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. Initial evaluation (consult)

Teaching focus. Assessing postoperative pain by function and ruling out a surgical cause first; reading a PCA log and resetting demand, lockout, and basal settings in an opioid-naive patient; stratifying and monitoring for opioid-induced respiratory depression; building the non-opioid base when renal function is falling.

1. Pain on the first postoperative morning

At the bedside: how will you assess her pain? Which number do you treat, rest or cough? Goal for today? Her vital signs: all pain? DDx? What finding makes you call the surgeon now? Pain localizes to the incision; abdomen soft away from the wound, no rebound. Bleeding? What tells you? Somatic or visceral? How does that change your analgesic choices?

Considerations and pitfalls AI draft

Assessment. Location and character, rest versus dynamic pain, and function: can she cough, take a deep breath, use the spirometer, turn, sit up. Sedation level and RR belong in the same look, along with how she is using the PCA and whether she understands it. A pain score alone, without function and sedation, is an incomplete assessment.
Rest or cough. Dynamic pain is the one that limits coughing, deep breathing, and mobilization, so it drives pulmonary and functional outcomes. Rest pain can improve while she still cannot cough.
Goal. Functional: an effective cough, spirometer use, out of bed to a chair or walking today, at a pain level she finds tolerable, with sedation light enough to stay safe. Chasing a score of zero is the wrong target and is how opioid-naive patients get oversedated.
Vital signs and DDx. Tachycardia, hypertension, and tachypnea fit pain, but on POD 1 also consider hypovolemia (low urine output and a rising creatinine), bleeding, atelectasis (low-grade fever, basal breath sounds), and less likely PE, myocardial ischemia, or early sepsis. Attributing every abnormal vital sign to pain without examining her is the trap.
When to call the surgeon. Pain out of proportion or not incisional, peritonism (rigidity, rebound, diffuse tenderness), increasing distension, a soaked dressing, hemodynamic instability, a falling Hgb, or a sudden change in the character of the pain. These come before any analgesic adjustment.
Bleeding. A Hgb from 12.6 to 10.8 after 350 mL EBL and 2.5 L of crystalloid is consistent with measured loss plus dilution. Dry dressing, soft abdomen, and no hypotension argue against active bleeding; the low urine output points more toward under-resuscitation. Repeat the Hgb later today rather than dismissing it.
Somatic or visceral. Both are present; incisional somatic pain dominates with movement and cough, visceral pain is cramping and poorly localized. Opioids cover both; NSAIDs and wound or fascial plane techniques act mainly on the somatic component. A strong learner ties the mechanism to the multimodal choices that follow.

2. The PCA log

PCA log, last 8 hours: 52 demands, 21 delivered, 4.2 mg. Interpretation? Loading dose now? Dose? Endpoint? Assume you give 0.8 mg over 15 minutes. Now 4/10 at rest, awake and conversing, RR 16. New demand dose? Lockout: change? Why/why not? Basal infusion? Why/why not? Hourly or 4-hour limit? Set to what? Stay on hydromorphone, or switch? Morphine? Fentanyl? Why?

Considerations and pitfalls AI draft

Interpretation. 31 of 52 demands landed inside the lockout: she is pressing repeatedly and each 0.2 mg dose is too small for her. 4.2 mg over 8 hours is about 0.5 mg/h. The PCA is the right tool set too low, not a failed modality. Also confirm she understands it, the IV is patent, and the pump line is connected.
Loading. A PCA cannot catch up from severe pain. Clinician-given hydromorphone 0.2-0.4 mg IV every 5-10 minutes, reassessing pain, sedation, and RR between doses. Endpoint is tolerable pain or the first sign of sedation, whichever comes first.
Demand dose. Increase to 0.3-0.4 mg and titrate by use and sedation; a 50% step is reasonable in an opioid-naive patient.
Lockout. Keep it at 8-10 minutes. IV hydromorphone takes 10-20 minutes to peak, so a shorter lockout lets doses stack before the previous one has acted. Fix the dose, not the lockout.
Basal. No. In opioid-naive adults a basal infusion adds respiratory depression without improving analgesia, and it defeats the safety design of PCA, in which a sedated patient stops pressing. Adding a basal to fix this log is a flag.
Limit. An hourly or 4-hour limit is a backstop, not a substitute for monitoring. At 0.3 mg every 10 minutes the pump can deliver 1.8 mg/h; set the limit near realistic need.
Agent. The rising creatinine argues against morphine, whose active (M6G) and neuroexcitatory (M3G) metabolites accumulate in renal impairment. Hydromorphone remains reasonable with attention to dose; fentanyl, with no active metabolites, is an alternative. Switching drugs to fix an underdosed PCA misses the problem.

3. What her husband reports

Her husband says she snores loudly and he has watched her stop breathing in her sleep for years. Of concern? Why? Diphenhydramine: continue? Why/why not? Itching Rx instead? Monitoring on the PCA: what? Continuous pulse oximetry: enough? Why/why not? Capnography? Why/why not? Sedation checks: how often? At what level do you hold the opioid? Oxygen: keep it on, or wean to room air? Why? CPAP tonight without a diagnosis? Why/why not?

Considerations and pitfalls AI draft

Concern. Probable undiagnosed OSA in an opioid-naive patient with obesity whose opioid dose is about to go up. Risk of opioid-induced respiratory depression is highest in the first 24 hours, at night, and with co-sedatives; REM rebound over POD 2-3 can worsen obstructive events.
Diphenhydramine. Stop it. A sedating antihistamine adds CNS and respiratory depression and does little for opioid-induced pruritus, which is largely centrally mediated rather than histamine-driven.
Itching Rx. Lower the opioid dose or change opioid; nalbuphine 2.5-5 mg IV; a low-dose naloxone infusion (about 0.25-1 mcg/kg/h) in some practices. Rule out a true allergic rash.
Monitoring. Regular sedation and RR checks, more often at the start, after any dose change, and overnight; continuous pulse oximetry; capnography for her.
Pulse oximetry. Not enough on its own. Supplemental oxygen keeps the SpO2 normal while CO2 climbs, so desaturation is a late sign of hypoventilation.
Capnography. Yes: suspected OSA plus opioid-naive plus PCA is the group in whom continuous nasal capnography catches hypoventilation and apnea early.
Sedation checks. Increasing sedation precedes respiratory depression, so sedation is the earliest warning. There is no single mandated interval; a common standard is at least every 1-2 hours for the first 24 hours and after any dose change, again 15-30 minutes after a clinician bolus (near its peak), and through the night. Using a validated scale (POSS or RASS): on POSS, a 3 (frequently drowsy, drifts off mid-conversation) means hold or reduce the opioid; a 4 means stop it, stimulate, and treat.
Oxygen. Wean to room air if her SpO2 allows, so oximetry stays sensitive, or keep oxygen only with capnography in place. Either is defensible when the learner explains the trade-off.
CPAP. Empiric auto-CPAP is reasonable if she will wear it, along with semi-upright or lateral positioning; formal diagnosis can follow discharge. Ignoring the history entirely is the flag.

4. The non-opioid base

Acetaminophen order: change? Dose? Interval? PO or IV? Why? Ketorolac? Why/why not? Celecoxib instead? Why/why not? The surgeon wants NSAIDs held for the anastomosis. Agree? Why/why not? Gabapentin 300 mg three times daily: start? Why/why not? What is scheduled and what is prn when you leave the room?

Considerations and pitfalls AI draft

Acetaminophen. Scheduled, not prn: 1 g PO every 6 hours, maximum 4 g/day (over 50 kg, no liver disease). PO is appropriate because she is taking clear liquids; IV is for patients who cannot take oral medication and offers little when the gut works.
Ketorolac. Contraindicated today. Creatinine is up more than 50% from baseline (1.3 from 0.8) with urine output near 0.25 mL/kg/h, on an ACE inhibitor: that is AKI with probable hypovolemia, the setting in which NSAIDs remove prostaglandin-dependent renal perfusion. Lisinopril should be held and volume addressed.
Celecoxib. No. COX-2 selectivity spares platelets and gastric mucosa, not the kidney.
Anastomosis. Some data associate NSAIDs with anastomotic leak after colorectal surgery, but the evidence is mixed. Accepting the surgeon's preference is reasonable, and it is moot today because of the kidney; revisit when creatinine recovers.
Gabapentin. Not routinely. Postoperative analgesic benefit is small and inconsistent, while it adds sedation and respiratory depression with opioids (the FDA warns about this in patients with respiratory risk factors) and is renally cleared. In suspected OSA on an escalating opioid, the risk outweighs the benefit.
Scheduled vs prn. Scheduled acetaminophen; PCA at the revised settings; NSAID deferred; antiemetic prn; no sedating prn medications. A learner who leaves acetaminophen prn has not built a multimodal base.

B. Multimodal management plan

Teaching focus. Adding ketamine and lidocaine with doses on the right weight and in the right setting; recognizing and treating opioid-induced respiratory depression with titrated naloxone and planning for renarcotization; converting IV to oral opioid; a sized discharge prescription with naloxone and counseling.

1. Still limited by pain at midday

Early afternoon. Assume demand 0.3 mg, lockout unchanged, scheduled acetaminophen. 8.1 mg hydromorphone over the last 6 hours. Pain 6/10 at rest, 9/10 with cough; awake, RR 18. Next step? Ketamine infusion? Why/why not? Bolus? Dose? Infusion rate in mg/kg/h? mg/h for her? What do you monitor? Three hours later she is frightened, seeing insects on the ceiling. Rx? Midazolam? Why/why not? Assume the rate is halved; the insects are gone and pain is 4/10 with cough. What changes on the PCA?

Considerations and pitfalls AI draft

Next step. More opioid alone has diminishing returns in a patient with suspected OSA; the move is an opioid-sparing adjunct. Ketamine is the usual next step; a fascial plane catheter technique is another option where available.
Ketamine. Yes: NMDA antagonism reduces opioid requirement after major abdominal surgery with little respiratory depression at subanesthetic doses. Contraindications include psychosis, poorly controlled cardiovascular disease, pregnancy, severe hepatic disease, and raised ICP or IOP; none apply here. Her hypertension is pain-driven; ketamine's sympathomimetic effect is small at these doses and is not a reason to withhold it here.
Bolus. Optional: 0.1-0.3 mg/kg, not above 0.35 mg/kg. Many skip it on the ward to limit psychomimetic effects.
Rate and weight. 0.1-0.2 mg/kg/h is typical on a ward; consensus guidance puts the upper limit for analgesic infusions at 1 mg/kg/h, and wards usually run well below it. Actual weight 82 kg, ideal about 55 kg, adjusted about 66 kg. The dosing weight for ketamine in obesity is not settled: ideal or adjusted weight (roughly 5-13 mg/h) is a common, defensible choice, and actual weight at the low end of the range (about 8 mg/h) is also defensible. What matters is that the learner names a weight and stays subanesthetic; starting high in the range on actual weight in a patient with suspected OSA is the overshoot.
Monitoring. Sedation, RR, SpO2 and capnography as for the PCA; BP and HR; hallucinations, dysphoria, vivid dreams, nystagmus.
Hallucinations. Stop or halve the infusion, reassure her, reduce stimulation; psychomimetic effects fade over minutes to hours.
Midazolam. A small dose treats ketamine dysphoria but adds respiratory depression in an opioid-treated patient with suspected OSA. Reduce the ketamine first; reserve a small benzodiazepine dose for severe distress with monitoring.
PCA. No change now; demand use should fall as the ketamine works. If sedation appears, reduce the demand dose. Adding a basal now that pain is better controlled is still wrong.

2. The surgeon's request that evening

Early evening. The surgeon asks for IV lidocaine for her bowel function and pain. Add it? Why/why not? Assume you agree. What do you check before you start? ECG: sinus rhythm, PR 180 ms, QRS 90 ms. Bolus? Why/why not? Infusion rate in mg/kg/h? On what weight? mg/h for her? Ceiling? How long will you run it? Where can she be while it runs? The ketamine is still running at the halved rate. Both at once? Why/why not? Monitoring while it runs?

Considerations and pitfalls AI draft

Add it. Reasonable either way if reasoned. IV lidocaine after open colorectal surgery is associated with earlier return of bowel function and modestly less pain and opioid use, but the evidence is low certainty and comes almost entirely from infusions started intraoperatively; evidence for starting it on POD 1 is thin, so any gain is likely smaller.
Before starting. No other local anesthetic in effect (the incisional bupivacaine was given about a day ago; no block or catheter dosed in the last 4 hours), no conduction disease or significant arrhythmia, no decompensated heart failure, no severe hepatic impairment, no seizure disorder, no allergy; normal electrolytes; correct dosing weight.
Bolus. Optional: 1-1.5 mg/kg ideal body weight over 10 minutes; often omitted when starting on the ward.
Rate, weight, ceiling. 1-1.5 mg/kg/h on ideal body weight: about 55 kg for her, so roughly 55-85 mg/h, and not above about 120 mg/h for anyone. Dosing on her actual 82 kg at 1.5 mg/kg/h gives 123 mg/h, which is the overdose.
Duration. Usually up to about 24 hours; longer runs need a reduced rate and, where available, plasma levels, because lidocaine accumulates.
Setting. Continuous ECG, frequent observations, and lipid emulsion immediately available; many hospitals restrict it to a monitored bed. Running it on an unmonitored floor without checking is the flag.
Both at once. Acceptable together, and both are opioid-sparing, but both cause CNS effects (confusion, perceptual change), so attributing a new symptom is harder. Separate lines and dedicated pumps.
Monitoring. Perioral numbness, tinnitus, metallic taste, lightheadedness, and confusion come before cardiovascular toxicity; the infusion stops at the first such symptom. BP, HR, ECG, and sedation alongside.

3. Unrousable overnight

POD 2, middle of the night. Assume the ketamine and lidocaine infusions are running. No capnography is running: the cannula kept slipping off and the alarm was silenced. Her nurse cannot rouse her: RR 6, SpO2 84%, pinpoint pupils, HR 64, BP 104/60. First actions? Naloxone? Dose? Two doses later: RR 14, opens her eyes to voice, pain 7/10. More naloxone? Why/why not? DDx? Her husband says he pressed the button while she slept so she would not wake in pain. Of concern? Why? 45 minutes later: RR 7, drowsy again. Why? Rx? Naloxone infusion: dose? Where does she go now? Ketamine and lidocaine: continue? Why/why not?

Considerations and pitfalls AI draft

First actions. Stimulate her, call for help, stop the PCA, open the airway (jaw thrust, head up), 100% oxygen and bag-mask ventilation if her breathing is inadequate. Ventilation comes before any drug.
Naloxone. Titrate it: dilute 0.4 mg to 10 mL (40 mcg/mL) and give 40 mcg IV every 2-3 minutes to RR 10 or more and rousable. A full 0.4 mg bolus causes abrupt severe pain, hypertension, tachycardia, arrhythmia, and pulmonary edema; large doses are for apnea or arrest.
More naloxone. No. The endpoint is adequate ventilation and arousal, not wide awake. More naloxone at this point only reverses her analgesia.
DDx. Pinpoint pupils and the response to naloxone make opioid the leading cause, but also consider hypercarbia (get an ABG), lidocaine toxicity, ketamine contribution, hypoglycemia, stroke, sepsis, and bleeding or hypovolemia.
Husband's report. PCA by proxy. The safety of PCA rests on a sedated patient no longer pressing the button; a family member pressing for her removes that check, and it explains the stacked hydromorphone. Before any PCA restarts, her husband needs to hear that only the patient presses the button. The silenced capnography alarm is the second failure: the monitor meant to catch hypoventilation early was not working, and both need fixing before any PCA restarts. A learner who hears this and does not connect it to the event, or who restarts the PCA unchanged, has missed it.
Recurrence. Naloxone lasts about 30-90 minutes, shorter than the hydromorphone she stacked over several hours; renarcotization is expected, not a surprise.
Rx and infusion. Repeat the titrated bolus, then a naloxone infusion at about two-thirds of the effective bolus dose per hour: 80 mcg was effective, so about 50 mcg/h, titrated to RR and arousal.
Level of care. A monitored setting (step-down or ICU) while on a naloxone infusion, with continuous capnography and oximetry, and CPAP if she will tolerate it.
Infusions. Stop the lidocaine until toxicity is excluded, since CNS depression can be lidocaine (send a level if available). Low-dose ketamine rarely depresses respiration but adds sedation; holding it until she is clearly awake and then restarting it as an opioid-sparing agent is reasonable. Leaving everything running unchanged is the flag.

4. Moving to oral analgesia

POD 3, morning. Back on the floor, passing flatus, tolerating clears. No infusions running. The PCA was restarted at a 0.2 mg demand dose once the naloxone infusion was off, and her husband was told only she presses it. PCA hydromorphone in the last 24 hours: 3.6 mg. Pain 3/10 at rest, 6/10 walking. Creatinine 0.9. Off IV opioid today? Why/why not? Oral opioid: which? Morphine? Why/why not? Tramadol? Why/why not? Assume oxycodone. Dose? Interval? Scheduled or prn? Why? Extended-release oxycodone at night? Why/why not? Ibuprofen now? Why/why not? Dose? Bowel regimen: what?

Considerations and pitfalls AI draft

Off IV. Yes: she is taking oral intake with bowel function returning and pain is manageable. Give the first oral dose before the IV opioid stops, since oral oxycodone takes 30-60 minutes to act and about an hour to peak.
Which. Oxycodone or oral hydromorphone. Morphine is a weaker choice so soon after AKI because of its renally cleared active metabolites.
Tramadol. Avoid it with sertraline: additive serotonergic risk, a lower seizure threshold, and sertraline's CYP2D6 inhibition can reduce conversion to tramadol's active metabolite, so it is both riskier and weaker for her.
Oxycodone dose. By standard tables 1.5 mg IV hydromorphone is about 20 mg oral oxycodone, so 3.6 mg IV is about 48 mg oral oxycodone per day (about 8 mg every 4 hours). Her pain is improving, so start lower: oxycodone 5 mg every 4 hours prn, 10 mg for severe pain. Converting the full calculated dose to a scheduled regimen overshoots in an improving opioid-naive patient.
Scheduled or prn. Prn opioid on top of scheduled non-opioids; a dose before walking or physical therapy is reasonable. Scheduled opioid in an improving opioid-naive patient invites oversedation, especially at night.
Extended-release. No. Extended-release and long-acting opioids are not for opioid-naive patients or acute postoperative pain, and the overnight risk is higher in her given the OSA history and the overnight event.
Ibuprofen. Reasonable now that creatinine is near baseline (0.9 from 0.8) and she is eating, with lisinopril still held and creatinine rechecked, if the surgeon agrees about the anastomosis: 400-600 mg PO every 6 hours with food. Sertraline plus an NSAID raises GI bleeding risk; she stays on omeprazole.
Bowel regimen. A stimulant laxative (senna) or polyethylene glycol while she is on opioid, agreed with the surgical team; docusate alone does little.

5. Discharge on POD 5

POD 5, going home today. Last 24 hours: oxycodone 5 mg twice, scheduled acetaminophen and ibuprofen; pain 3/10 walking. Opioid at discharge? Why/why not? How many tablets? Refills? Oxycodone alone or oxycodone-acetaminophen? Why? Acetaminophen and ibuprofen at home: doses? For how long? Naloxone: prescribe? Why/why not? The witnessed apneas: what do you arrange before she leaves? She asks for a month's supply "so I don't have to call anyone." What will you tell her?

Considerations and pitfalls AI draft

Opioid at discharge. A small supply is reasonable; opioid use in the last 24 hours in hospital is the best guide to need after discharge, and her pain should keep falling.
Tablets and refills. Up to about 10 tablets of oxycodone 5 mg (about five days at her current use, tapering; published procedure-specific recommendations for colectomy in opioid-naive patients are 0-10 tablets), no refills, reassess at follow-up; check the state prescription monitoring program as required. More than a week of opioid is rarely needed after this kind of recovery. A 30- or 60-tablet prescription is the flag.
Single agent. Oxycodone alone, because she is already taking scheduled acetaminophen; combination tablets risk exceeding the acetaminophen maximum and tie the non-opioid to the opioid, so stopping one stops both.
Home non-opioids. Acetaminophen 1 g every 6 hours (maximum 4 g/day) and ibuprofen 400-600 mg every 6 hours with food, scheduled for about a week, then as needed. Non-opioids first; the opioid only for pain they do not control, and it is the first drug she stops.
Naloxone. Prescribe it and teach her husband to use it. The usual triggers include sleep-disordered breathing, and she had an opioid-related respiratory event this admission; it costs little. Declining is defensible only with a reason.
Suspected OSA. Referral for a sleep study; document the suspected OSA and the respiratory event in the discharge summary for her primary care physician and future anesthetics. No alcohol, sleep aids, or other sedatives with the oxycodone.
Month's supply. Acknowledge the worry; explain that pain should improve week by week, that a small supply is safer for her breathing at night and leaves fewer unused pills in the house, and that pain getting worse instead of better needs a call to the surgical team because it can signal a complication that needs a look, not more pills. Safe storage and disposal of leftovers. No lecture about addiction and no promise that she will be pain-free.

Non-perioperative

Multiple rib fractures with flail chest and failing pulmonary mechanics

A 72 y.o., 80 kg man is admitted after a fall down a flight of stairs. The acute pain service is consulted for analgesia.

HPIHe fell the previous evening. CT shows seven right-sided rib fractures (ribs 4 through 10) with a flail segment and an underlying pulmonary contusion. There is no head, abdominal, or long-bone injury. He is in severe pain, splinting, and unable to cough or take a deep breath.

PMHCOPD, on home oxygen at night. Former 40 pack-year smoker. Atrial fibrillation. Hypertension. Chronic kidney disease, stage 3. Mild cognitive impairment at baseline.

MEDSApixaban for atrial fibrillation, last dose yesterday morning. Tiotropium and albuterol. He received subcutaneous prophylactic heparin (5000 units) in the evening and intermittent IV hydromorphone overnight, 6 mg in total.

PHYS EXAMAwake but drowsy, oriented to person and place. HR 104; RR 28 and shallow; BP 158/88; SpO2 91% on nasal cannula; T 37.2 C. He splints the right chest with paradoxical movement of a right lateral segment and has decreased breath sounds at the right base.

IMAGINGCT chest: seven right rib fractures with a flail segment, right pulmonary contusion, small right pleural effusion, no pneumothorax.

LABSABG on nasal cannula: pH 7.31; PaCO2 54; PaO2 62; HCO3 26. Hgb 11.5 g/dL; platelets 210 K/uL; creatinine 1.7 mg/dL; INR 1.2. Incentive spirometry effort is poor.

CURRENT STATEPain is 8 of 10 at rest and worse with any movement. He has become more somnolent over the last two hours while still reporting pain.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. Initial evaluation (consult)

Teaching focus. Framing rib-fracture analgesia as a pulmonary intervention; reading the ventilatory trajectory; recognizing failing opioid monotherapy in a patient tipping toward respiratory failure; how current anticoagulation constrains the regional plan.

1. The consult and the trajectory

The surgical team asks whether you can see him this afternoon. Now, or the afternoon list? Why? What do you measure at the bedside to follow him? Which of those numbers do you trust most here? He splints the right chest and his spirometry effort is poor. What does that cost him over the next 12 hours? He has had 6 mg of IV hydromorphone overnight, is drowsy, and still reports 8/10. Undertreated, oversedated, or both? Why? Nothing changes today. Where is he in 24 hours?

Considerations and pitfalls AI draft

Now, not the afternoon. Flail segment plus contusion plus a PaCO2 of 54 in a COPD patient is a respiratory emergency in slow motion; analgesia here is a pulmonary intervention, not comfort care. Triaging this as routine is a flag.
Bedside measures. Respiratory rate and effort, SpO2, serial PaCO2, cough strength and secretion clearance, and an inspiratory or vital-capacity effort; the CO2 trend is the one that predicts intubation.
Cost of splinting. Atelectasis and retained secretions within hours, then hypoxemia and pneumonia; it is a reason to escalate analgesia, not to sedate.
Both at once. Under-analgesed and over-sedated simultaneously is the signature of failing opioid monotherapy. The trap is reading the drowsiness as adequate treatment.
Trajectory. Progressive hypoventilation, hypercarbia, and atelectasis with intubation likely inside a day if he cannot breathe deeply and cough.

2. Rising CO2

Repeat ABG two hours later: pH 7.28, PaCO2 61, PaO2 60 on nasal cannula. DDx? How do you separate those at the bedside? Start non-invasive ventilation now, or hold? Why? On NIV his rate settles to 22 but the PaCO2 an hour later is 58. Good enough? What is your next move? He is now oriented to person only. Does that change the NIV plan? Why? What number or finding moves him to the ICU?

Considerations and pitfalls AI draft

DDx. Pain-limited splinting, contusion shunt, flail mechanics, opioid-induced hypoventilation, and COPD with baseline CO2 retention; several are operating at once.
Separating them. Response to analgesia and to a block, drug timing versus the ABG trend, exam of the flail segment, and serial gases; a CO2 that falls with effective analgesia identifies the pain-limited component.
NIV now. Yes, if he can protect his airway and cooperate; it buys hours while analgesia is established. NIV is a bridge, not the analgesic plan, and using it as a substitute for a block is the error.
58 is not success. The direction is right but he is still hypercarbic on support; escalate analgesia and get the block in rather than settle.
Worsening mentation. Delirium threatens airway protection and NIV tolerance; it lowers the threshold for intubation rather than justifying more NIV.
To the ICU. Rising PaCO2 despite support, falling pH, fatigue, failure to clear secretions, or deteriorating mental status.

3. Failing opioid monotherapy

He is drowsy and still reports 8/10. Double the hydromorphone? Why/why not? Set him up on a PCA? Why/why not? What do you monitor to catch him tipping into ventilatory failure, and how often? RR 9 and he is difficult to rouse. Rx now? Naloxone — yes/no? Dose? What does it cost you in him? If you are not escalating opioid, what carries his analgesia in the next hour?

Considerations and pitfalls AI draft

Doubling the opioid. No; more opioid deepens hypoventilation and sedation without reliably covering movement and cough pain. Escalating opioid into a rising CO2 is the central error of this case.
PCA. PCA requires an awake patient who can self-titrate; drowsiness plus baseline cognitive impairment makes an unmonitored PCA unsafe here. A nurse- or family-controlled substitute is worse.
Monitoring. Sedation score and respiratory rate hourly with continuous pulse oximetry and capnography; sedation precedes respiratory depression, so the sedation score is the early warning.
RR 9. Stimulate, oxygen, support ventilation, hold further opioid, and get the regional plan moving now.
Naloxone. Reserve it for a patient you cannot rouse or ventilate; 40 mcg IV increments titrated to respiration, not to consciousness. A full 400 mcg dose restores his 8/10 pain instantly, drives catecholamines in a 72-year-old, and wears off before the hydromorphone does.
What carries analgesia. A regional technique plus scheduled non-opioids and ketamine; the plan has to move off systemic opioid, not up the dose.

4. Anticoagulation and the regional plan

Apixaban last dose yesterday morning, prophylactic heparin last evening, INR 1.2, platelets 210, creatinine 1.7. Thoracic epidural tonight? Why/why not? Paravertebral? Erector spinae plane catheter? Which of the three can you offer him tonight? Why? How many hours from the last apixaban dose before you would place an epidural? From the heparin dose? Waiting that long costs him what? The trauma team wants the apixaban restarted tonight for his AF. Your answer? Why?

Considerations and pitfalls AI draft

Epidural tonight. No; apixaban dosed roughly 36 hours ago with stage-3 CKD plus prophylactic heparin the same evening puts him inside the interval for a deep neuraxial technique, and epidural hematoma in an anticoagulated 72-year-old is the complication that ends the case.
Which of the three. Erector spinae plane catheter — a superficial, compressible fascial-plane block, the one technique that is defensible tonight. Paravertebral is deep and non-compressible and belongs with the epidural on the no list.
Intervals. Apixaban 72 hours before neuraxial placement in this renal function per ASRA, and 4-6 hours after a prophylactic heparin dose; the point is that the numbers do not line up before tomorrow at the earliest.
Cost of waiting. Two to three more days of splinting is how he earns an intubation; the technique that can be done now beats the better technique that cannot.
Restarting apixaban. Not tonight if you intend to run a catheter and reassess; hold it, use a shorter-acting agent if his stroke risk demands bridging, and time removal of the catheter to trough. Restarting a DOAC with a fresh catheter in place and no plan for removal is the miss.

B. Multimodal management plan

Teaching focus. Selecting a regional technique within his coagulation constraints; building the non-opioid regimen around his kidneys, lungs, and cognition; sorting ongoing respiratory decline; recognizing local anesthetic accumulation from a continuous catheter; weaning and safe transitions.

1. Placing and dosing the catheter

Erector spinae catheter it is. Which level, which side? Single injection or catheter? Why? Agent and concentration for the initial bolus? How many mL? Infusion or programmed intermittent bolus, and at what rate? Ropivacaine ceiling in mg/kg/h for him? Same number as a healthy 80 kg man? Why/why not? Thirty minutes after the bolus: 3/10 at rest, still 7/10 with cough. Block failed? What do you check? Two hours on: spirometry effort improved, RR 22, PaCO2 52. What do you do with the regimen now?

Considerations and pitfalls AI draft

Level and side. Right side, transverse process around T5 for fractures of ribs 4-10; a mid-span level lets spread cover the segments above and below.
Catheter, not single shot. Seven fractures need days of analgesia; a single injection buys hours and leaves him splinting again by morning.
Bolus. 20-30 mL of ropivacaine 0.25-0.5% (or bupivacaine 0.25%); volume is what produces craniocaudal spread in a fascial plane, so do not under-volume it.
Infusion. Ropivacaine 0.2% at 6-10 mL/h, or programmed intermittent boluses of 15-20 mL every 4 hours, which spread better than a continuous trickle.
Ceiling. Keep continuous ropivacaine near or below roughly 0.4-0.5 mg/kg/h and lower it here: age, a 30-hour horizon of accumulation, and stage-3 CKD that clears ropivacaine's active metabolite PPX poorly. The parent drug is hepatically cleared; the metabolite is the renal problem.
Better at rest, not with cough. Expected early - assess spread and dermatomal effect, check the catheter and the volume delivered, and add to the regimen rather than declaring failure. Pulling a working fascial-plane catheter at 30 minutes is the trap.
Working. Keep it, layer the non-opioids on, and hold him at a dose that lets him cough; the endpoint is cough and vital capacity, not the resting pain score.

2. Multimodal pharmacology

Scheduled acetaminophen — dose and interval in this 80 kg man? Ketorolac — yes or no in him? Why? Ketamine infusion — dose range, and what makes you stop it? Gabapentin 300 mg three times daily — start it? Why/why not? Breakthrough opioid — agent? Morphine? Why/why not? A lidocaine infusion on top of the running ropivacaine catheter — yes/no? Why?

Considerations and pitfalls AI draft

Acetaminophen. 1 g every 6 hours scheduled, capped at 3-4 g/day; a low-risk backbone and it should be scheduled, not PRN.
Ketorolac. Avoid at eGFR in the stage-3 range in a 72-year-old with acute trauma and a hematoma risk; a reflexive NSAID here is a flag. If an NSAID is used at all, it is a short, low-dose course with an explicit risk statement.
Ketamine. 0.1-0.2 mg/kg/h, opioid-sparing and useful for movement pain; stop or halve it for dysphoria, hallucinations, or worsening delirium in a man with baseline cognitive impairment.
Gabapentinoid. 300 mg TID is too much too fast for a 72-year-old with CKD and drowsiness; sedation and respiratory depression stack with opioid. If used, a low dose (100 mg at night) and renal adjustment.
Breakthrough opioid. Avoid morphine - the renally-cleared active metabolites M3G and M6G accumulate at his creatinine and cause exactly the delayed sedation you are trying to prevent. Hydromorphone or oxycodone in small doses, monitored.
Lidocaine plus a catheter. No; systemic lidocaine on top of a continuous ropivacaine infusion stacks amide load toward toxicity with no way to attribute the resulting symptoms. This is the beat that separates additive thinking from arithmetic.

3. Respiratory decline despite analgesia

Twelve hours on: pain 3/10 at rest, cough improved, but he is more somnolent with RR 12, PaCO2 68, and pH 7.24. What is driving this? Opioid, block, or the injury — how do you tell them apart at the bedside? Rx now? He is already on NIV. Intubate, or keep going? What has to be true to keep going? You intubate. What happens to the catheter and the ketamine? Sedation agent — which, and why that one in him?

Considerations and pitfalls AI draft

Driver. Pain is better while CO2 climbs, so this is not analgesic failure - it is residual opioid plus COPD plus fatigue outpacing the benefit, in a man whose flail segment still costs him work of breathing.
Telling them apart. Drug timing against the gas trend, sedation score, block assessment (is he actually covered?), and secretion burden; an effective block with a rising CO2 points away from pain as the cause.
Rx now. Stop systemic opioid, optimize the block, suction and recruit, treat the COPD component, and escalate support while you reassess.
Intubate. PH 7.24 with obtundation on NIV is a failing trial; intubate rather than watch. Continuing NIV requires an improving pH, a protected airway, and a cooperative patient - he has none of the three.
Catheter and ketamine. Both continue - the catheter reduces sedative and opioid requirement and is what will let you wean him later; stopping regional analgesia because he is intubated is the classic misstep.
Sedation. Dexmedetomidine or propofol with the catheter carrying analgesia; avoid benzodiazepines in a man with baseline cognitive impairment.

4. Local anesthetic accumulation

Hour 30 of the infusion: he is confused with perioral numbness and a metallic taste. Dx? What about his infusion and his physiology makes this happen now rather than on day one? Rx now? He has a generalized seizure. First drug and dose? Lipid emulsion — give it now or hold? Bolus and infusion dose? Once he is stable, what changes about how you run the catheter?

Considerations and pitfalls AI draft

Dx. Local anesthetic systemic toxicity, neurologic prodrome - perioral numbness, metallic taste, and confusion in a man with a running amide infusion.
Why now. Cumulative absorption over 30 hours of continuous infusion. Ropivacaine's parent compound is hepatically cleared, but its active metabolite PPX is renally excreted and accumulates in stage-3 CKD; his acidemia reduces protein binding and lowers the seizure threshold. Blaming a single bolus misses the accumulation.
Rx now. Stop the infusion, 100% oxygen, monitor, get the lipid emulsion to the bedside, and call for help before he progresses.
Seizure. Midazolam 2-4 mg IV (or a small propofol dose only if hemodynamically stable); control ventilation, because hypercarbia and acidosis worsen toxicity.
Lipid emulsion. Give it now, at the seizure - do not wait for cardiovascular collapse. 20% emulsion 1.5 mL/kg (about 100 mL) over 2-3 min, then 0.25 mL/kg/min, redosing the bolus for persistent instability, with a total ceiling around 12 mL/kg.
Restarting. Restart only after symptoms clear, at a lower concentration and a lower hourly dose, with a written cumulative cap that accounts for his renal function; the original miss was dosing him as if he had normal clearance.

5. Weaning and transitions

Day 3: extubated, PaCO2 44, coughing to command, up in a chair, pain 3/10 at rest. What comes off first — the catheter or the IV opioid? Why? Catheter out. Oral regimen — agents and doses? How many days of opioid does he go home with? Two hours after the catheter comes out his RR is 26 and he will not cough. Rx? What has to be true before the pain service signs off?

Considerations and pitfalls AI draft

Order of weaning. Overlap effective oral multimodal analgesia first, then remove the catheter, then taper systemic opioid. Pulling the catheter while he is still opioid-dependent for cough is how the rebound happens.
Oral regimen. Scheduled acetaminophen 1 g q6h, low-dose oxycodone 5 mg q4-6h PRN, and a taper plan; no NSAID at his renal function, no morphine, gabapentinoid only if already tolerated.
Days of opioid. A short, defined course - roughly 3-5 days with no automatic refill - plus a written taper; rib fracture pain lasts weeks but the opioid should not.
Rebound at two hours. Re-treat now: analgesic bolus, reassess whether he needs the catheter replaced, resume incentive spirometry and coughing. A patient who stops coughing is going backward, not simply uncomfortable.
Sign-off criteria. Pain controlled on oral medication, adequate cough and spirometry, stable gas exchange off support, and a documented taper with a threshold to call back.

Non-perioperative

Thoracic epidural not working after open pancreaticoduodenectomy

A 66 y.o., 74 kg, 163 cm woman is in the PACU after an open pancreaticoduodenectomy (Whipple) through an upper midline incision. The acute pain service is called because she is in pain despite her thoracic epidural.

HPIPancreatic head adenocarcinoma presenting with painless jaundice; a biliary stent was placed 4 weeks ago and her bilirubin has normalized. Surgery ran 0800 to 1430 under general anesthesia and she was extubated in the OR.

PMHHypertension. Obstructive sleep apnea on CPAP at night. Type 2 diabetes. No prior surgery other than the stent. Baseline BP in clinic 142/84.

MEDSAmlodipine (taken the morning of surgery), lisinopril (held), metformin (held), aspirin 81 mg daily (continued).

EPIDURALPlaced at 0700 before induction, sitting, at the T7-8 interspace by a paramedian approach. Loss of resistance to saline at 6 cm on the first pass; catheter taped at 11 cm at the skin, leaving 5 cm in the epidural space. Test dose of 3 mL lidocaine 1.5% with epinephrine 1:200,000 was negative. A bolus of 5 mL bupivacaine 0.25% was given before incision, then an infusion of bupivacaine 0.1% with hydromorphone 10 mcg/mL at 6 mL/h was started and is still running.

INTRA-OPERATIVE COURSEEBL 700 mL. 3 L lactated Ringer's and 500 mL 5% albumin. Phenylephrine infusion at 20 to 40 mcg/min for most of the case, off at closure. UOP 280 mL total.

PACUArrived 1500. Hydromorphone 0.4 mg IV three times since arrival. Now 1900: pain 8/10 on the left side of the incision, worse with coughing; she says the right side feels fine. HR 94; BP 108/62; RR 20; SpO2 95% on 2 L nasal cannula. Drowsy between questions but rouses to voice. UOP 30 mL/h. Loss of cold sensation to ice from T6 to T11 on the right and at T10 to T11 only on the left. Moves both legs fully.

LABSEnd of case: Hgb 10.4 g/dL (preop 12.6); platelets 214 K/uL; glucose 168 mg/dL. Preop INR 1.1; creatinine 0.8 mg/dL.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. Initial evaluation (consult)

Teaching focus. Bedside assessment of an epidural that is not working; reading a one-sided dermatomal map; a stepwise rescue (bolus, position, withdraw); sorting and treating hypotension after an epidural bolus without abandoning the block; matching the evening anticoagulation orders to an indwelling catheter.

1. Pain on one side of the incision

The PACU nurse pages for an order for more IV hydromorphone. Order the hydromorphone by phone, or see her now? Why? At the bedside, before you touch the pump, what do you check? Dressing dry, catheter at the taped 11 cm mark, pump running at the programmed rate, tubing connected end to end. Interpretation of her ice map? Is the catheter in the epidural space? What tells you? Possible causes? Most likely in her? Why? Another 0.4 mg of IV hydromorphone now while you work on the catheter? Why/why not?

Considerations and pitfalls AI draft

See her now. A failing epidural in a fresh upper-abdominal incision costs her cough, deep breathing, and early mobility, and the default fix (more IV opioid) collides with her OSA and her current drowsiness. Treating this as a phone order is a flag.
Before the pump. Look at the site for leak or blood under the dressing, confirm the skin mark has not moved, trace the line from catheter to pump for disconnection or a closed clamp, check the pump history for occlusion alarms and the actual volume delivered. Dislodgement and disconnection are common and cheap to exclude.
Ice map. A dense six-segment block on the right centered on the incision, with only a sliver on the left, is a working but unilateral block. A level that is too low or too narrow on both sides would point to too little volume or a catheter too far from the incision; this pattern points to catheter position.
In the space?. Yes: a dermatomal block over several thoracic segments from a thoracic catheter does not happen from a subcutaneous or intravascular catheter. Strong learners say a unilateral block means the catheter works and can often be rescued, which is a different decision from a catheter with no block at all.
Causes. Catheter tip drifted laterally or out toward an intervertebral foramen, a risk that rises the more catheter is threaded (beyond about 5 cm); a dorsomedian fold or septum limiting spread (its role is debated); too little volume; patient lying on one side. With 5 cm in the space, lateral tip position is the leading candidate.
More IV hydromorphone. Small doses are defensible to bridge while the catheter is fixed, but she is already drowsy after 1.2 mg, has OSA with her CPAP not on, and has neuraxial hydromorphone running. A weak answer keeps stacking IV opioid without first fixing the block; a strong one holds or limits it and puts monitoring in place if any is given.

2. Working on the catheter

Raise the infusion rate, or give a bolus? Which? Why? Bolus agent? Concentration? How many mL? Incremental, or all at once? Why? Position her for it? Which side down? Why? Bolus given. Thirty minutes later: cold loss deeper on the right, left unchanged, still 7/10 on the left. Next move? Bolus again? Withdraw? Re-site? Which? Why? How many cm do you leave in the space? Withdrawn 2 cm and re-bolused. Twenty minutes later: cold loss T6 to T11 on both sides, pain 2/10 at rest and 4/10 with cough. Infusion: same solution and rate, or change? Why?

Considerations and pitfalls AI draft

Rate vs bolus. Raising the rate alone changes the spread slowly and unreliably; a block that is too narrow or one-sided needs a bolus to re-establish spread, with the rate adjusted afterward. Turning the pump up and leaving is the common weak answer.
Agent and volume. A thoracic epidural needs roughly 1 to 1.5 mL per segment: about 4 to 6 mL of bupivacaine 0.25% or lidocaine 1.5 to 2%, given in 3 mL increments with aspiration, watching BP and the level between doses. Lidocaine gives a fast, clear answer about whether the catheter can be rescued. Large lumbar-style volumes in a thoracic catheter in a patient who is already 108/62 is a flag.
Position. Left side down (unblocked side dependent) for the bolus; gravity helps but does not fix a catheter tip that is lateral. It is a cheap first step, not a guarantee.
Next move / cm left in the space. After a positional bolus fails, a second bolus through the same tip position rarely fixes a one-sided block; withdrawing the catheter to leave about 3 to 4 cm in the space, then re-bolusing, is the usual next step, with re-siting held for a block that still fails. With 5 cm in, pulling back 1 to 2 cm is reasonable; leaving less than about 3 cm raises the risk of dislodgement. Withdraw under sterile technique, aspirate, and re-tape at the new mark.
Infusion. Bilateral T6 to T11 covers an upper midline incision. Cough pain of 4/10 is acceptable and lets her clear secretions. Reasonable to resume the same solution, perhaps at 6 to 8 mL/h, reassessing the level in an hour. Strong learners set a plan for when to re-bolus versus when to stop chasing it, and write down the new catheter depth for the next shift.

3. BP after the bolus

Shortly after the infusion restarts: BP 82/46, HR 76, she feels lightheaded. DDx? First thing you check at the bedside? Cold loss now to T3 on both sides; hand grip strong; talking in full sentences. Interpretation? Rx now? Phenylephrine? Ephedrine? Volume? Which? Why? How much volume? UOP 15 mL/h for the last hour; point-of-care Hgb 9.9. Of concern? Why? Target MAP for her? The surgeon asks you to turn the epidural off for the night. Agree? Why/why not? Infusion: change it? How?

Considerations and pitfalls AI draft

DDx. Sympathectomy from a block that spread higher with the bolus, hypovolemia (ongoing third-space and drain losses after a six-hour open case), bleeding, intrathecal or subdural spread, residual opioid, and less likely cardiac causes. A learner who names only the epidural, or only bleeding, has anchored.
First check. The block level and its symmetry, then mental status, breathing, hand strength, drains, and the abdomen. Level is the fastest way to decide whether the epidural is the main driver.
Interpretation (T3, HR 76). The block now reaches the upper thoracic segments; the fall in heart rate from 94 is consistent with partial block of the cardioaccelerator fibers (T1 to T4). Strong grip and normal speech argue against a high or intrathecal block threatening breathing. A dense bilateral motor block of the arms or trouble speaking would change the plan to airway and hemodynamic support.
Rx: pressor? volume? how much?. With relative bradycardia, ephedrine 5 to 10 mg IV is a sensible first choice; phenylephrine 50 to 100 mcg is reasonable but may slow the heart further. Pair the pressor with a fluid bolus of 250 to 500 mL and reassess. If repeated boluses are needed, a low-dose vasopressor infusion (phenylephrine or norepinephrine) is a common bridge while the block recedes. Large fluid loads to treat a sympathectomy alone risk bowel edema and anastomotic problems after a Whipple, and surgeons may raise this.
UOP 15, Hgb 9.9: of concern?. Hgb 9.9 from 10.4 after more crystalloid fits dilution; bleeding is judged by drain output and character, abdominal exam, serial Hgb, and the response to volume. Low UOP here is consistent with hypovolemia or low pressure and is a reason to reassess, not proof of bleeding.
Target. MAP of at least 65, and in a patient with chronic hypertension and a baseline near 142/84 many would aim for no more than about 20 to 30% below baseline, judged against mentation, UOP, and lactate.
Surgeon: turn it off?. Stopping the epidural throws away a block that just started working and pushes her onto IV opioid with OSA. Most hypotension from a thoracic epidural is managed by treating the BP and adjusting the dose. Agreeing reflexively, or refusing without a plan for the BP, are both weak.
Infusion change. Hold for 30 to 60 minutes or reduce the rate, consider a lower bupivacaine concentration (for example 0.0625 to 0.075%) while keeping the opioid, and recheck the level hourly. Treat the cause of hypotension rather than stopping all analgesia.

4. The evening enoxaparin order

BP now 112/64. The surgical order set has enoxaparin 40 mg SC due at 2100 tonight. Give it at 2100 with the catheter in? Why/why not? Earliest time it could go in? Why that hour? The surgeon wants 30 mg twice daily instead, given her cancer. Agree? Why/why not? Aspirin: continue it? Why/why not? Ketorolac tonight as an adjunct? Why/why not? Neuro checks overnight: what, and how often? What finding makes the nurse call you at 0300?

Considerations and pitfalls AI draft

Give at 2100 with the catheter in?. Once-daily low-dose LMWH may be given with an indwelling neuraxial catheter, provided no other drug affecting hemostasis is added. Strong learners also ask whether placement was atraumatic (it was, first pass) and notice that aspirin is the other hemostasis drug already on board.
Earliest time. The first postoperative dose should be at least 12 hours after needle and catheter placement: placement at 0700 makes 1900 the earliest, and 2100 meets it. Strong learners also count from the catheter withdrawal at about 1945. Pulling a catheter back moves the tip as removal does, and some would apply the 4-hour removal-to-dose interval, which pushes the dose toward midnight; others treat it as no new puncture and give it at 2100. Both are defensible (the guideline does not address withdrawal); a learner who gives the dose without counting from either event is a flag.
Twice daily. Twice-daily low-dose LMWH is associated with higher hematoma risk. The catheter should be out before twice-daily dosing starts, the first dose given the day after placement and at least 12 hours after it, and at least 4 hours after removal. So the choice is once daily with the catheter, or twice daily without it. Subcutaneous heparin 5000 units two or three times daily also works with a catheter in place; removal needs 4 to 6 hours after a dose.
Aspirin. Aspirin alone does not meaningfully add neuraxial hematoma risk, but ASRA recommends against combining other drugs that affect hemostasis, antiplatelet agents included, with LMWH while a catheter is in. Her aspirin has no stated cardiac or stent indication, so holding it while the catheter is in and LMWH is running is the guideline-concordant choice, with the surgical team told why. Continuing it after discussion is defensible only with a strong indication (a recent coronary stent or stroke), with closer neuro checks.
Ketorolac. With LMWH and an indwelling catheter, adding an NSAID falls under the same advice against combining hemostasis-altering drugs, and surgeons often avoid NSAIDs early after pancreatic surgery. Holding it tonight is the safer choice; if it is used later, 15 mg IV is the dose at her age (over 65). Giving it without accounting for the LMWH and aspirin is a flag.
Neuro checks. Sensory level and lower-extremity motor function (knee lift, dorsiflexion) while the catheter is in and after removal, plus back pain and bladder function. ASRA sets no interval; every 2 to 4 hours is common practice. The low-concentration solution is part of the safety plan: a dense leg block should not happen from this catheter.
Call triggers. New leg weakness or numbness, back pain, new bowel or bladder dysfunction, a level climbing above T4, SBP below a stated number, RR below 10 or a rising sedation score. Strong learners say leg weakness is reported immediately, not at morning rounds.

B. Multimodal management plan

Teaching focus. When to stop rescuing a catheter and what replaces it; timing a re-site and the next anticoagulant dose; building non-opioid adjuncts around OSA and an indwelling epidural; neuraxial opioid and respiratory depression; new leg weakness as a red flag with a defined response; timing catheter removal against the LMWH schedule and moving to oral analgesia.

1. POD 1 morning

POD 1, 0700: 7/10 on the left again. Cold loss T7 to T11 on the right, T11 only on the left. Assume enoxaparin 40 mg was given at 2100. Bolus and withdraw again? Why/why not? Re-site, or abandon the epidural? Which? Why? Abandoning: what replaces it for this incision? She wants another try. Earliest time for a new needle? Why that hour? Interspace? Old catheter out at 0900, new catheter in at 1000 with a negative test dose and a bilateral T5 to T11 block after a bolus. Next enoxaparin dose: when? Why?

Considerations and pitfalls AI draft

Withdraw again. With 3 cm left in the space, pulling back further risks losing the catheter entirely, and a block that failed again overnight after rescue is unlikely to hold. Strong learners know when to stop chasing a catheter.
Re-site vs abandon. Both are defensible. Re-siting keeps the best analgesia for an upper midline incision in a patient with OSA, at the cost of another neuraxial procedure while on LMWH. Abandoning is reasonable if she declines, the anticoagulation timing is unfavorable, or placement was difficult.
Alternatives. IV opioid PCA with full multimodal adjuncts and monitoring for OSA, bilateral rectus sheath or other fascial plane catheters (good for the midline somatic pain, no visceral coverage), or ketamine as an opioid-sparing adjunct. Strong learners note each option's limits.
Earliest needle. 12 hours after the last low-dose LMWH dose: 2100 plus 12 hours gives 0900. Removing the old catheter also needs 12 hours from the last dose, so 0900 for both.
Interspace. T7-8 again or T8-9; the target is a catheter tip near the middle of the incision's dermatomes, threaded 4 to 5 cm. Choosing a lumbar interspace for an upper abdominal incision is a flag.
Next dose. Two constraints: at least 4 hours after catheter removal (0900 removal gives 1300) and at least 12 hours after the new needle placement (1000 gives 2200). The later one wins: 2200 at the earliest, which also keeps the second once-daily dose at least 24 hours after the first (2100). Giving it at 2100 by habit is the trap.

2. Building the rest of the regimen

Afternoon of POD 1: pain 2/10 at rest, 4/10 with cough, NPO with an NG tube. Acetaminophen: route, dose, interval? Gabapentin: start it? Why/why not? Dose? IV lidocaine infusion as an adjunct? Why/why not? Ketamine infusion: yes/no? Dose? What makes you stop it? Breakthrough IV opioid: agent? Dose? Monitoring overnight: what, and for how long? CPAP tonight with an NG tube in? Why/why not?

Considerations and pitfalls AI draft

Acetaminophen. IV while NPO, 1 g every 6 hours (or 650 mg to 1 g every 6 to 8 hours), maximum 4 g per day at 74 kg; some lower the ceiling to 3 g with hepatic concerns. Her bilirubin has normalized, so full dosing is reasonable.
Gabapentin. Gabapentinoids add sedation and respiratory depression risk, more so with OSA, age over 65, and neuraxial plus systemic opioid. Withholding it, or a small dose such as 100 to 300 mg at night only, are defensible; routine 300 mg three times daily in her is a flag. Route also matters with an NG tube and NPO status.
IV lidocaine. Not with an epidural local anesthetic infusion running: the local anesthetic doses add, raising toxicity risk, and IV lidocaine offers little on top of a working epidural.
Ketamine. Reasonable if pain control is still marginal or opioid needs climb: about 0.1 to 0.2 mg/kg/h (roughly 7 to 15 mg/h at 74 kg), with or without a small bolus. Stop for hallucinations, dysphoria, or excess sedation; monitor as for any sedating infusion.
Breakthrough. Small IV doses ordered through the pain service only (for example hydromorphone 0.2 mg every 2 to 3 hours as needed), so that systemic and neuraxial opioid are not ordered by two teams independently. Strong learners note that neuraxial hydromorphone already adds to the systemic opioid load.
Monitoring. Continuous pulse oximetry and, ideally, capnography, with sedation score and RR checked hourly for the first 12 hours of the neuraxial opioid and every 2 hours for the next 12, then at least every 4 hours for as long as the infusion runs and for a period after it stops. Supplemental oxygen alone can mask hypoventilation on oximetry.
CPAP. She should use CPAP whenever sleeping, including in the day. An NG tube complicates mask fit, and some surgeons worry about gastric distension stressing a fresh upper anastomosis; the evidence after upper GI and bariatric surgery has not shown CPAP to raise leak rates, and the NG tube decompresses the stomach. This needs a direct conversation with the surgeon. A full-face mask with an NG seal pad is one option; nasal pillows seal poorly with an NG tube in one nostril. Closer monitoring if CPAP cannot be used.

3. POD 2, 0200: hard to rouse

POD 2, 0200: RR 7, SpO2 86% on 2 L, rouses only to a sternal rub. CPAP is on the chair. She got hydromorphone 0.4 mg IV twice since midnight for left shoulder pain. Cold loss T5 to T11, unchanged. Rx first? Naloxone: yes/no? Dose? Repeat how often? Awake after 80 mcg, RR 14, incision pain 3/10. Why does the incision stay comfortable after naloxone? How long do you watch her before you relax? Epidural solution: keep it as is? Why/why not? The left shoulder pain returns. Possible causes? Rx?

Considerations and pitfalls AI draft

Rx first. Stimulate, airway maneuvers, oxygen, bag-mask ventilation if needed, call for help, and stop all opioid including the epidural infusion until she is awake. Check a fingerstick glucose (type 2 diabetes) and keep other causes in mind (hypercapnia, sepsis, a new neurologic event) if she does not respond to naloxone. An unchanged sensory level argues against a high block as the cause.
Naloxone. Yes: RR 7 with hypoxemia and deep sedation. Small titrated doses, about 40 mcg IV every 2 to 3 minutes, to restore breathing and arousal, not full reversal. A 0.4 mg bolus risks pain crisis, hypertension, and pulmonary edema.
Incision still comfortable. The bupivacaine block of the somatic incision pain is untouched by naloxone; only the opioid component is reversed. Strong learners use this to explain why the epidural is still worth keeping.
Observation. Naloxone lasts about 30 to 90 minutes, shorter than both IV and neuraxial hydromorphone, so re-sedation is expected. Watch closely for at least 2 hours after the last dose with continuous oximetry and capnography; a naloxone infusion and a higher level of care are options if she re-sedates.
Epidural solution. Remove the hydromorphone and run plain bupivacaine, or switch to a lipophilic opioid such as fentanyl 2 mcg/mL that spreads less rostrally. Stop IV opioid orders other than the pain service's and restart CPAP.
Shoulder pain causes. Referred pain from diaphragmatic irritation (blood, fluid, or a subphrenic drain), carried by the phrenic nerve (C3 to C5) and outside any thoracic epidural block. Cardiac ischemia and PE must be considered, and a pneumothorax if a central line was placed; an ECG is cheap.
Shoulder Rx. Acetaminophen on schedule, position change, heat, and if needed very small monitored opioid doses. Raising the epidural rate will not reach C3 to C5 safely and is the trap.

4. Heavy legs on POD 2

POD 2, 1800: walking in the hall this morning; now she cannot hold either leg off the bed and her thighs feel numb. No back pain. DDx? First action? Cold loss now T5 to L2 on both sides. Enoxaparin last given at 2200 last night. Infusion stopped. MRI now, or wait? Why? How long? Exam in that window: what, and how often? What finding sends her to MRI before then? Two hours later: knee lift and dorsiflexion full on both sides, cold loss T6 to T12. Interpretation? Restart the infusion? Same rate and concentration? Why/why not? Tonight's enoxaparin: give it? Why/why not?

Considerations and pitfalls AI draft

DDx. New bilateral leg weakness with a mid-thoracic catheter running dilute bupivacaine is a red flag: 0.1% bupivacaine at a thoracic level should not produce a dense leg block. Candidates: caudal spread of local anesthetic (for example after a rate increase when the opioid was removed at 0200), catheter migration (including intrathecal), epidural hematoma, and epidural abscess. The absence of back pain does not exclude a hematoma.
First action. Stop the infusion, examine her yourself, check the site, and review the anticoagulant timing and platelet count. Strong learners stop the infusion as the diagnostic test: a local anesthetic effect should recede.
MRI now or wait? How long?. Both are defensible. Stopping the infusion and re-examining is the common approach: a local anesthetic effect should start to recede, and protocols commonly allow about 1 to 3 hours for clear improvement. With LMWH given 20 hours ago and a dense block this solution should not produce, ordering the MRI and calling neurosurgery now, while watching for recovery, is also reasonable. A deficit that does not clearly improve within that window, or any progression, needs an emergent MRI. Waiting until morning, or restarting the infusion before the deficit resolves, is the failure.
Exam. Motor (hip flexion, knee lift, dorsiflexion) and sensory level every 30 minutes until resolved, plus back pain and bladder function.
Straight to MRI. Worsening weakness, a rising sensory level, new back pain, bladder or bowel dysfunction, or asymmetric findings. Neurosurgery is called at the same time as the MRI: neurologic recovery is best when decompression happens within about 8 hours of symptom onset.
Interpretation / restart?. Full motor return and a falling level within 2 hours point to local anesthetic spread. Before restarting, aspirate the catheter (CSF or blood suggests migration). Restarting at a lower rate or concentration with hourly checks for the first few hours is reasonable; restarting at the old settings invites the same picture and blurs the next exam.
Enoxaparin tonight. Once the deficit has fully resolved and the cause is clear, the scheduled dose is reasonable; if any doubt remains, holding it until the exam is clear or the MRI is done is safer. Strong learners say the decision depends on the exam, not on the schedule.

5. Removing the catheter

POD 4, 0700: walking the hall, tolerating clears, pain 2/10. The surgeon wants the catheter out today. Last enoxaparin 2200 last night. Earliest removal time? Why that hour? Infusion: stop it before removal, or run it until the catheter comes out? Why? Oral regimen: acetaminophen? Dose? NSAID? Why/why not? Oral opioid: agent? Dose? Infusion off at 0700. 1100: pain 4/10 walking. Pull it now? Why/why not? Out at 1100, tip intact, site clean. The surgeon now wants enoxaparin 30 mg twice daily. First dose: when? Why? Neuro checks after removal: what, and for how long? She asks what she should watch for once she goes home. What will you tell her?

Considerations and pitfalls AI draft

Earliest removal. At least 12 hours after the last low-dose LMWH dose: 2200 plus 12 hours gives 1000. Pulling it on 0800 rounds by habit is the trap. There is also a back end: to keep a 2200 dose tonight, it has to be out by 1800; later than that, tonight's dose moves.
Stop before removal?. Both defensible. Turning it off a few hours ahead, with the oral regimen already started, tests whether she manages without it while the catheter is still there to restart. Pulling it while running is simpler but leaves no fallback if the oral plan falls short. A trial off that runs past the removal window is the trap.
Acetaminophen. Scheduled, 1 g orally every 6 hours (maximum 4 g per day), started before the infusion stops so it is on board for the gap.
NSAID. Useful for opioid sparing, but surgeons often avoid NSAIDs after pancreatic and bowel anastomoses (a debated leak signal), and it adds bleeding risk with LMWH; with the catheter still in, ASRA advises against adding it to LMWH. If used at all, after removal and with the surgeon's agreement.
Oral opioid. A short-acting agent as needed at a low dose (for example oxycodone 2.5 to 5 mg every 4 hours as needed), no extended-release product. After her respiratory event on POD 2, start at the low end, keep CPAP on, and monitor the first night off the epidural.
Pull now at 4/10?. 4/10 with walking on oral agents after 4 hours off is a workable result, and 1100 sits inside the removal window. Had she been 7/10, restarting and removing later (still by 1800 to keep the 2200 dose), or removing and adjusting the oral plan, are both reasonable; keeping it past the window means holding a dose and restarting the 12-hour clock.
First twice-daily dose. Twice daily is now allowed because the catheter is out: at least 4 hours after removal, so 1500 at the earliest.
Neuro checks after removal. Hematomas also occur at removal, so sensory level, leg strength, and back pain continue after the catheter is out; ASRA sets no interval, and checks at least every 4 hours for about 24 hours with the same call triggers are common practice.
What to tell her. In plain words: call right away or come to the emergency department for new leg weakness or numbness, new back pain, or trouble passing urine or controlling the bowels. A bleed is most likely in the first day; an infection can show up days to weeks later, so fever, new back pain, or redness, swelling, or drainage at the old site after she goes home also need a same-day call. Give her a number to call. Telling her nothing can go wrong now that it is out, or listing complications in jargon, are both failures.

Long stem

Aortic valve replacement for bicuspid valve with chronic severe aortic regurgitation

A 56 y.o., 82 kg, 5'10" man with a bicuspid aortic valve and chronic severe aortic regurgitation is scheduled for aortic valve replacement, with possible aortic root replacement.

HPIProgressive exertional dyspnea and declining exercise tolerance over the past two years, now winded after one flight of stairs, with occasional orthopnea and bounding pulsations he feels in his neck at rest. No chest pain, no syncope.

PMHBicuspid aortic valve with chronic severe aortic regurgitation. Long-standing hypertension. A dilated aortic root noted on prior imaging. No prior cardiac surgery.

MEDSLisinopril, amlodipine, atorvastatin, furosemide as needed for swelling.

PHYS EXAMHR 58; BP 158/52; RR 16; SpO2 97% on room air; T 36.8°C. Wide pulse pressure with a bounding, collapsing peripheral pulse. Apex displaced laterally; a high-pitched early diastolic murmur at the left sternal border and a soft systolic flow murmur.

ECGSinus rhythm at 58. Left ventricular hypertrophy with a strain pattern. First-degree AV block (PR 218 ms). Occasional PVCs.

ECHOBicuspid aortic valve with severe aortic regurgitation, wide regurgitant jet with holodiastolic flow reversal in the descending aorta. Dilated LV (LVEDD 68 mm) with declining systolic function, LVEF now 40–45%, down from 55% a year ago. Aortic root dilated to 46 mm. Mild functional MR. Estimated PA systolic pressure 40 mmHg.

LABSHgb 13.6 g/dL; platelets 205 K/uL; INR 1.0; K+ 4.1 mEq/L; creatinine 1.2 mg/dL; BNP elevated; glucose 108 mg/dL.

OR ARRIVALAwake radial arterial line placed; line traces a wide pulse pressure with a low diastolic. Two large-bore peripheral IVs. External defibrillator/pacing pads on. Consent includes possible root replacement and a mechanical prosthesis.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Hemodynamic goals for chronic severe AR at induction — keeping forward flow in a regurgitant, volume-loaded ventricle; the costs of bradycardia and rising afterload; protecting a dilated, eccentrically hypertrophied LV going onto bypass; and separating a volume-loaded, dysfunctional ventricle from CPB.

1. Induction and hemodynamic goals in AR

Induction agents and doses in this man? Targets for rate, rhythm, preload, and afterload? Why those in this lesion? After induction: BP 88/38, HR 46. Rx? Phenylephrine 100 mcg — yes or no? Why? Which drug instead, and what heart rate are you aiming for? He is now 96/42 at HR 85 with a diastolic that is still 42. Are you satisfied? Why? Sternotomy: HR 118, BP 100/40, and 1 mm of ST depression in V5. Rx? Rate target now? Why not 118?

Considerations and pitfalls AI draft

Goals. Full, fast, and forward - preserve preload, keep the rate around 80-100 to shorten diastole and cut regurgitant time, and keep SVR low so forward flow wins over the leak. A plan built on slowing him down or squeezing the SVR up runs directly against this lesion.
BP 88/38 with HR 46. The bradycardia is the problem, not just the number - a long diastole is more time for the ventricle to fill backwards through an incompetent valve. Treat the rate.
Phenylephrine. No as the reflex first move - raising SVR increases the diastolic gradient driving regurgitation and the reflex bradycardia compounds it. It is not absolutely forbidden, but reaching for it first in AR deserves a probe.
What instead. Ephedrine 5-10 mg or glycopyrrolate 0.2-0.4 mg for chronotropy, epinephrine 10-20 mcg if he needs inotropy with rate, plus volume; target a rate near 90 and an adequate diastolic, not a systolic number.
96/42 at 85. Better - the rate is doing the work. A low diastolic is expected in severe AR and chasing it with alpha-agonism undoes the gain; judge him by forward flow and rhythm, not by the diastolic alone.
HR 118 with ST depression. He has overshot - 118 shortens filling and perfusion of a hypertrophied wall with a low diastolic pressure. Deepen anesthesia for the stimulus, back the chronotropy off toward 90, and treat the ischemia; the trade was regurgitant fraction for coronary perfusion time and it has gone too far.

2. Going onto bypass with a dilated LV

Cross-clamp on, surgeon delivers antegrade cardioplegia into the aortic root. TEE: the LV is distending. Why? What is that doing to this ventricle right now? Rx in the next minute? Cardioplegia route from here — antegrade root, retrograde coronary sinus, or direct ostial once the aorta is open? Which? Why? LV vent is in and the ventricle decompresses. What else protects this myocardium during the clamp? Cross-clamp time will be about 110 minutes. What does that change about how you set up for separation?

Considerations and pitfalls AI draft

Why it distends. An incompetent aortic valve means root pressure fills the LV in diastole; on the arrested heart, antegrade root cardioplegia crosses the valve straight into the ventricle instead of down the coronaries, and bronchial return adds to it.
What distension costs. Wall tension rises, subendocardial perfusion falls, and the cardioplegia never reaches the myocardium - so the ventricle is both stretched and unprotected. In a dilated, eccentrically hypertrophied LV that is the setup for a heart that will not wean.
Rx now. Stop the root dose, vent the LV (aortic root vent or vent via the right superior pulmonary vein), and switch the delivery route; say it to the surgeon immediately rather than watching the TEE.
Route. Retrograde coronary sinus now, direct ostial delivery once the aorta is open; antegrade root delivery in severe AR is the error this probe exists to catch.
Other protection. Keep it decompressed, adequate cooling and repeat doses on schedule, avoid ventricular fibrillation with a distended chamber, watch for aortic insufficiency during rewarming.
110-minute clamp. Expect a stunned ventricle - have inotrope and pacing ready before the clamp comes off, plan a slow controlled wean with TEE, and anticipate that this LV will need afterload reduction, not just squeeze.

3. Separation from bypass

A 23 mm mechanical valve is in, root preserved. Weaning: TEE shows a well-seated valve with no paravalvular leak, and a dilated, hypocontractile LV. BP 84/46, CI 1.6 on epinephrine 0.03 mcg/kg/min. DDx? Give 500 mL more volume — yes or no? Why? Inotrope — epinephrine, milrinone, or both? Doses? Name the numbers you are titrating to. Back on partial bypass; MAP 75 but the LV still looks distended on TEE. Next move? He will not come off after a second attempt. IABP — in or not? Why?

Considerations and pitfalls AI draft

DDx. Stunned, chronically dilated LV now facing a competent valve; also residual ischemia (coronary air, a compromised ostium after annular work), inadequate protection from the earlier root cardioplegia, RV dysfunction, vasoplegia, or a valve or surgical problem - TEE narrows it.
More volume. No by reflex - this ventricle has been volume-loaded for years and is already at the flat end of its Starling curve; more preload raises wall tension and worsens function. Fill to TEE, not to a CVP number.
Inotrope. Milrinone 0.25-0.5 mcg/kg/min is well matched here - inodilation unloads an afterload-sensitive dilated ventricle - paired with low-dose epinephrine 0.03-0.06 mcg/kg/min or norepinephrine to hold perfusion pressure against the vasodilation. Pure alpha-agonism to chase the pressure works against forward flow.
Targets. CI above roughly 2.2 L/min/m2, MAP 65-75, SvO2 above 60%, and a decompressed, better-contracting LV on TEE - a number, not 'more epi'.
Still distended at MAP 75. He is not unloading - reduce afterload, confirm rate and rhythm (pace to 90 with AV synchrony), vent and decompress, and re-examine the valve and coronaries on TEE. Escalating inotrope into a distending ventricle is the trap.
IABP. Yes, defensible now - diastolic augmentation plus afterload reduction is exactly what this LV-predominant low-output state needs, and the AR that would have contraindicated a balloon has just been replaced. Tie the commit to mechanical unloading, not reflex.

4. Conduction block and pacing

Off bypass the rhythm is complete heart block with a junctional escape at 40 and BP 76/40. Rx in the next minute? He had first-degree block before and now has a new prosthetic aortic valve. Why is he blocked? Epicardial wires — which chambers, which mode, what rate? AV-sequential or ventricular only? Why in this ventricle? Paced at 90 with capture, then twenty minutes later you lose ventricular capture. DDx? What do you check, in what order? Threshold has climbed from 2 mA to 8 mA over the last hour. What do you do about it?

Considerations and pitfalls AI draft

First minute. Pace - epicardial wires or transcutaneous pads while wires go on; chronotropic drugs (isoproterenol, epinephrine) buy seconds but pacing is the treatment. Perfusion pressure support in parallel.
Why blocked. The AV node and bundle of His sit immediately beneath the non-coronary and right coronary cusps; annular debridement of a calcified bicuspid valve and suture placement injure them. His pre-existing first-degree block marks conduction that had no reserve.
Mode and rate. Atrial and ventricular wires, DDD pacing at 90 - this dilated, dysfunctional ventricle still needs the atrial contribution and a forward-favoring rate. Settling for VVI here throws away filling he cannot spare.
Loss of capture. Lead dislodgement or poor epicardial contact, rising threshold from edema, output set below threshold, connection or generator problem, hyperkalemia or acidosis, or a drug effect. Check connections and polarity, turn the output up, confirm capture, verify sensing, send a potassium.
Rising threshold. Edema or ischemia at the lead-myocardium interface; keep output at least 2-3 times threshold, keep pads on him, and do not rely on epicardial wires alone for a pacing-dependent patient overnight.

B. POST-OPERATIVE CARE

Teaching focus. Owning the consequences of a dilated, volume-loaded ventricle into the ICU: post-CPB LV failure and inotrope selection; recognizing new atrial fibrillation and RV strain on top of LV dysfunction; managing pacing dependence and anticoagulation for a mechanical valve; weaning a heart-limited patient from the ventilator; and disclosing an unexpected course.

1. Post-CPB LV failure

First hours in the ICU on epinephrine 0.06 mcg/kg/min and milrinone 0.375: BP 88/50, CI 1.7, SvO2 48%, lactate 4.2, cool peripheries. The valve is competent now — why is this ventricle doing worse than it did before surgery? Turn the epinephrine up, or do something else first? What? Vasopressin — start it? Why? Name your MAP and CI targets. Bedside TEE — what one finding would change your plan? Six hours on: CI 1.6, lactate 6.0, urine 10 mL/h. IABP, Impella, or VA-ECMO? Which, and why in him?

Considerations and pitfalls AI draft

Why worse now. For years the LV ejected a huge total stroke volume, most of it regurgitating back at low resistance; the competent prosthesis has abolished that low-impedance escape route, so the ventricle now has to move its whole output forward against systemic afterload. Its declining function is unmasked, not new. Recognizing this as predictable physiology is the judgment.
Before more epinephrine. Optimize rate and rhythm (pace 90, AV synchrony), reduce afterload, correct calcium, potassium, and acidosis, and confirm there is no tamponade or valve problem. Piling catecholamine onto an afterload-sensitive dilated ventricle raises demand and arrhythmia risk without moving forward flow.
Vasopressin. Yes - 1-3 units/h holds perfusion pressure against milrinone-induced vasodilation without adding chronotropy or beta-driven arrhythmia, and it does not raise PVR the way high-dose alpha agents can.
Targets. MAP 65-75, CI above 2.2, SvO2 above 60%, lactate falling; titrate to those, not to 'more support'.
TEE finding that changes things. A pericardial collection or RV compression (tamponade), new RV failure, a valve or paravalvular problem, or new regional wall-motion abnormality suggesting a coronary problem - each sends you somewhere different from more inotrope.
Mechanical support. IABP first for LV-predominant low output - it unloads and augments coronary perfusion, and the prosthetic valve now permits it. Impella if he needs true LV unloading and flow; VA-ECMO if the RV fails too or he arrests. Tie the choice to which ventricle is failing.

2. New atrial fibrillation and RV strain

Overnight: atrial fibrillation at 150, BP 82/48, CVP climbs to 22, PA 58/32, and the RV is dilated and hypokinetic on echo. DDx for the deterioration? Rate control or cardioversion? Why? Synchronized shock — how many joules? Amiodarone — load and infusion? He converts to sinus at 95, BP 92/54, but CVP is still 22 and the RV still looks poor. Rx for the RV? Inhaled nitric oxide or epoprostenol — dose, and what are you watching systemically? PaCO2 is 55 on his current ventilator settings. Change them? Why?

Considerations and pitfalls AI draft

DDx. New AF with loss of atrial contribution on a marginal LV, evolving RV failure with pulmonary hypertension, tamponade, ischemia, electrolyte or volume derangement. AF plus a rising CVP and a distending RV is the pattern.
Rate versus rhythm. He is unstable - synchronized cardioversion, not titrated rate control. A dilated LV on inotropes at 150 with no atrial kick has no reserve to negotiate with. Treating this as routine post-op AF is a flag.
Energy. Biphasic synchronized 120-200 J (start at 150-200 for AF), with sedation and pads already on him.
Amiodarone. 150 mg IV over 10 min, then 1 mg/min for 6 h and 0.5 mg/min for 18 h; correct potassium above 4 and magnesium above 2 first.
RV after conversion. The RV is the problem now - reduce PVR, avoid over-filling it, keep AV synchrony and a rate near 90, support RV contractility with epinephrine or milrinone, and hold coronary perfusion pressure with vasopressin or norepinephrine so the RV keeps its own supply.
Inhaled vasodilator. Inhaled nitric oxide 10-40 ppm or inhaled epoprostenol 10-50 ng/kg/min - selective pulmonary vasodilation without systemic hypotension; watch for a fall in systemic pressure, methemoglobin with prolonged high-dose NO, and rebound pulmonary hypertension if it is stopped abruptly.
PaCO2 55. Yes, change them - hypercarbia and acidosis raise PVR and load the failing RV. Increase minute ventilation toward a normal or low-normal PaCO2 while keeping plateau pressure and PEEP moderate, since high mean airway pressure also raises RV afterload.

3. Pacing dependence and anticoagulation

POD 1: still in complete heart block, pacing-dependent, and back in atrial fibrillation. He is on DDD pacing at 90. Change the mode? To what? Why? Chest tube output is 30 mL/h and stable, Hgb 9.4. Start anticoagulation today or wait? Mechanical valve plus AF — warfarin, apixaban, or heparin first? Why? Heparin — bolus or no bolus, and what target? INR target for this valve in this man? What must you confirm about the pacing system before you rely on it overnight?

Considerations and pitfalls AI draft

Mode. Switch to VVI or VVIR at 90 - with fibrillating atria, atrial pacing captures nothing and atrial tracking can drive an erratic ventricular rate. Leaving him in DDD while he fibrillates is the miss.
Timing. Start once hemostasis is durably secure - about 30 mL/h of stable output on POD 1 qualifies. Mechanical aortic valve plus AF plus pacing dependence is a high thrombotic burden and waiting days is its own risk.
Agent. Warfarin is mandatory for a mechanical valve - DOACs are contraindicated (RE-ALIGN showed excess thrombosis and bleeding with dabigatran). Start warfarin now and bridge with an infusion of unfractionated heparin, which is titratable and reversible if he bleeds.
Heparin. No bolus this soon after sternotomy - start an infusion around 12 units/kg/h and titrate to a PTT roughly 1.5-2 times control (or anti-Xa 0.3-0.7), rechecking Hgb and chest tube output.
INR target. A bileaflet mechanical aortic valve alone targets 2.5 (range 2.0-3.0); with atrial fibrillation as an added risk factor, target 3.0 (range 2.5-3.5), with low-dose aspirin added.
Before relying on the wires. Capture threshold with an output margin of at least 2-3 times, sensing checked, secure connections, a spare generator and fresh battery at the bedside, transcutaneous pads on him, and a defined escalation plan if capture is lost.

4. Failure to wean from the ventilator

POD 2: off epinephrine, still on milrinone. During a spontaneous breathing trial his rate goes to 32, tidal volumes fall, PaCO2 rises to 52, and PA pressures climb from 30/16 to 48/26. Stop the trial or push through? What is failing here — lungs or heart? What at the bedside settles that? Rx? Chest film shows bilateral edema and he is 4 L positive. Furosemide — dose, and what end point? He diureses 2.5 L and his CI falls to 1.8. Now what? When do you try again, and what must be true first?

Considerations and pitfalls AI draft

Stop the trial. Stop it - he is failing, and grinding on adds ischemic and fatigue debt. A failed trial is information, not a defeat.
Lungs or heart. Heart. Spontaneous negative-pressure breathing increases venous return and LV afterload at once; a recently failing dilated LV cannot take that load, so filling pressures and PA pressures rise during the trial. Weaning failure after this operation is cardiac until proven otherwise.
Bedside proof. The rise in PA and filling pressures timed to the trial, new B-lines or edema, a falling SvO2 during the trial, and echo showing worsening MR or LV function under load - a purely pulmonary failure would not track this way.
Rx. Back to support, keep him unloaded (milrinone, afterload reduction), pace at a rate that helps, and treat the volume.
Furosemide. 40 mg IV (or an infusion at 5-10 mg/h) targeting net negative 1-2 L/day, with filling pressures, oxygenation, and renal function as the end points - not a fixed weight.
CI falls after diuresis. He has been taken past his preload sweet spot - give back a modest 250-500 mL, reassess on echo, and diurese more slowly. Over-diuresing a dilated ventricle into low output is the mirror-image trap.
Next trial. When the CI is stable off escalating support, he is closer to even fluid balance, the rhythm and pacing are reliable, and gas exchange and mechanics are adequate; use pressure support with a low PEEP rather than a bare T-piece in a heart-limited patient.

5. Disclosure and the permanent device

POD 4: extubated, off inotropes, still in complete heart block and paced at 80, still in AF. Permanent pacemaker now, or keep waiting? Why? Single-chamber ventricular or dual-chamber device — which in him? Why? The family asks whether the operation caused the heart block. What will you tell them? His INR is 1.8 on warfarin with a heparin infusion running and the device is planned for tomorrow. What do you do with the anticoagulation? Before he leaves the ICU with epicardial wires still in, what has to be confirmed?

Considerations and pitfalls AI draft

Now or wait. Post-surgical high-grade block that persists past about 5-7 days rarely recovers; POD 4 in a pacing-dependent patient is the usual window to commit, and there is little to gain from waiting much longer in someone with no reliable escape rhythm. A defended call either way is what is wanted, not a recited criteria list.
Device. With permanent AF and complete block, a single-chamber ventricular system (VVIR) is appropriate - an atrial lead has nothing to pace. If he is expected to be pacing nearly all the time with an EF of 40-45%, raise conduction-system or biventricular pacing to avoid pacing-induced cardiomyopathy.
What you tell the family. Plainly and without hedging: the valve was replaced successfully, and the electrical wiring of the heart runs right beside where the valve sits, so replacing it injured that wiring; his heartbeat is now being run by the pacing wires and he will need a permanent pacemaker. Say what is known, say what is uncertain, do not assign blame, and leave room for their questions.
Anticoagulation for the implant. Stop the heparin infusion 4-6 hours before implant; a mechanical valve does not permit a long unprotected window, so restart heparin once hemostasis is confirmed. Do not reverse the warfarin with vitamin K in a mechanical-valve patient for an elective device.
Before he leaves the ICU. A confirmed permanent pacing plan or a reliable temporary system, thresholds and sensing documented with margin, wires secured and labeled, pads available, anticoagulation plan written, and the team aware he has no escape rhythm.

Long stem

Surgical aortic valve replacement for severe aortic stenosis

A 78 y.o., 68 kg, 5'4" woman is scheduled for surgical aortic valve replacement for severe aortic stenosis.

HPIProgressive dyspnea on exertion over the past year, now limited after half a flight of stairs, with one pre-syncopal episode while gardening last month. Occasional exertional chest tightness that resolves with rest.

PMHSevere calcific aortic stenosis. Long-standing hypertension. Paroxysmal atrial fibrillation. Type 2 diabetes. Chronic kidney disease, stage 3.

MEDSApixaban (last dose 72 hours ago), metoprolol, lisinopril (held), amlodipine, atorvastatin, metformin (held).

PHYS EXAMHR 62; BP 160/88; RR 16; SpO2 96% on room air; T 36.7°C. Late-peaking systolic ejection murmur radiating to the carotids; soft, single S2.

ECGSinus rhythm, left ventricular hypertrophy with a strain pattern, first-degree AV block (PR 224 ms), occasional PACs.

ECHOAVA 0.7 cm²; mean gradient 48 mmHg; peak velocity 4.5 m/s. Severe concentric LVH. LVEF 55% with grade II diastolic dysfunction. Mild MR. Estimated PA systolic pressure 44 mmHg.

LABSHgb 11.8 g/dL; platelets 180 K/uL; INR 1.3; K+ 3.4 mEq/L; Mg 1.6 mg/dL; creatinine 1.6 mg/dL (eGFR 32); glucose 184 mg/dL.

OR ARRIVALAwake radial arterial line placed. Two 18 g peripheral IVs and an introducer with a pulmonary artery catheter. External defibrillator/pacing pads on. Apixaban held 72 hours; INR 1.3.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Hemodynamic goals and coronary perfusion in severe AS at induction; the cost of losing sinus rhythm in a hypertrophied, stiff ventricle; separating a non-compliant LV from bypass; and managing post-valve conduction block with epicardial pacing.

1. Induction and coronary perfusion

Induction agents and doses in this woman? Targets for rate, rhythm, preload, and afterload? Why those in this lesion? After induction: BP 78/44 with new inferolateral ST depression. Rx — drug and dose? Fluid bolus first instead? Why/why not? She is back to 108/62 and the ST changes resolve. After sternotomy, HR 108 in sinus. Rx? Why does the rate cost her more than it would a normal ventricle? PA pressures rise to 70/40 and the CVP climbs to 16. More volume, or not? What do you do?

Considerations and pitfalls AI draft

Goals. Sinus rhythm, a rate around 60-80, generous preload for a stiff ventricle, and high-normal SVR to hold coronary driving pressure. A fixed obstruction tolerates neither hypotension nor a fast, poorly filled ventricle; a big propofol bolus that drops SVR is worth challenging.
78/44 with ST depression. Subendocardial ischemia of a hypertrophied LV - restore aortic diastolic pressure now. Phenylephrine 100-200 mcg, or norepinephrine 4-8 mcg, or vasopressin 1-2 units; volume follows, because volume takes minutes and this ischemia is happening now. Reaching first for an inotrope or chronotrope here is a red flag.
Coronary perfusion. Coronary perfusion pressure is aortic diastolic minus LV end-diastolic pressure. LVH and diastolic dysfunction raise the LVEDP, so the gradient is already narrow, and a low diastolic closes it. This ventricle is supply-dependent.
HR 108. Deepen anesthesia for the stimulus, correct hypovolemia, and treat the rate (esmolol 10-20 mg cautiously if she remains hypertensive and tachycardic). Tachycardia raises demand and shortens diastole, cutting both filling of a stiff ventricle and coronary perfusion time - doubly harmful.
Rising PA pressure and CVP. This is the stiff LV failing to accept the volume it has already been given - more fluid will make it worse. Slow the rate, restore sinus function and perfusion pressure, check for ischemia and MR on TEE, and reassess before another bolus.

2. Atrial fibrillation before bypass

Before cannulation she converts to atrial fibrillation at 142 with BP 84/50. Rx? Rate control or cardioversion? Why in this lesion? Synchronized shock — how many joules? She converts, then reverts to AF within two minutes. What do you correct before shocking again? K+ 3.4 and Mg 1.6 — doses? She is still 130 and hypotensive and the surgeon is ready to cannulate. Go on bypass in AF or fix it first? Why?

Considerations and pitfalls AI draft

Why this matters here. A hypertrophied, non-compliant LV takes up to 40% of its filling from atrial contraction; losing the kick at 142 collapses stroke volume and coronary perfusion at once. Treating this as routine AF is a flag.
Cardioversion. She is unstable in a fixed-obstruction lesion - synchronized cardioversion, not a titrated drug. Rate-controlling agents all cost negative inotropy or vasodilation she cannot afford.
Energy. Biphasic synchronized 150-200 J, with the pads already on her and adequate anesthetic depth.
Before the second shock. Correct what is keeping her in it - potassium, magnesium, oxygenation, depth of anesthesia, perfusion pressure, and any ischemia; shocking repeatedly into a hypokalemic, ischemic, under-perfused heart just fails again.
Doses. Potassium 20-40 mEq via a central line at 10-20 mEq/h with monitoring, magnesium 2 g IV over 10-20 min; amiodarone 150 mg over 10 min to hold sinus once restored.
Going on pump in AF. Acceptable if she is deteriorating and the pump is the fastest route to a decompressed, perfused heart - but restore perfusion pressure first and plan to cardiovert during rewarming or after the clamp comes off. Do not linger unstable in the pre-bypass period simply to chase rhythm.

3. Separation from bypass

A 21 mm bioprosthesis is in; weaning from bypass. TEE: well-seated valve, no paravalvular leak, a hypocontractile and underfilled LV. BP 80/45, CI 1.6 on epinephrine 0.03 mcg/kg/min. DDx? Volume — how much, and what tells you to stop? Inotrope — epinephrine, milrinone, or calcium? Doses? Name the numbers you are titrating to. The RV now distends with PA 60/35 and CVP 18. What changed? Rx? She still will not wean. IABP, or an RV strategy? Which, and why?

Considerations and pitfalls AI draft

DDx. Stunned hypertrophied LV, inadequate preload, residual ischemia or coronary air (classically the right coronary, which sits anterior), RV dysfunction, vasoplegia, incomplete de-airing, or a valve or surgical problem - TEE narrows it quickly.
Volume. This stiff LV is preload-dependent; give 250 mL at a time from the pump and watch LV end-diastolic area and function on TEE. Stop when filling stops improving contraction, because over-distension of a failing ventricle is the opposite trap.
Inotrope. Epinephrine 0.03-0.06 mcg/kg/min for contractility; milrinone 0.25-0.375 mcg/kg/min improves lusitropy and unloads the RV but vasodilates a soft patient and needs a vasoconstrictor beside it; calcium chloride 500-1000 mg is a brief bridge, not a plan. A defended choice tied to this ventricle is what is wanted, not a list.
Targets. CI above roughly 2.2 L/min/m2, MAP 70-75 to perfuse a hypertrophied ventricle, SvO2 above 60%, and a filling, contracting LV on TEE.
RV distension. The failure is shifting to the right - pulmonary hypertension, RV ischemia from coronary air, volume overload, or acidosis and hypercarbia raising PVR. Reduce PVR (inhaled nitric oxide 20-40 ppm or epoprostenol), avoid over-filling the RV, hold coronary perfusion pressure with vasopressin, and support RV contractility.
IABP versus RV support. An IABP unloads the LV and augments diastolic coronary perfusion, but it does nothing for a distending RV. Recognizing that the failure has become RV-predominant and reaching for an RV strategy is the better reasoning; either commit is defensible if it is tied to which ventricle is failing.

4. Conduction block and pacing

Off bypass the rhythm is complete heart block with a junctional escape at 42 and BP 74/42. Rx in the next minute? She had first-degree block and a heavily calcified annulus. Why is she blocked now? Epicardial wires — which chambers, which mode, what rate? AV-sequential or ventricular only? Why in this ventricle? Paced at 80 with capture, then twenty minutes later ventricular capture is lost. DDx? What do you check, in what order? Threshold climbs from 3 mA to 9 mA over an hour. What do you do about it?

Considerations and pitfalls AI draft

First minute. Pace - epicardial wires, or transcutaneous pads while the wires go on. Isoproterenol or epinephrine buys seconds; pacing is the treatment, with pressure support in parallel.
Why blocked. The AV node and bundle of His run immediately below the non-coronary and right coronary cusps; debriding a heavily calcified annulus and placing sutures injures them, and her pre-existing first-degree block marks conduction with no reserve.
Mode. Atrial and ventricular wires, AV-sequential (DDD) at 80-90. A hypertrophied ventricle with grade II diastolic dysfunction depends on the atrial kick; settling for VVI here gives away filling she cannot spare.
Loss of capture. Lead dislodgement or poor epicardial contact, rising threshold from edema, output set too low, connection or generator failure, hyperkalemia or acidosis, drug effect. Check connections and polarity, raise output, confirm capture and sensing, send a potassium.
Rising threshold. Edema or ischemia at the lead-myocardium interface; keep output 2-3 times threshold, keep pads on her, have a spare generator, and do not rely on epicardial wires alone in a pacing-dependent patient.

B. POST-OPERATIVE CARE

Teaching focus. Distinguishing surgical from medical bleeding after bypass and treating it by targeted product; recognizing tamponade in a postsurgical chest; managing pacing dependence and re-anticoagulation; an embolic deficit after a calcific valve and what it does to the anticoagulation plan; and extubation judgment with honest disclosure.

1. Post-bypass bleeding

First hour in the ICU: chest-tube output 250 mL/hr of bright blood, BP 96/50, Hgb 8.9. Surgical or medical? What at the bedside separates them? ACT is 150 and a heparinase TEG comparison shows no residual heparin. What do you send next? Fibrinogen 120, platelets 90, R time normal. What do you give, in what order, and how much? Apixaban last dosed 72 hours ago — does that explain this bleeding? Why/why not? After cryoprecipitate and a pool of platelets the output is still 250 mL/hr. Back to the OR now, or keep correcting? Why?

Considerations and pitfalls AI draft

Surgical versus medical. Brisk, sustained, bright output with a coagulation profile that is correcting points surgical; diffuse ooze from line sites and suture holes with abnormal viscoelastic studies points medical. The distinction decides re-exploration versus product.
Heparin excluded. No ACT elevation and no heparinase gap means protamine was adequate and rebound is not the driver - do not keep redosing protamine, which itself impairs platelet function at high doses.
Next tests. Fibrinogen, platelet count, viscoelastic tracing (R time, alpha angle, MA), Hgb, calcium, and temperature - hypothermia and ionized hypocalcemia are correctable causes of coagulopathy that get skipped.
Targeted product. Fibrinogen 120 is the deficit that matters after CPB - cryoprecipitate 10 units or fibrinogen concentrate to get above 150-200 mg/dL; platelets 90 with CPB-induced qualitative dysfunction justifies a pool. A normal R time means she does not need FFP; blind FFP is volume without benefit.
Apixaban. No. Seventy-two hours is at least five half-lives even with her renal function, so residual effect is negligible and it does not explain brisk bright bleeding. Note it is a factor Xa inhibitor - FFP does not reverse it; 4-factor PCC would be the agent if reversal were truly needed (andexanet alfa was withdrawn from the US market in December 2025, and it also complicated heparin anticoagulation around bypass).
Back to the OR. Now. Sustained 250 mL/hr with corrected coagulation is surgical bleeding, and endless transfusion without surgical control is the trap - it also sets up the tamponade you will see when the tube clots off.

2. Sudden hemodynamic collapse

Three hours later the chest-tube output abruptly drops to near zero. CVP 20, PA 42/24, CI 1.4, BP 86/52, urine 5 mL/hr. DDx? What is your first move? TEE is equivocal for a discrete effusion in a postsurgical chest. Does that reassure you? Why? Furosemide for the oliguria — yes or no? Why? The surgeon is on the way. Until then — drugs and doses? Induction for re-exploration — agent and dose, and what must be true before you give it?

Considerations and pitfalls AI draft

DDx. Localized tamponade from clot, given a tube that stopped and equalizing filling pressures with low output; also RV failure, hypovolemia, valve or graft problem, pneumothorax. A stopped chest tube plus rising filling pressures is the pattern to recognize unprompted.
First move. Call the surgeon and prepare for re-exploration while you support her - do not spend twenty minutes assembling studies.
Equivocal TEE. No, it does not reassure. A localized posterior or retro-atrial clot compressing one chamber is easily missed in a postsurgical chest and does not look like a classic circumferential effusion; suspicion beats an equivocal image.
Furosemide. No - the oliguria is from low forward flow, not volume overload, and diuresing a tamponading patient removes the preload that is still filling her. A reflexive diuretic order here is a red flag.
Holding her until the OR. Full, fast, and tight: volume to maintain filling, keep the paced rate up at 90, norepinephrine 0.05-0.2 mcg/kg/min or epinephrine to hold perfusion pressure, avoid anything that drops venous return - and be prepared to open the chest at the bedside if she arrests.
Induction. Surgeon scrubbed, prepped and draped, chest open kit ready before induction. Ketamine 0.5-1 mg/kg or etomidate 0.1-0.2 mg/kg with a small opioid dose, no propofol bolus, no big positive-pressure breaths - the induction that drops preload or afterload arrests a tamponading patient. Anticipate the swing to hypertension and volume overload the moment the clot is evacuated.

3. Pacing dependence and anticoagulation

After the re-exploration, POD 1: she is in atrial fibrillation with complete heart block, paced, and remains pacing-dependent. She is on DDD pacing at 80. Change the mode? To what? Why? Chest-tube output is 25 mL/hr and Hgb is stable. Restart anticoagulation today, or wait? Heparin infusion, warfarin, or apixaban — which first? Why? Her creatinine is 1.9 — does that change the agent or the dose? What must you confirm about the pacing system before you rely on it overnight?

Considerations and pitfalls AI draft

Mode. VVI or VVIR at 80-90. With fibrillating atria the atrial output paces nothing and atrial tracking can drive an erratic ventricular response; keeping her in DDD while she fibrillates is the miss. Also recognize that the atrial kick this stiff ventricle depended on is already gone - rate, volume, and perfusion pressure now carry her output.
Timing. Yes, start today - hemostasis is secure after the re-exploration with 25 mL/hr and a stable Hgb, and AF plus a fresh bioprosthesis is real stroke risk. The judgment is not delaying for days out of reflex after yesterday's bleeding.
Agent. An unfractionated heparin infusion first, without a bolus - titratable and immediately reversible if the chest starts bleeding again. Move to oral anticoagulation once she is stable; a bioprosthesis does not mandate warfarin, so apixaban is an option for the AF, unlike with a mechanical valve.
Renal function. At creatinine 1.9 with an eGFR near 30, apixaban is dose-reduced to 2.5 mg twice daily only when two of the three criteria are met (age 80+, weight 60 kg or less, creatinine 1.5 or more) - at 78 and 68 kg she meets only the creatinine criterion, so the full 5 mg twice daily dose applies; eGFR near 30 is at the edge of the trial population, which is a reason for caution, not dose reduction. Heparin is monitored by PTT or anti-Xa and is not renally dose-adjusted.
Before relying on the wires. Capture threshold with 2-3 times output margin, sensing verified, connections secure, spare generator and battery at the bedside, pads on her, and a written plan if capture fails - she has no reliable escape rhythm.

4. Delayed awakening

POD 1 afternoon, sedation off for six hours: she does not follow commands and the right arm and leg are weak. DDx? Which is most likely, and why does this operation set her up for it? Workup — what, and how fast? CT shows an acute left MCA infarct without hemorrhage. What happens to the heparin infusion you started this morning? Neurology asks about thrombectomy — what is your answer on candidacy? Her BP is 118/60. Target now, and why?

Considerations and pitfalls AI draft

DDx. Residual sedation, metabolic or renal drug accumulation, embolic stroke, watershed hypoperfusion injury, seizure, intracranial hemorrhage on heparin; a lateralizing deficit moves this away from sedation and toward a structural cause.
Why this operation. Surgery on a heavily calcified aortic valve showers calcific and atheromatous debris, and aortic cannulation, cross-clamping, and intracardiac air add to it; her AF compounds the risk. Embolic stroke is a recognized complication of calcific AVR, not a surprise.
Workup speed. Immediate neurologic exam and non-contrast head CT with CT angiography and perfusion imaging, within minutes not hours - it changes the anticoagulation plan and may open a treatment window.
Heparin after the infarct. Hold it. A fresh large infarct carries hemorrhagic conversion risk, especially on systemic anticoagulation the day after a bleeding re-exploration; restarting is a decision made with neurology after repeat imaging, usually days later, and typically balanced against her AF and bioprosthesis risk.
Thrombectomy. Mechanical thrombectomy is not excluded by recent cardiac surgery and is worth pursuing if she has a large-vessel occlusion and salvageable tissue on perfusion imaging, within the extended window up to 24 hours. IV thrombolysis is contraindicated - major surgery within 14 days and a fresh sternotomy.
BP target. Permissive hypertension around a systolic of 140-180 to perfuse the ischemic penumbra while the vessel is occluded; hypotension extends the infarct. Tighten the target after successful reperfusion.

5. Extubation and disclosure

POD 2: awake, follows simple commands, residual right-sided weakness and dysarthria, on ventricular pacing and epinephrine 0.02 mcg/kg/min. Extubate today? Why/why not? What has to be true first? Her cough is weak and she pools secretions. Extubate anyway, or plan a tracheostomy? On what timeline? The family asks whether the operation caused the stroke. What will you tell them? She remains pacing-dependent — what must be settled before she leaves the ICU?

Considerations and pitfalls AI draft

Extubate or not. The deficit is the deciding variable - dysarthria and weak cough predict aspiration and reintubation, but prolonged intubation carries its own harms. Either commit is defensible if airway protection, secretion clearance, gas exchange, and hemodynamics are explicitly addressed.
Before extubation. Following commands and protecting the airway, a swallow and cough assessment, acceptable gas exchange and mechanics, stable hemodynamics not on escalating support, controlled bleeding, and a reliable paced rhythm.
Weak cough with pooling. A bedside swallow evaluation and a defined trial; if she cannot clear secretions after several days, tracheostomy around day 7-10 rather than repeated failed extubations - each failure costs her.
What you tell the family. Plainly: the valve was severely calcified, and operating on that kind of valve can dislodge small pieces of debris that travel to the brain; that appears to be what happened, it was recognized quickly and imaged, and the extent of recovery is uncertain over weeks to months. State what is known, name the uncertainty, do not assign blame, and leave room for questions.
Before leaving the ICU. The permanent pacemaker decision (high-grade block persisting beyond about 5-7 days rarely recovers), confirmed thresholds and sensing with margin, the anticoagulation plan reconciled between her AF and her fresh infarct, and stroke rehabilitation and swallow follow-up arranged.

Long stem

Urgent CABG for left main / three-vessel disease with failure to separate from bypass

A 64 y.o., 92 kg, 5'9" man is scheduled for urgent coronary artery bypass grafting for left main plus three-vessel disease.

HPIAdmitted four days ago with an NSTEMI; troponin peaked and has plateaued. Cardiac catheterization showed a 90% left main stenosis with severe disease in the LAD, circumflex, and right coronary arteries. Recurrent rest angina on the floor despite a heparin infusion and nitrates; cardiology and surgery have called the case urgent.

PMHLeft main plus three-vessel coronary artery disease. Recent NSTEMI. Ischemic cardiomyopathy. Insulin-requiring type 2 diabetes. Chronic kidney disease, stage 3.

MEDSAspirin (continued) and ticagrelor (last dose this morning), heparin infusion for four days, metoprolol, atorvastatin, lisinopril (held), insulin glargine and sliding-scale insulin.

PHYS EXAMHR 78; BP 104/68; RR 18; SpO2 95% on 2 L nasal cannula; T 36.6°C. Jugular venous distension to the angle of the jaw, bibasilar crackles, a soft S3, trace pedal edema.

ECGSinus rhythm with deep T-wave inversions and 1–2 mm ST depressions across the anterolateral leads; first-degree AV block (PR 218 ms).

ECHOLVEF approximately 35%. Anterolateral and inferior hypokinesis. Moderate functional mitral regurgitation. Mildly dilated, mildly hypokinetic RV. Estimated PA systolic pressure 48 mmHg. No significant valvular stenosis.

LABSHgb 10.6 g/dL; platelets 165 K/uL; INR 1.2; PTT therapeutic on heparin; K+ 4.1 mEq/L; creatinine 1.7 mg/dL (eGFR 44); glucose 212 mg/dL.

OR ARRIVALAwake radial arterial line placed. Two large-bore peripheral IVs and an introducer with a pulmonary artery catheter. External defibrillator/pacing pads on. He reports ongoing chest pressure on arrival; the heparin infusion is running and the surgeon is scrubbing.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Protecting a fixed-coronary, poorly compensated circulation through induction and maintaining coronary perfusion pressure; anticoagulating for bypass against heparin resistance; and separating a low-output, ischemic ventricle from CPB with rational inotrope, vasopressor, and mechanical-support choices.

1. Induction in a fixed-coronary circulation

Induction agents and doses in this man? Targets for rate, rhythm, preload, and afterload? Why those with a 90% left main? After induction: BP 76/42 and the anterolateral ST depressions deepen to 3 mm. Rx — drug and dose? Fluid bolus first instead? Why/why not? He is back to 102/62 but the HR is 104. Rx? Nitroglycerin — start it here? Why/why not? PA pressures rise to 64/34 and the tracing shows large v waves. What is happening? Rx?

Considerations and pitfalls AI draft

Goals. Sinus rhythm at 60-70, preserved diastolic pressure and SVR, adequate but not excessive preload in a 35% EF ventricle. With a critical left main the whole myocardium is supply-dependent and there is no collateral reserve. A generous propofol bolus that drops SVR in this man is worth challenging - an opioid-based or etomidate induction with a vasopressor drawn up and running is the safer plan.
76/42 with deepening ST. This is an ischemic emergency, not transient induction hypotension. Give a vasoconstrictor now - phenylephrine 100-200 mcg or norepinephrine 4-8 mcg, escalating to an infusion - because restoring diastolic pressure is the only thing that reperfuses him in the next 30 seconds. Volume takes minutes and a failing LVEF-35 heart tolerates over-filling poorly.
CPP terms. Aortic diastolic pressure minus LV end-diastolic pressure. Hypotension is lowering the numerator while the ischemic, failing LV raises the LVEDP - the gradient is being squeezed from both ends, and the left main means nothing downstream can compensate.
HR 104. Deepen anesthesia for the stimulus, confirm he is not hypovolemic or ischemic-driven, then treat the rate - esmolol 10-20 mg titrated, given his beta-blocker at home. Tachycardia raises demand and shortens diastolic perfusion time at the same time.
Nitroglycerin. Not as the first move while he is soft - it drops preload and coronary driving pressure and can worsen ischemia in a left-main lesion. Once perfusion pressure is restored, low-dose nitroglycerin for ongoing ischemia is reasonable.
Large v waves. Acute worsening of his functional MR from ischemic papillary muscle and LV dysfunction; the v wave is regurgitant flow into the left atrium, and the rising PA pressures are its consequence. Treat the ischemia - perfusion pressure, rate control, afterload reduction once he tolerates it, inotropic support if the LV is failing - and tell the surgeon, because it changes what the operation may need to include.

2. Anticoagulation for bypass and heparin resistance

Surgeon is ready to cannulate. ACT target before bypass? Baseline ACT is 140. You give 400 units/kg of heparin and the ACT comes back 360. Next? Another 10,000 units brings it to 375. What is going on? Why him in particular? Rx — what do you give and how much? Recheck is 520. Go on pump? What do you do differently for the rest of the case? He has had four days of heparin with platelets 165. Does HIT belong on your list? What would change your anticoagulant?

Considerations and pitfalls AI draft

ACT target. Above 480 seconds for full CPB (many centers use 400-480 with heparin concentration monitoring); name the number rather than say 'high enough'. The target protects against circuit thrombosis and consumptive coagulopathy.
360 after a full dose. Give more heparin first - but a second dose that barely moves the ACT is the signal to stop redosing and find the cause. Cannulating and going on pump on a subtarget ACT risks circuit clot and DIC; it must be resolved before bypass.
What is going on. Heparin resistance, most often antithrombin depletion from four days of continuous preoperative heparin. Heparin works by potentiating antithrombin - with antithrombin consumed, more heparin has nothing to work through. Also consider high factor VIII or fibrinogen states, thrombocytosis, and a lab or sampling artifact.
Rx. Restore antithrombin - antithrombin III concentrate (commonly 500-1000 units, or a dose calculated to the deficit) where available, otherwise 2 units of FFP as a source; then recheck the ACT to confirm the response before committing to bypass.
520 - proceed. Yes, go on pump, but recheck the ACT frequently, expect a shorter interval before the next dose, and anticipate needing less protamine at the end than the total heparin dose would suggest.
HIT. Keep it on the list - four days of heparin is the classic window and a 50% fall from baseline matters more than an absolute count, so a platelet count of 165 that was 300 on admission is a warning. If HIT is suspected or confirmed, heparin comes off entirely and bypass is run with bivalirudin, which is why the diagnosis has to be raised before cannulation, not after.

3. Failure to separate from bypass

Grafts complete; attempting to wean. TEE shows a globally hypokinetic, dilated LV with persistent anterolateral hypokinesis. BP 78/46, CI 1.5 on epinephrine 0.03 mcg/kg/min. DDx? What on TEE would send you back to the surgeon rather than to the drug drawer? Volume — give it? How much, and what stops you? Inotrope — epinephrine, milrinone, or calcium? Doses? Name your targets. The RV now distends with PA 58/32 and CVP 20. What changed? Rx? He still will not wean after a second attempt. IABP, or something else? Why?

Considerations and pitfalls AI draft

DDx. Stunned and ischemic LV after a recent infarct and cross-clamp, incomplete revascularization or a graft problem (kinked, occluded, or air in a graft - classically the right), residual ischemia, RV dysfunction, vasoplegia, inadequate preload, worsening MR.
Back to the surgeon. A new or worsened regional wall-motion abnormality in a grafted territory, air in the right coronary distribution, worsening MR, or an unexpected structural finding - a graft problem is fixed at the table, not with more epinephrine.
Volume. Give it in 250 mL increments from the pump with TEE watching LV end-diastolic area; stop when filling no longer improves contraction. A dilated failing LV needs enough preload to eject but over-distension raises wall tension and worsens ischemia.
Inotrope. Epinephrine 0.03-0.08 mcg/kg/min for contractility, milrinone 0.25-0.375 mcg/kg/min for inodilation and RV unloading paired with a vasoconstrictor because it will drop his SVR, calcium chloride 500-1000 mg as a brief bridge only. Defend the choice against this post-ischemic, low-output ventricle rather than listing agents.
Targets. CI above roughly 2.2 L/min/m2, MAP 70-75 to perfuse fresh grafts, SvO2 above 60%, lactate falling, and improving contraction on TEE.
RV distension. RV failure superimposed on the LV problem - RV ischemia or air in the right coronary, a rising PVR from hypercarbia, hypoxia, acidosis, or protamine, or simple over-filling. Reduce PVR with inhaled nitric oxide 20-40 ppm or epoprostenol, hold coronary perfusion pressure with vasopressin, support RV contractility, avoid volume loading it further, and keep AV synchrony.
IABP or something else. An IABP is well matched to an ischemic, LV-predominant low-output state with fresh grafts - it augments diastolic coronary perfusion and cuts LV afterload, and it needs a reasonably regular rhythm to time to. But it does little for a failing RV; if the picture has become RV-predominant, an RV strategy (inhaled vasodilator, RV mechanical support, or VA-ECMO) is the better answer. Either commit is defensible if it is tied to which ventricle is failing.

4. Post-bypass low output and pressor selection

On the IABP at 1:1 with epinephrine and milrinone, CI improves to 2.0 but BP is 82/40 with an SVR of 600. DDx for the low SVR? Vasopressor — norepinephrine, vasopressin, or phenylephrine? Which, and why in him? Dose? Name your perfusion-pressure target and justify the number. He needs norepinephrine 0.4 mcg/kg/min and vasopressin 3 units/hr to hold it. Methylene blue — give it? Dose? What are its risks here? Lactate is climbing to 5 and urine output is 0.2 mL/kg/hr despite a CI of 2.0. What does that tell you? Priorities before he leaves the OR?

Considerations and pitfalls AI draft

Low SVR DDx. Post-CPB vasoplegia from circuit-driven inflammation, his preoperative ACE inhibitor, milrinone-driven vasodilation, residual anesthetic, rewarming; also consider that a low SVR calculated on a low pressure can mask a still-failing pump, and sepsis or adrenal insufficiency in a four-day inpatient.
Vasopressor. Norepinephrine 0.05-0.3 mcg/kg/min is the workhorse - restores SVR with some beta support. Vasopressin 1-3 units/hr is the right partner in vasoplegia with RV dysfunction because it raises SVR without raising PVR. Phenylephrine loads afterload onto a struggling LV with no inotropic offset and is the weakest choice here.
Target. MAP 70-75 - higher than a routine post-op target because fresh grafts, a hypertrophied ischemic myocardium, and CKD-stage-3 kidneys all need driving pressure; name a number and the reason.
Methylene blue. Reasonable now for catecholamine-refractory vasoplegia at 1-2 mg/kg over 20-30 min - it inhibits guanylate cyclase and restores vascular tone. Not a first move. Risks: serotonin syndrome with serotonergic drugs, hemolysis in G6PD deficiency, transient pulse-oximetry interference, and pulmonary vasoconstriction that a failing RV may not tolerate.
Lactate up, urine down at CI 2.0. The number is not adequate for this patient's demand, or perfusion pressure and regional flow are inadequate despite it - look for ongoing ischemia, IABP timing errors, tamponade, and a mixed venous saturation to test the assumption. Do not accept the CI as proof of adequacy.
Before leaving the OR. Secure perfusion pressure and a defined hemodynamic plan, confirm rhythm and working pacing wires with margin, verify IABP timing and augmentation, check TEE for a mechanical cause, correct coagulation and temperature, and confirm graft flows with the surgeon.

B. POST-OPERATIVE CARE

Teaching focus. Owning the consequences of the intra-op course: distinguishing surgical from medical bleeding on a recent-ticagrelor background and treating it by targeted product; separating tamponade from RV failure in a postsurgical chest; managing new atrial fibrillation in a low-output patient; glycemic and renal management after CPB; and extubation judgment with an honest family disclosure.

1. Post-bypass bleeding on a DAPT background

First hour in the ICU: chest-tube output 300 mL/hr of bright blood, BP 92/48, Hgb 8.4. Surgical or medical? What at the bedside separates them? He took ticagrelor this morning. Platelet count 165 before surgery. Does that count reassure you? Why/why not? TEG: R time prolonged, MA 42, fibrinogen 130, platelet count 110. What do you give, in what order, and how much? He gets two pools of platelets and the MA barely moves. Why? Now what? Output falls to 120 mL/hr after products. Take him back to the OR anyway?

Considerations and pitfalls AI draft

Surgical versus medical. Brisk, sustained, bright output with a correcting coagulation profile points surgical and toward re-exploration; diffuse ooze from line sites and suture holes with abnormal viscoelastic studies points medical and toward targeted product. Both can be true after this operation.
Ticagrelor. A potent, reversibly-binding P2Y12 inhibitor dosed hours before bypass produces a real qualitative platelet defect that the count does not capture at all - a count of 110 tells you nothing about function. It is not dialyzable and stopping it does not help acutely; its half-life is roughly 7-9 hours with an active metabolite.
Targeted product. Prolonged R time means factor deficiency - FFP, or PCC if volume matters in a man with RV dysfunction. Fibrinogen 130 calls for cryoprecipitate or fibrinogen concentrate to get above 150-200. A low MA with an adequate count is qualitative platelet dysfunction from CPB plus ticagrelor - give platelets. Correct the specific defect rather than blind product, and do not forget calcium and temperature.
MA barely moves. Circulating ticagrelor and its active metabolite inhibit the platelets you just transfused - this is the practical consequence of a reversible, high-plasma-level agent, unlike clopidogrel. Expect incomplete correction, redose as the drug clears, and note that standard kaolin MA is relatively insensitive to the P2Y12 effect itself (platelet mapping or ADP aggregometry demonstrates it). Desmopressin has limited benefit here and is not the answer.
Take him back. Yes if the total picture is surgical - a fall to 120 mL/hr after a large product load is not resolution, and the tube that keeps flowing today is the tamponade tomorrow. Persistent high-volume output despite corrected coagulation, tamponade physiology, or instability mandates re-exploration; endless transfusion without surgical control is the trap.

2. Tamponade versus RV failure

Three hours later the chest-tube output abruptly drops to near zero. CVP 22, PA 44/26, CI 1.3, BP 84/50, urine 5 mL/hr. DDx? What is your first move? TEE is equivocal for a discrete effusion. Does that reassure you? Why? What on echo would tell you this is RV failure instead? Furosemide for the oliguria — yes or no? Why? How do you hold him until the surgeon arrives — drugs and doses? Induction for re-exploration — agents, doses, and what must be true before you give them?

Considerations and pitfalls AI draft

DDx. Localized tamponade from clot, given the abruptly stopped tube and equalizing filling pressures; versus RV failure in a man whose RV was already mildly dysfunctional and recently strained; also hypovolemia, graft occlusion, or pneumothorax. A stopped tube plus rising filling pressures is the pattern to name unprompted.
First move. Call the surgeon and prepare for re-exploration while you support him - a bedside decision, not a workup.
Equivocal TEE. No. Localized posterior or retro-atrial clot compressing a single chamber is easily missed in a postsurgical chest and does not look like a circumferential effusion; an equivocal study does not exclude it, and suspicion outweighs the image.
RV failure instead. A dilated, hypokinetic RV with a flattened septum and reduced TAPSE, without a compressing collection, and typically a distended rather than compressed right atrium - the treatments diverge sharply, so the distinction is worth the extra look.
Furosemide. No - the oliguria reflects low forward output, not volume overload; diuresing either a tamponading or an RV-failing patient strips the preload that is still generating output. A reflexive diuretic order is a red flag.
Holding him. Full, fast, and tight: volume to maintain filling, pace at 90 with AV synchrony, norepinephrine 0.05-0.3 mcg/kg/min or epinephrine for perfusion pressure, avoid anything that drops venous return, be ready to open the chest at the bedside if he arrests.
Induction. Surgeon scrubbed and the chest prepped and draped before induction. Ketamine 0.5-1 mg/kg or etomidate 0.1-0.2 mg/kg with a modest opioid dose; no propofol bolus, gentle positive pressure, preserve preload, afterload, and rate - and anticipate hypertension and sudden volume overload the moment the clot is evacuated.

3. New atrial fibrillation in a low-output patient

Overnight, hemostasis now secure after the re-exploration, he goes into atrial fibrillation at 150 with BP 88/52 and a falling CI. Rx? Rate control or cardioversion? Why in this ventricle? Synchronized shock — how many joules? What do you correct before you shock him? He converts, then reverts within ten minutes. Amiodarone — load and infusion? What is its cost in him? He is back in AF at 140 on the third day. When do you restart anticoagulation given the bleeding two nights ago, and with what?

Considerations and pitfalls AI draft

Why this matters here. A dilated 35% EF ventricle on inotropes loses both the atrial contribution and diastolic filling time at 150; new post-op AF is common but in this patient it collapses a marginal output and threatens fresh grafts. Treating it as routine is a flag.
Cardioversion. He is unstable - synchronized cardioversion rather than titrated rate control. Beta-blockers and calcium-channel blockers carry negative inotropy he cannot afford.
Energy. Biphasic synchronized 150-200 J, adequately sedated, with pads already on him.
Correct first. Potassium above 4.0 and magnesium above 2.0, oxygenation and acid-base, ischemia, volume status, and excess catecholamine from his own infusions - shocking into an uncorrected substrate just fails again.
Amiodarone. 150 mg IV over 10 min, then 1 mg/min for 6 hours and 0.5 mg/min for 18 hours. It is the least negatively inotropic option, but it is not free - hypotension with rapid loading, bradycardia in a man with first-degree block, and thyroid, pulmonary, and hepatic effects with prolonged use.
Anticoagulation. AF persisting past 48 hours in a post-cardiac-surgery patient warrants anticoagulation. Start once hemostasis is durably secure - typically 48-72 hours after a bleeding re-exploration - with a titratable unfractionated heparin infusion without a bolus, moving to oral anticoagulation as he stabilizes. A bioprosthesis or grafts do not mandate warfarin, but his renal function shapes any DOAC dose.

4. Glycemic and renal management

By the next morning he is stable on epinephrine 0.02 mcg/kg/min. Glucose is running 240-280 on his sliding scale, creatinine has risen to 2.3, and urine output is 0.3 mL/kg/hr. Target glucose range in this patient? How do you get there — regimen and monitoring interval? Epinephrine comes off tomorrow. Change the insulin plan then? Why/why not? DDx for the rising creatinine? Which of his exposures over the last five days did the most damage? Which drugs come off today? He becomes hyperkalemic at 6.2 with a rising bicarbonate deficit. Rx now? When do you start renal replacement?

Considerations and pitfalls AI draft

Target. Roughly 140-180 mg/dL. Tighter targets have not improved outcomes in cardiac surgery and cause hypoglycemia; naming a defended range beats saying 'control the sugar'.
How. A continuous IV insulin infusion with hourly point-of-care glucose until stable, then spacing out; subcutaneous sliding scale on a vasopressor-dependent, edematous patient absorbs unpredictably and is why he is at 280.
Epinephrine and glucose. Epinephrine drives gluconeogenesis, glycogenolysis, and insulin resistance - it is an active cause of his hyperglycemia, so his insulin requirement will fall as the infusion weans, and failing to anticipate that produces hypoglycemia.
Rising creatinine DDx. Cardiac-surgery-associated AKI, multifactorial: contrast from the catheterization four days ago, CPB itself (nonpulsatile flow, hemolysis with free hemoglobin, inflammation), the intraoperative and post-op low-output and hypotensive periods, and nephrotoxins, all on a stage-3 CKD baseline.
What to stop. The ACE inhibitor stays off, avoid NSAIDs, avoid further contrast, dose-adjust or stop nephrotoxic antibiotics, and revisit the choice of hydroxyethyl starch or high-dose vancomycin if present. Optimize perfusion pressure and cardiac output - that is the treatment that matters more than any drug.
Hyperkalemia at 6.2. Calcium chloride 1 g (or calcium gluconate 3 g) for membrane stabilization, insulin 10 units with dextrose, bicarbonate for the acidosis, a beta-agonist, and a binder if he is making urine - but in an oliguric post-CPB patient this is temporizing.
Renal replacement. Start for refractory hyperkalemia, refractory acidosis, volume overload he cannot diurese, or uremic complications - not at a creatinine number. In a patient this volume-sensitive, earlier continuous renal replacement to control volume is often the right call.

5. Extubation and disclosure

Postoperative day 3: awake and following commands, off the IABP, on epinephrine 0.02 mcg/kg/min, but with a prolonged low-output period behind him. Extubate today? What has to be true first? His P/F ratio is 190 and he is 6 L positive. Does that change your answer? What do you do about it? The family asks whether the surgery went as planned and why he needed so much support. What will you tell them? He may need inotropic support for several more days — what does that mean for where he goes and what has to happen before he leaves the ICU?

Considerations and pitfalls AI draft

Extubate today. A defensible commit either way, but the case has to be made on specifics: following commands and protecting the airway, acceptable gas exchange and respiratory mechanics, hemodynamics stable on non-escalating support, controlled bleeding, a stable rhythm with pacing available, and normothermia.
P/F 190 and 6 L positive. This is cardiogenic and post-CPB pulmonary edema on top of a marginal heart - extubating into that buys a reintubation. Diurese toward even balance with a furosemide infusion, keep him unloaded, and extubate onto high-flow or non-invasive support once the P/F and fluid balance improve.
What you tell the family. Plainly: the bypass grafts were completed as planned, but his heart was weak after the operation because of the recent heart attack, so it needed medicines and a balloon pump to support it, and he also needed to go back to the operating room for bleeding. He is improving but the next several days are uncertain. State what happened, name the uncertainty, do not overpromise and do not assign blame, and leave room for their questions.
Days ahead. Continued inotropic support means he stays in the ICU with invasive monitoring and a slow, deliberate wean; before he leaves, the inotropes must be off or stably low, the rhythm and pacing plan settled, anticoagulation for his AF decided, renal function trending, glycemic control on a workable regimen, and the goals-of-care conversation had if he is not improving.

Long stem

Cardiogenic shock and mechanical circulatory support after a large anterior MI

A 64 y.o., 88 kg, 5'9" man with ischemic cardiomyopathy is in the cardiac ICU in decompensated cardiogenic shock after a large anterior MI, and the team is deciding on and placing mechanical circulatory support.

HPIAnterolateral STEMI five days ago, late-presenting, with a culprit proximal LAD lesion stented but a large infarct territory. Progressive low-output failure since, now cool and mottled with worsening confusion over the last several hours. Urine output has fallen to 10 mL/hr.

PMHIschemic cardiomyopathy with prior MIs. Hypertension. Type 2 diabetes. Prior tobacco use with claudication on long walks. No prior valve surgery.

MEDSNorepinephrine 0.3 mcg/kg/min, epinephrine 0.1 mcg/kg/min, dobutamine 5 mcg/kg/min, all escalating over the last 12 hours. Aspirin and ticagrelor (post-stent). Heparin infusion.

PHYS EXAMHR 118; BP 78/58 (MAP 64) on the above support; RR 26; SpO2 92% on high-flow nasal cannula; T 35.9°C. Cool extremities, faint pedal pulses bilaterally, rising lactate. Soft S3, no diastolic murmur.

ECGSinus tachycardia, anterior Q waves with persistent ST elevation, frequent PVCs and short runs of nonsustained VT.

ECHOLVEF ~15%, akinetic anteroapical wall, severely dilated LV. No LV thrombus seen. Trileaflet aortic valve, no significant AS or AR. Moderately depressed RV function. Estimated PA systolic pressure 52 mmHg. No pericardial effusion.

LABSHgb 9.6 g/dL; platelets 140 K/uL; INR 1.4; lactate 6.2 mmol/L; creatinine 2.1 mg/dL; AST and ALT rising; ABG 7.28 / 32 / 78 on high-flow.

CURRENT STATEFemoral access obtained. The interventional and surgical teams are at bedside debating device selection; pressor and inotrope requirements continue to climb and lactate is not clearing.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Device selection under shock for a failing LV and the contraindications that actually decide it; hemodynamic support around cannulation in a patient with no reserve; the afterload and venting consequences once VA-ECMO is running; and differential hypoxia when native lung disease meets retrograde ECMO flow.

1. Device selection under shock

IABP, Impella CP, or VA-ECMO for him. Which? Why? — How much flow does each one actually give this ventricle? — SpO2 drifts to 87% on high-flow; RV moderately depressed on the echo. Same device? Why/why not? — The interventionalist wants an Impella CP alone through the femoral sheath already in. Take it or push for ECMO? Why? — Faint pedal pulses, claudication. Femoral arterial cannula for VA-ECMO — what size? What do you do for the leg, and when? — Lactate 6.2, creatinine 2.1, ticagrelor on board. Anything here that stops you cannulating? Why/why not? — Commit: device, cannulation sites, initial flow target.

Considerations and pitfalls AI draft

Which device. IABP gives roughly 0.5–1 L/min of augmentation and afterload reduction — not enough for an EF 15% ventricle on escalating triple support; Impella CP gives 3–3.5 L/min of LV-to-aorta flow and unloads; VA-ECMO gives full flow and oxygenation but loads the LV. Expect a commit to Impella or ECMO, not IABP; reciting all three without picking is the flag.
SpO2 87% and RV down. An oxygenation problem plus RV dysfunction is what pushes the choice to VA-ECMO: Impella CP needs an RV that can fill it and does nothing for gas exchange. The resident should change the answer when these two facts land.
Impella CP alone. Push back: RV dysfunction starves the inlet (suction), CP flow may not meet his need, and falling SpO2 is not addressed. ECMO first, with Impella later as a vent if needed, is the defended plan. Contraindications the examiner keeps in reserve: moderate-or-worse AR forecloses IABP, Impella, and unvented ECMO; mechanical AVR or LV thrombus forecloses Impella.
Cannula and the leg. Arterial cannula 15–17 Fr, sized to vessel by ultrasound or CT, in a PAD patient; place a 6–8 Fr antegrade distal perfusion cannula at cannulation, not after the foot goes white. Skipping the DPC in a claudicant is the error.
Lactate, creatinine, ticagrelor. None of these stop cannulation — they are the reasons to cannulate. Ticagrelor and heparin raise bleeding risk at the site; note it and plan, do not delay. Waiting for 'better numbers' in unrelenting shock is the trap.
Commit. Peripheral VA-ECMO, femoral venous and femoral arterial with distal perfusion, initial flow ~60–70 mL/kg/min (about 4–4.5 L/min), sweep to normocarbia, MAP target 65. A defended package, not a hedge.

2. Induction and support around cannulation

He needs airway control and sedation for cannulation. Agent? Dose? — What is running, drawn up, and on him before you push anything? — Ketamine 40 mg, rocuronium 100 mg. BP 60/40, runs of VT. Vasopressor — which? Dose? Target MAP? — VT sustains at 180, pulse present, BP 55/30. Shock, amiodarone, or lidocaine? Which? Why? — Sinus at 120 after 100 J, BP 70/45. Perfusion is 10 minutes from cannulating. Cannulate now or stabilize first? Why? — He loses the pulse. Compressions start. What changes in your resuscitation because ECMO is minutes away? — He is on a heparin infusion. Bolus before the cannulae go in? Dose? What do you check? — Flow up at 4 L/min, MAP 65, no native pulse. Stop compressions? Why/why not?

Considerations and pitfalls AI draft

Agent and dose. Hemodynamically neutral and small: ketamine 0.25–0.5 mg/kg or etomidate 0.1–0.15 mg/kg, fentanyl 50–100 mcg, rocuronium. A propofol induction or a full-dose anything is the red flag; naming a generous dose is the fail.
Before you push. Pressors on pumps and titratable, push-dose epinephrine 10–20 mcg/mL and vasopressin drawn up, pads on and connected, surgeon scrubbed and perfusion primed. Inducing a shock patient without rescue in hand is the error.
BP 60/40, VT runs. Epinephrine 10–20 mcg boluses or vasopressin 1–2 U while pumps go up; target MAP back above 60–65. Expect a named drug, a dose, and a number, not 'support the pressure.'
Sustained VT with a pulse, BP 55/30. Unstable — synchronized cardioversion 100 J now; amiodarone after, not instead. Drug-first on an unstable rhythm is the flag.
Cannulate or stabilize. Cannulate. The device is the treatment; there is nothing to stabilize him with. Delaying for a better MAP that the drugs cannot deliver is the trap.
Arrest with ECMO minutes away. High-quality CPR, epinephrine per ACLS, and go straight to cannulation during compressions (ECPR); minimize interruptions, keep the field still for the wire. Recognize the device is the exit from the arrest.
Heparin bolus. Heparin: full bolus to ACT > 200–250 before cannulation (about 50–100 units/kg on top of the infusion), then confirm the ACT once the circuit is running; skipping the bolus because 'he is already on a drip' is the miss.
Flow up, no native pulse. Stop compressions once the circuit is delivering full flow with an adequate MAP; compressions now risk cannula dislodgement. Continue rhythm management for the LV itself — a fibrillating or standstill heart on ECMO will distend.

3. LV distension on VA-ECMO and venting

Peripheral VA-ECMO at 4.5 L/min, MAP 70. An hour in, the arterial line goes flat, PA diastolic 32, and the film is white. What is happening? — TEE: aortic valve not opening, smoke in the LV and aortic root. What is the danger? — Turn flow down, add inotrope, or vent. First move? Why? — Epinephrine to 0.1 and flow to 3.5 L/min: pulsatility returns for ten minutes, then flat again, lactate 5. Now? — IABP, Impella, or a surgical vent. Which? Why? — Impella CP goes in at P6. VT runs return, 8–10 beats every minute. Rx? Amiodarone? Lidocaine? Shock? — Anticoagulation on ECpella — what do you follow and what number?

Considerations and pitfalls AI draft

What is happening. Retrograde ECMO flow raises root afterload; an EF 15% LV cannot open the valve against it, so LVEDP and LA pressure climb and the lungs flood. ECMO is loading this ventricle, not resting it.
Valve not opening, smoke. Stasis in the LV and root with thrombus risk — including the coronaries — despite heparin; plus worsening pulmonary edema. This is the urgency behind venting.
First move. Reduce flow modestly and add or increase inotrope to restore ejection while keeping MAP adequate; a small amount of native ejection is the goal. Cranking flow up for the MAP is the wrong direction. Keeping low-dose inotrope running on VA-ECMO to preserve ejection is standard.
Fails within minutes. Medical measures are not enough; the LV needs an active vent. Lactate 5 also says flow reduction cost him perfusion — he needs both flow and a vent.
Which vent. Impella (ECpella) actively unloads and is the usual choice; IABP is a weak vent; surgical LV/pulmonary-vein vent or atrial septostomy is most definitive but needs the chest or the cath lab. Commit and tie it to severity.
VT on Impella. VT compromises filling of the Impella inlet and worsens stasis; amiodarone 150 mg then infusion, correct K and Mg, check inlet position (the catheter itself can be ectopic against the septum); shock only if hemodynamically meaningful, and on ECMO the pressure may not tell you. Treating the rhythm rather than tolerating it is the point.
Anticoagulation. Unfractionated heparin to PTT 60–80 s or anti-Xa 0.3–0.5; ACT 180–220 if that is what the unit follows — not CPB-level 400+. Impella purge contributes heparin; count it.

4. Differential hypoxia on VA-ECMO

Day 2. Pulsatility is back, native ejection recovering, lungs still wet. Right radial ABG PaO2 55; femoral arterial PaO2 320. What is happening? — Which organs are getting the 55? — What else do you check to confirm it? — Fix it: ventilator, ECMO flow, or reconfigure. First move? — FiO2 1.0, PEEP 14, right radial PaO2 62. Next? — Converted to VAV, total pump flow unchanged at 4.5 L/min. MAP falls to 55. Why? Fix? — Target right radial SpO2 or PaO2? — Next gas: right radial 50 and femoral 52. What now?

Considerations and pitfalls AI draft

What is happening. Differential (north–south, Harlequin) hypoxia: the recovering LV is ejecting blood from wet lungs into the arch, and the ECMO mixing point has moved distal; the head and right arm get native, deoxygenated blood while the lower body gets oxygenator blood.
Who gets the 55. Coronaries, brain, right arm — the highest-stakes territory; this is why the right radial line exists.
Confirm. Right-hand versus foot pulse oximetry, right radial versus post-oxygenator and femoral gases, and cerebral NIRS.
First move. Ventilator: raise FiO2, PEEP, recruit — get the lungs to oxygenate what the LV ejects. Raising ECMO flow to push the mixing point proximal is a temporizer with an LV-distension cost.
Vent fails. The lungs cannot do it; reconfigure to VAV — add a return cannula to the IJ/RA so oxygenated blood goes through the lungs and out the LV.
Arterial flow on VAV. Total pump flow is split; arterial flow falls unless total flow rises and the venous return limb is clamped/restricted to a set ratio. Recognizing the split and managing it (partial clamp on the venous return, raise total flow) is the judgment.
Target. Right radial SpO2 ≥ 90% or PaO2 ≥ 60 — upper-body oxygenation is the endpoint.
Both sites low. Not differential hypoxia — a circuit or oxygenator problem (membrane failure, FdO2 or sweep down, recirculation in the VAV limb) — check the post-oxygenator gas and the blender. Different problem, different fix.

B. POST-OPERATIVE CARE

Teaching focus. The ICU course on support: anticoagulation and bleeding while the device runs, recognizing and acting on a suction event and hemolysis, managing limb ischemia from the cannula, the weaning-versus-escalation decision, and an honest family conversation about bridge-to-what.

1. Anticoagulation and bleeding on support

Overnight on ECpella: oozing from both groin sites, Hgb 9.6 to 7.8, PTT 78, still on aspirin and ticagrelor, heparin infusing. Heparin — continue, reduce, or hold? Target? — What do you send now? — Fibrinogen 140, platelets 140 to 62 over 48 hours, no clot in the circuit. DDx for the platelet drop? — 4T score 6, PF4 antibody positive. Now? Agent? Dose target? What about the Impella purge? — Ticagrelor: the stent is five days old. Hold it? Why/why not? — Transfusion threshold on support — Hgb? Platelets? — Twelve hours later he has had 4 units, groins still oozing, Hgb 7.5. What changes?

Considerations and pitfalls AI draft

Heparin. Reduce, do not hold: drop the target to the low end (PTT 50–60 / anti-Xa 0.2–0.3), and rely on the Impella purge for local anticoagulation. Holding heparin on ECpella invites pump and circuit thrombosis; full-target heparin plus DAPT with a falling Hgb is the other failure.
Send. PTT/anti-Xa, ACT, fibrinogen, platelets, CBC, TEG, plasma-free Hgb/LDH, and a look at the groins for a surgical (cannula-site) source.
Platelet drop DDx. Consumption on the circuit and Impella, HIT, dilution, sepsis, drug effect; a 55% fall on day 5 of heparin with no other explanation puts HIT at the top.
HIT confirmed. Stop all heparin, switch to bivalirudin (start ~0.05–0.1 mg/kg/h, no bolus, titrate to PTT 50–70 or per protocol; start low because bivalirudin is partly renally cleared and his creatinine is 2.1 — argatroban is the alternative if renal failure progresses), and convert the Impella purge to a bicarbonate-based purge. Send the SRA. Missing the purge is a real harm.
Ticagrelor. Hold it if bleeding is life-threatening, but a 5-day-old proximal LAD stent thromboses without DAPT; keep aspirin at minimum and discuss with cardiology — the defensible answer is to hold ticagrelor briefly for active bleeding with a plan to resume, not reflexively stop everything or refuse to touch it.
Thresholds. Hgb 7–8 on support, higher if oxygen delivery is marginal; platelets > 50 with bleeding, > 20–30 without; fibrinogen > 150. Numbers expected.
Continued bleeding. Stop transfusing into the problem: surgical exploration of the cannula sites, reassess anticoagulation, and reconsider whether the current configuration is sustainable. Endless product is the trap.

2. Suction event and hemolysis

Impella at P8. Console alarms: flow drops from 3.3 to 1.8 L/min, placement signal abnormal. DDx? — Before any volume, what do you look at? In what order? — TEE: inlet against the septum, LV cavity small, RV dilated. Fix? — P-level to P6, alarm clears, CI falls from 2.4 to 1.8. Now? — Same shift: plasma pink, LDH 1400, plasma-free Hgb 80. Cause? — What confirms it, and what do you change? — Repositioned and at P6, plasma-free Hgb still climbing at 12 hours. Next?

Considerations and pitfalls AI draft

DDx. Suction from underfilling or malposition, RV failure starving the LV, pump thrombosis, VT, tamponade or bleeding dropping preload. Alarm plus a wrong placement signal points to position/preload first.
Look before volume. Arterial pulsatility and CVP, then echo for position and LV filling and RV size, then the purge and motor current. Blind boluses into a heart-failure patient on an RV that is already dilated is the trap.
Fix. Reposition under echo so the inlet sits ~3.5 cm below the valve away from the wall, and lower the P-level; give volume only for a demonstrated preload deficit. Here the RV is the real limit — support it (inotrope, iNO, ECMO flow) so it can fill the LV.
P6 clears the alarm, CI 1.8. Do not accept inadequate flow: add RV support or raise ECMO flow to cover the gap rather than turning the Impella back up into the wall. Escalate support, not P-level.
Hemolysis cause. Shear from high P-level, inlet or outlet against the wall or valve apparatus, or pump thrombus — worse when anticoagulation has been lightened for bleeding.
Confirm and change. Trend plasma-free Hgb, LDH, haptoglobin, bilirubin, urine color; check anticoagulation; reposition and lower speed. Renal protection: urine output, alkalinize if free Hgb is high.
Still climbing. Suspect pump thrombosis; exchange the device or remove it and rely on ECMO with another vent strategy. Persisting hemolysis on a device that is not fixing the problem is the flag.

3. Limb ischemia from the cannula

Cannulated leg is cool, mottled, and pulseless below the groin; distal perfusion cannula is in. DDx? — How do you confirm? — No Doppler signal at the foot, NIRS 38% on that calf vs 72% on the other. Rx now? — DPC flushed and repositioned: flow 180 mL/min, foot pinks up. Six hours later the calf is tense and painful, CK 15,000. Dx? Rx? — Fasciotomy done. Urine dark, K+ 5.8, creatinine 2.6. Rx? — What do you watch on that leg from here, and how often?

Considerations and pitfalls AI draft

DDx. Occluded or kinked distal perfusion cannula, cannula occluding the vessel in a PAD limb, thrombus at the access site, embolus, vasospasm. His claudication is the setup.
Confirm. Exam, Doppler at DP/PT, calf NIRS against the other leg, DPC flow check; treat a clear deficit, do not wait for a confirmatory study.
Rx now. Flush and interrogate the DPC, reposition or replace it, call vascular surgery; if it cannot be restored, move the arterial cannula or add a graft. Watching a pulseless leg is the failure.
Tense painful calf. Reperfusion compartment syndrome; emergent four-compartment fasciotomy, not observation.
Rhabdomyolysis. Aggressive volume within what the RV tolerates, treat the hyperkalemia (calcium, insulin/glucose), consider CRRT early given creatinine 2.6 and the potassium; alkalinization is an option.
Surveillance. Hourly limb checks — color, temperature, Doppler, NIRS — and DPC flow, documented; this is how the next one is caught before it is a fasciotomy.

4. Weaning versus escalation

Day 5. Lactate 1.8, norepinephrine 0.05, arterial line pulsatile. Ready to wean? What are you looking at? — Echo at 4 L/min: LVEF 25%, LVOT VTI 9 cm. What numbers do you want before you go down? — Flow to 2 L/min for 30 minutes: VTI 8, MAP 56, lactate 3.1. Continue? Why/why not? — Back to 4 L/min. Anticoagulation during the trial? — Day 8, same result. What are the options now? — Creatinine 2.8, on CRRT since day 4. LVAD or transplant candidate? What decides it? — Day 10: still on CRRT, no recovery. What is the plan now?

Considerations and pitfalls AI draft

Ready to wean. Improving LV function on echo, sustained pulsatility, falling filling pressures, minimal pressor and inotrope, clearing lactate, and lungs that can oxygenate. A number-by-number look, not a gestalt.
Numbers to go down. LVEF > 20–25%, LVOT VTI > 10–12 cm, TAPSE > 12 mm, at minimal flow, with MAP held and lactate flat; these are the usual wean-trial thresholds.
Fails at 2 L/min. Stop the trial — MAP falling and lactate rising are the answer. A failed wean is information; pushing to decannulation is the error.
Anticoagulation during the trial. Full — low flow through the circuit clots it; give a heparin bolus or raise the target before turning down.
Options day 8. The fork: bridge to durable LVAD, bridge to transplant, or withdrawal. Name it as the decision now, not 'keep waiting.'
Candidacy. Irreversibility of end-organ injury, frailty, comorbidity, and social support; persistent dialysis dependence is a relative contraindication to LVAD and a barrier to transplant listing. His renal course decides more than his heart.
Where it goes. No recovery, no destination: support is sustaining him without a path, and the conversation with the family about goals is now due.

5. Family conversation and withdrawal

Day 10. No recovery, on CRRT, declined for LVAD and transplant. The family asks whether the machine is healing his heart. What will you tell them? — They ask for two more weeks on the machine. Medically reasonable? Why/why not? — They agree to comfort-focused care. How do you actually stop VA-ECMO? What do you give first? — What do you expect to happen, and how fast? — Chest compressions or shocks after the pump stops — yes/no? Why?

Considerations and pitfalls AI draft

Healing his heart. No — plainly. The pump replaced his circulation while the team waited for recovery or a next step; his heart has not recovered and he is not a candidate for LVAD or transplant. Honest, without foreclosing questions; agreed in advance with surgery and heart failure so the message is one message.
Keep it going. Acknowledge the wish; explain that support without a destination sustains without a path, carries continuing harms (bleeding, limb, infection, stroke), and that the decision before them is continued support versus comfort — not a negotiation over days.
Stopping ECMO. Opioid and benzodiazepine for comfort before anything else, stop CRRT and pressors, then clamp and stop the circuit; cannulae stay in. A resident who reaches for the clamp before the comfort medications is the flag.
Expectation. Circulatory failure within minutes; tell the family this so they are not surprised.
Compressions. No — a comfort-focused plan with a DNR order is documented before the clamp goes on.

Long stem

Mitral valve repair for severe degenerative mitral regurgitation

A 64 y.o., 82 kg, 5'10" man is scheduled for mitral valve repair for severe degenerative mitral regurgitation.

HPIProgressive dyspnea on exertion over the past eight months, now breathless climbing one flight, with two episodes of paroxysmal nocturnal dyspnea this month. Reduced exercise tolerance and fatigue; no chest pain. Referred after a murmur was worked up.

PMHSevere primary mitral regurgitation from a flail posterior leaflet with ruptured chordae. Hypertension. Hyperlipidemia. Remote tobacco use. No prior cardiac surgery.

MEDSLisinopril (held morning of surgery), metoprolol, furosemide, atorvastatin, aspirin (continued).

PHYS EXAMHR 78; BP 134/72; RR 18; SpO2 95% on room air; T 36.6°C. Laterally displaced apex; holosystolic murmur at the apex radiating to the axilla; bibasilar crackles; trace pedal edema.

ECGSinus rhythm at 80, left atrial enlargement, left axis deviation, occasional PACs, no acute ST changes.

ECHOFlail posterior mitral leaflet with an eccentric anteriorly directed regurgitant jet; severe MR by quantitative criteria. LV dilated, LVEDD 64 mm, LVESD 44 mm; LVEF 56%. Dilated left atrium. Estimated PA systolic pressure 52 mmHg; mildly dilated RV with preserved function.

LABSHgb 13.9 g/dL; platelets 205 K/uL; INR 1.0; K+ 4.0 mEq/L; creatinine 1.1 mg/dL; BNP elevated; type and screen sent.

OR ARRIVALAwake radial arterial line placed; large-bore peripheral access; pulmonary artery catheter and TEE planned. External pads on. Patient anxious but cooperative.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Hemodynamic goals in severe regurgitation — forward versus regurgitant fraction, and why bradycardia and high afterload are the enemy; a measured induction that protects forward flow; the masked true ventricle revealed once the low-impedance leak is repaired; and the counterintuitive recognition and management of systolic anterior motion after repair.

1. Induction and hemodynamic goals

Induction agent? Dose? — Heart rate target for him? Why not 55? — After induction: BP 82/40, PA 50/28 from 36/20. Phenylephrine, ephedrine, or volume? Which? Why? — Ephedrine 10 mg: BP 100/58. HR now drifts to 52. Rx? Why? — Glycopyrrolate 0.2 mg: HR 76, BP 112/64. The surgeon asks for a nitroglycerin infusion before bypass. Yes/no? Why? — PA catheter in: wedge 24 with a v wave to 48. What is the v wave telling you?

Considerations and pitfalls AI draft

Agent and dose. Etomidate 0.2 mg/kg or a small propofol dose (0.5–1 mg/kg) with fentanyl 2–4 mcg/kg and rocuronium, titrated against the arterial line; a full propofol bolus that drops SVR and rate together is the flag. Preload kept, afterload low-normal, contractility preserved.
Rate. 80–90; slower lengthens diastole, distends the dilated ventricle, and raises regurgitant volume per beat. Want the mechanism, not 'keep it stable.'
BP 82/40, PA up. Forward flow fell and the leak is backing up; pure phenylephrine raises SVR and the regurgitant fraction. Ephedrine (rate plus inotropy) or a small volume bolus is better matched; a small phenylephrine dose for coronary pressure is acceptable if defended. Reflexive phenylephrine alone gets a probe.
HR 52. Bradycardia is the enemy in MR — treat it, do not tolerate it: glycopyrrolate 0.2 mg or ephedrine, or pace if wires were available. Tachycardia to 120 is comparatively well tolerated in this lesion; that contrast lives here, not in the question.
Nitroglycerin. Reasonable at BP 112 — afterload reduction favors forward flow — but not into hypotension; a defended yes with a BP floor, or a defended no because he has just been hypotensive, both pass.
v wave. Regurgitant volume filling the left atrium in systole; its size tracks the leak and LA compliance, not simple volume overload. Read it as a severity marker.

2. Pulmonary hypertension and RV strain before bypass

After sternotomy, before cannulation: PA 70/38, BP 85/50, ETCO2 30, PaCO2 48 on the gas. First move? — PaCO2 target? Vent settings to get there? — PaCO2 34, PA still 66/36, BP 88/52. Inhaled nitric oxide — start? Dose? End point? — TEE: RV dilating, TAPSE 12 mm. Volume? Why/why not? — Inotrope? Which? Why that one? — Epinephrine 0.03: BP 95/58, PA 60/32, RV still dilated. The surgeon says 15 minutes to cannulation. Wait, or heparinize now and go? Why?

Considerations and pitfalls AI draft

First move. Ventilate: PaCO2 48 raises PVR — increase minute ventilation, FiO2 1.0, check depth of anesthesia, treat acidosis. Fix the controllable PVR drivers before reaching for a drug.
PaCO2 target. 30–35, tidal volume 6–8 mL/kg, moderate PEEP 5, avoid high mean airway pressure; a specific goal, not 'ventilate well.'
iNO. Yes — 20 ppm; end point is a falling PA pressure with a stable systemic pressure and a smaller RV on TEE; it lowers PVR without lowering SVR, unlike a systemic vasodilator.
Volume. No — a dilating RV with TAPSE 12 does not need more preload; overfilling shifts the septum and starves the LV. Cautious, TEE-guided, not reflexive.
Inotrope. Epinephrine 0.03–0.05 or milrinone 0.25–0.375 (with norepinephrine to hold SVR); dobutamine is defensible. Tie it to RV contractility and coronary perfusion pressure.
Wait or go. Go — heparinize and cannulate; bypass unloads everything and 15 more minutes of a failing RV buys nothing. Titrating into a distending RV is the trap.

3. Separation from bypass and the unmasked ventricle

Repair complete with an annuloplasty ring; TEE shows no residual MR. Weaning: LV hypocontractile and dilated, BP 84/46, CI 1.7 on epinephrine 0.03. Why does this ventricle look worse than it did an hour ago? — DDx for failure to separate? — Volume? What on TEE tells you? — Epinephrine up, milrinone, or both? Why? — Milrinone 50 mcg/kg loaded: BP 72/40, CI 2.0. Rx? — Norepinephrine on, BP 90/55. The lateral wall is newly hypokinetic. Cause? What do you tell the surgeon? — Back on bypass; a vein graft goes to the circumflex. Off again at CI 2.2 on epinephrine 0.05. IABP? Why/why not?

Considerations and pitfalls AI draft

Why worse. The regurgitant orifice was a low-impedance pop-off; closing it makes the chronically volume-loaded ventricle eject the whole stroke volume into the aorta. Pre-repair EF of 56% with LVESD 44 mm was already a flattered number. Want this stated explicitly.
DDx. Unmasked LV dysfunction, preload, ischemia or air, RV failure from his pulmonary hypertension, vasoplegia, a repair problem (TEE excludes).
Volume. Give only if the LV is small on TEE with low filling pressures; a dilated hypocontractile LV does not want more. LVEDA and the wedge decide it.
Inotrope. Epinephrine for contractility; milrinone for lusitropy and unloading — both together is the common defended plan for an unmasked ventricle, with the vasodilation of milrinone anticipated.
BP 72/40 on milrinone. Expected vasodilation; add norepinephrine or vasopressin to restore SVR, do not stop the inotropy that is raising the CI.
Lateral wall. Circumflex compromise from an annuloplasty suture — the circumflex runs behind the posterior annulus. Tell the surgeon it is a new regional wall-motion abnormality in circumflex territory, not stunning; it needs a look (flow probe, angiogram, or release/bypass).
IABP. Reasonable at CI 2.2 on rising epinephrine after an ischemic insult — augments coronary flow and unloads; a defended no (adequate CI, wait and watch) is also acceptable. Endless epinephrine escalation without considering mechanical support is the flag.

4. Systolic anterior motion after repair

Off bypass on epinephrine and milrinone: BP 70/40. TEE: turbulent LVOT flow, anterior leaflet drawn to the septum in systole, new MR. Dx? — Epinephrine and milrinone — keep them? Why/why not? — Volume — how much? What does it do? — Phenylephrine or norepinephrine? Target MAP? — HR 108. Slow it? With what? Dose? — Esmolol, 500 mL, phenylephrine: LVOT gradient 20 mmHg, trace MR. Done, or more? — Gradient 80 mmHg despite all of it. Now?

Considerations and pitfalls AI draft

Dx. Systolic anterior motion with dynamic LVOT obstruction — an underfilled, hypercontractile, vasodilated small ventricle after annuloplasty. Naming the obstruction, not chasing the pressure, is the point.
Inotropes. Stop both — they empty and overdrive the ventricle and worsen the obstruction; treating this hypotension with more inotrope is the classic error.
Volume. 500–1000 mL guided by TEE; enlarging the cavity moves the leaflet out of the outflow tract.
Pressor. Phenylephrine (or norepinephrine) to raise afterload and hold the outflow tract open — MAP 70–80; the reverse of MR management before repair.
Rate. Slow to 70–80 with esmolol 0.5 mg/kg then infusion once filled and afterloaded; longer diastole fills the cavity and beta-blockade lowers contractility.
Gradient 20. Acceptable — mild residual SAM often resolves as the ventricle remodels; continue the strategy and reassess. No further action needed beyond avoiding the triggers.
Gradient 80 refractory. Structural — the repair needs revision (sliding plasty, larger ring, leaflet reduction); tell the surgeon this is SAM, not low output, and go back on bypass.

B. POST-OPERATIVE CARE

Teaching focus. Owning the consequences of the case in the ICU: distinguishing surgical from medical bleeding after bypass; recognizing right-heart failure from persistent pulmonary hypertension; managing new post-operative atrial fibrillation in a fresh repair; an embolic deficit and its bearing on anticoagulation; and honest disclosure to the family.

1. Post-bypass bleeding

First ICU hour: chest tube 300 mL of bright blood. DDx? — What do you send? — ACT 150, PTT 45, TEG native R 9 min, heparinase R 6 min. Interpretation? Rx? Dose? — Protamine 50 mg given. Fibrinogen 110, platelets 95, MA 42. What do you give? In what order? — He continued aspirin to surgery. Does that change what you give? — Second hour: 350 mL, labs now corrected, BP 95/60, CVP 8. Back to the OR? Why/why not? — What must be ready before he goes?

Considerations and pitfalls AI draft

DDx. Surgical bleeding at suture or cannulation sites versus medical: residual heparin or rebound, platelet dysfunction, low fibrinogen, fibrinolysis, hypothermia. Bright, brisk, sustained output leans surgical; diffuse ooze with abnormal labs leans medical.
Send. CBC, fibrinogen, PTT/ACT, TEG or ROTEM with heparinase, ionized calcium, temperature, ABG.
Native vs heparinase R. R shortens with heparinase — residual heparin or rebound; protamine 25–50 mg titrated, recheck. Both channels equally abnormal would mean a factor problem, not heparin.
Products. Fibrinogen first — cryoprecipitate 10 units or fibrinogen concentrate 2–4 g to > 150–200; platelets one apheresis unit for a count of 95 with MA 42 and aspirin on board; FFP only for a persistently long R. Reflexive FFP-for-everything is the trap.
Aspirin. Yes — qualitative platelet dysfunction on top of bypass; lowers the threshold to give platelets; not a reason to withhold surgical control.
Back to OR. Yes — 300+ mL/hr for two hours with corrected labs is surgical until proven otherwise; transfusing into a surgical bleed is the error. Tamponade physiology or instability makes it emergent.
Before he goes. Blood checked and in the room, products ordered, access and monitoring intact, pressors and the surgeon; anticipate hypotension when the chest opens and tamponade relieves.

2. Right-heart failure

Overnight: CVP 18, wedge 9, CI 1.6, BP 88/54, PA 64/34, lactate 3.4, urine 15 mL/hr. DDx? — TEE: dilated poorly contracting RV, septum flat, small underfilled LV. Dx? — Volume — give or hold? Why? — Inotrope? Which? Pulmonary vasodilator — which, dose? End point? — Ventilator: PEEP 12, tidal volume 8 mL/kg, PaCO2 47. What do you change? — Epinephrine 0.08, iNO 20 ppm, vasopressin 0.04: CI 1.8, lactate 4.2. Next escalation? Which device? Why?

Considerations and pitfalls AI draft

DDx. RV failure from his pulmonary hypertension, tamponade, RV ischemia (right coronary air or graft issue), volume overload, pneumothorax. High CVP with a low wedge separates it from LV failure and tamponade (which equalizes).
Dx. RV failure with septal shift starving the LV — the low output is right-sided; treating it as LV failure with fluid is the trap.
Volume. Hold — CVP 18 with a distended RV; more preload worsens septal shift. Consider cautious removal if overloaded.
Drugs. Epinephrine or milrinone (with norepinephrine/vasopressin for SVR) for RV contractility; inhaled NO 20 ppm or inhaled epoprostenol 50 ng/kg/min to lower PVR; end point is a smaller RV, CI > 2.2, MAP 65, lactate clearing. Vasopressin holds SVR with less PVR effect than phenylephrine.
Ventilator. Drop PEEP to 5–8, tidal volume 6 mL/kg, raise the rate to normocarbia, FiO2 up; high mean airway pressure and hypercarbia load the RV.
Escalation. Mechanical RV support — RVAD (Impella RP or ProtekDuo) or VA-ECMO; call the surgeon and perfusion now, not after the third pressor.

3. New atrial fibrillation

POD 2: atrial fibrillation at 150, BP 92/56, dyspneic, still on milrinone 0.25. Why does this hurt him more than the average post-op patient? — First moves? — K+ 3.4, Mg 1.6. Rx? Dose? — Rate or rhythm? Which? Why? — BP 78/45 and confused. Cardiovert? Energy? Sedation? — 150 J synchronized: sinus at 90, BP 110/65. What do you start to keep him there? Dose? — Anticoagulation: chest tubes 40 mL/hr. Heparin now? When? What agent?

Considerations and pitfalls AI draft

Why worse here. A fresh repair with a stiff recovering LV and pulmonary hypertension: loss of atrial kick and a rate of 150 drop output and raise LA and PA pressures, loading the RV again. Not routine post-op AF.
First moves. Restore pressure, treat triggers (electrolytes, hypoxia, pain, ischemia), get a 12-lead, decide by stability.
Electrolytes. KCl to > 4.0, magnesium 2 g IV; magnesium alone converts some.
Rate vs rhythm. He is symptomatic on an inotrope — rhythm control (amiodarone) is favored; beta-blockers and calcium-channel blockers cost inotropy and pressure in this heart.
Cardioversion. Unstable — synchronized 120–200 J biphasic now, with a small dose of propofol or midazolam; pads are already on.
Keep him in sinus. Amiodarone 150 mg IV then 1 mg/min x6 h, 0.5 mg/min x18 h; correct electrolytes; beta-blocker once hemodynamics allow.
Anticoagulation. Heparin infusion without a bolus once chest-tube output is reliably low (< 50 mL/hr for several hours) — POD 2–3 is typical; a titratable agent first, warfarin later. Restarting full anticoagulation the day after a bleeding re-exploration, or ignoring stroke risk, are both flags.

4. Delayed awakening and embolic deficit

POD 3, sedation off six hours: no commands, right arm and leg do not move. DDx? — What do you do in the next 30 minutes? — CT: acute left MCA infarct, no hemorrhage. Cause here? — Heparin was started this morning for the AF. Continue, hold, or reverse? Why? — Neurology asks about thrombectomy. Candidate? — BP 165/95. Treat it? Target?

Considerations and pitfalls AI draft

DDx. Embolic stroke, residual sedation or metabolic cause, watershed injury from low flow, seizure, intracranial bleed on heparin; a lateralized deficit points structural.
Next 30 minutes. Neuro exam, glucose, stop sedation confounders, stat non-contrast CT with CTA, call neurology; this is a time-critical event.
Cause. Embolism — new AF with a large left atrium, fresh atrial suture line and ring, intracardiac air or debris from the repair; the mitral operation and the AF together are the setup.
Heparin. Hold, do not reverse: hemorrhagic conversion risk in a large fresh infarct versus embolic risk from AF and a fresh repair; typical practice is to hold 3–7 days depending on infarct size, then resume. The resident must hold the three risks (bleeding chest, embolic AF, hemorrhagic conversion) against each other.
Thrombectomy. Possibly — a large-vessel occlusion within the window is a thrombectomy candidate even after cardiac surgery; thrombolysis is contraindicated. Call, do not decide it alone.
BP. Permissive hypertension — leave up to 220/120 untreated without thrombolysis, or ~180/105 after intervention; dropping the pressure into a fresh infarct is the error.

5. Extubation and disclosure

POD 5: awake, right-sided weakness, still intubated, off inotropes, rate-controlled AF. Extubate? Why/why not? — What must be true first? — Cuff-leak present, follows commands, RSBI 60, swallow uncertain. Extubate now or trach? — Extubated; four hours later coughing after sips. Next? — His wife asks whether the heart operation caused the stroke. What will you tell her?

Considerations and pitfalls AI draft

Extubate or not. A hemispheric deficit raises airway-protection and aspiration questions, but prolonged intubation has its own harms; either is defensible if the airway assessment is done.
What must be true. Follows commands, protects the airway with a cough and gag, acceptable gas exchange on minimal support, stable rhythm and pressure, no escalating support.
Extubate or trach. Extubate with a speech-swallow evaluation and NPO until cleared; tracheostomy on POD 5 for a single failed criterion is premature.
Coughing after sips. NPO, aspiration precautions, formal swallow study, chest film; do not let the family feed him.
Wife's question. Honestly: the stroke was an embolic complication, a known risk of mitral surgery and of the atrial fibrillation that followed; it was recognized and imaged promptly; recovery is uncertain and rehabilitation starts now. One message agreed with the surgeon; no blame, no false reassurance.

Long stem

Mitral valve replacement for severe rheumatic mitral stenosis

A 54 y.o., 60 kg, 5'3" woman is scheduled for mitral valve replacement for severe rheumatic mitral stenosis.

HPIProgressive dyspnea over the past year, now after walking one block, with two recent nights of orthopnea. Last week she coughed up a small amount of blood-streaked sputum. Palpitations for several months. Emigrated from a high-prevalence region as a young adult; childhood febrile illness with joint pains.

PMHSevere rheumatic mitral stenosis. Atrial fibrillation. Pulmonary hypertension. Two prior episodes of pulmonary edema requiring admission.

MEDSWarfarin (held; bridged), metoprolol, digoxin, furosemide. Penicillin prophylaxis as a child.

PHYS EXAMHR 88, irregularly irregular; BP 112/74; RR 20; SpO2 93% on room air; T 36.8°C. Loud S1, opening snap, low-pitched diastolic rumble at the apex. Bibasilar crackles. JVD with prominent waves; trace pedal edema.

ECGAtrial fibrillation, controlled ventricular response. Right axis deviation. Right ventricular hypertrophy with right atrial enlargement pattern. No acute ST changes.

ECHOMVA 0.9 cm²; mean transmitral gradient 12 mmHg. Dilated left atrium with spontaneous echo contrast; doming “hockey-stick” anterior leaflet, fused commissures, thickened subvalvular apparatus. LVEF 60% with an underfilled, small LV. Dilated, mildly hypokinetic RV. Estimated PA systolic pressure 68 mmHg. Moderate tricuspid regurgitation.

LABSHgb 11.2 g/dL; platelets 168 K/uL; INR 1.4 on bridge; K+ 3.6 mEq/L; creatinine 1.1 mg/dL; BNP elevated.

OR ARRIVALAwake radial arterial line placed. Two large-bore peripheral IVs and an introducer. External defibrillator pads on. Heparin infusion stopped per protocol; INR 1.4. Anxious, breathing 24, SpO2 92% on 2 L nasal cannula.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Protecting a fixed transmitral obstruction at induction — preload, rate, rhythm, and SVR at once; the cost of rapid atrial fibrillation across a stenotic valve; the pressure-loaded RV and pulmonary hypertension escalating to pre-bypass pulmonary edema and hemoptysis; and separating a chronically pressure-loaded RV from bypass.

1. Induction across a fixed obstruction

On the table, anxious. Premedicate? With what? Dose? — Induction agent? Dose? Rate target? — After induction: HR 120 in AF, BP 80/46. Rx? Phenylephrine, volume, or esmolol? Which first? Why? — Phenylephrine 100 mcg and esmolol 20 mg: HR 98, BP 96/58. More esmolol? To what rate? — SpO2 falls to 85% as you treat. Cause? Rx? — K+ 3.6 on the morning labs, digoxin on board. Replace it? To what?

Considerations and pitfalls AI draft

Premedication. Midazolam 1 mg IV titrated with oxygen and a pulse oximeter on — anxiety drives the rate, but oversedation brings hypercarbia and hypoxemia that raise PVR in a strained RV. Either extreme (reflexive 2 mg or refusing anxiolysis) gets a probe.
Induction. Etomidate 0.2 mg/kg or propofol in 20 mg increments against the arterial line, fentanyl 3–5 mcg/kg to blunt the rate response, rocuronium; rate target 60–80. A propofol bolus that drops SVR, or ketamine that drives rate, are both flags.
HR 120, BP 80/46. Diastole is the only filling window across a 0.9 cm² valve; the fast rate collapses stroke volume and raises LA pressure. Phenylephrine first to restore SVR and coronary pressure without rate, esmolol to buy diastole, cautious volume only if underfilled. An inotrope or chronotrope first is the red flag.
More esmolol. Yes, toward 70–80, in 10–20 mg increments watching the pressure; digoxin and metoprolol are already on board, so go gently.
SpO2 85%. Rising LA pressure flooding the lungs, plus atelectasis; FiO2 1.0, PEEP 5, slow the rate further, avoid volume; hypoxia raises PVR and threatens the RV — the resident must hold oxygenation, rate, and the RV together.
Potassium. Replace to > 4.0 before bypass — hypokalemia on digoxin invites arrhythmia and AF with rapid rate is her failure mode.

2. Rapid atrial fibrillation and rate control

Before cannulation her ventricular rate accelerates to 150, BP 78/48. Why does this rate hurt this valve? — First moves? — Rate or rhythm control? Which? Why? — The LA has spontaneous echo contrast. Cardiovert her? Why/why not? — You choose drugs: agent? Dose? What does it cost her? — Amiodarone 150 mg: rate 140, BP 74/44. Heparin is drawn up; cannulation is five minutes away. Cardiovert now, or heparinize and go on? Why?

Considerations and pitfalls AI draft

Why this rate. Diastole shortens; filling across the fixed orifice fails; LA pressure climbs and output falls — the classic MS decompensation, not routine AF.
First moves. Restore pressure (phenylephrine/vasopressin), check depth, electrolytes, oxygenation, and tell the surgeon; prepare to cardiovert.
Rate vs rhythm. She is unstable — synchronized cardioversion is the ACLS answer; rate control is for the stable patient. Commit.
Cardioversion with smoke. Spontaneous echo contrast raises embolic concern, but she is heparin-bridged (INR 1.4, heparin stopped hours ago) and unstable — name the risk and act anyway; a giant chronically fibrillating rheumatic LA often does not hold sinus, which is the counter-argument.
Drugs and cost. Amiodarone 150 mg over 10 min is the least hemodynamically costly; esmolol and diltiazem drop SVR and contractility in a strained RV; digoxin is too slow. The cost, not the name, is the point.
Cardiovert or go on. Both defensible: synchronized 120–200 J now, or heparinize and expedite bypass, which definitively unloads the valve. Endless drug titration into a failing patient is the trap; want a committed choice with a reason.

3. Right heart, pulmonary hypertension, and pre-bypass decompensation

Repositioning for cannulation: SpO2 86%, ETCO2 28, PaCO2 52 on the gas, CVP 18, RV distending on TEE. What is raising her PVR right now that you can change? — PaCO2 target? Vent settings? — PA 75/40, RV dilating further. Inhaled NO — start? Dose? — Inotrope for the RV — which? Why that one? — Pink frothy fluid in the ETT, SpO2 84%. DDx? Most likely? — PEEP — up, down, or leave it? Why? — Furosemide? Why/why not? — The surgeon needs ten more minutes for the cannulation sutures. Wait, or tell him to cannulate now? Why?

Considerations and pitfalls AI draft

Controllable PVR drivers. Hypercarbia, hypoxia, acidosis, light anesthesia, atelectasis, hypothermia — all correctable now; naming and fixing them is the core of RV protection in MS.
PaCO2 and vent. 30–35, tidal volume 6–8 mL/kg, moderate PEEP, FiO2 1.0, avoid high mean airway pressure; a number, not 'ventilate well.'
iNO. Yes — 20 ppm; lowers PVR without dropping SVR; a systemic vasodilator here would drop the SVR a fixed-output patient needs.
Inotrope. Epinephrine 0.03–0.05 for RV contractility with coronary pressure preserved; milrinone helps PVR but vasodilates — pair with a pressor. Defend the choice against this RV.
Pink froth. Cardiogenic pulmonary edema from an obstructed LA under a high rate and pressure; hemoptysis from ruptured bronchial veins is the same physiology (the blood-streaked sputum in the HPI); TRALI and aspiration are far behind.
PEEP. Modest increase (8–10) recruits and reduces the oxygenation deficit; excessive PEEP impedes venous return and RV output in a pressure-loaded RV — a titrated answer.
Furosemide. No — she is preload-dependent behind a fixed obstruction; diuresing now drops output. The fix is mechanical.
Wait or go. Cannulate now — bypass is the only thing that relieves the obstruction; temporizing into worsening edema is the error.

4. Separation from bypass with RV failure

MVR done: mechanical prosthesis seated, no paravalvular leak, LA decompressed, but the RV is dilated and poorly contracting with septal bowing. BP 84/50, CI 1.7. DDx for failure to separate? — Volume? Why/why not? — Epinephrine, milrinone, or both? Why in this RV? — iNO is running at 20 ppm. Anything else inhaled? — Epinephrine 0.08, milrinone 0.375, vasopressin 0.04, iNO 20: CI 1.9, CVP 20, RV bigger. Now? — IABP? Why/why not? — What device, and what do you need in place before you pull the cannulae?

Considerations and pitfalls AI draft

DDx. RV failure from chronic pulmonary hypertension now unmasked, residual high PVR, RV ischemia or air down the right coronary, over- or under-filling, rhythm, prosthesis problem (TEE excludes). Septal bowing points RV.
Volume. No — CVP high and RV distended; more preload worsens the septal shift and starves the LV. TEE-guided, cautious.
Inotrope. Epinephrine for contractility and perfusion pressure; milrinone for PVR and lusitropy with a pressor to hold SVR; both together is the common defended plan.
Other inhaled. Inhaled epoprostenol or milrinone as an adjunct; check for air in the right coronary on TEE.
Maximal medical failing. This is mechanical support territory; do not titrate a fourth drug into a distending RV.
IABP. No — it unloads the LV and augments coronary flow but does little for an RV-predominant failure; naming why is the judgment.
Device. Temporary RVAD (RA-to-PA, or a percutaneous ProtekDuo/Impella RP later) or VA-ECMO if oxygenation is also failing; bypass stays in until the device is running; anticoagulation plan for the mechanical valve considered with the device.

B. POST-OPERATIVE CARE

Teaching focus. Delayed extubation and respiratory failure in a pulmonary-hypertensive RV; post-bypass bleeding on a held-anticoagulant, mechanical-valve background and when to re-anticoagulate; pulmonary hypertensive crisis in the ICU; postoperative atrial fibrillation and pacing; and an honest family conversation about a hard course.

1. Post-bypass bleeding and anticoagulation

First ICU hour, RVAD running: chest tube 300 mL of bright blood. DDx? — What do you send? — ACT 160, TEG native R 10 min, heparinase R 6 min. Interpretation? Rx? Dose? — Fibrinogen 130, platelets 95, MA 44. What do you give, in what order? — INR 1.4 from the held warfarin. FFP or PCC for that? Why/why not? — Mechanical mitral valve and an RVAD. Heparin — when? What target? — Hour three: 350 mL/hr with corrected labs, CVP 16, BP 85/50. Back to the OR? Why?

Considerations and pitfalls AI draft

DDx. Surgical (suture lines, cannulation sites, RVAD cannulae) versus residual heparin/rebound, platelet dysfunction, low fibrinogen, fibrinolysis, hypothermia. Bright and brisk leans surgical; diffuse ooze with bad labs leans medical.
Send. CBC, fibrinogen, PTT/ACT, TEG with heparinase, ionized calcium, temperature, ABG.
Heparinase corrects R. Residual heparin or rebound — protamine 25–50 mg, recheck. Equal abnormality on both channels would mean factors, not heparin.
Products. Fibrinogen first (cryo 10 units or concentrate 2–4 g to > 150–200), then platelets for count 95 with MA 44 after bypass; FFP only for a persistently long R. Blind FFP is the trap.
INR 1.4. Not the cause of this bleeding; do not give FFP or PCC to chase a warfarin-tail INR of 1.4 — PCC in particular is a thrombotic risk with a fresh mechanical valve and a device.
Heparin timing. Staged: secure hemostasis first, then heparin without a bolus at a low target (PTT 50–60) within 24–48 h, higher once dry; the RVAD raises the urgency. Full anticoagulation in the same hour she is bleeding invites disaster; no anticoagulation for days with a mechanical mitral valve and a device is the other failure.
Back to OR. Yes — sustained surgical-rate bleeding with corrected labs and a rising CVP; re-explore before tamponade.

2. Delayed extubation and post-bypass respiratory failure

POD 3: RVAD out yesterday, on iNO 20 ppm, epinephrine 0.03. Morning gas on pressure support 8/5: pH 7.31, PaCO2 52, PaO2 78 on FiO2 0.4. Extubate now or wait? Why? — What do you fix before a trial? — Next day: PaCO2 42, off epinephrine, iNO 10 ppm. Extubate? On iNO — how? — Extubated; one hour later RR 34, PaCO2 58, SpO2 88%. What drove it? — Reintubate now or try BiPAP? Why? — POD 8, second failed trial. Tracheostomy? Why/why not?

Considerations and pitfalls AI draft

Extubate or wait. Wait — a respiratory acidosis on pressure support in a pulmonary-hypertensive RV is a set-up: hypercarbia raises PVR and a failed extubation tips the RV. A low threshold to defer is defensible.
Fix first. Diuresis toward euvolemia without underfilling, secretion clearance, sedation off, normocarbia, and RV support optimized.
Extubate on iNO. Yes, with iNO delivered by nasal cannula or a bridging sildenafil dose to prevent rebound; do not stop iNO to extubate.
What drove it. Work of breathing and hypercarbia raised PVR and RV afterload, with residual edema; reason from her physiology, not 'she wasn't ready.'
Reintubate or BiPAP. Reintubate — rising PaCO2 with a strained RV does not tolerate a BiPAP trial that fails an hour later; do not delay into an RV crisis.
Tracheostomy. Comes out when she is off ventilatory support, clearing secretions, tolerating capping, and no longer needs the airway for suctioning; likely weeks.

3. Pulmonary hypertensive crisis in the ICU

That night the iNO is weaned from 10 to 0 over an hour. PA 80/45, SpO2 84%, CVP 22, BP 70/40. What just happened? — First move? — Restart iNO at 20: PA 65/35, BP 78/45. Triggers to look for? — Vent and sedation — what do you change? — Pressor or inotrope for the RV now? Which? Why? — Next week, how do you wean the iNO differently? — She loses the pulse, PEA. What is different about this arrest?

Considerations and pitfalls AI draft

What happened. Rebound pulmonary hypertension on abrupt iNO withdrawal; RV afterload spiked and the RV failed, dropping LV preload and output. Recognize the rebound unprompted.
First move. INO back on at 20 ppm now, FiO2 1.0.
Triggers. Hypoxia, hypercarbia, acidosis, pain, agitation, light sedation, hypothermia, the abrupt wean itself.
Vent and sedation. Normocarbia to mild hypocarbia, FiO2 up, avoid high mean airway pressure, deepen sedation and analgesia to blunt sympathetic surges.
Pressor or inotrope. Vasopressin for SVR and RV coronary perfusion (spares PVR) plus epinephrine or milrinone for contractility; the RV-perfusion logic, not a single reflexive agent.
Re-wean. Slowly — 1–2 ppm steps over days from 5 ppm downward, with sildenafil 20 mg TID started before the wean.
RV arrest. Compressions do little for an afterload-obstructed RV; treat the cause (iNO, oxygen, ventilation, acidosis), epinephrine, and call for ECMO early.

4. Postoperative arrhythmia and pacing

POD 10: atrial fibrillation at 140, BP 84/50. The valve is fixed. Why does this rate still hurt her? — First moves? — Rate or rhythm? Which? Why? — Heparin is at PTT 65 for the mechanical valve. Change anything before cardioverting? — Amiodarone loaded: rate drops, then a junctional rhythm at 45, BP 80/48. Epicardial wires are in. Pacing mode? — What do you check on the atrial wire first? — Atrial wire shows organized P waves that capture. Mode now? Rate?

Considerations and pitfalls AI draft

Why still. The RV is still pressure-loaded and rate-sensitive; a fast rate shortens RV filling and drops output, and loss of atrial transport still costs her. She remains rate-sensitive after MVR.
First moves. Restore pressure, magnesium, potassium, oxygenation, rule out tamponade, then rate versus rhythm by stability.
Rate vs rhythm. Amiodarone for rhythm control — beta-blockade and diltiazem drop the contractility her RV needs; cardiovert if she becomes unstable.
Anticoagulation. She is already therapeutically heparinized for the valve, which covers cardioversion; no change, just confirm the PTT is actually at target.
Junctional 45. Pace — the atrium's state decides the mode; check the atrial wire before choosing.
Atrial wire check. Whether there is organized atrial activity that captures; if she is still fibrillating the atrial lead cannot capture and VVI at 80–90 is what delivers rate.
Organized and capturing. AV-sequential (DDD or AAI if AV conduction is intact) at 80–90 to restore the atrial kick — valuable in a stiff, pressure-loaded RV. Running DDD through ongoing AF, or dismissing the atrial contribution when she is organized, both get a probe.

5. Family disclosure on a hard course

POD 12: tracheostomy in, on iNO 5 ppm, paced, on a heparin drip. Her husband asks why she is so much sicker than they were told to expect and whether something went wrong. What will you tell him? — Tracheostomy — what has to be true before it comes out? — Anticoagulation after discharge — agent? INR target? How long?

Considerations and pitfalls AI draft

Something went wrong. No — plainly: her pulmonary hypertension and right-heart strain predated surgery and are why the course has been hard; the bleeding and the arrhythmias were complications that were recognized and treated; recovery will be slow and is uncertain. One message agreed with surgery and the ICU; no blame, no false reassurance.
Tracheostomy. Comes out when she is off ventilatory support, clearing secretions, tolerating capping, and no longer needs the airway for suctioning; likely weeks.
Anticoagulation. Lifelong warfarin for a mechanical mitral valve, INR target 3.0 (2.5–3.5) plus low-dose aspirin; DOACs are contraindicated with a mechanical valve; her atrial fibrillation would require anticoagulation anyway.

Long stem

Post-CPB coagulopathy and massive transfusion after redo aortic root/ascending replacement under DHCA

A 66 y.o., 92 kg, 5'10" man is undergoing a redo aortic root and ascending aortic replacement for an expanding root aneurysm at the site of a prior bioprosthetic aortic valve.

HPIBioprosthetic AVR eleven years ago for a bicuspid valve. Surveillance imaging over the past year shows a 5.6 cm root and ascending aneurysm. Reoperative sternotomy with extensive mediastinal adhesions was anticipated.

PMHBicuspid aortic valve, prior bioprosthetic AVR. Hypertension. Hyperlipidemia. Mild chronic kidney disease. Remote tobacco use. No prior bleeding disorder.

MEDSAspirin 81 mg (continued through surgery), metoprolol, losartan (held), atorvastatin.

INTRAOP COURSEReoperative dissection of dense adhesions was slow and bloody. Cardiopulmonary bypass time is now 4 hours and 20 minutes, with a 26-minute interval of deep hypothermic circulatory arrest at 18°C during the open distal anastomosis. Rewarming to a core temperature of 36.5°C is now complete. Cell-salvage and homologous transfusion have been ongoing throughout the case. Tranexamic acid was given at induction.

PHYS EXAM / HEMODYNAMICSFully rewarmed to 36.5°C core and now stably separated from bypass: BP 92/54 on low-dose norepinephrine and epinephrine, CVP 12, PA 36/20, CI 2.2 by TEE. Diffuse oozing is visible from every suture line, cannulation sites, and raw mediastinal surfaces as the surgeon tries to close.

LABS / POCPre-protamine: Hgb 8.1 g/dL; platelets 88 K/uL; fibrinogen 110 mg/dL; INR 1.9; ACT 540 s; ionized Ca 0.94 mmol/L; K+ 5.6 mEq/L; pH 7.24; base excess -8; lactate 4.8; temp 36.5°C.

CURRENT STATEThe aortic and root grafts are in and the surgeon reports the suture lines look surgically intact, but the field will not dry. Now that he is fully rewarmed and stably off bypass, protamine is being given and the cannulae are coming out. The surgeon is asking for product.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Anticipating coagulopathy in a redo, long-bypass, DHCA patient; confirming heparin neutralization after protamine and recognizing rebound; distinguishing surgical from medical bleeding at the field; and driving point-of-care–guided, targeted product therapy rather than blind transfusion while separating from bypass.

1. Anticipating the coagulopathy on separation

Off bypass, fully rewarmed, oozing from every surface. Why is this patient bleeding? — What can you fix in the next ten minutes, and how? — Ionized calcium 0.94. Rx? Dose? Target? — pH 7.24, base excess -8. Bicarbonate? Why/why not? — Calcium and ventilation corrected; still oozing. Surgical or medical? What at the field tells you? — The surgeon says, 'It's all suture lines — give me product.' Do you agree? Why?

Considerations and pitfalls AI draft

Why bleeding. Redo raw surfaces, 4+ hours of bypass, DHCA, hemodilution, consumption, platelet dysfunction (bypass plus aspirin), fibrinolysis, acidosis, hypocalcemia, and heparin not yet neutralized. Treating this ooze as routine is the flag; the resident should tie the list to this case.
Fixable now. Calcium, acidosis and ventilation, confirm normothermia (done), complete protamine, start targeted product while the TEG runs; concrete moves, not a recited list of CPB coagulopathy causes.
Calcium. Calcium chloride 1 g centrally, repeat to ionized > 1.1–1.2; 0.94 impairs both clot formation and contractility. Ignoring it is a probe.
Bicarbonate. Defensible either way: correct ventilation and perfusion first; bicarbonate 50–100 mEq is reasonable at pH 7.24 with base excess -8 because coagulation enzymes fail below ~7.2, but it raises CO2 and does nothing for the cause.
Surgical or medical. Diffuse ooze from every raw surface with abnormal labs is medical; a localized, brisk, bright bleed with normalizing studies is surgical. Here it is medical until the labs are corrected and it still bleeds.
Surgeon's demand. Partly — product is coming, but it goes by the TEG, not by the surgeon's request; and the field being medical now does not exempt him from a surgical bleed later once the labs are fixed.

2. Heparin neutralization and rebound

Full-dose protamine is in. ACT 180. Interpretation? — How do you confirm residual heparin rather than something else? — TEG: native R 14 min, heparinase R 6 min. What does that tell you? — Rx? How much? — ACT 130 after 50 mg more. An hour later the field oozes again; native R 11, heparinase R 6. What is this? — Rx? Dose? — Protamine total is now 550 mg and the field is still damp. Another 50 mg? Why/why not?

Considerations and pitfalls AI draft

ACT 180. Incomplete neutralization, heparin redistribution, or a non-heparin coagulopathy prolonging the ACT — ACT is not heparin-specific, and with platelets 88 and fibrinogen 110 a residual elevation may not be heparin at all.
Confirm. Heparinase versus native TEG/ROTEM channel, or an anti-Xa/heparin level; ACT alone cannot separate the two.
R 14 vs 6. R corrects with heparinase — residual heparin is real and is most of the R prolongation; equal channels would have meant factors.
Rx. Protamine 25–50 mg titrated, recheck; not another full empiric dose.
Recurrent ooze with heparinase-correctable R. Heparin rebound — tissue-bound heparin redistributing after protamine has cleared; a recurrence, not a new surgical bleed.
Rebound Rx. Protamine 25–50 mg, guided by the TEG; consider a low-dose infusion if it recurs.
More protamine. No — with heparin already neutralized on the TEG, excess protamine is itself an anticoagulant and platelet inhibitor, and carries hypotension, pulmonary hypertension, and anaphylactoid risk; titrate to evidence of heparin, not to the ooze.

3. Point-of-care–guided targeted therapy

Heparin neutralized, still oozing. TEG: R 9 min, K 5 min, angle 40°, functional-fibrinogen MA 8 mm, kaolin MA 42 mm; platelets 90, fibrinogen 110. Read it for me, channel by channel. — What do you give first? Second? — Fibrinogen 110: cryoprecipitate or fibrinogen concentrate? Which here? Dose? — Why is the MA 42 with a count of 90? — Tranexamic acid was given at induction. Redose? Why/why not? — Two rounds of targeted product later: fibrinogen 210, platelets 120, R 6, MA 55, field dry except for the raw surfaces, still oozing. rFVIIa or PCC? Why/why not?

Considerations and pitfalls AI draft

Channels. R 9 = factor deficiency (modest); K/angle and functional-fibrinogen MA 8 = fibrinogen deficit; kaolin MA 42 with count 90 = platelet function and number. Reading the channels into a plan is the skill.
Order. Fibrinogen and platelets first — clot strength is the problem; FFP or PCC for R only if it stays long. FFP-for-everything is the trap.
Cryo vs concentrate. Fibrinogen concentrate 4 g (roughly 50 mg/kg) is low-volume, fast, and pathogen-reduced — attractive when volume matters; cryoprecipitate 10 units is the alternative. Target > 150–200. A defended choice, not a list.
MA 42 at count 90. Bypass acquires platelet dysfunction — extracorporeal contact, activation, hypothermia during DHCA — plus aspirin; the count overstates function. One to two apheresis units.
TXA redose. Yes — long bypass and DHCA drive fibrinolysis; a second 1 g dose or infusion (LY30 on the TEG informs it); seizure risk rises with high total doses and renal impairment, so not unlimited.
rFVIIa / PCC. With substrate corrected and a dry surgical field, low-dose rFVIIa (20–40 mcg/kg) or 4-factor PCC 15–25 U/kg is a defensible last resort for refractory microvascular bleeding, with explicit thrombotic risk to fresh grafts; reaching for it before substrate correction or before excluding surgical bleeding is the red flag.

4. Transfusion, calcium, potassium, and closing the chest

Transfusing briskly. Ionized calcium 0.82, pressure sags with each unit. Mechanism? Rx? End point? — K+ 6.4, peaked T waves. Rx now? Which agents, in what order? — Calcium, insulin 10 units with dextrose, ventilation up: K+ 5.6, T waves normal. Hgb 6.9 on the same gas. Transfuse? To what? — He is soft: norepinephrine 0.15, epinephrine 0.05, CI 2.0. The surgeon wants to close. Close now, or pack and leave it open? What decides it? — Trial closure: BP 70/40, CVP 20. Now? — He leaves for the ICU with the chest open. Ventilator and sedation — what changes for an open chest?

Considerations and pitfalls AI draft

Calcium 0.82. Citrate from rapid product chelates calcium faster than a hypoperfused liver clears it; hypocalcemia costs both contractility and coagulation. Calcium chloride 1 g per 2–4 units of product, titrated to ionized > 1.1 and to the pressure.
K+ 6.4 with T waves. Transfusion load plus cardioplegia plus acidosis; calcium chloride first (stabilizes the membrane and treats the calcium), then insulin 10 units with dextrose 25 g, ventilate to lower CO2, bicarbonate if acidotic; furosemide or CRRT if it persists. Membrane-stabilize-then-shift, not one drug.
Hgb 6.9. Yes — actively bleeding on two pressors after a long pump run: transfuse toward 8–9, not to a stable-patient threshold of 7; each unit brings more citrate and potassium, which is why the calcium and K+ are re-checked with it.
Close or open. Leave open if the field is not dry, the myocardium is edematous, or hemodynamics will not tolerate closure; damage control with packing and planned re-exploration beats closing into tamponade. Pressor requirement and ongoing loss decide it.
Trial closure fails. Reopen — that is tamponade physiology on closure; pack, leave the sternum open with a patch, return in 24–48 h.
Open chest to the ICU. Full sedation with analgesia and usually paralysis (no coughing or bucking against a patched sternum), lung-protective volumes with modest PEEP, and a bedside reopening kit; the handoff carries the product plan by TEG, expected calcium and potassium trends, protamine total and rebound history, pressor doses, and the trigger for emergent reopening.

B. POST-OPERATIVE CARE

Teaching focus. Carrying the coagulopathy into the ICU: ongoing point-of-care–guided correction and the limits of transfusion; recognizing surgical re-bleeding and tamponade in a postsurgical chest; the complications of massive transfusion (TRALI/TACO, dilutional, citrate, hyperkalemia); deciding when to re-explore; and an honest family disclosure.

1. Ongoing ICU coagulopathy

ICU, chest open and packed: chest tube 200 mL/hr of dark blood, line sites oozing. TEG: R 6, MA 46, functional fibrinogen MA 10; fibrinogen 130, platelets 95, temp 36.2, pH 7.32. What do you give? What do you stop giving? — Targets — fibrinogen? Platelets? — He has had 14 units PRBC, 6 FFP, 2 platelets, cryo. What has that volume done to him? — What do you check, and how often? — Two hours later: labs at target, output still 200 mL/hr. What is it now?

Considerations and pitfalls AI draft

Give and stop. R has corrected — stop FFP; MA and functional fibrinogen still low — fibrinogen and platelets. Correcting to the current TEG, including stopping what is no longer indicated, is the judgment.
Targets. Fibrinogen > 150–200, platelets > 100 with active bleeding after bypass, ionized calcium > 1.1, normothermia.
Massive transfusion effects. Dilutional coagulopathy and thrombocytopenia, citrate hypocalcemia, hyperkalemia, hypothermia, acid-base shifts, TACO and TRALI, immunomodulation and infection; the syndrome, not one item.
Monitoring. Ionized calcium and potassium every hour while transfusing, TEG every 1–2 hours, temperature, filling pressures and oxygenation to separate TACO from TRALI.
Corrected labs, still bleeding. Surgical until proven otherwise — the coagulopathy has been treated and no longer explains it; call the surgeon rather than keep transfusing.

2. Re-bleeding versus tamponade

Two hours later the chest tube output abruptly stops. CVP 22, PA 40/26, CI 1.5, BP 88/52, 5 mL of urine this hour, pulsus on the arterial line. Dx? — TEE: no discrete effusion, RV 'looks compressed maybe.' Does that change your mind? — Rx while the surgeon is called? Volume? Pressor? Which? — Nurse asks for furosemide for the urine output. Yes/no? Why? — BP 60/30, HR 130. Bedside sternotomy in the ICU — yes/no? — Chest open at the bedside: a large clot over the RA. What do you expect the pressure to do? Rx?

Considerations and pitfalls AI draft

Dx. Tamponade from retained clot — a bleeding chest that suddenly drains nothing, rising and equalizing pressures, pulsus. Recognize the pattern unprompted.
Equivocal TEE. No — a localized postsurgical clot is easily missed; a bleeding chest with a stopped tube and this hemodynamic picture is tamponade until the chest is open. A clean echo must not reassure.
Temporizing. Full, fast, tight: volume to keep preload, norepinephrine or epinephrine for pressure, avoid anything that drops venous return or slows the rate; the definitive treatment is opening the chest.
Furosemide. No — the oliguria is low forward flow from impaired filling; diuresing a tamponading patient is the red flag.
Bedside sternotomy. Yes — peri-arrest tamponade is opened where he lies; a defended yes, with the hemodynamic plan through it (epinephrine ready, blood in the room, surgeon or trained ICU team).
Clot evacuated. Abrupt rise in venous return and pressure, sometimes hypertension and a tachyarrhythmia; be ready to back off pressors and treat the rhythm; then find the bleeder.

3. Transfusion-related lung injury

After the washout the bleeding stops. Two hours later: SpO2 86% on FiO2 1.0, pink frothy secretions, bilateral infiltrates. DDx? — Wedge 10, CVP 8, BNP low, no response to a furosemide trial. TRALI or TACO? What makes the distinction? — Rx? — Ventilator: tidal volume? Plateau limit? PEEP? — Does this change what you give for any further oozing? — The other units from the same donation are still in the blood bank. Can they be issued? Why/why not?

Considerations and pitfalls AI draft

DDx. TRALI, TACO, cardiogenic edema, aspiration, ARDS from a long pump run and shock — a desaturation within hours of heavy transfusion puts the transfusion causes first.
TRALI vs TACO. TRALI: non-cardiogenic, normal-to-low filling pressures, within 6 hours, no response to diuresis; TACO: hydrostatic, high filling pressures, improves with diuresis. His numbers say TRALI. Reason from the data.
Rx. Supportive — oxygenation, lung-protective ventilation, hemodynamic support; diuresis is not the treatment; most resolve in 48–96 hours.
Ventilator. 6 mL/kg PBW (~440 mL for 5'10"), plateau ≤ 30, PEEP 10–14 titrated, permissive hypercapnia; concrete numbers.
Further product. Only TEG-targeted, minimal-volume product (concentrates over FFP); avoid volume-heavy blind transfusion.
Co-components. No — the blood bank quarantines every component from the implicated donations and evaluates the donor for anti-HLA/HNA antibodies; the case is reported as a suspected TRALI.

4. When to return to the OR

That evening: chest tube 120 mL/hr for four hours, TEG normal, calcium and temperature normal, no heparin effect. What is this bleeding now? — Numbers or trends that send him back? — The surgeon wants to watch it overnight. Agree? Why/why not? — He drops to 75/40 with a tense, full chest. Decision? — The chest opens in the OR. What do you expect the pressure to do? What is drawn up?

Considerations and pitfalls AI draft

What it is. Surgical — the medical coagulopathy is corrected and no longer explains it; continuing to transfuse into a surgical bleed is the trap.
Thresholds. > 200 mL/hr for 2 hours, > 150 mL/hr for 4, > 1 L total in a few hours, an acute increase, tamponade physiology, or instability — a defended trend, not a recited number.
Watch overnight. No — 120 mL/hr for four hours with corrected labs in a chest that has already tamponaded once is a return to the OR tonight; the resident should say so to the surgeon plainly rather than defer.
Tense chest, hypotension. Tamponade again — emergent return to the OR (or bedside opening if he arrests); not more observation.
Chest opens. Relief of tamponade: abrupt rise in venous return and pressure, sometimes hypertension and a tachyarrhythmia; then the bleeder. Blood and products checked in the room, access and monitoring intact, pressors running and drawn up, epinephrine ready to back off.

5. Disclosure to the family

Next morning after the second washout, closed, sedated, off escalating support. His daughter asks whether all the bleeding was a complication and whether the transfusions could still hurt him. What will you tell her?

Considerations and pitfalls AI draft

Complication. Honestly: bleeding after a difficult reoperation on prolonged bypass with circulatory arrest was a known risk; it was heavy, was treated with blood products and two returns to the operating room, and has stopped; one message agreed with the surgeon, without blame or false reassurance. Name the transfusion risks plainly — the lung injury he is being ventilated for, fluid overload, electrolyte shifts, reactions, small infection risks — framed as monitored for and outweighed by the need to treat life-threatening bleeding.

Long stem

Elective on-pump CABG for multivessel CAD

A 64 y.o., 92 kg, 5'10" man is scheduled for elective coronary artery bypass grafting on cardiopulmonary bypass: planned LIMA to LAD and saphenous vein grafts to the first obtuse marginal and the distal right coronary artery.

HPIFour months of exertional chest pressure, now brought on by one flight of stairs and relieved by rest. No rest pain. Exercise stress test positive at 5 METs with inferolateral ST depression. Cardiac catheterization 2 weeks ago showed multivessel disease, and the heart team recommended surgery. He was loaded with clopidogrel at the catheterization; last dose 6 days ago.

PMHHypertension. Type 2 diabetes for 12 years. Hyperlipidemia. Former smoker, 30 pack-years, quit 5 years ago. Inferior Q waves found on a routine ECG 3 years ago, never evaluated. Two prior general anesthetics without problems.

MEDSAspirin 81 mg, metoprolol succinate 100 mg, lisinopril 20 mg, atorvastatin 80 mg, all taken this morning with a sip of water. Metformin 1000 mg BID, last dose yesterday morning. Insulin glargine 36 units nightly; took half the dose last night. No known drug allergies.

PHYS EXAMHR 68; BP 158/86; RR 14; SpO2 96% on room air. Lungs clear. No murmur. No JVD or edema. Mallampati 2, full dentition, good neck extension. Both saphenous veins mapped as adequate.

ECGSinus rhythm. Q waves in II, III, and aVF. No acute ST changes.

CATHETERIZATIONLeft main normal. Proximal LAD 85%. First obtuse marginal 90%. Mid RCA 80%. LVEDP 16 mm Hg.

TTELVEF 45% with inferior and inferoseptal hypokinesis. Mild MR. Trileaflet aortic valve without stenosis or regurgitation. Normal RV size and function.

LABSHgb 13.6 g/dL; platelets 241 K/uL; INR 1.0; aPTT 29 s; Na+ 139 mEq/L; K+ 4.4 mEq/L; creatinine 1.3 mg/dL; glucose 176 mg/dL; HbA1c 8.2%.

OR ARRIVALVisibly anxious. One 18 g IV in the left hand. Standard monitors on.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Induction that protects the supply-demand balance in multivessel CAD; heparin, ACT, and the transition onto bypass; anesthetic, glucose, hemoglobin, and myocardial protection decisions on pump; a stepwise separation from bypass and protamine reversal.

1. Induction

Midazolam now? Dose? Why/why not? Arterial line: before induction or after? Why? Central line? PA catheter? Why/why not? Induction agents? Doses? Goals through induction: HR? BP? Two minutes after induction, before laryngoscopy: BP 82/46, HR 56, 1.5 mm ST depression in V5. Of concern? Why? Rx? Phenylephrine? Ephedrine? Which? Target BP? Laryngoscopy: BP 184/102, HR 98. Rx? Dose?

Considerations and pitfalls AI draft

Midazolam. A small titrated dose (1-2 mg IV) with monitors and oxygen on is reasonable: anxiety drives tachycardia and hypertension, which raise myocardial oxygen demand across fixed stenoses. A large dose before monitoring, or none at all in a frightened patient with three-vessel disease, are both weaker answers.
Arterial line timing. Before induction, under local. Induction hypotension and the laryngoscopy surge are the two moments this patient is most likely to become ischemic, and a cuff cycling every few minutes misses them.
Central line and PA catheter. A central line (usually internal jugular) for vasoactive drugs and CVP is standard, commonly placed after induction. A PA catheter is defensible either way: with EF 45%, a normal RV, and TEE in the room, many would skip it; others want cardiac output and mixed venous saturation in the ICU. A learner who places one by reflex and cannot say which number would change management has the weaker answer.
Induction agents. The goal is stability, not a particular drug. For example: fentanyl titrated to 3-5 mcg/kg (or a balanced opioid dose that still allows extubation within hours), etomidate 0.2-0.3 mg/kg or a reduced dose of propofol, and a nondepolarizing relaxant, with a pressor drawn up. He took lisinopril and metoprolol this morning, so expect a larger fall in BP than usual; a learner who does not anticipate that has missed a hook.
Goals. HR roughly 50-70 and no tachycardia, which shortens diastole and raises demand. BP near baseline, with attention to diastolic pressure: coronary perfusion pressure is roughly diastolic pressure minus LVEDP. With LVEDP 16, a diastolic of 46 leaves a perfusion pressure of about 30.
Of concern. Yes. Low diastolic pressure across fixed stenoses plus a stiff, dysfunctional LV produces subendocardial ischemia; the V5 change is the warning. Causes: induction vasodilation, ACE inhibitor on board, beta-blockade blunting compensation, and no stimulation yet.
Rx. Treat now. Phenylephrine 50-100 mcg boluses raise diastolic pressure without raising HR; norepinephrine is equally reasonable. Ephedrine adds HR and contractility, defensible with HR 56 but it raises demand. A modest fluid bolus is fine in a fasted patient. If the ACE inhibitor makes it refractory, vasopressin 0.5-1 unit is an option. Waiting for laryngoscopy to bring the pressure up is the flag.
Target. Back toward baseline: MAP roughly 70-80 or higher, diastolic pressure around 60 or above, and ST segments back to baseline. Resolution of the ST change is the endpoint, not just a number.
Laryngoscopy surge. Deepen (propofol bolus, more opioid) and give esmolol 0.5 mg/kg (about 45 mg) or 10-20 mg increments; nitroglycerin if ST changes recur with hypertension. Better prevented with opioid timed before laryngoscopy. Long-acting antihypertensives now leave him hypotensive at the next lull.

2. Heparin and going on bypass

Before incision. Antifibrinolytic? Which? Dose? Why? Sternotomy done; LIMA harvested. Heparin dose? ACT target? Why that number? 32,000 units given through the central line; ACT 3 minutes later is 560. Aortic cannulation: BP target? Why? Cannulated. On bypass at full flow, MAP 38. Of concern? Rx? Flow target? MAP target on bypass? Why that number? Ventilation now? Why?

Considerations and pitfalls AI draft

Antifibrinolytic. Tranexamic acid is standard for on-pump CABG: it reduces bleeding and transfusion, and he is on aspirin with recent clopidogrel. Typical regimens are a 10-30 mg/kg load (about 0.9-2.8 g at 92 kg) then an infusion of 1-16 mg/kg/h, often with a pump-prime dose. The dose is debated: higher doses reduce transfusion slightly more, but seizure risk rises with dose, so many centers use the lower end; either is defensible. The infusion is reduced for renal impairment. Aminocaproic acid is an alternative. Choosing none without a reason is the weak answer.
Heparin dose. 300-400 units/kg, about 28,000-37,000 units at 92 kg, through a central line after aspirating blood to confirm the line is intravascular. ACT 3-5 minutes later.
ACT target. Above about 480 seconds in most centers (some accept 400 or more). Below that, thrombin generation in the circuit risks clot in the oxygenator and patient. Starting bypass before the target is reached is the flag.
Cannulation BP. SBP about 90-100 (MAP roughly 60-70) during aortic cannulation to lower the risk of a tear or dissection at the cannulation site. Deepen the anesthetic or give a short-acting vasodilator; do not cannulate at 160 systolic.
MAP 38 at initiation. A brief fall is common: hemodilution from the crystalloid prime lowers blood viscosity and dilutes circulating catecholamines. But check it is not something worse: is the pump at full flow, is the arterial line reading correctly, is the aortic cannula in the right place (high line pressure, unilateral facial blanching, or a TEE flap suggests malposition or dissection). Rx: phenylephrine boluses or infusion through the pump, and flow increase if not yet full. Accepting a sustained MAP in the 30s-40s in this patient is the weak answer.
Flow target. About 2.2-2.4 L/min/m2. BSA is about 2.1 m2 (178 cm, 92 kg), so roughly 4.7-5.1 L/min. Adequacy is judged by venous saturation on the pump (above about 65-70%) and lactate, not flow alone. The learner should derive the number from height and weight.
MAP target on bypass. Commonly 50-80. With long-standing hypertension and diabetes his autoregulation curve is likely shifted right, so many would aim for 65-80 to protect brain and kidneys. No single number is proven; the reasoning matters more than the value.
Ventilation. Stop once at full flow and the heart is no longer ejecting: there is no pulmonary blood flow, and moving lungs crowd the field and the LIMA. Lungs are left still or on low CPAP. Stopping while the heart still ejects sends desaturated blood to the coronaries and brain. If maintenance was a volatile through the ventilator, it now delivers nothing (see next probe).

3. On bypass

Cross-clamp on; antegrade cardioplegia; heart arrested. Temperature target on bypass? Why? Anesthetic now? Volatile? Propofol? Which? How delivered? Glucose 238. Rx? Target? Hgb 6.6. Transfuse? Why/why not? ACT 410. Rx? Twenty-five minutes after the first cardioplegia dose, the ECG shows organized electrical activity. Of concern? Rx? Distal anastomoses done. Rewarming: how fast? Maximum arterial blood temperature? Why?

Considerations and pitfalls AI draft

Temperature. Mild hypothermia (about 32-34°C) is common for CABG and lowers oxygen demand; some teams run near normothermia. Deep hypothermia has no role here.
Anesthetic on bypass. Either a volatile through a vaporizer on the oxygenator (with scavenging) or a propofol infusion, often with opioid. The point is continuous hypnosis: with the lungs not ventilated, a volatile on the anesthesia machine is not reaching him. Awareness risk peaks during rewarming. A learner who has not noticed the ventilator vaporizer is now irrelevant has missed the trap.
Glucose. Insulin infusion; aim below 180 mg/dL on bypass and avoid hypoglycemia. Hypothermia and the stress response cause insulin resistance; as he rewarms, sensitivity returns, so check every 30 minutes. Large boluses chasing the number invite a low glucose after bypass.
Hgb 6.6. Mostly hemodilution. Many teams transfuse on bypass around 6-7 g/dL; diabetes and vascular disease argue toward the higher end, so transfusing is defensible. Other moves: ultrafiltration or hemoconcentration, and limiting crystalloid. Look at venous saturation and lactate. Transfusing by reflex without these, or refusing when oxygen delivery is clearly inadequate, are the weak answers.
ACT 410. Below target. Give more heparin (about 5,000-10,000 units) and recheck. Heparin is metabolized and diluted over time. If repeated doses fail to raise the ACT, think antithrombin deficiency; nothing suggests it here.
Electrical activity. Yes. The arrest is wearing off: the myocardium is warming and using oxygen during ischemia. Redose cardioplegia (antegrade, retrograde, or down completed vein grafts), check that the LV is not distending (vent), and consider topical cooling. Noncoronary collateral flow washes cardioplegia out faster than expected. Ignoring it until the clamp comes off is the flag.
Rewarming. Once arterial outlet temperature is 30°C or more, rewarm no faster than about 0.5°C/min with an arterial-to-venous gradient of 4°C or less. Arterial outlet blood below 37°C. Why: arterial outlet temperature is the surrogate for brain temperature and is assumed to underestimate it during rewarming, and cerebral hyperthermia is linked to neurologic injury; large gradients cause gas to come out of solution. Aim for a nasopharyngeal or bladder temperature near 36-37°C before separation.

4. Coming off bypass

Cross-clamp off; proximal anastomoses done. Nasopharyngeal temperature 36.3°C. Junctional rhythm at 44; K 5.7. Surgeon: 'Ready to come off.' Ready to separate? Why/why not? Rx? Epicardial wires placed. Pacing mode? Rate? Atrially paced at 88. Re-inflating the lungs: how? Off bypass: BP 86/50, CVP 5; TEE shows a small, hyperdynamic LV. Rx? Two minutes later, ST elevation in II, III, and aVF; TEE shows the inferior wall now akinetic. DDx? Rx? MAP 78; resolves over 3 minutes. Protamine: dose? Rate? Halfway through, BP 70/38. DDx? Airway pressures unchanged; RV normal on TEE. Rx? Finish the protamine? Why/why not?

Considerations and pitfalls AI draft

Ready to separate. Not yet. Temperature is acceptable, but rate and rhythm are not, and K is high. A strong learner runs the checklist: temperature, rate and rhythm, K, calcium, ABG and Hgb, ventilation restored, monitors re-zeroed, de-airing checked on TEE, drugs ready. Coming off at a junctional 44 is the flag.
Rx (rhythm and K). Epicardial pacing. K 5.7 from cardioplegia contributes to the slow rhythm: calcium chloride stabilizes the membrane, while insulin with dextrose and ultrafiltration on the pump lower the K. Avoid chronotropes that raise demand when pacing does the job.
Pacing mode and rate. Atrial pacing (AAI) at about 80-90 if AV conduction is intact, to keep the atrial contribution to filling; DDD if AV conduction is impaired. Ventricular-only pacing loses the atrial kick in a stiff LV.
Lung re-inflation. Gently, under direct vision, after suctioning the airway. Overinflation can stretch or kink the LIMA pedicle, which lies over the lung; the surgeon watches it as the lungs come up. Check both lungs expand and look for a residual pneumothorax or atelectasis.
Off bypass, BP 86/50: Rx. Underfilled. Volume from the pump in aliquots (about 100 mL at a time) while watching the LV fill on TEE and the BP respond. A small pressor dose bridges. Starting an inotrope for a hyperdynamic, empty heart is the wrong reflex.
Inferior ST elevation. DDx: air in the RCA vein graft or native RCA (the RCA arises anteriorly, so air rises into it with the patient supine), a kinked or twisted graft, an anastomotic problem, or spasm. Air is most likely this soon after separation. The inferior wall was hypokinetic before surgery; it is the change from that baseline that matters.
Rx. Raise perfusion pressure (phenylephrine to MAP 80 or so) to push air through, tell the surgeon, who may vent the graft. If it does not resolve: the surgeon checks graft flow, and going back on bypass is an option. Nitroglycerin helps spasm if the pressure allows. Treating it as a lasting ischemic event before giving pressure a few minutes is premature.
Protamine dose. About 1 mg per 100 units of heparin, though many give less than a full 1:1 of the total heparin dose (for example 0.5-0.8 mg per 100 units of the initial dose, or a dose titrated to a heparin assay), since some heparin has been metabolized and excess protamine itself impairs clotting. Confirm with the ACT back near baseline.
Protamine rate. Slowly, over 10-15 minutes or longer. Before starting, pump suction is stopped so protamine does not reach the circuit, and the pump stays primed in case bypass must resume.
BP 70/38 during protamine: DDx and Rx. Most likely a rate-related vasodilatory reaction (histamine release). Unchanged airway pressures argue against an anaphylactoid reaction with bronchospasm; a normal RV argues against the rare catastrophic pulmonary vasoconstrictive reaction. Rx: pause the infusion, phenylephrine or calcium chloride, volume from the pump.
Finish the protamine. Yes, slowly, once stable. Leaving heparin unreversed means bleeding. If the RV were failing and BP collapsing, returning to bypass would be the move, and it requires full re-heparinization.

B. POST-OPERATIVE CARE

Teaching focus. Early ICU assessment of oxygen delivery and temperature; sorting chest tube bleeding by cause; fast-track extubation and safe analgesia after sternotomy; kidney injury and restarting home medications; new atrial fibrillation and talking with the patient about it.

1. ICU arrival

Arrives in the ICU intubated on propofol 25 mcg/kg/min and norepinephrine 0.03 mcg/kg/min. Tidal volume? PEEP? Temp 35.3°C and shivering. Of concern? Why? Rx? Meperidine? Dexmedetomidine? Which? Dose? Lactate 3.9 mmol/L; ScvO2 56%; Hgb 8.6. Interpretation? Rx? Transfuse? Why/why not? Glucose 214. Rx? Target? One hour later: warm, not shivering, lactate 3.1, ScvO2 67%. Next?

Considerations and pitfalls AI draft

Tidal volume and PEEP. Lung-protective volumes of 6-8 mL/kg predicted body weight: about 73 kg for a 178 cm man, so roughly 440-580 mL. PEEP 5, FiO2 titrated to SpO2 above about 92%, rate for a normal PaCO2. A plan aimed at extubation within hours.
Shivering, of concern. Yes. Shivering can multiply oxygen consumption and CO2 production, raises HR and myocardial demand, and can trigger ischemia in fresh grafts. Hypothermia also worsens coagulopathy and arrhythmias.
Rx. Active forced-air warming, and treat the shivering: meperidine 12.5-25 mg IV (a single small dose is acceptable even with his creatinine), or dexmedetomidine 0.2-0.7 mcg/kg/h without a loading bolus, watching for bradycardia and hypotension. Paralysis while sedated only if refractory.
Lactate and ScvO2. Oxygen delivery is not meeting consumption. Demand is up (shivering); delivery may be low (Hgb 8.6, possible low cardiac output from hypovolemia or ischemia). Some lactate rise after bypass is common, but a low ScvO2 points to a supply-demand problem, not just washout.
Rx. Stop the shivering, give a fluid challenge if he is preload responsive, check the ECG for ischemia, and look at function with echo if it does not improve. Trend lactate every 1-2 hours.
Transfuse. Not at 8.6 on that alone. Restrictive thresholds around 7.5 g/dL are standard after cardiac surgery; ongoing bleeding or clear evidence of inadequate delivery after the fixable causes are addressed would change the answer.
Glucose. Continue the insulin infusion; target roughly 140-180 mg/dL, avoiding hypoglycemia, with hourly checks.
One hour later. Improving: continue, wean norepinephrine as BP allows, and keep trending lactate, which should keep falling. Starting an inotrope now is overtreatment.

2. Chest tube output, hour 2

Chest tubes: 280 mL in the first hour, 250 mL in the second. BP 146/82, HR 86. ACT 164 (pre-bypass 122); platelets 132 K/uL; fibrinogen 240 mg/dL; INR 1.3; Hgb 8.1. DDx? Most likely cause? Why? Protamine? Platelets? FFP? Which? Why/why not? Dose? BP target now? How? Increase PEEP? Why/why not? Back to the OR now? Why/why not? What output would send him back?

Considerations and pitfalls AI draft

DDx. Surgical bleeding (anastomoses, LIMA bed, sternal wire sites, cannulation sites), residual heparin or heparin rebound, platelet dysfunction from bypass and antiplatelet drugs, dilution, hypothermia, hypertension, and fibrinolysis.
Most likely cause. Heparin rebound: the ACT is well above baseline while the count, fibrinogen, and INR are acceptable. Heparin released from tissue after protamine has cleared is common in the first hours. Hypertension is adding to it. The ACT is not heparin-specific (a lower platelet count and hemodilution also prolong it); a heparinase ACT or viscoelastic test with and without heparinase confirms it where available. Surgical bleeding is still possible and the response to treatment will tell.
Protamine and dose. Yes: 25-50 mg IV slowly, then recheck the ACT.
Platelets and FFP. Not yet. The count is adequate, though function may be impaired by bypass and aspirin; clopidogrel stopped 6 days ago has largely worn off. Platelets if bleeding continues after heparin is reversed, ideally guided by viscoelastic or platelet function testing. FFP is not indicated for an INR of 1.3 alone. Giving every product empirically is the weak answer.
BP target. Stop the norepinephrine first; he no longer needs it. Then aim for SBP roughly 100-130, with sedation and analgesia before vasodilators; nicardipine, clevidipine, or nitroglycerin if still high. Hypertension stresses fresh suture lines.
Increase PEEP. Raising PEEP to tamponade mediastinal bleeding is not reliably effective and can reduce venous return. Keep usual PEEP and treat the cause.
Back to the OR now; threshold. Not yet: the output does not meet the usual thresholds below, and there is a likely correctable cause to treat first and trend. Common thresholds: more than about 400 mL in the first hour, more than 300 mL/h for 2-3 hours, or more than 200 mL/h for 4 hours, or bleeding that continues after the coagulation picture is corrected. A sudden stop in drainage with falling BP and rising CVP suggests tamponade and is its own reason to call the surgeon. The trend matters more than any one hour.

3. Hour 5

Chest tubes 40 mL/h. Temp 37.1°C. Off norepinephrine. Propofol off 15 minutes: opens eyes, follows commands, squeezes both hands. On CPAP 5, pressure support 5, FiO2 0.4: RR 17, Vt 510 mL; ABG 7.37/41/104. Extubate? Why/why not? Extubated. Aspirin now? Why/why not? Dose? Severe pain at the sternotomy. Acetaminophen? Ketorolac? Why/why not? Opioid? Which? Dose? An hour later: RR 7, SpO2 88% on 4 L nasal cannula, hard to rouse. DDx? Rx? Naloxone? Dose? Why that dose?

Considerations and pitfalls AI draft

Extubate. Yes. Awake, following commands, normothermic, bleeding controlled, off pressors, adequate gas exchange on minimal support. Confirm neuromuscular blockade is reversed (train-of-four). Early extubation, within about 6 hours, shortens ventilator and ICU time in a routine CABG. Holding him intubated overnight without a reason is the flag.
Aspirin. Yes, now that drainage has slowed to 40 mL/h: 81-325 mg PO (or rectally if he cannot swallow), started within 6 hours of surgery and continued indefinitely, for vein graft patency. Brisk ongoing bleeding would justify a short delay; holding it once drainage has settled is the weaker answer.
Acetaminophen. Yes, scheduled: 1 g IV or PO every 6-8 hours, opioid-sparing.
Ketorolac. No. NSAIDs are contraindicated for pain after CABG (FDA boxed warning: higher risk of MI and stroke), and his creatinine adds kidney risk. A learner who offers ketorolac here has missed a firm contraindication.
Opioid. Small IV doses titrated to effect: hydromorphone 0.2-0.4 mg or fentanyl 25-50 mcg, or a PCA once he is alert. Dexmedetomidine and chest-wall blocks are reasonable additions where available.
RR 7, hypoxemic: DDx and Rx. Opioid-induced respiratory depression until proven otherwise; also consider residual neuromuscular blockade, residual sedation, CO2 narcosis from the hypoventilation itself, and a neurologic event (check pupils and limb movement). Stimulate, jaw thrust, increase oxygen, support with bag-mask if needed, ABG.
Naloxone dose. Dilute 0.4 mg to 10 mL and give 40 mcg every 2-3 minutes, titrated to breathing, not to full alertness. Full reversal brings back the pain all at once, with a catecholamine surge, tachycardia, hypertension, ischemia, and even pulmonary edema in a fresh CABG. If he does not respond, reintubate.

4. Morning of POD 1

POD 1, 0700. Urine output 20 mL/h for the last 6 hours. Creatinine 1.9 mg/dL. BP 108/62; HR 84, sinus; CVP 6. DDx? Furosemide? Why/why not? Fluid? Why/why not? Target MAP? Why that number? Today's medications: metoprolol? Dose? Lisinopril? Metformin? Why/why not?

Considerations and pitfalls AI draft

DDx. Acute kidney injury after bypass (hypoperfusion, inflammation, hemolysis, emboli), hypovolemia (bleeding, vasodilation with rewarming), low cardiac output, an obstructed Foley, the ACE inhibitor taken the morning of surgery (impairs renal autoregulation), and nephrotoxins (contrast 2 weeks ago is less likely now). Flush or check the Foley first; assess volume and function, with echo if unclear.
Furosemide. Not to make urine. A diuretic does not improve kidney outcome and can worsen hypovolemia; use it only for volume overload.
Fluid. A judicious bolus with a reassessment is reasonable if he is preload responsive (soft BP, low CVP). Repeated boluses without a response lead to overload.
Target MAP. At least 65, and many aim for 70-80 in a chronically hypertensive patient whose kidneys are used to higher pressures. The reasoning about his baseline matters more than the number.
Metoprolol. Restart within 24 hours if HR and BP allow: metoprolol tartrate 12.5-25 mg PO twice daily. Beta-blockers reduce postoperative AF, and stopping a chronic beta-blocker raises it. Holding it without a reason is the flag.
Lisinopril. Hold: kidney injury and soft BP. Restart once renal function and BP recover.
Metformin. Hold with an acute kidney injury and a recent lactate rise; cover with insulin, moving from the infusion to basal and correction insulin once he is eating. Restart when renal function is stable.

5. Palpitations on POD 2

POD 2, 0300, step-down unit. He reports palpitations. HR 146, irregular; BP 104/64; SpO2 95% on room air; no chest pain. ECG: irregularly irregular narrow-complex rhythm, no P waves, no new ST changes. Interpretation? Rx? Cardioversion now? Why/why not? IV metoprolol? Amiodarone? Which? Dose? K 3.7, Mg 1.8. Replete? Why? Converts by noon; two more episodes over the next 48 hours. Anticoagulate? Why/why not? With what? He asks: 'Did the surgery fail? Is my heart damaged?' What will you tell him?

Considerations and pitfalls AI draft

Interpretation. New atrial fibrillation with a rapid ventricular response, the most common arrhythmia after cardiac surgery, usually appearing on POD 2-3.
Rx. He is stable, so rate control or rhythm control are both reasonable; they give similar outcomes in AF after cardiac surgery. Look for triggers: electrolytes, hypoxemia, pain, volume shifts, and pericardial effusion.
Cardioversion. Not now. Synchronized cardioversion is for instability: hypotension, ischemia, or heart failure. BP 104/64 without symptoms of poor perfusion is not that.
Metoprolol or amiodarone. Either. Metoprolol 2.5-5 mg IV over 2 minutes, repeated every 5 minutes to about 15 mg, watching the BP; diltiazem is an alternative, used cautiously with an EF of 45%. Amiodarone 150 mg IV over 10 minutes, then 1 mg/min for 6 hours and 0.5 mg/min for 18 hours, is useful when BP limits beta-blocker doses or for rhythm control.
K and Mg. Yes, toward K at least 4.0 and Mg at least 2.0; low levels make AF more likely to persist or recur. After yesterday's kidney injury, give K in smaller doses and recheck.
Anticoagulation. Defensible either way, and decided with the surgeon once surgical bleeding risk allows. Guidelines call anticoagulation reasonable for AF after cardiac surgery, weighing stroke and bleeding risk, but the evidence is weaker than for AF outside surgery and AF after surgery often does not recur. His CHA2DS2-VASc score is 3 (hypertension, diabetes, vascular disease). Recurrent episodes push many toward anticoagulating: warfarin or a direct oral anticoagulant, commonly for several weeks with reassessment. Others rate-control, monitor, and reassess, given the bleeding risk of an anticoagulant on top of aspirin early after sternotomy. A learner who anticoagulates by reflex or dismisses it without weighing his score has the weaker answer.
What to tell him. Honest and specific: new AF is common after heart surgery, affecting roughly a quarter to a third of patients, and comes from inflammation and stress on the upper chambers, not from the grafts failing. His ECG shows no new heart damage. It usually settles within weeks; explain the medications and any blood thinner and why. Avoid both brushing it off and alarming him.

Long stem

Open repair of acute Stanford Type A aortic dissection

A 58 y.o., 92 kg, 5'11" man is brought emergently to the OR for open repair of an acute Stanford Type A aortic dissection.

HPISudden, severe tearing chest and interscapular back pain two hours ago while at work, with diaphoresis and a brief near-syncopal episode. Pain has migrated and remains unrelenting. Now reports a cold, mottled right leg.

PMHLong-standing poorly controlled hypertension. Hyperlipidemia. Former smoker. No prior cardiac surgery.

MEDSAmlodipine, hydrochlorothiazide, atorvastatin; admits to inconsistent adherence. Took a full aspirin in the ED.

PHYS EXAMHR 112; right-arm BP 178/96, left-arm BP 142/80; RR 22; SpO2 95% on 4 L nasal cannula; T 36.4°C. Diaphoretic and anxious. A new early diastolic murmur at the left sternal border. Diminished right femoral pulse with a cool, mottled right foot.

ECGSinus tachycardia, left ventricular hypertrophy, ST-segment depression in the inferior leads. No ST elevation.

IMAGING (CT / TEE)Outside CTA: intimal flap extending from the aortic root through the arch into the descending thoracic aorta, with the dissection reaching the right common iliac. A moderate pericardial effusion is noted. Post-induction TEE planned to confirm the diagnosis, grade aortic regurgitation, interrogate the coronary ostia and regional wall motion, and assess for tamponade and true-lumen wire position.

LABSHgb 12.6 g/dL; platelets 210 K/uL; INR 1.1; creatinine 1.5 mg/dL; lactate 3.2 mmol/L; troponin mildly elevated; type and crossmatch in progress.

OR ARRIVALAwake, in severe pain, hypertensive and tachycardic. One 18 g peripheral IV. No arterial line yet. External defibrillator pads on. Surgeon scrubbing; perfusion setting up for possible deep hypothermic circulatory arrest. Blood products being mobilized.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Anti-impulse hemodynamic control before and through induction in an unrepaired Type A dissection; arterial-line site and large-bore access decisions driven by the dissection anatomy and malperfusion; the collision of acute aortic regurgitation, tamponade, and induction; and cerebral protection for deep hypothermic circulatory arrest.

1. Anti-impulse control and access before induction

He is awake on the table. Before any drug: HR target? SBP target? Why those numbers? — First agent: esmolol or nicardipine? Why that order? — Esmolol running, HR 66, SBP still 168. Add what? Dose? — Left-arm cuff reads 36 mmHg lower than the right. Which arm reads the true central pressure? Why? — Arterial line: right radial, left radial, or femoral? Which? Why? — Surgeon says he will cannulate the right axillary. Does that change which radial you want? — Femoral line: right or left groin? Why? — He has one 18 g. What goes in before induction, and what waits until after?

Considerations and pitfalls AI draft

Targets. HR ~60, SBP 100-120 while keeping the mottled leg and the kidneys perfused; want numbers, not 'lower it.' The aim is dP/dt and rate, not the pressure alone — an unrepaired dissection extends or ruptures on a high-impulse aorta.
Esmolol first. Rate control before vasodilation; nicardipine or nitroprusside alone provokes reflex tachycardia and a rise in dP/dt. Vasodilator-first is the classic error.
Add a vasodilator. Nicardipine 5 mg/h titrated, or nitroprusside 0.3-0.5 mcg/kg/min, once rate is controlled. Caution: with the new diastolic murmur (acute AR), heavy beta-blockade removes the compensatory tachycardia; do not chase HR 60 at the cost of forward flow.
Which arm. The higher pressure is the true-lumen pressure; the 36 mmHg differential means the left subclavian is compromised. A single arbitrary radial is the trap.
Art line site. Right radial reads central pressure now but goes false once right axillary antegrade perfusion starts; left radial is under-reading. Defensible answer: right radial for induction plus a left radial or femoral before bypass, tied to the surgical plan.
Axillary cannulation. Yes — during axillary perfusion the right radial reads pump pressure, so a second site (left radial or femoral) is required.
Femoral side. Left. The dissection reaches the right common iliac and the right femoral pulse is diminished; a right femoral line may read a false-lumen pressure.
Access sequence. Awake art line and a second large-bore IV before induction; central line and rapid infuser immediately after induction; PA catheter or central access for vasoactives before bypass. Inducing on one 18 g is a flag.

2. Induction with acute aortic regurgitation and effusion

Induction agent? Dose? Why that one? — The new early diastolic murmur: through induction, do you want him faster or slower than your anti-impulse target? Why? — Controlled induction, then BP 74/40, HR 50. Rx? Phenylephrine, ephedrine, or volume — which first? Why? — End point? — TEE: severe AR, moderate effusion, early diastolic RV collapse. Dx? — Surgeon wants to open the pericardium before cannulating. What happens to the pressure the moment it is open? What do you have drawn up? — Pericardium open, BP 196/100, HR 95. Rx? Agent? Dose?

Considerations and pitfalls AI draft

Agent. Etomidate 0.2-0.3 mg/kg or a small propofol dose with generous opioid (fentanyl 5-10 mcg/kg) and esmolol available; goal is no surge on laryngoscopy and no collapse. Either direction is dangerous: surge extends the dissection, hypotension drops coronary and limb perfusion.
Rate with acute AR. Faster is better for AR (shorter diastole, less regurgitant volume, less LV distension); this collides with anti-impulse slowing. Want the conflict named and resolved: HR 70-80, no lower, avoid high afterload.
74/40, HR 50. Bradycardia is poorly tolerated in acute AR — long diastole, big regurgitant fraction, low forward output, poor coronary perfusion of a hypertrophied LV. Treating as ordinary hypotension is a flag.
Which pressor. Ephedrine or small epinephrine for chronotropy plus modest volume; pure phenylephrine raises afterload and the regurgitant fraction. Defend the choice and name an end point: MAP 65-70 with HR 70-80, not 'better.'
TEE picture. Tamponade physiology on top of acute AR; RV collapse means hemodynamically significant. Accelerates sternotomy and cannulation; want tamponade named unprompted.
Opening the pericardium. Abrupt rise in venous return and pressure as tamponade is relieved — hypertensive surge onto an unrepaired aorta. Nicardipine or nitroprusside and esmolol in hand, cannulation strategy agreed, pump primed before the knife touches pericardium. Opening without that is the trap.
196/100 after decompression. Nitroprusside 0.5-1 mcg/kg/min or nicardipine 1-2 mg boluses, esmolol 0.5 mg/kg; deepen anesthetic; target SBP 100-120 within a minute or two.

3. Malperfusion across territories

The right leg is cold and the right femoral pulse is now absent. Arterial cannulation: right femoral, left femoral, right axillary, or central aorta? Which? Why? — Wire is in. How do you know it is in the true lumen? — TEE: new inferior wall hypokinesis. Cause? — Does that change the operation? What do you plan for separation from bypass? — Right axillary perfusion starts. Right rNIRS 70 to 50, left 68. DDx? — Checks, in order? — Lactate 3.2 to 6.1, urine 10 mL over the first hour on bypass. Meaning? Rx? — Central repair done, off bypass, leg still cold and pulseless. Next?

Considerations and pitfalls AI draft

Cannulation site. Not the right femoral — the right iliac is dissected and the pulse is gone, so a wire there may enter the false lumen. Right axillary (antegrade true-lumen flow, later used for cerebral perfusion) or direct true-lumen aortic cannulation under TEE; left femoral is a fallback.
True lumen. TEE: wire in the lumen that expands in systole, has the flap moving away from it, and communicates with the LV outflow; false lumen is larger, has spontaneous echo contrast, and expands in diastole.
Inferior hypokinesis. Coronary ostial dissection, usually the right coronary; the stem's inferior ST depression was the early clue. Not an old change.
Change the operation. The surgeon may need to reimplant or bypass the RCA; ask for a vein graft and plan inotropic support coming off bypass; expect RV dysfunction.
Right rNIRS drops. Antegrade circuit not reaching the right brain: cannula malposition, dissection of the innominate/right carotid by the cannula jet, kinked line, low flow, or compression of the true lumen. Accepting a 20-point fall as 'artifact' is the flag.
Checks. Cannula position and line pressure with perfusion, flow rate, TEE of the arch vessels, radial pressure on the right, then ask for a cannulation change or adjunctive left carotid perfusion.
Lactate and urine. Visceral and renal malperfusion continuing on bypass — ischemia is ongoing and time-critical; keep flow and pressure up (MAP 60-70 on pump), confirm true-lumen perfusion, and warn the surgeon that distal flow is not restored.
Persistent leg ischemia. Restoring true-lumen flow often fixes distal beds, but a leg still pulseless off bypass needs femoral exploration, fem-fem bypass, or fenestration now; also watch for reperfusion hyperkalemia and rhabdomyolysis.

4. Deep hypothermic circulatory arrest and cerebral protection

The arch must be opened. Temperature target for unprotected circulatory arrest? With antegrade cerebral perfusion added? — Which temperature site do you trust? EEG — what are you waiting for? — Antegrade or retrograde cerebral perfusion, with the right axillary already in? Why? — ACP flow rate? Perfusion pressure? — Twelve minutes into arrest, right rNIRS falls 15 points, left steady. Next? — Cooling rate? Rewarming gradient limit? Maximum arterial inflow temperature? Why? — Coming off arrest, glucose 240. Rx? Target? — Nasopharyngeal 37.2, bladder 34.1. Keep rewarming? Why/why not?

Considerations and pitfalls AI draft

Targets. ~18 C nasopharyngeal for unprotected DHCA; 24-28 C (moderate hypothermia) is standard when antegrade cerebral perfusion is used. Want a number with a rationale — CMRO2 falls ~6-7% per degree.
Site and EEG. Nasopharyngeal or tympanic tracks brain temperature; bladder and rectal lag. Electrocerebral silence on EEG (or a fixed cooling time, e.g. 30-45 min) before arrest confirms the brain is actually cold.
ACP. Antegrade via the axillary delivers oxygenated flow and permits longer arrest; retrograde via the SVC gives some cooling and de-airing but unreliable substrate. With the axillary in, ACP is the natural pick — want a committed choice.
ACP numbers. ~10 mL/kg/min (600-1000 mL/min), pressure 40-70 mmHg measured at the right radial, cold (20-28 C).
Right rNIRS falls during ACP. The perfused side is under-perfused: cannula or clamp position, innominate flow diverted, flow too low, or a dissected carotid. Check line pressure, flow, and TEE; ask the surgeon to add a left carotid cannula; do not wait for the number to recover on its own.
Cooling and rewarming. Cool over 30+ min with an arterial-venous gradient of 10 C or less; rewarm with a gradient of 10 C or less and arterial inflow capped at 37 C — cerebral hyperthermia after ischemia worsens outcome. Gas solubility and bubble formation are the mechanism behind the gradient limit.
Glucose 240. Insulin infusion to 140-180; hyperglycemia worsens ischemic neurologic injury around arrest. Ignoring the number is the flag; driving it to 100 risks hypoglycemia.
37.2 vs 34.1. Stop rewarming on the pump. The brain is already at target and the core gradient means afterdrop is coming; the risk now is cerebral hyperthermia, not residual hypothermia. Use forced-air warming and time, not more arterial heat.

B. POST-OPERATIVE CARE

Teaching focus. Coagulopathy and massive transfusion after a long circulatory-arrest run; tamponade in the fresh postsurgical chest; a post-op neurologic deficit after arch repair and arrest, with one honest disclosure to the family; and acute kidney injury layered on intra-op malperfusion; and POD 3 liberation with new atrial fibrillation, where anticoagulation and blood-pressure targets are set against a fresh stroke and a residual dissection.

1. Coagulopathy and massive transfusion off a long arrest

Off bypass after 42 minutes of arrest, protamine given, field oozing everywhere, chest tubes 300 mL in the first hour. Surgical or medical? What tells you? — ACT 168, baseline 128. Residual heparin? How do you tell? — ROTEM: FIBTEM A10 6 mm, EXTEM CT 110 s; platelets 80; temp 34.8. First product? Second? — Cryo: how many units? Fibrinogen target? — Platelets 80 and a full aspirin in the ED. Transfuse platelets at 80? Why? — Temp 34.8, iCa 0.92, pH 7.24. Targets? — TXA was given on bypass. More? Dose? — Two hours later coags are corrected and output is still 350 mL/h. Next?

Considerations and pitfalls AI draft

Surgical vs medical. Diffuse ooze from every raw surface with abnormal studies is medical; brisk bright bleeding from one place with normalizing studies is surgical. Both coexist after an arch repair with multiple suture lines.
ACT 168. Modest elevation: residual heparin, heparin rebound, or just coagulopathy and hypothermia. Heparinase-ACT or HEPTEM vs INTEM comparison separates them; if heparin, protamine 25-50 mg. Blind repeat protamine is not harmless.
First product. Fibrinogen — FIBTEM A10 6 mm (fibrinogen ~110) is the deficit that matters most; cryo or fibrinogen concentrate first. Then platelets, then plasma/PCC for the long CT.
Cryo. 10 units (or 2 pooled) raises fibrinogen ~70-100 mg/dL; target >150-200 mg/dL in ongoing surgical bleeding.
Platelets. Yes — 80 K of aspirin-inhibited, bypass-damaged platelets in a bleeding chest is a transfusion indication; the number alone understates the defect.
Triad. Rewarm to 36 C, ionized calcium >1.1 mmol/L (calcium chloride 1 g increments), correct acidosis with perfusion not bicarbonate. Products will not clot cold and hypocalcemic — ignoring temperature and calcium is the trap.
TXA. Reasonable to redose (e.g., 1 g) if lysis on ROTEM or ongoing ooze; watch seizure risk with high cumulative doses after arrest.
Corrected but still bleeding. Re-exploration. Continued transfusion into a chest that is bleeding with normal studies is the error; also excludes early tamponade.

2. Postoperative tamponade

Four hours into the ICU: tubes drained 350, then 200, then 20 mL/h. CVP 21, PA 40/23, CI 1.5, BP 84/50, urine 8 mL/h. Dx? DDx? — Study? How fast? — TTE: poor windows, no discrete effusion seen. Reassured? Why not? — Nurse asks for furosemide for the oliguria. Yes/no? Why? — Until the chest is open: HR target? Volume? Which pressor? — Bedside or OR? What decides it? — Back in the OR for re-exploration. The surgeon is still changing. Induce now? Why/why not? — Induction agent? Dose? — Chest open, clot out, BP 172/95. Rx?

Considerations and pitfalls AI draft

Dx. Tamponade from localized clot — a tube that stopped draining plus equalizing pressures and a falling index. Alternatives: RV failure, hypovolemia, suture-line bleeding, pneumothorax; but the stopped tube is the pattern to name unprompted.
Study. TTE now, at the bedside, within minutes; TEE if TTE is nondiagnostic. Do not send him to CT.
Negative TTE. No — loculated posterior clot is missed easily in a fresh chest with poor windows. Clinical picture outweighs the study; call the surgeon.
Furosemide. No. The oliguria is low forward flow; diuresing a tamponading patient collapses filling. A reflexive diuretic order is a red flag.
Bridge. Full, fast, tight: HR 90-100 (avoid bradycardia), small volume boluses to maintain the gradient, norepinephrine or epinephrine; avoid PPV increases and sedation boluses that drop venous return.
Bedside vs OR. OR if he is holding on the bridge; bedside sternotomy if he arrests or is arresting. Pads on, sternotomy tray at the bedside either way.
Induce before the surgeon is scrubbed. No — surgeon scrubbed and prepped before induction; induction can collapse a tamponading heart and the only rescue is the knife. Then ketamine 0.5-1 mg/kg or etomidate, minimal positive pressure, pressor running; expect either collapse on induction or a surge on decompression.
172/95 after decompression. Fresh suture lines on a repaired aorta: nicardipine or nitroprusside to SBP 100-130, deepen anesthetic, rule out pain/light plane.

3. Postoperative neurologic deficit

Six hours post-op, sedation off for an hour: eyes open, does not follow commands, right side localizes, left arm and leg do not move to pain. DDx? — Most likely? Why after this operation? — Next step? How fast? — CT: acute right MCA infarct, no hemorrhage. Thrombolysis? Thrombectomy? Why/why not? — BP target now? Why that range? — Glucose 192, temp 38.3. Rx? — His wife asks whether the operation caused this. What will you tell her?

Considerations and pitfalls AI draft

DDx. Embolic or hypoperfusion stroke, watershed injury from the arrest, intracranial hemorrhage on coagulopathy, seizure with post-ictal deficit, residual sedation. A lateralizing deficit means structural until proven otherwise.
Most likely. Embolic stroke — arch manipulation, atheroma and air, the dissected innominate/carotid, and the arrest period itself. Want it tied to the operation.
Next. Neuro exam then non-contrast CT (with CTA of the arch vessels) within the hour; stroke neurology called. Waiting to 'let the sedation wear off' is the flag.
Lysis / thrombectomy. Thrombolysis contraindicated (major surgery within hours, recent aortic repair); thrombectomy is possible for a large-vessel occlusion if CTA shows one and the access route is intact — the call belongs to neurointervention with the surgeon.
BP. Permissive but bounded: the fresh aortic repair caps SBP (roughly 120-140 max), while the penumbra needs pressure; avoid hypotension, no aggressive lowering. Name the tension.
Glucose and fever. Insulin to 140-180, acetaminophen and cooling to normothermia; both worsen infarct evolution.
Wife. Plain and honest: he has had a stroke; it is a known risk of emergency repair of a dissection that involves the arch; it was recognized and is being treated; recovery is uncertain and will take time. No blame, no false reassurance, and the same account the surgeon gives.

4. Renal injury and ongoing instability

POD 1 morning: creatinine 1.5 to 3.0, urine 10 mL/h, MAP 76 on norepinephrine 0.05. Cause? — Fluid bolus or furosemide? Which? Why? — TTE: LV hyperdynamic, IVC 1 cm and collapsing, CVP 5. Now? — What else do you stop or check? — K+ 6.4, peaked T waves. Rx, in order? Doses? — Calcium chloride or gluconate? How much? — Insulin/glucose given, K+ 6.0 an hour later, urine still 10 mL/h. Dialyze? Which indication? — Chest tubes still 90 mL/h. Circuit anticoagulation?

Considerations and pitfalls AI draft

Cause. Ischemic ATN from intra-op renal malperfusion, bypass, arrest, and hypotension; contributors: CTA contrast, transfusion pigment load, low output. Want it tied to his course.
Fluid vs diuretic. Neither reflexively — assess volume and forward flow first. A diuretic will not save an ATN kidney and can hide it; a bolus into an overloaded RV worsens congestion.
Underfilled on echo. Volume: 500 mL crystalloid or blood if Hgb is low, reassess; the earlier tamponade and bleeding make hypovolemia plausible. Stated MAP 76 on a pressor with an empty heart is a pressor propping up an empty tank.
Stop / check. Nephrotoxins (NSAIDs, aminoglycosides, contrast), abdominal pressure, Foley patency, CK and hemolysis labs, recheck the malperfused leg.
K+ 6.4. Calcium first (membrane), then insulin 10 units with dextrose 25 g, albuterol nebulized 10-20 mg, bicarbonate if acidotic; then removal — but a 10 mL/h kidney will not remove it, which is the point.
Calcium. Chloride 1 g centrally (three times the elemental calcium of gluconate) or gluconate 3 g peripherally; repeat if T waves persist.
RRT. Yes — hyperkalemia refractory to shift therapy with oliguric AKI; CRRT rather than intermittent HD in a patient on pressors.
Anticoagulation. Regional citrate or a no-anticoagulant circuit; systemic heparin into a chest putting out 90 mL/h is the error. Watch ionized calcium with citrate.

5. POD 3: liberation, new atrial fibrillation, and the residual dissection

POD 3: on CRRT, norepinephrine off, awake, follows commands, left hemiparesis unchanged. FiO2 0.4, PEEP 5, PS 8. Spontaneous breathing trial now? What must be true first? — On the trial: RR 24, TV 380 mL, SpO2 95%, cough weak on the left. Extubate? Why/why not? — Extubated. Two hours later: HR 138 irregular, BP 96/58. Dx? First move? — Amiodarone, esmolol, or cardioversion? Which? Why? — Rate 95, still in AF at 24 hours. Heparin now, three days after the MCA infarct? Why/why not? If not now, when? — Off drips: BP 152/88, HR 92. Dissection persists from the arch to the right iliac. SBP target? HR target? — First oral agent? Second? Nicardipine off — when? — CTA before he leaves the ICU: contrast with his kidney? Why/why not?

Considerations and pitfalls AI draft

SBT. Yes — pressor off, modest support, awake; the hemiparesis is not a reason to wait. First: a fluid balance at or below even via CRRT, no active bleeding, electrolytes corrected, and a swallow and secretion assessment, because the left-sided weakness raises aspiration risk.
Extubate. Yes — awake, following commands, adequate tidal volume, no distress. A weak left-sided cough is the stroke, not the lungs; keep him NPO pending a swallow evaluation and aggressive pulmonary toilet. Leaving him intubated for the deficit alone is the flag; heavy secretions he cannot clear would change the answer.
HR 138 irregular. Postoperative AF (peak POD 2-4). First: is he unstable? BP 96/58 is borderline — check K+ and Mg2+, exclude recurrent tamponade, bleeding, and ischemia before treating the rhythm as the whole problem.
Agent. Amiodarone 150 mg IV over 10 min then infusion — rate control without dropping the pressure further; esmolol is titratable but BP 96/58 limits it; synchronized cardioversion if he becomes unstable, and it is safe without anticoagulation this early after onset.
Anticoagulation. Not today — a large fresh MCA infarct carries hemorrhagic-transformation risk that outweighs the embolic risk of new AF in the first days; aspirin now, repeat head CT, and start heparin or a DOAC at roughly 7-14 days from the stroke if imaging shows no hemorrhage, with neurology. A reflexive heparin drip because 'AF plus stroke' is the error; so is an open-ended hold.
Targets. SBP 100-120, HR <60-70 for the residual dissection; three days out from the stroke the penumbra argument no longer justifies higher pressure. Name the tension and the resolution.
Oral agents. Beta blocker first (metoprolol or carvedilol) — it is the anti-impulse agent; then an ACE inhibitor or ARB (limited by the kidney) or amlodipine. Wean nicardipine as orals take hold, usually over 24-48 h; a beta blocker is never the drug that gets dropped.
CTA. Yes — he is dialysis-dependent so contrast nephropathy is not the constraint; the study defines false-lumen patency, entry tears, branch-vessel perfusion, and the iliac, and sets the surveillance baseline.

Short stem

Pacemaker-dependent ICD patient for noncardiac surgery with EMI

A 79 y.o., 88 kg man with an implantable cardioverter-defibrillator placed for nonischemic cardiomyopathy and an episode of monomorphic VT is scheduled for an elective laparoscopic sigmoid colectomy. He is pacemaker-dependent, in permanent atrial fibrillation after an AV-nodal ablation, and his last device interrogation was 11 months ago. The surgical team plans extensive monopolar electrocautery, and the patient will be in steep Trendelenburg with the device generator on the left upper chest. He has an LVEF of 25% and chronic kidney disease; he takes carvedilol, sacubitril-valsartan, furosemide, and apixaban. He tells you he 'gets the device checked sometimes' and once 'felt a big jolt' a year ago, and he has brought no card or printout. P 70 (paced); BP 142/80; SpO2 95% on room air; K+ 5.1 mEq/l.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. What you must know about a CIED before an EMI-heavy case, and how to get it: device type, indication, pacing dependence, tachytherapy status, and currency of interrogation; building the EMI and reprogramming plan from those facts rather than reflexively reaching for a magnet.

1. Device information you need and how to get it

He is in preop holding, no card, no printout. What do you need to know about this device before you proceed? — Which of those matters most for this case? Why? — He cannot tell you the settings. Where do you get them? — Last interrogation 11 months ago. Current enough for this case? Why/why not? — Monitor shows a paced rhythm at 70. Can you read his underlying rhythm off it? Why not? — The 'big jolt' a year ago. What was it? Does it change what you order?

Considerations and pitfalls AI draft

What you need. Device type (pacemaker vs ICD vs CRT), manufacturer, indication, pacing dependence and underlying rhythm, current mode and rate, tachytherapy status, battery and lead status, last interrogation date — and from the interrogation, escape rate, lead impedances and thresholds, and a written plan for reprogramming and reactivation. Reciting NBG letters instead of these facts is a flag.
Matters most. Pacing dependence — it decides whether EMI inhibition means a dropped beat or asystole, and therefore whether asynchronous pacing must be secured.
Source. A recent interrogation report from the managing EP clinic, the manufacturer registry, or a perioperative interrogation now. Not the patient's recollection.
11 months. Stale for an ICD — consensus is within ~6 months for ICDs (12 for pacemakers, 3-6 for CRT); with dependence plus planned EMI, this needs a fresh interrogation before the OR, not a recited number.
Underlying rhythm. No — the monitor shows paced complexes; in an AV-node-ablated patient the escape (or absence of one) is only known by inhibiting the device during interrogation. Assuming the monitored rhythm is the intrinsic rhythm is the trap.
Big jolt. An ICD shock — confirms tachytherapy is active and that he has had an arrhythmia the device treated; raises the stakes both for disabling therapy during cautery and for what protects him while it is off.

2. Pacing dependence and underlying rhythm

Interrogation: 100% ventricular pacing, no escape rhythm below 30 bpm. During monopolar cautery the device oversenses and inhibits. What does this patient do? — For how long? — Magnet or reprogramming to protect pacing? Which? Why? — A magnet over this ICD — what does it do to the pacing function? — So what mode do you want programmed? — Before incision: pads on, or pads on and connected to a pacing-capable defibrillator? Why? — Transcutaneous pacing through the pads — how do you confirm capture?

Considerations and pitfalls AI draft

Inhibition consequence. Asystole, not a dropped beat — the ablated AV node means no conduction and no reliable escape. Recognizing the catastrophic rather than nuisance nature is the point.
Duration. For as long as the cautery burst lasts; a 10-second burst is 10 seconds of asystole in this patient.
Magnet vs reprogram. Reprogramming. A magnet over an ICD suspends tachytherapy only and does nothing to the pacing mode; it will not prevent inhibition.
Magnet on the ICD. No effect on pacing — demand mode persists. A learner who expects the magnet to force asynchronous pacing has the core misconception.
Mode. VOO (asynchronous ventricular) at a set rate; DOO is irrelevant with permanent AF.
Pads. On and connected to a device that can both pace and defibrillate, with the pacing function tested for connection; pads lying on the chest unattached cost the same minute you cannot afford during asystole.
Transcutaneous capture. A wide QRS with a T wave after each spike plus a palpable pulse or arterial waveform at the paced rate; the spike alone or pectoral twitching is not capture.

3. Tachytherapy and the ICD before this case

Tachytherapy is on and he is about to get extensive monopolar cautery. What can the ICD do to him? — Leave it on or turn it off for this case? When off? When back on? — From the moment it is off, what has to be true in the room? — Incision is below the umbilicus, generator upper chest. Low EMI risk — skip the reprogramming? Why/why not? — A magnet taped over the generator in steep Trendelenburg — what can go wrong? How would you know? — Reprogram or magnet for the ICD in him? Commit.

Considerations and pitfalls AI draft

What the ICD can do. Misread cautery noise as VF and deliver a shock — an inappropriate shock in a 25% EF ventricle can itself provoke VT/VF and hemodynamic collapse. This is the ICD-specific hazard, distinct from pacing inhibition.
Off / on. Off for the cautery portion, programmed just before incision by the device team; reactivated and confirmed in PACU before monitoring is withdrawn. Want timing, not just 'turn it off.'
While off. Continuous ECG monitoring, external pads on and connected, defibrillator in the room, someone watching the rhythm during cautery — the device cannot rescue a real arrhythmia.
Below the umbilicus. Consensus says infra-umbilical surgery with a well-placed pad often needs no reprogramming — but this is a hedge, not a pass: extensive monopolar cautery, a dependent patient, a stale interrogation, and Trendelenburg bringing the field closer to the generator all argue for securing the device. Want the argument engaged both ways and a defended choice.
Magnet in Trendelenburg. It slips, and tachytherapy is back on with no warning; the first sign may be a shock. In steep Trendelenburg a taped magnet is unreliable; monitoring the magnet is not a plan.
Commit. Reprogram — it secures both asynchronous pacing and tachytherapy off in one step and does not depend on a magnet staying put. Magnet-only for a dependent ICD patient deserves a hard probe.

4. Optimization and the EMI plan

K+ 5.1, CKD, on sacubitril-valsartan. Treat before you pace him? Why/why not? — What number or finding would make you treat? — Succinylcholine for induction? Why/why not? — Bipolar or monopolar? Surgeon says monopolar only. What do you ask him for? — Dispersive pad: where on him? Why there? — Apixaban — last dose 36 hours ago, CrCl 40. Proceed today? Why/why not? — Central line: needed? Which side, given the leads? — Before incision: what must you have confirmed?

Considerations and pitfalls AI draft

K+ 5.1. No — mild, chronic (CKD plus ARNI), no ECG change; hyperkalemia raises capture threshold, so it matters in a dependent patient, but 5.1 is not a barrier. Demanding shift therapy for a stable 5.1 is overtreatment, not vigilance.
Would treat. K+ >5.5-6.0, a rising trend, peaked T waves, or loss of capture; recheck the morning of surgery and avoid potassium-containing fluids and acidosis.
Succinylcholine. Avoid — a 0.5 mEq/L rise on 5.1 in a pacing-dependent patient is a threshold problem; rocuronium with sugammadex available.
Cautery. Bipolar where feasible eliminates the EMI; if monopolar, short bursts (<5 s) at lowest effective power, harmonic scalpel for dissection, no cautery over the generator or lead path.
Dispersive pad. Right thigh or buttock so the current path from the pelvis runs away from the left upper chest; the heart and leads must be out of the arc.
Apixaban. No — hold 48 h for a major surgery with CKD (72 h if CrCl <30); at 36 h he is short, and a laparoscopic colectomy in an anticoagulated CKD patient is a bleeding setup; delay to the 48 h mark unless the surgeon accepts the risk. No neuraxial plan here anyway.
Central line. Reasonable for vasoactives with EF 25%; use the right IJ under ultrasound — the leads run through the left subclavian/SVC and a wire can dislodge or perforate them; a stale interrogation makes lead integrity unknown.
Before incision. VOO at the programmed rate with capture on the monitor, tachytherapy off and documented, pads on and connected, defibrillator in room, dispersive pad placed, K+ rechecked, device team reachable for reactivation.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Executing and adapting the EMI plan: securing asynchronous pacing and disabling tachytherapy, recognizing and responding to oversensing/inhibition and inappropriate shocks in real time, managing loss of capture, and the hazards of asynchronous pacing itself in this failing ventricle.

1. Securing the device for cautery

Device team is at the bedside. Mode? Rate? Why that rate for an EF of 25% about to get pneumoperitoneum and Trendelenburg? — Tachytherapy off in holding or after induction? Why? — The device team is now delayed 40 minutes and the surgeon wants to start. Magnet and go? What does the magnet do here, and what does it not do? — The case is entirely below the umbilicus. Does that let you proceed on the magnet alone? Why/why not? — Device programmed. Before you clear the surgeon for cautery, what do you confirm on the monitor?

Considerations and pitfalls AI draft

Mode and rate. VOO; rate 80-90 rather than a nominal 60-70 — fixed stroke volume from a 25% EF ventricle means output is rate-dependent, and pneumoperitoneum plus Trendelenburg cut venous return. A learner who ignores rate adequacy deserves a probe.
When off. After induction and monitors, immediately before incision, to minimize unprotected time; in holding is acceptable only with pads on and continuous monitoring from that moment.
Magnet and go. The magnet suspends shocks but leaves pacing in demand mode — a dependent patient can still be inhibited to asystole. It solves half the problem. Proceeding on a magnet alone with extensive monopolar cautery in a dependent patient is the wrong call; wait, or use bipolar/harmonic only until the team arrives.
Below the umbilicus. The consensus carve-out exists, and the learner should know it; but extensive cautery, dependence, and an upper-chest generator with the field tilted toward it argue for waiting. A defended choice either way; 'always reprogram' without engaging the carve-out is weaker than a reasoned wait.
Confirm. Spikes at the programmed rate with a wide QRS after every spike and an arterial trace matching, tachytherapy status read back, pads connected, defibrillator on.

2. Oversensing and inhibition

VOO 85, tachytherapy off. First monopolar burst: monitor shows 2-3 second pauses. First check? — Arterial line stays pulsatile through the pauses. Meaning? — Next burst: arterial trace flat-lines with the pauses, BP dips to 58/30. In a device you programmed VOO, what does that mean? — Actions, in order? — Magnet now — helps? — Cautery stopped, pauses continue. Rx? — Transcutaneous pacing: rate? Output? — What has to be true before cautery resumes?

Considerations and pitfalls AI draft

First check. Artifact vs true pauses: look at the arterial line or pleth during the burst. ECG noise from cautery mimics dropout.
Pulsatile through the pauses. Artifact — the heart is beating; no action beyond confirming and noting it.
Flat art line in VOO. True asystole in a device that should not be inhibitable: either loss of capture or an EMI-induced electrical reset to a backup demand mode (VVI at a nominal rate) that cautery can now inhibit. Recognize that a programmed setting can be undone by EMI.
Actions. Surgeon stops cautery; support circulation (chest compressions if no pulse); pads to pace; call the device team back for urgent interrogation; consider epinephrine 10-20 mcg boluses for a paced but hypotensive patient.
Magnet. No — over an ICD it does not change pacing mode; it is not the rescue for inhibition.
Persistent pauses. Pace externally via the pads now; a device that has reset is not trusted until interrogated.
Transcutaneous. Rate 80-90, output up from 40 mA until electrical and mechanical capture (arterial pulse at the paced rate); expect 60-100 mA; analgesia if awake — not relevant here.
Endpoint. Interrogation confirms mode and settings, reliable capture at the programmed rate, and pads ready; then bipolar or short bursts only.

3. Inappropriate shock and arrhythmia

Interrogation: the device had reset to VVI with tachytherapy back on. The team reprograms VOO, but before the tachytherapy step is done the surgeon buzzes once — the patient jerks and BP drops to 70/40. What happened? — Actions? — Magnet now — yes/no? — Ten minutes later, tachytherapy correctly off, the monitor shows VF. What protects him? — Energy? Through which pads? — Two shocks, back to paced rhythm, BP 95/60. Before you let the case continue, what must happen to the device? — Continue the colectomy at all? What decides it?

Considerations and pitfalls AI draft

What happened. An inappropriate shock — cautery noise read as VF; concern is the shock itself, a shock-induced arrhythmia, and hemodynamic compromise in a 25% EF. The predicted hazard of therapy being on.
Actions. Stop cautery, assess rhythm and pressure, support with pressor/volume, get the tachytherapy step completed immediately.
Magnet. Yes — now it is the right tool: it suspends further shocks while the team finishes reprogramming, and it costs nothing.
What protects him in VF. Nothing internal — with tachytherapy off the device will not rescue him; the pads and the external defibrillator are the safety net. This is why they were on and connected.
Energy. 200 J biphasic through the pads already on him; place them anterior-posterior or at least 8 cm from the generator; ACLS between shocks; amiodarone 300 mg if refractory; look for a reversible cause (ischemia, potassium, the shock itself).
Before continuing. Full reinterrogation: confirm mode and capture, lead impedances unchanged (a shock plus a reset can hide lead problems), tachytherapy status intentional, and a decision about when it goes back on.
Continue?. An elective colectomy after VF with a 25% EF: abort if the arrhythmia was not clearly cautery-provoked, if he is unstable, or if ischemia is suspected; continue only if the cause is understood and the device is secured. Want the judgment, not a reflex either way.

4. Loss of capture

Two hours in, pneumoperitoneum on. Pacing spikes march at 85, many with no QRS after them. Arterial rate 34, BP 72/40. Dx? — Spike on the monitor — is that capture? How do you confirm? — DDx? — Gas: K+ 6.8, pH 7.21. Why now? — Rx, in order? Doses? — Device output can be raised by the team, who are 10 minutes away. Meanwhile? — Transcutaneous pacing on: how do you know it is capturing? — Pneumoperitoneum: release it? Why/why not?

Considerations and pitfalls AI draft

Dx. Loss of capture — spikes delivered, myocardium not depolarizing; the 34 is whatever is capturing intermittently. Spike frequency is not heart rate.
Spike vs capture. The spike is the device firing; capture is a wide paced QRS (LBBB morphology from RV pacing) followed by a T wave and a pulse. Confirm on the arterial trace, not the ECG count.
DDx. Acutely raised threshold from hyperkalemia or acidosis, ischemia, lead dislodgement or fracture (positioning plus a stale interrogation), inadequate output after the reset, hypoxia, antiarrhythmic effect.
Why 6.8 now. CKD plus ARNI baseline, pneumoperitoneum-driven hypercapnic acidosis shifting potassium out of cells, low-output tissue hypoperfusion, and possibly the earlier shocks and compressions. The acute rise from 5.1 is what raises threshold; the baseline 5.1 was never the problem.
Rx. Calcium chloride 1 g (repeat), insulin 10 units with dextrose 25 g, ventilate down the CO2 (pH correction alone lowers K+ and threshold), albuterol 10-20 mg nebulized, bicarbonate 50 mEq given the acidosis, furosemide if making urine. Expect threshold to fall as K+ and pH correct.
Meanwhile. External pacing through the pads at 80-90 while treating the potassium; do not keep watching uncaptured spikes.
Capture. Wide complex after each pacer artifact plus an arterial waveform at the set rate; skeletal twitching alone is not capture.
Pneumoperitoneum. Release it: it is driving the hypercapnia, cutting venous return, and stressing a failing ventricle; the surgeon pauses until capture is reliable.

5. Hazards of asynchronous pacing

Capture restored on the device, K+ 5.3, cautery finished, quiet field for closure. Leave him VOO? Why/why not? — PVCs appear at 6 per minute while still VOO. Concern? — Mode for closure and transport? — Tachytherapy back on in the OR or in PACU? Why? — What do you confirm before he leaves the OR? — PACU: monitoring for how long? What ends it?

Considerations and pitfalls AI draft

Leave VOO. No — with no EMI source, asynchronous pacing carries only risk: a fixed-rate spike can land on the vulnerable period of an intrinsic beat (R-on-T) and start VF. VOO is not free.
PVCs in VOO. This is exactly the competition R-on-T needs — ectopy in a VT-prone cardiomyopathic ventricle after hyperkalemia and shocks; reprogram to demand pacing now, check K+ and ischemia.
Mode. Back to the original demand mode (VVI/VVIR here) before transport; never travel asynchronous unless explicitly intended.
Tachytherapy. Reactivate in the OR once cautery is over and before transport, with pads still on until confirmed; leaving a VT-prone patient unprotected for a PACU handoff is the error.
Confirm before leaving. Interrogation printout: mode, rate, capture threshold and lead impedances unchanged, tachytherapy on; a rhythm strip showing appropriate pacing; pads on for transport.
PACU. Continuous ECG until the device is confirmed in its intended settings and he is rhythmically stable; cardiology/EP follow-up for a full check before discharge given the reset and shocks.

Non-perioperative

High-dose oxycodone patient for open ventral hernia repair

A 58 y.o., 104 kg, 5'10" man is referred for a chronic pain consultation two weeks before an elective open ventral hernia repair with component separation.

HPIMidline incisional hernia after a laparotomy for perforated appendicitis at age 30, enlarging over 5 years; two ED visits in the past 3 months for painful incarceration, both reduced at the bedside. CT: 10 cm wide periumbilical fascial defect containing small bowel, no obstruction. The surgeon plans an open repair with bilateral posterior component separation (transversus abdominis release) and retromuscular mesh through a midline incision, xiphoid to below the umbilicus; expected stay 4 to 5 days. Chronic low back pain for 12 years from lumbar spondylosis with right L5 radiculopathy; spine surgery has not been offered. On opioids for 8 years, the current regimen unchanged for 2 years, all prescribed by one pain physician under an opioid agreement. Back pain 5/10 on his regimen; works part-time and walks a mile most days. After an open cholecystectomy four years ago his pain was uncontrolled for three days on a hydromorphone PCA; he went home on twice his usual oxycodone and took four months to return to his usual dose.

PMHObstructive sleep apnea (AHI 34) on CPAP, uses it most nights. Hypertension. Obesity, BMI 33. Depression and generalized anxiety, stable. Midline laparotomy for perforated appendicitis at age 30; open cholecystectomy four years ago. Drinks rarely; never smoked.

MEDSOxycodone ER 60 mg every 12 hours. Oxycodone IR 15 mg every 4 hours as needed, about four tablets a day. Gabapentin 600 mg three times daily. Duloxetine 60 mg daily. Alprazolam 0.5 mg at bedtime. Lisinopril 20 mg daily. Senna and polyethylene glycol daily.

PHYS EXAMHR 74; BP 136/84; RR 14; SpO2 95% on room air. Mallampati III, neck circumference 45 cm. Midline and right subcostal scars; reducible periumbilical hernia, nontender. Lumbar paraspinal tenderness; decreased sensation over the right dorsal foot; strength 5/5 throughout; gait normal.

LABSHgb 13.6 g/dL; platelets 248 K/uL; INR 1.0; creatinine 0.9 mg/dL; AST and ALT normal; albumin 3.9 g/dL. ECG: sinus rhythm, QTc 438 ms.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INITIAL EVALUATION

Teaching focus. Quantifying a high-dose opioid baseline and keeping it intact through surgery; the chronic co-medications on the day of surgery; postoperative respiratory risk from stacked sedatives and sleep apnea; choosing a regional and multimodal plan for a large open abdominal wall repair in an opioid-tolerant patient.

1. How much opioid he takes

The surgeon asks: "How much opioid is he actually on?" Daily oxycodone in mg? In MME? Conversion factor? He adds that on a bad day he takes six IR tablets, about twice a week. Does that change the baseline you plan around? Why/why not? How do you confirm what he takes? PDMP: one prescriber, monthly fills on schedule, quantities match the prescriptions. Urine drug screen as well? Why/why not? His pain score on this regimen: interpretation? After this incision, his opioid need compared with an opioid-naive patient? More? Same? Less? Why?

Considerations and pitfalls AI draft

Daily total. ER 60 mg twice a day = 120 mg, plus IR about 4 x 15 mg = 60 mg: 180 mg oxycodone a day. Oxycodone converts to oral morphine at 1.5, so about 270 MME. The learner should do the arithmetic out loud; a learner who cannot convert this number will mis-size every dose that follows.
Bad days. Two extra tablets twice a week adds roughly 60 mg over a week; the baseline is the typical day (about 180 mg), and the occasional higher day tells you the range he already tolerates, which helps size breakthrough doses. Treating the bad-day number as aberrant behavior is a flag.
Confirming. PDMP, the prescriber's records or a call to the pain physician, pharmacy fill history, and his own account. The point is an accurate baseline for dosing, not policing him.
Urine drug screen. Not needed for the surgical plan when the PDMP, the prescriber, and his account agree; it is the prescriber's monitoring tool under the agreement. Ordering one reflexively at a surgical consult can cost trust; it earns a place only if the history does not add up.
Pain score. Persistent moderate pain on a high dose after years reflects some mix of tolerance, possible opioid-induced hyperalgesia, the underlying spine disease, and mood (depression, anxiety). His function (working, walking) matters more than the number. None of it is a reason to change his regimen two weeks before surgery.
Postop need. More, often substantially more: the full baseline has to continue just to keep him even, and the surgical pain sits on top of it, with reduced opioid responsiveness from tolerance. Expect higher pain scores and a harder first 72 hours; plan multimodal and regional analgesia from the start. "His home dose will cover it" is the error.

2. Home medications before surgery

His pain physician offers to cut his oxycodone by half over the two weeks before surgery. Agree? Why/why not? Postpone the repair to taper first? Why/why not? Morning of surgery: oxycodone ER, take it? Why/why not? Gabapentin that morning? Why/why not? Duloxetine? Why/why not? Alprazolam the night before? Why/why not? Anything to add to his home medications before surgery? Why?

Considerations and pitfalls AI draft

Halving in two weeks. No. A fast taper right before a painful operation risks withdrawal, a pain flare, poor sleep, and anxiety going into surgery, and it destabilizes the baseline you are about to try to maintain. If a reduction is a goal, it is a slow, consented taper after recovery (for someone on opioids for years, on the order of 10% a month), led by his pain physician.
Postponing. No. Two incarcerations in three months make delay risky (strangulation turns this into emergency surgery, which is worse surgery in a worse setting), and a safe taper takes months, not weeks. A taper, if wanted, belongs after recovery.
ER morning of surgery. Yes, his usual dose with a sip of water. It is his baseline and covers roughly the first 12 hours; skipping it sets up withdrawal and a pain crisis in PACU. Intraoperative opioid is added on top of it. If the dose is missed, the intraoperative plan has to replace it.
Gabapentin. Continue, including the morning dose; stopping abruptly risks withdrawal and rebound pain. Dose adjustment after surgery is a separate question.
Duloxetine. Continue; stopping causes discontinuation symptoms and loses its effect on pain and mood. It makes tramadol and meperidine poor choices (serotonergic), and adds to the case against tramadol in a man already on high-dose opioid.
Alprazolam. His usual dose the night before is reasonable; stopping it abruptly now buys little and risks rebound anxiety and insomnia. The real issue is the combination with escalating opioid after surgery, which belongs in the postoperative plan.
Add. Naloxone, with teaching for whoever lives with him: he is above 50 MME, on a benzodiazepine, and has sleep apnea. That gap exists regardless of surgery. Missing it is a flag.

3. Postoperative orders and monitoring

The surgical team's draft postop orders: ward bed, vitals every 4 hours, oxygen 2 L by nasal cannula overnight. Vitals every 4 hours: enough? Why/why not? Monitoring: what? Where? Continuous pulse oximetry alone? Why/why not? Oxygen 2 L overnight: keep it? Why/why not? CPAP after surgery: from when? Sedation scale: which? Score at which you hold the next opioid dose? Gabapentin after surgery: same dose? Why/why not? Alprazolam the first night after surgery? Why/why not?

Considerations and pitfalls AI draft

Every 4 hours. No. His risks stack: high-dose opioid that will escalate after surgery, moderate-to-severe OSA, a nightly benzodiazepine, a gabapentinoid, obesity, and a xiphoid-to-infraumbilical incision with a tightened abdominal wall after the repair, both of which limit breathing. Respiratory depression clusters in the first 24 to 48 hours and at night. He needs continuous monitoring, on a ward that can provide it or in a step-down bed.
Monitoring. Continuous pulse oximetry plus capnography or continuous respiratory-rate monitoring, with alarms that reach a nurse, and frequent sedation checks in the first 24 hours. Where depends on what the ward can actually deliver; a bed without continuous monitoring is not adequate for him.
Pulse oximetry alone. Late for hypoventilation, especially on supplemental oxygen: SpO2 can stay normal while CO2 climbs. Capnography detects hypoventilation earlier.
Oxygen. Give it to treat hypoxemia, titrated to a target, not by reflex overnight. If he needs it, monitor ventilation as well, because oxygen hides hypoventilation from the oximeter.
CPAP. From PACU onward, whenever he sleeps, naps included; bring his own machine and mask. Opioids worsen obstructive events.
Sedation scale. POSS (Pasero) or RASS. On POSS, at 3 (frequently drowsy, drifts off mid-sentence) hold or cut the next dose by 25 to 50% and watch closely; at 4, stop opioid and treat. Sedation rises before respiratory rate falls, so the sedation score is the early warning.
Gabapentin. Continue rather than stop, with a dose reduction (for example 300 mg three times daily) reasonable for the first days, because gabapentinoids add to opioid respiratory depression. Restore his home dose as the opioid requirement falls.
Alprazolam. Hold or minimize while he is on parenteral or escalating opioid; the opioid-benzodiazepine combination multiplies respiratory risk. One or two missed bedtime doses of 0.5 mg cause rebound insomnia or anxiety, not a dangerous withdrawal. If it is given, the lowest dose under continuous monitoring with CPAP on.

4. Analgesic technique for the repair

Analgesic technique for the repair. Thoracic epidural? Bilateral rectus sheath catheters? Bilateral TAP blocks? Which? Why? Assume a thoracic epidural. Interspace? Heparin 5000 units SC every 8 hours is ordered from the evening of surgery. Epidural still? Why/why not? Catheter removal: timing relative to a heparin dose? Next heparin dose after removal? Epidural solution: agent, concentration, rate? Add an opioid? Why/why not? Ketamine? Why/why not? Systemic lidocaine infusion as well? Why/why not? Intraoperative methadone? Why/why not?

Considerations and pitfalls AI draft

Which. A thoracic epidural is a defensible first choice for a xiphoid-to-infraumbilical incision with component separation in an opioid-tolerant man with OSA: the best dynamic analgesia and the largest opioid sparing. The case against it: hypotension, urinary retention, a failure rate that can approach 30%, and heparin timing; some abdominal wall programs prefer surgeon-placed catheters in the retromuscular plane for those reasons. Either, defended, is acceptable. Rectus sheath blocks placed before incision sit in the retrorectus space the surgeon will open, and TAP spread is less predictable once transversus abdominis is divided; neither covers visceral pain, and TAP blocks do not reliably reach the xiphoid. Planning no regional technique at all in this patient is the flag. His lumbar spine disease is not a reason to avoid a thoracic epidural.
Interspace. About T8-9 (T7-8 to T9-10) for a xiphoid-to-infraumbilical incision, aiming for roughly T6 to T11 coverage.
Heparin. Low-dose SC heparin is compatible with an indwelling epidural. ASRA: needle placement and catheter removal a minimum of 4 to 6 hours after a dose; the next dose may be given immediately after removal. Check platelets if heparin runs more than 4 days.
Solution. Bupivacaine 0.1 to 0.125% (or ropivacaine 0.1 to 0.2%) at about 6 to 10 mL/h. Adding fentanyl 2 mcg/mL or hydromorphone 10 mcg/mL improves analgesia and is defensible; in a man with OSA on a benzodiazepine it adds respiratory risk and requires the monitoring above. Plain local anesthetic is also defensible. Neither choice replaces his systemic baseline.
Ketamine. Yes; NMDA antagonism reduces opioid consumption and pain scores, with the clearest benefit in opioid-tolerant patients having painful surgery, and may blunt hyperalgesia.
Lidocaine. Not alongside a working epidural: two sources of local anesthetic add toxicity risk. It is the systemic option if the epidural is not used or fails and has been stopped.
Methadone. A reasonable option, especially without an epidural: a single dose at induction, commonly 0.1 to 0.2 mg/kg of ideal body weight (about 73 kg, so roughly 7 to 15 mg); his QTc 438 is acceptable. With a working epidural, OSA, and a benzodiazepine, its long and variable half-life adds delayed respiratory depression risk, and many would leave it out. Either answer, defended, is acceptable.

B. TREATMENT PLAN AND INTERVENTION

Teaching focus. Intraoperative ketamine and epidural management; oversedation and uncontrolled pain at once from a failed block; continuing the baseline beside an epidural; separating withdrawal from pain and surgical complication and converting to IV; a discharge regimen with a defined return to baseline.

1. Intraoperative analgesia

Assume a thoracic epidural: placed at T8-9, catheter 5 cm in the space, test dose negative. Assume he took his oxycodone ER this morning. Assume you use ketamine. Bolus dose? Infusion rate? Incision: epidural bolus 6 mL bupivacaine 0.25%. Ten minutes later BP 84/46 from 128/78, HR 64. Phenylephrine? Ephedrine? Volume? Which? Why? Hour 2, epidural infusing at 8 mL/h: HR 114, BP 166/96, BIS 44, EtCO2 36. DDx? A further 5 mL bupivacaine 0.25% through the catheter: no change after 15 minutes. Interpretation? Next? Assume systemic opioid. Agent? How much are you prepared to give him? To what end point? Closure: ketamine, stop or continue to the ward? Why?

Considerations and pitfalls AI draft

Ketamine. Bolus 0.3 to 0.5 mg/kg at induction (about 30 to 50 mg), then an infusion of about 0.1 to 0.25 mg/kg/h (roughly 10 to 25 mg/h) through the case. A bolus alone wears off before the incision pain does.
Hypotension. Sympathectomy from the bolus on top of general anesthesia. Ephedrine 5 to 10 mg with a HR of 64, or phenylephrine 100 mcg boluses; modest fluid. Liters of fluid to treat a block is the wrong reflex: bowel edema raises intra-abdominal pressure and the tension on a fascial closure that component separation was done to achieve.
DDx at hour 2. Inadequate analgesia (block not covering the surgical field, one-sided, or migrated catheter), light anesthesia (BIS 44 argues against), hypovolemia or bleeding, hypoxemia, hypercarbia (EtCO2 36 excludes), withdrawal (unlikely after his morning ER dose).
No response to the second bolus. The block is not covering the stimulus. The earlier hypotension does not prove a bilateral block; a one-sided block still causes sympathectomy. Treat with systemic opioid now and plan to test and fix the catheter on emergence. If the epidural is abandoned, it is stopped before a lidocaine infusion starts.
Opioid. Hydromorphone in 0.5 to 1 mg increments or fentanyl in 50 to 100 mcg increments, titrated, not capped at an opioid-naive ceiling. End points: hemodynamic response now, and at emergence a spontaneous rate of about 10 to 12 or more with him comfortable. A fixed maximum dose leaves a tolerant patient in agony; untitrated large boluses near emergence cause apnea.
Ketamine at closure. Continuing a low-dose infusion (about 0.1 mg/kg/h, ~10 mg/h) into the postoperative period is reasonable on a monitored ward for 24 to 72 hours; stopping at closure is also defensible. A bolus near emergence raises the risk of emergence phenomena.

2. PACU call 40 minutes after arrival

PACU, 40 minutes after arrival. He arrived extubated, reporting severe pain; the nurse has given IV hydromorphone 0.5 mg six times. Now RR 7, SpO2 86% on 4 L nasal cannula, rouses only to sternal rub, pupils pinpoint. First move? Naloxone: dose? Why that dose? After two doses: RR 16, awake, 9/10, writhing. Interpretation? More hydromorphone? Why/why not? Next? Ice: cold sensation lost T7 to T12 on the left, T11 to T12 on the right. Interpretation? Rx? Thirty minutes later: bilateral T6 to T11, pain 4/10, RR 16. Of concern over the next hour? Why? Disposition from PACU? Why?

Considerations and pitfalls AI draft

First move. Stimulate, jaw thrust, raise the oxygen, bag-mask or CPAP if he does not breathe adequately; stop all opioid. Airway and ventilation before the antidote.
Naloxone. 40 mcg IV (0.4 mg diluted to 10 mL), repeated every 2 to 3 minutes, titrated to rate and arousal, not to full wakefulness. A 0.4 mg push in a man on 270 MME precipitates acute withdrawal, severe pain, hypertension and tachycardia, occasionally pulmonary edema, and strips all opioid analgesia.
Interpretation. Oversedation and severe pain at the same time: the opioid sedates him without reaching the pain, so the pain is coming from tissue the opioid is not covering. Pain and respiratory depression are not opposites.
More hydromorphone. No, not before the block is checked; 3 mg on top of the intraoperative opioid just made him apneic. Repeating it repeats the event.
Ice. A left-sided, low block: the catheter has likely migrated laterally or is positioned to one side, and the right side above T11 and the top of the incision (T6) are uncovered.
Rx. Withdraw the catheter 1 to 2 cm (leaving 3 to 4 cm in the space) and bolus 5 to 8 mL of bupivacaine 0.25% or lidocaine 2% in increments with BP monitoring, then reassess the level; if it stays one-sided, re-site the catheter. Scheduled acetaminophen if not yet given.
Next hour. Naloxone lasts about 30 to 90 minutes, shorter than the hydromorphone already given, so re-sedation is possible even with good analgesia. Continuous monitoring and an observation period in PACU after the last dose; a naloxone infusion if he re-sedates.
Disposition. A continuously monitored bed (step-down, or a ward with continuous oximetry and capnography), CPAP whenever asleep, epidural working, no PRN IV opioid without reassessment. An event requiring naloxone is not a routine ward transfer.

3. POD 1 morning regimen

POD 1, 7 AM. Assume the epidural runs bupivacaine 0.1% with hydromorphone 10 mcg/mL at 10 mL/h, now bilateral T6 to T11, and ketamine continues at 10 mg/h from the OR. Pain 4/10 at rest, 7/10 walking. No naloxone since PACU. Tolerating clears. The surgical team has held all his home oxycodone "because the epidural has opioid in it." Agree? Why/why not? Oxycodone ER: restart? Dose? Breakthrough: oral or IV? Agent, dose, interval? IV PCA on top? Why/why not? Ketorolac: yes/no? Why? Afternoon: he says the ceiling is moving; anxious; BP 150/90. Most likely cause? Rx? Ketamine from here: how long? What decides when it comes off?

Considerations and pitfalls AI draft

Holding his oxycodone. No. Epidural hydromorphone at this rate is 2.4 mg a day; even if all of it acted systemically, that is about 48 MME (1.5 mg IV hydromorphone is about 30 mg oral morphine), under a fifth of his 270 MME baseline, so it is not a systemic replacement; holding the oral baseline invites withdrawal, which will look like uncontrolled pain. The epidural treats the surgical pain; the baseline treats his dependence.
ER dose. Restart today at his home dose, 60 mg every 12 hours, since he is taking clears. A modest reduction (about 25%) is defensible after the PACU event and with epidural opioid running; holding it is not.
Breakthrough. Oral while the gut works: oxycodone IR at his usual 15 mg, with room to go to 20 to 30 mg, every 3 hours as needed (10 to 20% of his daily oral dose is a common sizing rule), each dose preceded by a sedation check. Opioid-naive breakthrough doses (5 mg) are a predictable failure.
IV PCA. Not while the epidural works and the oral route is available. Stacking a neuraxial opioid, a full oral baseline, and IV boluses is how the PACU event repeats; if added, only with continuous monitoring and no basal.
Ketorolac. Reasonable as 15 mg IV every 6 hours for up to 5 days with normal renal function and no bleeding, though some surgeons avoid NSAIDs after a large retromuscular dissection over hematoma and seroma concern; confirm with the surgeon. Scheduled acetaminophen 1 g every 6 hours (max 4 g/day) belongs in the plan regardless. Not a reflexive add.
Ceiling moving. Ketamine psychomimetic effects: halve or stop the infusion and reassure him. Avoid reaching for a benzodiazepine on top of opioids and his OSA. Rule out the other causes of new confusion (hypoxemia, hypercarbia, sepsis, and withdrawal if his baseline was not restarted this morning) rather than assuming.
Ketamine from here. Typically 24 to 72 hours; it comes off once the oral regimen controls his pain, or earlier for side effects (hallucinations, dysphoria, sedation, hypertension or tachycardia). Its value is the first days of the steepest pain.

4. POD 2 night call

POD 2, near midnight. The epidural catheter was found disconnected at the hub at 4 PM and removed. Vomiting since noon; NG to suction; NPO. Ketamine was stopped on POD 1. Last oxycodone ER at 8 AM; nothing by mouth since. Now: pain 9/10, HR 122, BP 168/96, T 37.6, RR 22, SpO2 94% on room air, sweating, yawning, rhinorrhea, gooseflesh, loose stools. DDx? Most likely? What do you check before you settle on it? Abdomen distended, soft, tender at the incision, no guarding; drains serosanguineous; bladder pressure 10 mmHg; lactate 1.3; WBC 13.1. Rx now? Assume IV hydromorphone. His home oxycodone as IV hydromorphone per 24 hours? Reduce that number? Why? By how much? Delivery: PCA? Basal rate? Demand dose? Clonidine? Why/why not? Re-site the epidural tonight? Why/why not?

Considerations and pitfalls AI draft

DDx. Opioid withdrawal, uncontrolled incisional pain after losing the epidural, unrecognized bowel injury (enterotomy during adhesiolysis) with peritonitis or intra-abdominal sepsis, ileus or obstruction (including bowel kinked or trapped at the repair), rising intra-abdominal pressure after closing a large defect, PE, hypovolemia from vomiting, delirium, MI. Several can coexist.
Most likely. Withdrawal on top of uncovered pain: 16 hours since his last ER dose with no oral intake (vomiting from noon and NG suction may also have cost him part of that dose), the epidural gone since 4 PM, and the signs (yawning, rhinorrhea, piloerection, sweating, diarrhea, tachycardia) are withdrawal, not just pain. A COWS score helps quantify.
Check before settling. A missed enterotomy can produce the same tachycardia and distress, and declares itself late: examine for peritonitis, check lactate, WBC, temperature trend, and drain output and character (enteric or turbid fluid), and measure bladder pressure if the abdomen is tense or ventilation or urine output worsens (10 mmHg is below the 12 mmHg threshold for intra-abdominal hypertension). Low threshold for CT and surgical review if it does not settle with opioid replacement.
Conversion. 180 mg oral oxycodone is about 270 mg oral morphine; 30 mg oral morphine is about 1.5 mg IV hydromorphone, so his baseline is about 13.5 mg IV hydromorphone a day.
Reduce. Yes, about 25 to 50% for incomplete cross-tolerance when changing drug and route: roughly 7 to 10 mg a day. Then titrate to effect. Converting at 100% risks overdose; failing to replace the baseline at all is the error that created this call.
Delivery. IV PCA with a basal rate of about 0.3 to 0.4 mg/h to replace the baseline (7 to 10 mg a day; one of the few settings where a basal rate is defensible, with scheduled IV doses as the alternative), demand doses of about 0.2 to 0.4 mg every 6 to 10 minutes for the acute pain, and a titrated loading dose now. Continuous oximetry and capnography, CPAP, sedation checks, alprazolam held. Switch back to oral oxycodone ER at the home dose as soon as the gut works.
Clonidine. An adjunct for the autonomic symptoms, not a substitute for opioid replacement: 0.1 mg by NG with the tube clamped 30 to 60 minutes, or a transdermal patch (slow onset). Watch BP once the opioid deficit is corrected.
Re-site tonight. Possible within the heparin timing (4 to 6 hours after a dose), but not the first move in an agitated, withdrawing man near midnight. A disconnected catheter is not reconnected. Treat the withdrawal and pain now; reconsider a new epidural in the morning if ileus and high needs persist; anterior abdominal wall blocks (TAP, rectus sheath) are less predictable after the component separation and mesh.

5. Discharge on POD 5

POD 5: eating, bowels moving, walking the halls. Last 24 hours: both home ER doses and seven IR tablets; pain 4/10 walking, POSS 1. Daily MME now? Discharge regimen: ER dose? IR: dose, how many a day, for how long? Back to his home IR use by when? His pain physician can be reached today. Discharge opioid prescription from the surgical team or from her? Why? Alprazolam at home: resume? Why/why not? He says the extra tablets are the first time in years his back hasn't hurt and asks to keep them. What will you tell him?

Considerations and pitfalls AI draft

MME. 120 mg ER plus 105 mg IR = 225 mg oxycodone, about 340 MME (337.5): roughly 25% above his baseline.
ER. Unchanged at his home dose; the long-acting baseline is not the place to absorb short-term surgical pain.
IR. 15 mg, up to about seven a day at discharge, stepping down by roughly one tablet a day every few days to his usual four a day, with a written schedule; a limited quantity covering the taper (about 1 to 2 weeks), no automatic refill. His last surgery left him on double his dose for four months; this time the end point is written down before he leaves.
Prescriber. One prescriber for the ongoing regimen. Either is defensible if it is explicit: the surgical team writes a short, defined supply for the postoperative excess and the pain physician resumes everything else, or the pain physician writes it all. Two uncoordinated prescriptions, or one that breaks his opioid agreement without her knowledge, is the error. Follow-up with her within about a week; check the PDMP before prescribing.
Alprazolam. Resume his home dose once he is off parenteral opioid and back on CPAP at home; it is part of his long-standing regimen and is his prescriber's to change. Naloxone in the house and family teaching, given the combination.
What to tell him. Acknowledge the relief honestly; explain the extra doses are for surgical pain that will settle over the next couple of weeks, that staying on a higher dose long term raises his risk of overdose with his sleep apnea and alprazolam, and that any lasting change to his back pain regimen is a decision with his pain physician, who will see him within the week. Not a refusal and not a lecture; an exact taper and a named next visit.

Non-perioperative

Lumbar radiculopathy on apixaban, referred for epidural steroid injection

A 58 y.o., 82 kg, 5'4" woman is referred to the pain clinic by her primary care physician for a lumbar epidural steroid injection.

HPISeven weeks ago she felt a pop in her low back while helping a client out of bed at work (home health aide). Within two days the pain moved into her left buttock, posterior thigh, and lateral calf, with tingling over the top of her foot into the big toe. Leg pain 8/10, back pain 4/10. Worse with sitting, coughing, and bending; eased lying on her right side with a pillow between her knees. Out of work for 3 weeks. Her PCP started ibuprofen, cyclobenzaprine, and gabapentin and referred her to physical therapy; she went to 2 of 8 sessions and stopped because therapy made the leg pain worse. Referral note: 'L-spine ESI please.'

PMHParoxysmal atrial fibrillation, diagnosed 3 years ago. Hypertension. Type 2 diabetes. Obesity (BMI 31). No prior spine surgery or spine injections.

MEDSApixaban 5 mg twice daily. Metformin 1000 mg twice daily. Lisinopril 20 mg daily. Ibuprofen 600 mg three times daily for 6 weeks. Gabapentin 300 mg three times daily for 4 weeks ('maybe a little' help). Cyclobenzaprine at bedtime. No known drug allergies.

SOCIALLives with her husband. Never smoker. Occasional alcohol.

PHYS EXAMBP 148/86, HR 84 irregularly irregular, afebrile. Antalgic gait, keeping weight off the left leg; sits shifted onto her right hip. Lumbar flexion limited by left leg pain.

IMAGINGLumbar MRI 2 weeks ago, ordered by her PCP: L3-4 mild disc bulge, no stenosis. L4-5 left subarticular disc extrusion narrowing the left lateral recess, with nerve root contact. L5-S1 disc desiccation with a small central protrusion, no nerve root contact. No marrow signal abnormality.

LABSHbA1c 7.6% (last month). Creatinine 0.9 mg/dL. Hgb 13.1 g/dL, platelets 245 K/uL.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INITIAL EVALUATION

Teaching focus. The history that changes the plan (red flags, mood, the opioid request); localizing the root on exam and matching it to the MRI; whether she has had an adequate trial of conservative care; planning the apixaban hold.

1. The referral

Referral reads 'L-spine ESI please.' Book the injection today? Why/why not? History you still need from her? Which answers would stop you from injecting? No fever, no weight loss, no cancer history, no IV drug use, bowel and bladder normal, no saddle numbness. Pain wakes her when she rolls over at night. Of concern? Why/why not? PHQ-9 is 14; she says she feels useless since she stopped working. Next? Still inject? Why/why not? She asks for oxycodone 'until the shot kicks in.' Prescribe? Why/why not? Which pain will the epidural treat: leg, back, or both? Why?

Considerations and pitfalls AI draft

Book today. The referral is a request, not an indication. Booking before your own history, exam, and image review is the flag; a same-day injection also runs straight into her apixaban, which needs a planned hold.
History still needed. Red flags for fracture, infection, malignancy, and cauda equina (fever, weight loss, cancer history, IV drug use, immunosuppression, chronic steroid use, trauma or osteoporosis, saddle numbness, urinary retention or incontinence, progressive weakness); prior episodes; function, work, and goals; mood and sleep; what she expects from an injection.
Answers that stop you. Saddle numbness or retention (cauda equina: emergency MRI and surgery, not an injection); fever or IV drug use (epidural abscess, discitis); cancer history with weight loss or constant rest pain (metastasis); rapidly progressive weakness (surgical opinion first). Skin infection at the site and uncorrected anticoagulation are procedural contraindications.
Night pain. Pain on rolling over is mechanical and common with a disc herniation. The red flag is constant, unrelenting pain at rest that no position relieves, especially with weight loss or a cancer history. Ordering a bone scan for positional night pain is the overcorrection; dismissing constant rest pain is the miss.
PHQ-9 14. Moderate depressive symptoms. Depression, fear-avoidance, catastrophizing, and time off work predict a poorer outcome and progression to chronic pain. Ask item 9 (thoughts of self-harm) directly. It does not cancel the injection; it adds treatment (PCP or behavioral health, a return-to-work plan, graded activity) and calls for realistic expectations.
Oxycodone. Opioids show little benefit over placebo for sciatica and add dependence, falls, and sedation on top of gabapentin and cyclobenzaprine. A small, short supply for severe acute pain is defensible only with a stop date and a prescription-monitoring check; an open-ended bridge to the injection is the error.
Leg vs back. An ESI treats radicular pain from an inflamed root; leg-dominant pain with a concordant disc herniation is the best predictor of response. Axial back pain responds poorly, and promising relief of the back pain sets her up for disappointment.

2. Examination of the left leg

Exam of the left leg: which maneuvers? Left straight-leg raise reproduces calf pain at 40 degrees; raising the right leg gives back pain only. Interpretation? Ankle dorsiflexion 4/5, great-toe extension 4/5, plantarflexion and knee extension full; light touch reduced over the dorsum of the foot; knee and ankle reflexes 2+ and symmetric. DDx for the weak dorsiflexion? How do you separate them at the bedside? Ankle inversion 4/5, hip abduction 4+/5, no Tinel sign at the fibular head. Root? Why? Which MRI level explains it? Why? The L5-S1 protrusion — does it matter? Why/why not? EMG before injecting? Why/why not? Weakness at 4/5 — surgical opinion before the injection? Why/why not?

Considerations and pitfalls AI draft

Exam. Gait with heel walking (L5) and toe walking (S1); myotomal strength including ankle inversion and hip abduction; dermatomal sensation; reflexes (patellar L4, Achilles S1, medial hamstring L5); straight-leg raise and crossed straight-leg raise; femoral stretch for upper lumbar roots; hip exam to exclude hip disease; fibular head palpation; distal pulses; saddle sensation if any bladder or bowel complaint.
Straight-leg raise. Leg pain below the knee between roughly 30 and 70 degrees indicates L5 or S1 root tension: sensitive, not specific. A crossed straight-leg raise counts only when raising the other leg reproduces pain in the affected leg; back pain alone is negative.
DDx. L5 radiculopathy; common peroneal (fibular) neuropathy at the fibular head; lumbosacral plexopathy, including diabetic radiculoplexus neuropathy; sciatic neuropathy; L4 radiculopathy (tibialis anterior is L4-L5); a central cause if upper motor neuron signs.
Separating them. Test muscles that share the L5 root but not the peroneal nerve: tibialis posterior (inversion, tibial nerve) and gluteus medius (hip abduction, superior gluteal nerve). Weakness there places the lesion at the root or plexus. Peroneal neuropathy spares inversion and hip abduction and produces no buttock pain or positive straight-leg raise.
Root. Left L5: dorsiflexion, great-toe extension, inversion, hip abduction, dorsum-of-foot sensation. A normal Achilles reflex and full plantarflexion argue against S1; a normal patellar reflex and knee extension argue against L4.
MRI level. The L4-5 left subarticular extrusion compresses the traversing L5 root in the lateral recess. A paracentral disc at L4-5 hits the traversing L5 root; a foraminal or far-lateral disc at L4-5 hits the exiting L4 root. Concordance of symptoms, exam, and image is what justifies the injection.
L5-S1 protrusion. A small central protrusion without root contact would affect S1, if anything, and she has no S1 signs. Disc degeneration is common in asymptomatic adults her age; treating the image rather than the patient is the flag.
EMG. Not needed when history, exam, and MRI agree. Useful when the picture is discordant, when peroneal or diabetic neuropathy is a real question, or when weakness progresses.
Surgical opinion. Mild, stable weakness with radicular pain is not an indication for urgent surgery; progressive weakness, severe foot drop, or cauda equina is. A non-urgent surgical opinion is reasonable but not a prerequisite. Document baseline strength now so progression is recognized later.

3. Conservative care to date

Inject now, or more conservative care first? Why? Likely course over the next two months without an injection? Her ibuprofen — continue? Why/why not? Replace it — acetaminophen? Topical diclofenac? Which? Dose? Gabapentin — increase? To what? Why/why not? Oral prednisone burst instead of an injection? Why/why not? Physical therapy — restart now or after the injection? Why? She chooses the injection. Expected benefit for her leg? For how long? Does it lower her chance of surgery? Why/why not?

Considerations and pitfalls AI draft

Inject now. Leg-dominant pain for nearly two months, concordant imaging, an NSAID and gabapentin that have not worked, therapy she cannot tolerate, and lost work: a reasonable time to inject. Continuing conservative care is also defensible because many patients improve without procedures; a strong learner weighs her function and work loss, not the referral.
Natural history. Most disc-related radiculopathy improves substantially over 6-12 weeks, and extruded fragments often regress on repeat imaging; a minority have persistent pain.
Ibuprofen. Stop. An NSAID on top of apixaban raises bleeding risk, especially GI. Six weeks of scheduled ibuprofen in a hypertensive diabetic on an ACE inhibitor also carries renal and blood-pressure risk, and NSAIDs give only a small benefit in sciatica. It has to stop before the procedure anyway.
Replacement. Scheduled acetaminophen, 1 g every 6-8 hours, maximum 3-4 g per day (no liver disease, light alcohol use); topical diclofenac is reasonable if she wants an NSAID effect, with minimal systemic absorption; heat; stay active rather than bed rest.
Gabapentin. Evidence for gabapentinoids in sciatica is weak, with no meaningful benefit over placebo in pooled data, and dizziness and sedation are common, more so with cyclobenzaprine. Escalating to a high dose because the low dose did nothing is the error; tapering off, or keeping a low dose she feels helps, is reasonable.
Prednisone. Oral steroids give a modest functional improvement and little pain benefit in radiculopathy, at the cost of systemic exposure and hyperglycemia in a diabetic. Reasonable to discuss; not preferred here.
Physical therapy. Restart once she can participate, ideally within a week or two of the injection: directional-preference exercise and graded activity. The injection is a window for rehabilitation, not the treatment; waiting for the pain to resolve before rehab is the flag.
Expected benefit. A modest short-term reduction in leg pain and better function, lasting weeks to a few months, in a majority of well-selected patients. No reliable long-term benefit, and evidence that it prevents surgery is inconsistent. Promising a cure or permanent relief is the misstep.

4. Apixaban and the procedure date

Injection booked for next week. Apixaban — hold? How many days? Why that interval? Her renal function — does it change the interval? Why/why not? Stroke risk off apixaban for that window — how high? What tells you? Bridge with enoxaparin? Why/why not? Morning of the procedure: she says she took apixaban two evenings ago 'out of habit.' Proceed? Why/why not? Procedure rescheduled. Apixaban until the new date — restart tonight or stay off? Why?

Considerations and pitfalls AI draft

Hold. Yes. Interlaminar and transforaminal ESIs are intermediate-risk procedures in the interventional pain anticoagulation guidelines, and apixaban is held 3 days (about five half-lives) before; the approach does not change the hold. The hold is agreed with her prescribing clinician, who knows her stroke risk. Injecting on apixaban, or borrowing a short hold from a low-risk procedure, is the error. NSAIDs: a lumbar ESI alone does not require stopping one, but the guidelines treat a patient on another anticoagulant or antiplatelet as higher bleeding risk, so stop her ibuprofen too (about 1 day).
Renal function. Apixaban is about a quarter renally cleared. At a creatinine of 0.9 her estimated creatinine clearance is above 50 mL/min whichever weight you use, so no extension; severe renal impairment lengthens the hold. Age 80 or over, weight 60 kg or under, and creatinine 1.5 or over are the dose-reduction criteria, not hold criteria.
Stroke risk. CHA2DS2-VASc 3 (female sex, hypertension, diabetes): roughly 3% per year untreated, so a few days off adds a very small absolute risk. Interruption is reasonable; she should know the risk is small but not zero.
Bridging. No. DOACs have a short half-life and a predictable offset; bridging with LMWH adds bleeding without reducing thromboembolism, and the LMWH would need its own hold.
Dose two evenings ago. About 36 hours rather than 72; residual anti-Xa effect is possible. For an elective injection, reschedule rather than shorten the interval. Proceeding because she is already on the table is the flag.
Until the new date. Depends on the new date. If it is within a few days, staying off and counting the 3 days from her last dose is reasonable; if it is a week or more away, restart tonight and repeat a proper 3-day hold. Staying off for a week adds stroke exposure for nothing.

B. TREATMENT PLAN AND INTERVENTION

Teaching focus. Interlaminar versus transforaminal approach and the foramen for a traversing L5 root; consent; steroid selection and why particulates are avoided transforaminally; reading contrast before injecting; a new deficit in recovery; steroid side effects and follow-up; recognizing when the problem has become surgical.

1. Approach, level, and consent

Interlaminar or transforaminal? Which? Why? Level and side? Assume transforaminal. Which foramen reaches the compressed root? Why that one? Landmark technique without imaging? Why/why not? Contrast before the steroid? Why? Sedation for her? Why/why not? Risks you consent her for? Paralysis — mention it? Why/why not?

Considerations and pitfalls AI draft

Interlaminar vs transforaminal. Both defensible. Transforaminal places injectate in the ventral epidural space at the disc-root interface on the affected side and is often chosen for unilateral radicular pain from a disc; it carries the rare risk of injection into a radicular or radiculomedullary artery. A left parasagittal interlaminar approach also reaches the ventral space and avoids the foramen but carries a higher chance of dural puncture. A strong learner names the trade-off; knowing one approach without its risk is the flag.
Level and side. Left, at L4-5 for an interlaminar approach (the level of the pathology), angled parasagittally toward the left.
Which foramen. The traversing L5 root is compressed at L4-5 and exits through the L5-S1 foramen. A left L5-S1 transforaminal injection bathes the L5 root and can spread up to the disc; a left L4-5 transforaminal with the needle high in the foramen sends injectate medially to the disc-root interface. Either is defensible. The error is not knowing which root lives in which foramen: the L4-5 foramen carries the exiting L4 root.
Without imaging. No. Blind interlaminar injections miss the intended level or space a meaningful fraction of the time, and a transforaminal injection cannot be done safely without fluoroscopy or CT.
Contrast. Real-time fluoroscopy with contrast confirms epidural spread along the root and excludes intravascular, intrathecal, or soft-tissue placement before any steroid goes in. Negative aspiration alone misses many intravascular placements. Digital subtraction adds sensitivity where available.
Sedation. None or minimal anxiolysis. She needs to report paresthesia or new pain during needle placement and injection; deep sedation removes the warning of an intraneural or intra-arterial injection.
Consent. Common: transient increased pain, transient numbness or weakness from local anesthetic, vasovagal reaction, steroid effects (hyperglycemia, flushing, insomnia, mood change, fluid retention, menstrual change), no benefit. Less common: dural puncture with headache, infection, bleeding or epidural hematoma (higher with anticoagulation), nerve injury, contrast reaction. Rare: spinal cord infarction and paralysis.
Paralysis. Yes. Rare but catastrophic, and the FDA requires a label warning that epidural corticosteroid injection can cause serious neurologic events including spinal cord infarction, paraplegia, stroke, and death. Omitting it because it frightens patients is the flag.

2. Steroid choice and the injection

Assume left L5-S1 transforaminal under fluoroscopy. Steroid? Triamcinolone? Methylprednisolone? Dexamethasone? Which? Why? Dose? Local anesthetic in the injectate — yes/no? Why? Fingerstick glucose 182 on arrival. Proceed? Why/why not? Needle in the foramen. Live fluoroscopy: contrast outlines the root, then a thin branching column streams medially and fades within a second. Interpretation? Next? Needle withdrawn slightly and redirected; repeat contrast outlines the L5 root and spreads into the epidural space without washout. Inject now? Anything first? Why?

Considerations and pitfalls AI draft

Steroid. Dexamethasone, the non-particulate choice. Particulate steroids (triamcinolone, methylprednisolone acetate, betamethasone suspension) form aggregates that can embolize in a radicular or radiculomedullary artery and infarct the cord; dexamethasone particles are far smaller than red cells. Multisociety consensus calls for a non-particulate steroid for the initial lumbar transforaminal injection, with particulates reserved for a later attempt with added safeguards. Efficacy is similar or only slightly shorter-lived. Triamcinolone transforaminally without a reason is the flag; particulates remain acceptable interlaminar.
Dose. Dexamethasone 4-10 mg. Lower doses work about as well as higher ones, and more adds hyperglycemia without adding benefit, which matters in her diabetes.
Local anesthetic. Optional. A small volume (0.5-1 mL of 1% lidocaine) gives immediate diagnostic relief and can serve as a test dose, at the cost of transient numbness, weakness, and fall risk; preservative-free saline is the alternative diluent. Either is defensible; warn her about transient weakness if you use it.
Glucose 182. Not a reason to cancel. There is no universal cutoff; injections are commonly deferred for markedly elevated or symptomatic hyperglycemia. She needs a plan: expect higher readings for a few days, check more often, call above an agreed number.
Interpretation. Intravascular injection; a thin, branching, rapidly clearing medial column is arterial until proven otherwise and may be a radicular artery supplying the cord. The artery of Adamkiewicz usually enters between T9 and L2, more often on the left, but cord-supplying arteries can enter at lower lumbar levels.
Next. Stop; no steroid. Withdraw or redirect and repeat contrast under live fluoroscopy (digital subtraction if available); if the vascular pattern persists, move to another level or abandon. Injecting because the pattern was 'mostly epidural' is the error.
Before injecting. Confirm no vascular uptake under live imaging; some give a local anesthetic test dose and watch a minute or two for new neurologic symptoms before the steroid. Connect extension tubing so the needle does not move between contrast and steroid, inject slowly, and stop for new pain or paresthesia.

3. Leg weakness in recovery

Assume the injectate was dexamethasone with 1 mL of 1% lidocaine. Twenty minutes later in recovery: left leg numb below the knee, ankle dorsiflexion 2/5, unable to bear weight on the left. DDx? What do you check? Right leg full strength, perineal sensation normal, no new back pain, numbness stops at the knee. Interpretation? MRI now? Why/why not? How long do you watch her? Two hours later: dorsiflexion back to 4/5, numbness fading. Discharge? Criteria? Drive herself home? Why/why not? Apixaban — restart when? Why? Return precautions — which?

Considerations and pitfalls AI draft

DDx. Local anesthetic block of the L5 root (expected); intraneural injection or needle injury to the root; spinal cord or conus infarction after intravascular injection; epidural hematoma (unlikely this early, after a full apixaban hold); vasovagal weakness.
Check. Both legs for strength and sensation, a sensory level, perineal sensation, bladder function, back pain, reflexes, vital signs, and the time course against the expected duration of lidocaine.
Interpretation. Unilateral, single-root distribution matching the injection, with no contralateral, saddle, or back findings: local anesthetic effect.
MRI. Not now, while the deficit fits local anesthetic and is improving. Immediately, with a spine surgeon involved, for bilateral weakness, a sensory level, sphincter change, severe new back pain, or failure to recover beyond the expected block duration. Imaging every transient numbness is overuse; missing a bilateral deficit is the catastrophe.
Observation. Serial exams every 15-30 minutes until strength returns to baseline and she walks safely, usually within 1-3 hours after lidocaine.
Discharge. Baseline strength, safe ambulation (falls on apixaban matter once she restarts it), stable vital signs, and an escort.
Driving. No; transient weakness and the procedure itself. She needs a ride home.
Apixaban. Restart about 24 hours after an intermediate-risk procedure if there is no bleeding concern. DOACs reach peak effect within hours, so a same-evening restart is the error.
Return precautions. New or worsening weakness, saddle numbness, bladder or bowel change, severe new back pain, fever or redness at the site, a headache worse upright and relieved lying flat, and glucose above her agreed threshold. New weakness after restarting apixaban is an emergency, not a phone message.

4. The first two weeks

Day 1 call: fasting glucose 312 on her meter, face flushed, slept three hours; drinking well, no vomiting, no confusion. Cause? Home or ED? Why? How long will it last? Day 3 call: leg pain no better than before the injection. Failed? Why/why not? Two-week visit: leg pain 2/10, sitting an hour at a time, dorsiflexion 4+/5. Next step? Physical therapy — what kind? Assume she is still taking gabapentin. Continue? Why/why not? Repeat injection in two weeks 'to lock it in'? Why/why not? Back to lifting clients — when?

Considerations and pitfalls AI draft

Cause. Systemic absorption of dexamethasone: hyperglycemia, facial flushing, and insomnia. All expected and self-limited.
Home or ED. Home: alert, drinking, not vomiting, no sign of DKA or a hyperosmolar state. More frequent fingersticks, fluids, continue metformin, and involve her PCP if readings stay near or above 300 or symptoms develop. ED for confusion, vomiting, or persistently very high readings. Sending every steroid-related 300 to the ED overcalls it; ignoring it in a symptomatic patient is the miss.
Duration. Glucose usually settles within 2-3 days; flushing and insomnia within a few days.
Day 3. Too early to call. Lidocaine relief lasts hours; the steroid effect usually begins over 2-7 days and can take up to two weeks. Judge the response at about 2-4 weeks.
Two weeks. A good response; the plan now is rehabilitation and return to work.
Physical therapy. Active, directional-preference exercise (often extension-biased), hip and trunk strengthening, graded return to activity; passive modalities alone are not the treatment.
Gabapentin. Taper off; it added little and adds sedation and fall risk.
Repeat in two weeks. No. There is no support for a routine series. Repeat only for return of significant pain after a meaningful, lasting response, and space injections (commonly no more than 3-4 per region per year) to limit steroid exposure: glucose, bone density, adrenal suppression.
Return to lifting. Graded, as strength normalizes and pain allows: modified duty first, then full patient handling with safe-lifting equipment. Prolonged time off work predicts chronic disability.

5. Return of leg pain at week six

Week six: leg pain back to 7/10 over five days, ankle dorsiflexion 3/5, great-toe extension 3/5, her foot slaps when she walks. Of concern? Why? What else do you ask her? She denies saddle numbness and any bladder or bowel change. Repeat the injection? Why/why not? Surgical referral — how soon? Repeat MRI? Why/why not? Anything for her gait while she waits? Analgesia while she waits — which agents? She asks, 'Did the shot do this?' What will you tell her?

Considerations and pitfalls AI draft

Of concern. Progressive motor deficit, 4+/5 at two weeks to 3/5 with a foot drop, means ongoing compression of the root. The question is no longer pain control but protecting the nerve.
What else to ask. Saddle numbness, urinary retention or incontinence, bowel change, and symptoms or weakness in the other leg; ask explicitly every time weakness progresses. Any one raises cauda equina: emergency MRI, with decompression if confirmed. Also falls (she is anticoagulated), what she was doing when it came back (return to lifting), new trauma, and fever or anything at the injection site.
Repeat injection. Not as the plan. A second ESI may relieve pain but does not decompress the root; progressive weakness is a surgical indication, and delaying referral for another injection is the error. Return of pain alone after a good response would be a reasonable reason to repeat.
Referral. Urgent, within days, to spine surgery; same day through the ED if cauda equina signs appear or weakness is rapidly worsening. Discectomy gives faster relief of persistent radicular pain than continued nonoperative care, outcomes tend to converge over 1-2 years, but progressive or severe weakness favors earlier decompression.
MRI. Yes. Her exam has changed since the last study (recurrent or enlarged herniation, a new fragment), and the surgeon will need current imaging; it also excludes a late post-procedure collection, though the timeline argues against one.
Gait. Ankle-foot orthosis and fall precautions; a fall on apixaban carries added risk.
Analgesia. Scheduled acetaminophen, topical agents, and at most a short opioid supply with a stop date if pain is severe; no systemic NSAID on apixaban.
Did the shot do this. Honest and plain: the injection calms inflammation around the nerve but does not shrink the disc; the disc is still pressing on the nerve, and that is why the weakness has progressed. The weakness on the day of the injection was the numbing medicine and resolved. Acknowledge the worry, explain the next steps (surgeon this week, brace, what to call for), and do not promise that surgery restores strength.

Long stem

Small bowel obstruction, volume depleted, for urgent exploratory laparotomy

A 66 y.o., 74 kg, 5'4" woman is brought to the operating room for urgent exploratory laparotomy for a small bowel obstruction.

HPIThree days of crampy abdominal pain, distension, and vomiting; no flatus or stool for two days. Unable to keep liquids down since yesterday. Came to the ED early this morning after taking her usual morning medicines at home. A nasogastric tube placed 8 hours ago has drained 1.6 L of bilious fluid. Admitted for a trial of nonoperative management, but over the last 2 hours her pain has become constant and she has new focal tenderness. She is lightheaded when she sits up.

PMHHypertension. Type 2 diabetes, HbA1c 7.4%. Open abdominal hysterectomy 18 years ago, after which she had severe nausea and vomiting and stayed an extra night. Walks two miles most days without symptoms. Never smoked. No other surgery.

MEDSLisinopril 40 mg and hydrochlorothiazide 25 mg each morning (taken today). Metformin 1000 mg twice daily. Insulin glargine 18 units at bedtime (taken last night). Atorvastatin. No known drug allergies.

PHYS EXAMHR 114; BP 102/60 supine; RR 22; SpO2 95% on room air; T 37.7°C. Dry mucous membranes. Abdomen distended and tympanitic, tender with guarding in the right lower quadrant; healed lower midline scar. Mallampati 2, full dentition, normal mouth opening and neck extension. Lungs clear.

CT ABDOMEN (IV contrast, 6 hours ago)Dilated, fluid-filled small bowel to 4 cm with a transition point in the lower abdomen; collapsed distal ileum and colon. Mesenteric haziness and a small amount of free fluid. No free air. Stomach distended with fluid.

LABSNa+ 133 mEq/L; K+ 3.0 mEq/L; Cl- 89 mEq/L; HCO3- 33 mEq/L; BUN 46 mg/dL; creatinine 1.7 mg/dL (0.9 three months ago); glucose 236 mg/dL; Mg2+ 1.5 mg/dL; lactate 2.6 mmol/L (1.8 six hours ago); WBC 14.8 K/uL; Hgb 15.1 g/dL; platelets 310 K/uL; INR 1.1.

OR ARRIVALOne 20 g IV in the left hand with her second liter of lactated Ringer's running; 1 L was given in the ED. Nasogastric tube to low wall suction. Foley catheter: 60 mL of urine over the last 4 hours. Standard monitors on.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. How much resuscitation an urgent abdomen can wait for; electrolyte correction before induction; full-stomach RSI with an NG tube in place; post-induction hypotension in a dry patient on an ACE inhibitor; maintenance, fluid strategy, temperature, and PONV prophylaxis for an open bowel resection.

1. Before induction

Surgeon wants to incise in 20 minutes. Proceed on that clock, or take more time? Why? How much more? Fluid before induction — which? How much? To what end point? Labs: correct anything before induction? Which? How? Potassium — rate? Through the 20 g in her hand? Why/why not? Arterial line before induction? Why/why not? Thoracic epidural before induction? Why/why not? Glucose — insulin now? Target?

Considerations and pitfalls AI draft

Proceed or take time. Constant pain, new focal tenderness, and a rising lactate raise concern for strangulation; hours of optimization risk losing bowel. A strong learner resuscitates in parallel over roughly 30-60 minutes (second IV, fluid, electrolytes started) rather than either inducing a dry patient immediately or holding the case for hours to normalize every number. Insisting on a normal potassium or creatinine before surgery is a flag.
Fluid choice. Isotonic crystalloid. She has a hypochloremic metabolic alkalosis from gastric losses and the thiazide; normal saline supplies chloride and corrects it, and balanced crystalloid (LR) is also defensible and avoids hyperchloremic acidosis if volumes get large. Either, if reasoned. Dextrose-containing or hypotonic fluid is wrong.
How much, end point. She is likely several liters behind (three days of vomiting, 1.6 L of NG output, orthostatic symptoms, hemoconcentration, prerenal AKI). Boluses of 500-1000 mL with reassessment, aiming for falling HR, improving BP, and some urine, not a fixed total. A learner who gives one bolus and calls her ready, or who plans to fill her completely before induction while ischemic bowel waits, has missed the balance.
Labs to correct. Potassium and magnesium start now and continue intraop; do not delay the case to normalize them. Hypokalemia raises arrhythmia risk, potentiates nondepolarizing block, and worsens ileus; low magnesium makes potassium hard to correct. Magnesium sulfate 2 g IV over 30-60 minutes is reasonable with her creatinine. The alkalosis itself corrects with chloride and volume; no specific acid therapy.
Potassium rate and route. About 10 mEq/h through a peripheral IV is the usual safe ceiling (higher rates need a central line and ECG monitoring). A hand 20 g is a poor site for concentrated KCl; a second, larger IV is needed anyway for resuscitation. Much of her ongoing potassium loss is renal (bicarbonaturia from the alkalosis, volume-driven aldosterone, and the thiazide), so correcting volume and chloride helps the kidneys stop wasting it.
Arterial line before induction. Defensible either way. Arguments for: hypovolemia, ACE inhibitor taken today, expected induction hypotension, and frequent labs. Arguments against: delay. Placing it pre-induction under local is reasonable if it takes minutes; otherwise place it right after induction with pressors drawn up. Inducing without a plan for hypotension is the flag.
Epidural before induction. Most would not place it now: she is volume depleted (a sympathectomy adds hypotension at induction), the case is urgent, and sitting up makes her lightheaded. Deferring to the end of the case or the PACU, once resuscitated, keeps the option. A learner who places and doses it now without engaging the volume status is the concern.
Glucose. Yes, treat: an insulin infusion or IV boluses aiming for 140-180 mg/dL, with glucose checked every 1-2 hours. Hold metformin given the AKI, the rising lactate, and today's IV contrast. Her basal glargine was taken last night, so as the stress response settles she can drift low while NPO; check often rather than chase single values.

2. Airway and induction

Assume 40 minutes of resuscitation: second IV, 18 g, in; 1.5 L given since arrival; HR 102, BP 112/66. The NG tube: suction it? Pull it before induction? Why/why not? Position for induction? Preoxygenation — how? End point? Cricoid pressure? Why/why not? Induction agent? Dose? Rocuronium or succinylcholine? Why? Dose? Mask ventilate before laryngoscopy? Why/why not? Laryngoscopy: grade 1 view, green fluid pooling in the hypopharynx, cords clear. Next? Tube passed, cuff up. Suction down the tube before the first breath? Why/why not? ETCO2 confirmed, SpO2 97%. Bronchoscopy? Why/why not?

Considerations and pitfalls AI draft

NG tube. Aspirate it actively before induction, ideally with her in more than one position; this reduces gastric volume but never empties the stomach, so RSI is still indicated. Leaving it in place (open to suction) and removing it are both defended; leaving it in keeps the stomach vented, and an NG tube does not prevent effective cricoid pressure. Treating an NG tube as proof of an empty stomach is the error.
Position. Head up or reverse Trendelenburg (about 20-30 degrees) to reduce passive regurgitation and improve preoxygenation, with the ear-to-sternal-notch line aligned. Have suction on and under the pillow, not across the room.
Preoxygenation. Tight-fitting mask, FiO2 1.0, high fresh gas flow, 3 minutes of tidal breathing or 8 vital capacity breaths, to an end-tidal O2 of about 0.9. Apneic oxygenation by nasal cannula is reasonable. Her distended abdomen reduces FRC, so she will desaturate faster than her age suggests.
Cricoid pressure. Debated; either answer is acceptable if reasoned. Applied correctly (about 10 N awake, 30 N once asleep), many still use it in a vomiting patient with bowel obstruction. Release it if it worsens the view or ventilation, and during active vomiting. Not knowing how to apply or when to release it is the gap.
Induction agent. Hemodynamically gentle and fast: etomidate 0.2-0.3 mg/kg (15-22 mg), ketamine 1 mg/kg (about 75 mg), or a reduced propofol dose (0.5-1 mg/kg, 35-75 mg) with a pressor drawn up. She is still dry and on an ACE inhibitor; a full propofol dose with no plan for the BP is the flag.
NMB. Either, if defended. Rocuronium 1.2 mg/kg (about 90 mg) gives RSI conditions with sugammadex available. Succinylcholine 1-1.5 mg/kg (75-110 mg) is acceptable; she has no contraindication, and her potassium is low, not high. Rocuronium also avoids a short-acting agent wearing off during a slow laryngoscopy.
Mask ventilation before the tube. Classic RSI avoids it; gentle mask ventilation at low pressure (about 20 cm H2O or less) is now widely accepted to prevent desaturation in a patient with low reserve. A learner who would let her desaturate rather than ventilate gently has the risks out of order.
Fluid in the hypopharynx. Suction it, keep the head up, and intubate promptly; the cords are visible and the tube is the protection. Releasing cricoid briefly if needed to suction is acceptable. Pausing to mask ventilate with fluid in the pharynx, or abandoning the view, adds risk.
After the tube. Suction through the tube before positive pressure, and watch for aspiration: rising peak pressures, falling SpO2, wheeze, secretions on suction. Bronchoscopy is for suspected particulate material or lobar collapse, not routine for bilious fluid seen only above the cords. No prophylactic antibiotics or steroids for aspiration.

3. Blood pressure after intubation

Four minutes after intubation: BP 66/38, HR 106, sevoflurane 0.8 MAC. DDx? Rx? Phenylephrine? Ephedrine? Volume? Two doses of phenylephrine 100 mcg: BP 72/42. Next drug? Dose? Why that drug? Target MAP? Why that number? BP now 108/62. Assume a radial arterial line is now in: pulse pressure variation 18% on Vt 450 mL. Interpretation? Rx?

Considerations and pitfalls AI draft

DDx. Hypovolemia unmasked by loss of sympathetic tone, induction drug and volatile, ACE inhibitor taken this morning, positive-pressure ventilation reducing venous return, and the distended abdomen compressing the IVC. Less likely but checked: aspiration with hypoxemia, auto-PEEP from overventilation, anaphylaxis, tension pneumothorax. A learner who blames only the anesthetic misses the volume and the ACE inhibitor.
Rx. All three are reasonable together: reduce the volatile, a pressor bolus (phenylephrine 100 mcg, or ephedrine 5-10 mg with HR already 106 being less attractive), and a fluid bolus. Treat promptly; ischemic bowel and kidneys already at risk do not tolerate prolonged low pressure.
Refractory to phenylephrine. A strong learner connects this to the ACE inhibitor taken today: with angiotensin II blocked, the response to phenylephrine is blunted. Vasopressin 0.5-1 unit IV boluses works through a separate receptor; norepinephrine boluses or infusion are also reasonable. Repeating phenylephrine in larger doses without changing class is the flag.
Target MAP. At least 65, and many would aim closer to her usual (likely 85-95) given hypertension, AKI, and threatened bowel; intraoperative MAP below 65 is associated with kidney and myocardial injury, and the risk grows with duration. A bare number without a reason, or 'normal for anyone', misses her baseline.
PPV 18%. Above roughly 12-13% suggests she will increase stroke volume with fluid. It is reliable only with controlled ventilation, sinus rhythm, and a tidal volume around 8 mL/kg; her distended abdomen raises intra-abdominal pressure, which can raise PPV on its own, and it is less reliable at lower tidal volumes. Read it alongside the BP response and the clinical picture. Rx: another 250-500 mL bolus and reassess. Treating the number with more pressor alone ignores what it says.

4. Maintenance and fluids

Adhesions lysed; 45 cm of dark, nonviable ileum resected with a primary anastomosis. Two hours in: 3.5 L crystalloid total, EBL 200 mL, urine 28 mL in the last hour. Maintenance: sevoflurane? Propofol TIVA? Nitrous oxide? Which? Why/why not? More fluid now? Why/why not? What tells you? Fluid plan for the rest of the case: restrictive? Liberal? Goal-directed? Which? Why? Albumin? Why/why not? Temp 35.2°C. Of concern? Why? Rx? Antiemetic prophylaxis for this case: how many agents? Which? When? Dexamethasone? Dose? Why/why not?

Considerations and pitfalls AI draft

Volatile vs TIVA. Either is safe. Propofol TIVA reduces PONV and is a strong reason here given her history; it needs processed EEG or careful dosing to avoid awareness in a patient whose pressure limits the dose. Sevoflurane is easier to titrate around hypotension. The choice should connect to her PONV risk.
Nitrous oxide. No. It diffuses into gas-filled obstructed bowel faster than nitrogen leaves, distending the bowel, worsening the surgical field and closure, and possibly bowel perfusion. It also adds to PONV in a patient with a strong history.
More fluid now. Urine output alone is a poor guide intraop; oliguria under anesthesia and surgical stress is common and does not by itself mean hypovolemia. Look at the PPV or stroke volume trend, MAP and pressor need, lactate, and the field. If she still responds, a bolus; if not, stop. Reflexively giving liters to make urine is the error.
Fluid strategy. Goal-directed or a moderately restrictive, near-zero-balance approach once the deficit is repaid; both are defensible. The point is that she started several liters behind, so 'restrictive' cannot mean withholding resuscitation. Excess crystalloid causes bowel wall edema, ileus, anastomotic and wound problems; too little worsens AKI. A strong learner separates repaying the deficit from maintenance.
Albumin. Not routinely; crystalloid is appropriate for this resuscitation, and albumin has no outcome advantage here. Reasonable to consider only if large crystalloid volumes are needed and edema is a problem. Using it as a reflex 'to keep fluid in the vessels' is not supported.
Temperature. Yes. Mild hypothermia increases wound infection, bleeding, and cardiac events, and slows drug clearance, including the neuromuscular blocker. Forced-air warming on the upper body, warmed fluids, a warm room; aim for at least 36°C by the end of the case.
PONV prophylaxis. She has four risk factors (female, nonsmoker, prior PONV, postoperative opioids), so her risk is high. Three or four interventions, planned at the start rather than at the end: for example dexamethasone at induction, ondansetron near the end, TIVA, and minimizing opioids; low-dose haloperidol or droperidol or a scopolamine patch are additions (the patch can confuse older patients). One agent, or none, is undertreatment.
Dexamethasone. Yes, 4-8 mg at induction is reasonable, including in a diabetic. It raises glucose modestly for about a day; check and treat glucose rather than withholding effective prophylaxis. The concern is real but not a contraindication.

B. POST-OPERATIVE CARE

Teaching focus. Reversal and extubation in a full-stomach patient; reading a normal pH in a mixed disorder; PONV rescue; timing an epidural around resuscitation and heparin, and treating its hypotension; oliguria and NG loss replacement on POD 1; postoperative ileus versus leak, NG decompression, fluids and electrolytes, and opioid sparing.

1. Emergence and the first PACU hour

Fascia closing. TOF count 2; last rocuronium 40 minutes ago. Reverse with what? Dose? Neostigmine instead? Why/why not? NG tube before extubation: suction it? Leave it in? Pull it? Why? Extubate in the OR? Why/why not? Deep or awake? Why? Extubated awake. Assume hydromorphone 1.6 mg intraop. PACU, 30 minutes: drowsy, RR 8, SpO2 90% on 4 L nasal cannula. ABG: pH 7.44, PaCO2 52, PaO2 62. Interpretation? DDx for the low PaO2? Rx? Naloxone? Dose?

Considerations and pitfalls AI draft

Reversal. Sugammadex 2 mg/kg at TOF count 2 or more: about 150 mg. Confirm recovery with quantitative monitoring (TOF ratio at least 0.9) before extubation. Hypokalemia, hypothermia, and any magnesium given all prolong rocuronium.
Neostigmine. Possible but weaker here. At TOF count 2 it may not reach a TOF ratio of 0.9 reliably and takes 10 or more minutes; it works best at TOF count 4. In a full-stomach patient, residual weakness at extubation is a real aspiration risk. Choosing neostigmine without quantitative confirmation is the flag.
NG tube. Aspirate it before extubation and leave it in on suction; the bowel will be slow to work and the surgeon will want it. Pulling it to make extubation 'cleaner' throws away the decompression.
Extubate in OR. Yes, if she meets criteria: warm (or close), reversed, awake, hemodynamically stable off or on minimal pressor, adequate gas exchange. Staying intubated is reasonable if she remains on escalating pressor or has aspirated with poor oxygenation.
Deep or awake. Awake. She has a full-stomach physiology until the bowel works again, and a deep extubation leaves the airway unprotected. Deep extubation here is the error.
ABG interpretation. The normal pH hides a mixed disorder. HCO3 is about 34 (0.03 x 52 x 10^1.34). For a metabolic alkalosis with that HCO3, expected PaCO2 is about 0.7 x 34 + 20 = 44 (range 39-49); 52 is higher, so there is an added respiratory acidosis from opioid and residual anesthetic. Calling it 'normal' because the pH is 7.44 is the trap.
Low PaO2. Hypoventilation alone does not explain it. On 4 L, FiO2 is roughly 0.35: alveolar PO2 is about 0.35 x 713 - 52/0.8 = 185, so the A-a gradient is over 100. Atelectasis (midline laparotomy, distended abdomen, splinting) and aspiration (fluid in the pharynx at intubation) lead the DDx; residual block and fluid overload are also possible. A CXR is reasonable.
Rx and naloxone. Stimulate, sit her up, increase oxygen, encourage deep breaths, confirm TOF ratio. If RR stays low and she is hard to rouse, naloxone in small titrated doses, 40 mcg IV every 2-3 minutes, to restore breathing without stripping analgesia. A 0.4 mg bolus can cause abrupt severe pain, hypertension, and pulmonary edema. Noninvasive ventilation is defensible for atelectasis if she is awake and the NG tube is decompressing the stomach.

2. Retching in PACU

An hour later: awake, RR 16, SpO2 96% on 2 L. She retches, then vomits 150 mL of bilious fluid. Assume she received dexamethasone 4 mg and ondansetron 4 mg intraop. First thing you check? The NG tube has been clamped since transport. Unclamped: 350 mL out. Twenty minutes later, still nauseated. More ondansetron? Why/why not? Which drug now? Dose? Promethazine? Scopolamine patch? Why/why not?

Considerations and pitfalls AI draft

First check. The NG tube: position, patency, suction on. A blocked, clamped, or displaced tube lets the stomach refill, and vomiting an hour after an episode of hypoventilation and sedation is an aspiration risk. Also check BP (hypotension causes nausea), pain, and opioid dosing. Reaching straight for another antiemetic without looking at the tube is the flag.
Repeat ondansetron. No. A repeat dose of the same 5-HT3 antagonist within about 6 hours adds little; rescue uses a drug from a different class.
Rescue drug. A different class: low-dose haloperidol (0.5-1 mg IV) or droperidol (0.625 mg IV), with a QTc check; amisulpride 10 mg IV where available; promethazine 6.25 mg IV in small doses. Repeating dexamethasone is not a rescue.
Promethazine and scopolamine. Promethazine works but sedates, which matters in a woman who just hypoventilated; if used, low dose, and never into a small or hand IV that may extravasate. Scopolamine takes hours to work, so it is prophylaxis, not rescue, and causes confusion and urinary retention in older patients.

3. Pain on the night of surgery

Assume no epidural so far. 18:30, two hours in PACU: pain 8/10 despite hydromorphone 1 mg IV, RR 12, BP 118/68 without pressors. Thoracic epidural now? Why/why not? Platelets 255, INR 1.2. Surgeon has ordered heparin 5000 units SC every 8 hours, first dose at 21:00. Place it before or after that dose? Why? Interspace? Infusate? Rate? Assume an epidural placed at T9-10, bolused, and the infusion started at 20:00. At 23:00: BP 82/46, HR 98, sensory level T6 to T11 bilaterally, urine 12 mL/h. DDx? Rx? Stop the epidural? Why/why not?

Considerations and pitfalls AI draft

Epidural now. Reasonable and many would offer it now that she is resuscitated and off pressors: better analgesia for a midline laparotomy, less opioid (she just hypoventilated), and local anesthetic epidurals shorten ileus. Alternatives are defensible: rectus sheath or TAP catheters, IV lidocaine, ketamine, acetaminophen, and PCA. Check for signs of sepsis too (she had necrotic bowel). Choosing an epidural without checking volume status and coagulation, or refusing all regional options while escalating opioids, are the flags.
Before or after the heparin. Before, since no heparin has been given yet. Current ASRA guidance for low-dose SC heparin (5000 units two or three times daily): needle placement and catheter removal at least 4-6 hours after a dose (or with normal coagulation status); no contraindication to keeping the catheter in while on it; the next dose may be given immediately after catheter removal. ASRA gives no SC-specific wait after placement; giving the 21:00 dose an hour or more after an uneventful placement mirrors the 1-hour rule for IV heparin and is common practice. Placing it an hour after the first dose is the error.
Interspace, infusate, rate. For a midline laparotomy, about T8-T10 to center the block on the incision. Dilute local anesthetic with an opioid: bupivacaine 0.1% or ropivacaine 0.1-0.2% with fentanyl 2 mcg/mL or hydromorphone about 10 mcg/mL, at 6-8 mL/h. A lumbar catheter is too low for this incision.
DDx for the hypotension. Sympathectomy unmasking residual hypovolemia is most likely, especially with oliguria. Also bleeding, sepsis from the ischemic bowel, myocardial ischemia, and catheter migration intravascularly or intrathecally (a much denser or higher block). A T6-T11 level is appropriate for the incision, so the block level is not the problem; volume is.
Rx. Assess volume (bedside, POCUS, Hgb), a fluid bolus if she is responsive, and a vasopressor (phenylephrine or low-dose norepinephrine) to support MAP while you sort it out; reduce or drop the local anesthetic concentration or rate if needed.
Stop the epidural. Usually no. Stopping it trades a treatable pressure for poor pain control and more opioid; most would reduce the rate or switch to an opioid-only infusion and treat the volume. Stopping it is reasonable if the hypotension persists despite volume and pressor, or if bleeding or sepsis is found.

4. Urine output on POD 1

POD 1, 08:00. Assume the epidural is still running. Urine 12-16 mL/h for 5 hours; creatinine 2.1 (1.7 preop). HR 96, BP 106/60. NG output 1.3 L overnight. Na 137, K 3.2, Cl 99, HCO3 29, Mg 1.6. DDx? First thing you check? Foley flushes; bladder scan empty. Another bolus? How will you decide? Assume a passive leg raise with POCUS: VTI rises 16%. Rx? Replace the NG losses with what? How much? Potassium — how much? Furosemide? Why/why not? Restart her lisinopril? Hydrochlorothiazide? Metformin? Why/why not?

Considerations and pitfalls AI draft

DDx. Prerenal from ongoing losses (NG output, third spacing, epidural vasodilation), ischemic injury from preop hypovolemia and intraop hypotension, contrast exposure, ACE inhibitor effect, and obstruction of the catheter. Abdominal compartment syndrome is possible after laparotomy for obstruction; bladder pressure if the abdomen is tense.
First check. The catheter: flush it and scan the bladder. A blocked Foley is a two-minute fix that looks like AKI.
Another bolus, how to decide. Test, do not guess: passive leg raise with a stroke volume or VTI measure, or a small bolus with a measured response. CVP and urine output alone are poor predictors. Giving liters on oliguria alone, or reflexively withholding fluid because she is 'restrictive', are both errors.
PLR positive. A rise of 10-15% or more in VTI predicts fluid responsiveness. Give a bolus (500 mL), reassess, and add replacement for ongoing losses rather than a large fixed maintenance rate.
NG loss replacement. Gastric fluid is rich in hydrogen and chloride with some potassium. Normal saline with 20 mEq/L KCl, replacing roughly mL for mL (or half to all of the volume) every 4-6 hours, matches it. LR carries less chloride than gastric fluid and its lactate becomes bicarbonate, so it corrects the alkalosis poorly; hypotonic fluids risk hyponatremia.
Potassium. K 3.2 with an ileus and an anastomosis: replace toward at least 4.0, roughly 40-60 mEq IV over several hours at a peripheral-safe rate, with magnesium replaced too (Mg 1.6) so the potassium holds. Recheck in 4-6 hours. With creatinine rising, give it in measured doses and recheck rather than a large unmonitored load.
Furosemide. No. She is fluid responsive and prerenal; a diuretic worsens the volume deficit and the kidney injury, and converting oliguria to urine output does not help the kidney.
Home meds. Hold lisinopril and hydrochlorothiazide until she is euvolemic, normotensive, and her creatinine is recovering; both worsen prerenal AKI and the thiazide worsened her potassium. Hold metformin until her kidney function is stable and she is eating. Restarting them on schedule because they are 'home meds' is the gap.

5. POD 4

POD 4. Epidural removed yesterday; hydromorphone PCA, 10 mg in the last 24 hours. Distended, nauseated, no flatus; NG output 900 mL/day. T 37.4°C, HR 90, WBC 9.8, creatinine 1.2, K 3.4, Mg 1.7. DDx? Most concerning? How will you tell them apart? The NG tube: keep it? Pull it? Why? IV fluids: which? Rate? Potassium and magnesium: replace? Targets? The PCA: continue it? Change it? To what? Ketorolac? Why/why not? She asks: 'Did the anesthesia do this to my bowels?' What will you tell her?

Considerations and pitfalls AI draft

DDx. Postoperative ileus is most likely; after an open bowel resection it commonly lasts several days, and POD 4 is at the edge of what is expected. Also early postoperative obstruction (adhesions, internal hernia), anastomotic leak or intra-abdominal abscess, electrolyte contributors (potassium, magnesium), and opioid effect.
Most concerning, and how to tell. Anastomotic leak: fever, tachycardia out of proportion, rising WBC or lactate, peritonitis, new organ dysfunction. Her normal temperature, HR, and WBC are reassuring but do not exclude it. Examine the abdomen and trend vitals and labs; if anything points away from simple ileus, CT abdomen and pelvis (IV contrast if renal function allows; contrast through the NG tube helps show a leak or obstruction). A learner who calls it ileus without considering a leak is the flag.
NG tube. Keep it on suction. Routine NG decompression after laparotomy is not needed, but a distended, nauseated patient draining 900 mL/day is not emptying her stomach, and the tube relieves nausea and lowers aspiration risk. Remove it when output falls and bowel function returns; there is no single volume cutoff. Pulling it because 'NG tubes slow recovery' ignores her symptoms.
IV fluids. Replace measured NG losses plus modest maintenance, aiming for near-zero balance. Gastric losses favor a chloride-containing isotonic fluid with potassium (for example normal saline with 20 mEq/L KCl). Excess salt and water causes bowel wall edema and prolongs ileus; too little risks her recovering kidneys. A large fixed maintenance rate is the error.
Potassium and magnesium. Yes, both. Low potassium and magnesium slow bowel recovery. Replace potassium toward the normal range (at least 3.5-4.0) and magnesium toward about 2 mg/dL, with her creatinine now improving; recheck after each round rather than giving one large dose.
The PCA. Change it. A PCA delivering 10 mg of hydromorphone a day is itself slowing the bowel. Scheduled IV acetaminophen as the base, reduce the PCA dose or move to as-needed doses, and add a non-opioid where safe (low-dose ketamine is an option). Leaving the PCA unchanged while treating the ileus is the gap.
Ketorolac. Defensible but cautious: it spares opioid, but she had AKI three days ago and her creatinine is not back to baseline, and some surgeons avoid NSAIDs after a fresh anastomosis (the evidence on leak risk is mixed). If used, low dose (15 mg IV every 6 hours for her age), short course, with creatinine monitoring; many would wait until renal function recovers. Using it freely without mentioning the kidney is the gap.
What to tell her. Honest and specific: her bowel is slow to wake up, which is common after an operation on the bowel itself; the surgery, the inflammation from the obstruction, and pain medicines all contribute, and the pain medicines are the part we can reduce. It usually resolves over days; the team is checking that nothing else is going on. Avoid both denying any role of the medicines and blaming the anesthetic outright.

Short stem

Laparoscopic cholecystectomy in a morbidly obese patient with reflux and a suspected sleep disorder

A 46 y.o., 5'5", 128 kg woman is scheduled for elective laparoscopic cholecystectomy for symptomatic gallstones. She has heartburn most nights despite omeprazole and wakes coughing with sour fluid in her mouth when she lies flat. Her husband says she snores loudly and stops breathing in her sleep; she dozes off while stopped at red lights; she has never had a sleep study. Hypertension treated with lisinopril and hydrochlorothiazide; type 2 diabetes on metformin and weekly semaglutide for 8 months. Severe nausea and vomiting after her last anesthetic; does not smoke. BP 154/92; HR 86; SpO2 94% on room air; neck circumference 44 cm; Mallampati III. HCO3 29 mEq/L; HbA1c 7.6%.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Pre-op evaluation of the morbidly obese patient with a suspected but undiagnosed sleep disorder; aspiration risk from uncontrolled reflux plus a GLP-1 receptor agonist; day-of-surgery decisions on blood pressure, morning medications, potassium, and glucose; airway, positioning, and preoxygenation planning at BMI 47.

1. Sleep history before elective surgery

Working diagnosis for her sleep? How confident? What tells you? Sleep study before you proceed? Why/why not? Other tests before surgery? Why? ABG on room air: pH 7.43, PaCO2 44, PaO2 68. Interpretation? Why is her bicarbonate up? Echo before surgery? Why/why not? Surgeon wants to go today. Proceed? Why/why not? Delay a few weeks to start CPAP first? Why/why not? Under what findings would you postpone?

Considerations and pitfalls AI draft

Working diagnosis. OSA, likely moderate to severe: loud snoring, witnessed apneas, daytime sleepiness, hypertension, BMI 47, neck 44 cm (STOP-Bang 6 of 8; the elevated bicarbonate adds specificity). A strong learner treats her as having moderate-to-severe OSA for planning; the falling-asleep-at-red-lights detail is also a driving-safety issue worth raising with her primary team.
Sleep study first. Not required for an elective lap chole when OSA is suspected but there is no sign of hypoventilation, pulmonary hypertension, or uncontrolled comorbidity; the usual course is to proceed with presumed-OSA precautions and refer for a sleep study afterward. A learner who cancels reflexively for a PSG, or who ignores the history, both miss.
Other tests. The elevated bicarbonate is the prompt for an ABG to look for daytime hypercapnia (obesity hypoventilation); ECG given hypertension and age; BMP for potassium on HCTZ; glucose. Routine CXR or PFTs add little.
ABG. Normal PaCO2 with mild hypoxemia (A-a gradient roughly 25-30, from obesity-related atelectasis and V/Q mismatch). No daytime hypercapnia argues against obesity hypoventilation syndrome.
Bicarbonate. Most likely from hydrochlorothiazide (contraction alkalosis, with the low potassium), though nocturnal hypercapnia from untreated OSA can also raise it; with a normal awake PaCO2 it is not compensation for chronic daytime hypercapnia. A learner who labels her OHS on the bicarbonate alone has not read the gas.
Echo. Not indicated on this picture: no hypercapnia, no signs of right heart strain (JVD, edema, loud P2, RV strain on ECG), no unexplained exertional symptoms. Echo becomes reasonable if any of those appear or if hypoventilation is confirmed.
Proceed / delay for CPAP. Proceeding is defensible; a few weeks of CPAP is unlikely to change her risk enough to justify delay when the plan already treats her as having OSA. Delay is reasonable if she has hypoventilation, pulmonary hypertension, or hypoxemia at rest out of proportion.
Postpone triggers. Resting PaCO2 above 45, SpO2 persistently low on room air, signs of pulmonary hypertension or right heart failure, uncontrolled cardiac or metabolic disease. Naming concrete triggers rather than a vague 'if she's sick' separates strong from weak answers.

2. Reflux and semaglutide on the morning of surgery

Last semaglutide injection 5 days ago, same dose for 6 months, no nausea, bloating, or vomiting this week. Solids until midnight, clear liquids until 2 hours ago. Proceed? Why/why not? Gastric ultrasound — yes/no? Why/why not? Assume you scan. Position for the scan? Supine: antrum flat. Right lateral: small amount of clear fluid, no solid. Interpretation? She skipped her omeprazole this morning. Of concern? Aspiration prophylaxis now — famotidine? Sodium citrate? Metoclopramide? Which? Why? Dose? Timing? Should she have held the semaglutide last week? Why/why not?

Considerations and pitfalls AI draft

Proceed. Yes is defensible: stable maintenance dose, no GI symptoms, fasting intervals met. The concern is that delayed gastric emptying can leave solids despite a standard fast, so fasting time alone is not reassuring; the reflux is a separate and probably larger risk.
Gastric ultrasound. Reasonable and quick when the answer would change the plan; it is harder at BMI 47 but often feasible with a curvilinear probe. Supine then right lateral decubitus, antrum in the sagittal plane at the epigastrium near the left lobe of the liver and aorta or IVC.
Interpretation. Fluid visible only in right lateral (grade 1 antrum), no solid: consistent with a baseline low-volume, fasted stomach. Reassuring about the GLP-1 agonist; it does not remove the reflux-driven risk of regurgitation at induction.
Missed PPI. Raises the chance of acidic gastric contents; does not change the decision to proceed but supports giving a fast-acting acid reducer now.
Prophylaxis. Famotidine 20 mg IV (works within about 30-60 min), sodium citrate 30 mL shortly before induction for immediate neutralization, metoclopramide 10 mg IV to speed emptying and raise LES tone. Any combination is defensible if the learner can say what each does and when. A strong learner notes these raise gastric pH and lower volume but have not been shown to reduce aspiration itself; they may lessen its severity, and they do not replace the induction plan.
Holding semaglutide. Multisociety guidance supports continuing in most patients; higher-risk patients (dose escalation, GI symptoms, high dose) may be held or put on a liquid diet for 24 h. She is on a stable dose without symptoms; continuing is reasonable, and stopping it reflexively because she is obese is not the standard.

3. Morning medications and labs

She took lisinopril, hydrochlorothiazide, and metformin at 5 AM. Of concern? Which? Why? Cancel? Why/why not? BP in holding 158/94. Proceed? What number would stop you? K 3.3. Replace before induction? Route? How much? Point-of-care glucose 216. Proceed? Why/why not? Insulin now? Agent? Dose? Intra-op glucose target? How often do you check?

Considerations and pitfalls AI draft

Morning medications / cancel. Lisinopril is the one that matters: an ACE inhibitor within 24 h raises the risk of hypotension after induction that responds poorly to phenylephrine; it is commonly held the morning of surgery. Having taken it is not a reason to cancel: plan for it (vasopressor drawn up, vasopressin available, careful induction dose). Metformin taken the morning of a short laparoscopic case with normal renal function is not a concern; HCTZ matters mainly through the potassium.
BP. 158/94 is not a reason to delay. Elective surgery is commonly deferred for BP at or above 180/110; below that, proceeding is supported. Chasing a normal number in holding with IV agents is the error.
Potassium. 3.3 from HCTZ is mild; proceeding is standard. Oral KCl 20-40 mEq or a slow IV replacement (10 mEq/h peripherally) is reasonable; check magnesium. Cancelling for 3.3, or bolusing potassium quickly IV, are both flags.
Glucose 216. Proceed; this is not a cancellation threshold, and her HbA1c 7.6% shows reasonable chronic control. A reasonable cutoff for delaying elective surgery is much higher (often above 300 with ketosis or dehydration).
Insulin. Subcutaneous rapid-acting correction (a few units, e.g., 2-4 units lispro or aspart per the correction scale), or IV regular in similar doses; recheck in 1-2 h. Her hypoglycemia risk is low on metformin and semaglutide, but an aggressive bolus is still the wrong instinct.
Target / checks. Roughly 140-180 mg/dL (under 180); check every 1-2 h intra-op and again after dexamethasone if it is given. Tight targets near 80-110 risk hypoglycemia under anesthesia.

4. Airway and induction setup

Airway plan. Awake fiberoptic? Why/why not? Assume asleep intubation. Video or direct? Why? Backup plan if the first attempt fails? In what order? Position for induction? How do you know it's right? Preoxygenation — technique? End point? How long? Once she is apneic, how long before she desaturates? Why? Anything during laryngoscopy to extend that? How?

Considerations and pitfalls AI draft

Awake fiberoptic. Not required: BMI alone predicts difficult laryngoscopy poorly; her neck circumference and Mallampati III raise the risk of difficult mask ventilation and laryngoscopy, but she has no prior difficult airway, limited mouth opening, or neck pathology. Awake is defensible if the learner names a specific reason; reflexive awake intubation for BMI alone is a flag, and so is ignoring the risk.
First device. Video laryngoscopy is a reasonable first choice in morbid obesity; DL with VL immediately available is also defensible. Strong learners have a second-generation supraglottic airway and front-of-neck equipment in the room and a stated plan for a failed first attempt.
Backup. A different device or operator, limit attempts, SGA (second generation, gastric port) as rescue oxygenation, then front-of-neck access if she cannot be oxygenated. Wake-up is limited by short safe apnea time.
Position. Ramped so the external auditory meatus is level with the sternal notch, head-elevated or 25-30 degrees reverse Trendelenburg; improves the laryngoscopic view and FRC, and reduces passive regurgitation.
Preoxygenation. Tight-fitting mask at 100% O2 with high fresh gas flow, head up, with CPAP or PEEP 5-10 cmH2O (or NIV) to counter atelectasis; end point end-tidal O2 of at least 90%, typically 3-5 min of tidal breathing. High-flow nasal oxygen is an alternative.
Safe apnea time. Short, often 2-3 min to SpO2 90% even after good preoxygenation, because of reduced FRC and higher O2 consumption. A learner who expects the 6-8 min of a lean patient will plan too few contingencies.
Extending apnea time. Nasal cannula at 10-15 L/min left on during laryngoscopy, or high-flow nasal oxygen.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Induction choice and weight-based dosing in obesity; post-induction hypotension on an ACE inhibitor; hemodynamic effects of pneumoperitoneum and a BP target under reverse Trendelenburg; ventilation and CO2 under pneumoperitoneum; opioid-sparing analgesia and PONV prophylaxis in a high-risk patient; extubation and disposition with presumed OSA.

1. Induction

Ramped, preoxygenated, EtO2 91%. RSI or standard IV induction? Why? Cricoid pressure? Why/why not? Induction agent? Dose in mg? Weight you dose it on? Relaxant? Succinylcholine or rocuronium? Dose in mg? Mask ventilate before laryngoscopy? Why/why not? VL, grade 1 view, tube in, EtCO2 confirmed. Two minutes later BP 74/40, HR 88. DDx? Rx? Phenylephrine? Ephedrine? Volume? Which? Dose? Assume phenylephrine: three boluses, BP 78/42. Next? Dose?

Considerations and pitfalls AI draft

RSI. Reasonable given active regurgitation when supine, despite a reassuring gastric ultrasound. A modified RSI with gentle low-pressure mask ventilation during onset is also defensible in obesity because her safe apnea time is short. Standard induction is a weaker answer, but defensible only with a clear reason.
Cricoid. Optional and debated; if used, release it if it worsens the view or ventilation. A learner who applies it as mandatory with no plan to release it, or one who has no aspiration strategy at all, both miss.
Induction agent. Propofol dosed on lean body weight (about 59 kg for her), roughly 1.5-2 mg/kg LBW, so about 90-120 mg, reduced or slowed given ACE inhibitor; etomidate is a reasonable alternative. Dosing propofol on total weight (250+ mg) is the classic error and invites profound hypotension.
Relaxant. Succinylcholine 1 mg/kg total body weight (about 120-130 mg), or rocuronium 1.2 mg/kg ideal or lean weight (about 70 mg); IBW for her is about 57 kg. Sugammadex on hand supports a rocuronium RSI.
Mask ventilation. Gentle (peak under about 15-20 cmH2O) ventilation during onset trades a small insufflation risk for oxygen reserve; strict no-ventilation is classical RSI. Either is fine if the learner can defend it.
Hypotension DDx. Induction agent on top of an ACE inhibitor taken this morning, vasodilation with loss of sympathetic tone, positive-pressure ventilation reducing venous return, relative hypovolemia from fasting; anaphylaxis and tube problems are less likely but checked (airway pressures, rash, EtCO2).
Rx. Phenylephrine 50-100 mcg or ephedrine 5-10 mg boluses, lighten the volatile, modest crystalloid. Any of these first is reasonable.
Refractory. ACE-inhibitor vasoplegia responds poorly to alpha agonists; vasopressin 1-2 units IV boluses is a reasonable next step, or a norepinephrine infusion. Escalating phenylephrine indefinitely or giving liters of fluid is the weaker path.

2. Insufflation and positioning

Arm cuff readings are erratic. Mgmt? Arterial line? Why/why not? Veress needle in, CO2 insufflation begins. HR falls from 84 to 34, BP 70/38. DDx? First action? Drug? Dose? Insufflation stopped, HR back to 80. Restart? How? Target intra-abdominal pressure? Why? IAP 15, reverse Trendelenburg 30 degrees, tilted left. BP 112/68, HR 82. Target MAP for the rest of the case? Why?

Considerations and pitfalls AI draft

Cuff / arterial line. A correctly sized cuff (length about 80% and width about 40% of arm circumference), or a cuff on the forearm, which reads somewhat higher; an arterial line if no reliable noninvasive reading can be obtained. An art line is not mandatory for an uncomplicated lap chole, but unreliable BP in a patient on an ACE inhibitor who already had refractory post-induction hypotension is a fair reason.
Bradycardia. Vagal reflex from rapid peritoneal stretch with insufflation; less often CO2 embolism or capnothorax. Veress-related vascular or bowel injury belongs in the DDx if the picture does not reverse when insufflation stops.
First action. Tell the surgeon to stop insufflating and release the pneumoperitoneum; then atropine 0.5-1 mg IV or glycopyrrolate 0.2-0.4 mg. If asystole, stop insufflation, desufflate, CPR and epinephrine.
Restart. Slow insufflation at low flow, after an anticholinergic if needed.
IAP target. About 12-15 mmHg, the lowest pressure that gives the surgeon adequate exposure; higher pressures worsen venous return, ventilation, and renal and splanchnic perfusion.
Target MAP. At least 65 as a floor, and many would aim closer to her baseline (about 113) given chronic hypertension, e.g., within about 20% of it (roughly 90 or more); MAP 83 now sits about 25% below baseline, so either accepting it with a stated floor or nudging it up is defensible if reasoned. A strong learner anticipates that head-up tilt and pneumoperitoneum reduce preload, more so with an ACE inhibitor on board, and has volume or a low-dose pressor ready rather than reacting late. Accepting MAPs in the 50s is the flag.

3. Ventilation under pneumoperitoneum

Vent settings for the case — tidal volume in mL? On what weight? PEEP? Thirty minutes in, IAP 15, head up: peak 38, plateau 33, FiO2 0.5, SpO2 92%, EtCO2 48. DDx? First check? Breath sounds equal, tube depth unchanged, no wheeze. Rx? PEEP — how much? Recruitment maneuver — yes/no? How? Plateau 28, SpO2 97%. Plateau limit you accept? Why? RR 18 now, EtCO2 52. ABG: pH 7.33, PaCO2 58. Accept? Why/why not? Raise RR further? Why/why not? At what pH do you stop accepting it?

Considerations and pitfalls AI draft

Vt. 6-8 mL/kg predicted body weight: PBW for a 165 cm woman is about 57 kg, so about 340-460 mL. Setting tidal volume on total weight (700-900 mL) is the common and harmful error.
PEEP. Individualized; obesity and pneumoperitoneum both drive atelectasis, so most start above lean defaults (about 8-10 cmH2O) and titrate to compliance and oxygenation. Routinely high PEEP has not been shown to reduce postoperative pulmonary complications, so a learner who starts at 5 and titrates up is also defensible; zero PEEP is the flag.
DDx. Atelectasis and reduced compliance from pneumoperitoneum and obesity; endobronchial migration as the diaphragm shifts cephalad; secretions or a kinked tube; bronchospasm; capnothorax; light anesthesia or inadequate relaxation.
First check. Bilateral breath sounds, tube depth, suction, airway pressure trend, ask surgeon about IAP and depth of relaxation.
Recruitment. Sustained inflation (e.g., 30-40 cmH2O for 30 s) or stepwise PEEP increase with fixed driving pressure, watching BP; then PEEP higher than before (often 10-12 or more in obesity) to keep the lung open. Recruitment without raising PEEP afterward lasts minutes.
Plateau. Aim under about 30 cmH2O and driving pressure under about 15 where possible; in obesity with pneumoperitoneum part of the plateau is chest wall, so a plateau slightly above 30 is less alarming than in a lean patient but still a reason to reassess.
Hypercarbia. CO2 absorption from the peritoneum plus limited minute ventilation; pH 7.33 with PaCO2 58 is mild acute respiratory acidosis and is acceptable for a healthy heart and brain. Raise RR moderately (watch for auto-PEEP with short expiratory time), ask for lower IAP; tolerate permissive hypercapnia. Increasing Vt to well above 8 mL/kg PBW to chase the number is the flag; a sudden rise in EtCO2 with subcutaneous crepitus suggests extraperitoneal CO2.
Limit. PH roughly 7.20-7.25, rising arrhythmias, or hemodynamic compromise would prompt desufflation and a pause or lower pressure.

4. Analgesic and antiemetic plan

Analgesic plan for the case. Opioid — which? How much? Non-opioid agents — which? Acetaminophen dose? Ketorolac — yes/no? Why? Ketamine? Dexmedetomidine? Lidocaine infusion? Gabapentin? Which? Why? Port-site local, TAP block, or neither? Why? PONV prophylaxis — how many agents? Which? Dexamethasone in her — yes/no? Dose? Why? TIVA or volatile? Why? Gallbladder out, 15 min to close: HR 104, BP 164/96. DDx? Hydromorphone now? Dose? Why/why not?

Considerations and pitfalls AI draft

Opioid. Minimize, not eliminate: small fentanyl doses at induction and as needed, dosed on lean weight; avoid long-acting opioid in large doses given presumed OSA and her PONV history.
Non-opioid / acetaminophen. Acetaminophen 1 g IV or oral (daily maximum 4 g) and an NSAID form the base; the adjuncts below are add-ons.
Ketorolac. 15-30 mg IV near the end of the case is reasonable with normal renal function and no bleeding concern; caution because ACE inhibitor plus diuretic plus NSAID stresses the kidney. A learner who withholds it for a stated renal reason, or gives it, can both be right.
Adjuncts. Ketamine 0.25-0.5 mg/kg bolus on lean weight (about 15-30 mg), dexmedetomidine 0.25-0.5 mcg/kg or an infusion, IV lidocaine 1-1.5 mg/kg IBW then 1-2 mg/kg/h: each reduces opioid; one or two is plenty. Gabapentinoids add sedation and respiratory depression in OSA and are better avoided.
Regional. Surgeon port-site local infiltration is simple and effective; TAP or subcostal TAP and erector spinae blocks are options but add modestly for lap chole. Either answer is acceptable if defended.
PONV. Four risk factors (female, nonsmoker, prior PONV, postoperative opioids) plus laparoscopy: very high risk, so three or more agents. Ondansetron 4 mg at the end, dexamethasone 4-8 mg after induction, and propofol TIVA or a scopolamine patch (placed before surgery); aprepitant or amisulpride are additional options.
Dexamethasone in diabetes. Yes is reasonable: 4-8 mg raises glucose modestly over the next 12-24 h; check glucose in PACU and treat. Withholding it entirely because of diabetes in a patient this high-risk for PONV is the weaker call.
TIVA. Propofol TIVA reduces PONV and is a good choice here; volatile is acceptable with a full multimodal antiemetic plan.
DDx / hydromorphone. Pain is likely, but check depth of anesthesia, CO2, and bladder first. A small dose of hydromorphone (0.2-0.4 mg) is reasonable once other causes are excluded; more ketamine, dexmedetomidine, or ketorolac is an alternative. Large opioid boluses at closure in presumed OSA is the flag.

5. Emergence and disposition

Assume rocuronium for the case; TOF count 2 at closure. Reversal agent? Dose in mg? Weight you dose it on? Extubate deep or awake? Why? Position? What do you want to see before the tube comes out? Extubated, semi-upright, SpO2 95% on 4 L. PACU, 90 min: pain 3/10, SpO2 93% awake on room air, two episodes of obstruction with SpO2 85% while dozing, ended by stimulation. Home tonight? Why/why not? Where does she go? Monitoring? CPAP tonight — yes/no? Why? She asks whether she will need a breathing machine at home. What will you tell her?

Considerations and pitfalls AI draft

Reversal. Sugammadex 2 mg/kg at TOF count 2 (moderate block), dosed on actual body weight per labeling, about 256 mg; some dose on an adjusted weight (IBW plus 40% of the excess, about 85 kg, so about 170 mg), but plain IBW underdoses and risks incomplete reversal or recurarization. Current ASA guidance recommends sugammadex over neostigmine at moderate depth and suggests neostigmine only as an alternative at minimal depth (TOF ratio 0.4 to under 0.9); given at TOF count 2 its effect is slower and variable, so a learner who chooses it must wait for and confirm recovery. Quantitative TOF ratio at or above 0.9 before extubation either way.
Deep vs awake. Awake: she has a difficult-mask-airway profile, presumed OSA, and an aspiration risk. Deep extubation is the flag here.
Position. Semi-upright or reverse Trendelenburg, not supine; improves FRC and airway patency.
Criteria. Fully reversed with TOF ratio at least 0.9, following commands, regular spontaneous ventilation with adequate tidal volume, oxygenation acceptable on modest FiO2, airway reflexes intact, hemodynamically stable; suction the stomach via OG before extubation.
Home tonight. Not tonight: presumed OSA with recurrent obstructive desaturation in an unstimulated PACU environment is the classic reason not to discharge to an unmonitored setting. Same-day discharge in presumed OSA is reasonable only when she maintains baseline SpO2 asleep on room air and pain is controlled with mainly non-opioid analgesia.
Where / monitoring. Overnight admission with continuous pulse oximetry (and capnography if available) on a monitored bed, head of bed elevated, non-opioid analgesia scheduled, opioid as small rescue doses, no added sedatives.
CPAP tonight. Auto-titrating CPAP is reasonable if available and she tolerates it, given clear obstructive events; it does not replace monitoring. Lack of a formal diagnosis is not a reason to withhold it.
What to tell her. Plain language: her breathing paused while she slept in recovery, which fits sleep apnea; she is staying tonight to be watched; she needs a sleep study, and if confirmed a CPAP machine is the usual treatment and helps blood pressure and daytime sleepiness. Mention not driving drowsy. No false reassurance and no catastrophizing.

Short stem

Myasthenia gravis for abdominal hysterectomy

A 40 y.o., 50 kg, 5'2" woman is scheduled for abdominal hysterectomy for menorrhagia. History of myasthenia gravis and hiatal hernia with esophageal reflux. Medications: pyridostigmine (Mestinon) 360 mg/day, prednisone 15 mg/day, antacids. Vital signs: HR 80; BP 120/80; RR 18; T 37°C. Hgb 9.3 g/dL.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Assessing adequacy of MG therapy and predicting postop ventilatory risk; transfusion decision-making in chronic anemia; aspiration risk from hiatal hernia with reflux; stress-dose steroids in the chronically treated patient.

1. Myasthenia gravis

Her myasthenia — is she optimized? What do you look for at the bedside? — She reports diplopia by evening, no dysphagia, climbs two flights without stopping. Proceed? Why? — Bedside FVC 2.1 L (predicted 3.0), NIF -40 cm H2O. Interpretation? Proceed? — Pyridostigmine the morning of surgery: give or hold? Why? — Will she need a ventilator after this operation? Why/why not? — Muscle relaxant for this case: avoid it, or use it? Which agent? Why?

Considerations and pitfalls AI draft

Bedside. Ptosis, diplopia, dysphagia or nasal speech, neck flexion strength, proximal limb fatigue, single-breath count, cough; recent crises or hospitalizations; adherence to pyridostigmine.
Evening diplopia only. Mild ocular fatigue with no bulbar symptoms and good exercise tolerance — adequately treated; proceed. Cancelling for evening diplopia is over-caution; ignoring dysphagia would be the opposite error.
FVC 2.1 / NIF -40. FVC 70% predicted, NIF well beyond -25: adequate respiratory reserve; proceed with a plan for post-op monitoring. FVC <50% predicted or NIF weaker than -25 would predict post-op ventilation.
Pyridostigmine. Give the usual morning dose — she is dependent on it and holding invites weakness at emergence; the older practice of holding to limit secretions and succinylcholine interaction is defensible but weaker. Continue the steroid (covered in probe 4).
Predictors. Disease duration >6 years, chronic pulmonary disease, pyridostigmine >750 mg/day, preop FVC <2.9 L, bulbar symptoms; she has none of the strong ones except a dose close to the threshold. Coexisting risk: the abdominal incision itself impairs FVC.
NMB. Use it if the surgeon needs it, but rocuronium at 10-20% of the usual dose (0.1-0.2 mg/kg) titrated to a baseline TOF, with sugammadex on hand; avoid long-acting agents. An epidural for relaxation plus a light GA is the alternative.

2. Anemia

Hgb 9.3. Cause? — Ferritin 8, MCV 71. Transfuse before surgery? Why/why not? — The surgeon wants to go next week. Delay four weeks for IV iron, or proceed? Why? — She proceeds at 9.3. Transfusion threshold in the OR for her? Why that number? — Type and screen, or crossmatch? How many units?

Considerations and pitfalls AI draft

Cause. Chronic blood loss from menorrhagia — iron deficiency; the numbers confirm it. No surprise.
Transfuse preop. No — chronic, compensated, asymptomatic; red cells fix the number, not the deficit. IV iron is the treatment.
Delay. A 4-week delay for IV iron raises Hgb by ~1-2 g/dL and reduces transfusion; against it, ongoing monthly loss and a scheduled surgeon. Either is defensible; give iron regardless and proceed if the surgeon will not wait.
Threshold. 7 g/dL in a healthy 40-year-old with no cardiac disease; higher (8) only if bleeding is ongoing and brisk. A reflex threshold of 10 is the flag.
T&S vs crossmatch. Crossmatch 2 units — she starts low, an abdominal hysterectomy for menorrhagia can bleed, and a fibroid uterus makes it more likely.

3. Hiatal hernia and aspiration

Hiatal hernia with reflux, antacids only. Nightly regurgitation and a sour taste on waking. Aspiration risk — high or ordinary? — What do you give preop? Doses? Timing? — Induction: RSI? Why? — Cricoid pressure — yes/no? — Airway exam: Mallampati II, full neck extension. Awake intubation anyway, for the reflux? Why/why not? — She asks for her pyridostigmine at 6 a.m. with water. Allowed?

Considerations and pitfalls AI draft

Risk. High — hiatal hernia with nocturnal regurgitation is symptomatic, poorly treated reflux; add bulbar disease that can impair swallowing and airway protection.
Prophylaxis. Sodium citrate 30 mL within 30 min of induction, famotidine 20 mg IV or a PPI the night before and morning of, metoclopramide 10 mg IV 30 min before (it also has no adverse interaction with myasthenia at this dose). Standard fasting.
RSI. Yes — symptomatic reflux with a hernia; modified RSI with rocuronium at a reduced dose and sugammadex ready, or a full-dose rocuronium RSI accepting a long block and planned sugammadex reversal. See probe B3.
Cricoid. Reasonable to apply and release if the view is poor; evidence is weak either way, and a defended choice is what matters.
Awake intubation. No — reflux alone does not mandate awake intubation with a reassuring airway; an RSI protects her. Awake fiberoptic is reserved for a difficult airway plus a full stomach; bulbar weakness with dysphagia would tip it, and she has none.
Morning pill. Yes — a sip of water with an essential medication up to 1-2 h before induction is standard.

4. Steroid therapy

Prednisone 15 mg/day for three years. Stress dose for this surgery? Why? — Dose? When? For how long after? — Two hours into the case: BP 70/40 after 1 L crystalloid and phenylephrine, EBL 300 mL, Hgb unchanged, field quiet. Dx? — Rx? Dose? — Glucose 240 after the hydrocortisone. Treat? Target? — The surgeon asks you to continue hydrocortisone for a week 'for healing.' Agree? Why/why not?

Considerations and pitfalls AI draft

Stress dose. Yes — three years on 15 mg/day is HPA-suppressive (>5 mg/day for >3 weeks); a major abdominal surgery is a moderate-to-major stress.
Dose. Hydrocortisone 50-100 mg IV at induction (plus her usual prednisone), then 50 mg q8h for 24 h, then taper to baseline over 1-2 days. The old 100 mg q8h for days is more than needed.
Hypotension out of proportion. Adrenal insufficiency: hypotension out of proportion to blood loss, poor response to volume and phenylephrine, with hyponatremia, hyperkalemia, or hypoglycemia; bleeding would show a falling Hgb, tachycardia, and a field that explains it. Also anaphylaxis, deep anesthetic, high epidural.
Rx. Hydrocortisone 100 mg IV empirically while excluding the others; waiting for a cortisol level is the flag.
Glucose 240. Insulin to keep under 180; hyperglycemia impairs wound healing and infection defense in a steroid patient.
Week of hydrocortisone. No — hyperglycemia, fluid retention, impaired healing, and infection are dose- and duration-dependent; a 24-48 h course then taper to her home prednisone is enough, and a week buys risk without benefit.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Monitor selection in MG; regional vs GA when bulbar weakness limits both; muscle-relaxant choice and the sux-pyridostigmine interaction; transfusion and red-urine DDx during pelvic dissection; extubation readiness in the patient who cannot afford residual block.

1. Monitor selection

Beyond standard monitors, what do you add for her? Why? — TOF baseline before any relaxant — why? — Baseline TOF ratio 0.82 before rocuronium. What do you do with that? — Capnogram: sloped upstroke on phase III. Meaning? — Next? — Arterial line? Why/why not?

Considerations and pitfalls AI draft

Add. Quantitative neuromuscular monitor (a baseline and ratio, not tactile TOF); temperature; consider an arterial line only for the bleeding risk, not the myasthenia.
Baseline TOF. Myasthenics can show fade before any relaxant; without a baseline, a TOF of 0.8 after reversal may be her normal or residual block — you cannot tell.
Baseline 0.82. Record it; titrate rocuronium to change from this baseline; recovery target is return to 0.82, not to 0.9; flag that she has measurable baseline weakness and set the post-op monitoring plan accordingly.
Sloped phase III. Expiratory obstruction — bronchospasm, secretions (cholinergic from pyridostigmine), kinked tube, or COPD. Next: suction and listen before treating; glycopyrrolate for secretions, bronchodilator only if wheeze is real.
Arterial line. Not required for the myasthenia; reasonable if brisk bleeding is expected given her starting Hgb, or if an epidural plus GA makes hypotension likely. A defended choice either way.

2. Anesthetic technique

Regional for an abdominal hysterectomy in her — acceptable? Why? — Level needed? — Spinal or epidural? Why? — Epidural in at T10-11, test dose negative. Before you dose it she says she cannot bear being awake for this and wants to be asleep. Options now? — Epidural plus GA — what does the epidural buy you in her? — She settles and now asks for the epidural with sedation only, no GA. Acceptable? Why/why not?

Considerations and pitfalls AI draft

Regional acceptable. Yes — it avoids the airway, relaxants, and opioids; the cost is that a T4 block takes intercostal and abdominal muscles she may need, and a full stomach with sedation.
Level. T4-T6 for peritoneal traction; anything lower will not cover the case.
Spinal vs epidural. Epidural — titratable level, lower peak, a catheter for post-op analgesia that spares opioids; a spinal to T4 in a patient with baseline weakness is a one-shot commitment. Ester local anesthetics (chloroprocaine) may last longer with reduced pseudocholinesterase activity from pyridostigmine; amides are unaffected.
Options. GA with the epidural used for surgical relaxation and post-op analgesia; or a titrated epidural with light sedation; or GA alone. Her fear is legitimate and a coerced awake patient with a T4 block and a full stomach is a bad combination.
Epidural plus GA. Surgical relaxation without relaxant, less volatile, opioid-sparing post-op analgesia that protects breathing and cough; the biggest lever for a myasthenic laparotomy.
Epidural with sedation only. A sedated, full-stomach, weak patient with a T4 block who cannot cough — the airway is unprotected exactly when she cannot protect it; the trap answer.

3. Induction, sux, NDMR choice

GA with the epidural it is. Induction: agent, dose? — Succinylcholine for the RSI? Dose? Why/why not? — Rocuronium instead — dose? Why that dose? — Maintenance: volatile-heavy or opioid-heavy? Why? — Epidural bolused with 10 mL 0.25% bupivacaine after induction: BP 70/40, HR 46. Rx? Doses? — Surgeon asks for more relaxation at 40 minutes, TOF count 2. Give more? How much? — Sugammadex plan — dose at the end?

Considerations and pitfalls AI draft

Induction. Propofol 1.5-2 mg/kg (she is 50 kg: 75-100 mg), fentanyl 1-2 mcg/kg; RSI for the reflux.
Succinylcholine. Usable but awkward: resistance from fewer receptors (needs ~1.5-2 mg/kg, ED95 2.6x normal) and prolonged effect because pyridostigmine inhibits plasma cholinesterase; phase II block possible. Rocuronium with sugammadex is cleaner. Either answer defended is fine; not knowing both effects is the flag.
Rocuronium. 0.3-0.6 mg/kg for the RSI if the airway looks easy (still adequate conditions in a myasthenic), with sugammadex 16 mg/kg drawn up; full 1 mg/kg accepted if the airway is the bigger risk. Sensitivity is unpredictable — titrate to TOF.
Maintenance. Volatile-heavy: sevoflurane provides relaxation itself (myasthenics are exquisitely sensitive), offsets fast, and spares opioid; opioid-heavy risks respiratory depression at emergence. A TIVA with epidural is also defensible.
Epidural hypotension. Sympathectomy on top of GA with a starting Hgb of 9.3: ephedrine 5-10 mg (rate and pressure), 250-500 mL crystalloid, lighten volatile; glycopyrrolate 0.2 mg if bradycardia persists; smaller epidural increments (3-5 mL) from here.
More relaxant. TOF count 2 is already deep for her; small increments only (5 mg), or dose the epidural and deepen the volatile instead; keep the epidural doing the work.
Sugammadex. 2 mg/kg at TOF count 2, 4 mg/kg at post-tetanic count 1-2; target TOF ratio back to her baseline 0.82 or better. Neostigmine on top of 360 mg/day pyridostigmine risks cholinergic weakness and secretions.

4. Bleeding and red urine

Pelvic dissection, EBL 1200 mL, BP 85/50, HR 120. Transfuse? — Two units in, still bleeding, BP 80/40, HR 105, blood bank says 20 minutes for more. Now? — FFP — indicated? After how many units? What tells you? — Urine in the Foley turns red. DDx? — Do you stop the transfusion? What do you send? — The surgeon injected methylene blue 5 minutes ago to check the ureters. SpO2 reads 84%. Trust it? What do you do? — Plasma from the sample is pink, DAT positive. Dx? Rx? Targets?

Considerations and pitfalls AI draft

Transfuse. Yes — hemodynamic instability with ongoing loss from a starting Hgb of 9.3; do not wait for a number.
No blood for 20 min. Emergency-release O-negative (or type-specific uncrossmatched), activate MTP, cell saver, TXA 1 g, crystalloid to bridge, vasopressor, surgical pressure or packing, second large-bore line.
FFP. Not at 2 units unless coagulopathy is documented; after 4-6 units or with ongoing massive loss, move to 1:1:1; POC coags or a TEG guide it.
Red urine. Hemolytic transfusion reaction, bladder or ureteral injury during pelvic dissection, hemoglobinuria from cell saver, myoglobin; methylene blue makes urine blue-green, not red.
Stop. Yes, stop the unit; recheck the label and the patient; send the bag, a fresh sample for DAT, plasma free hemoglobin, haptoglobin, LDH, bilirubin, coags, K+, and urinalysis; tell the surgeon to inspect the bladder.
Methylene blue. False low reading — it absorbs at 660 nm and drags the SpO2 down for 1-5 minutes; confirm with an ABG or co-oximetry before treating; keep FiO2 up meanwhile.
Hemolytic reaction. Acute hemolytic transfusion reaction: stop, support BP, maintain urine output >1-2 mL/kg/h with fluid and mannitol or furosemide, alkalinize if pigment-heavy, treat hyperkalemia, watch for DIC; blood bank recrossmatch before any further units. Steroids and stress-dose cover already given.

5. Extubation

Case done at three hours, EBL 1600, Hgb 8.4 after 3 units. Extubate in the OR? Criteria — numbers? — Sugammadex 2 mg/kg given at TOF count 2; ratio 0.85. Enough for her? — Neostigmine instead of sugammadex? Why/why not? — Awake, following commands, FVC 11 mL/kg, NIF -18. Extubate? — Pyridostigmine tonight — she is NPO. Dose? Route? — Disposition?

Considerations and pitfalls AI draft

Criteria. Awake and following commands, TOF ratio at or above her 0.82 baseline, FVC >15 mL/kg, NIF stronger than -25, sustained head lift >5 s, normothermic, no residual volatile, hemodynamically stable after the bleed.
Ratio 0.85. At or above her baseline of 0.82 — adequate as far as the relaxant goes; a second dose will not fix myasthenic weakness. Now the question is her own strength, not the block.
Neostigmine. Additive with 360 mg/day of pyridostigmine: cholinergic crisis (weakness, secretions, bradycardia) is the risk, and it cannot reverse a deep block; acceptable only if sugammadex is unavailable and the block is shallow.
FVC 11, NIF -18. Not yet — below extubation thresholds after a laparotomy and a major bleed; leave the tube in, epidural running for analgesia, sedate lightly, reassess in an hour with the epidural working and volatile gone. Extubating a myasthenic to prove a point is the flag.
Pyridostigmine. IV neostigmine 1/30 of the oral pyridostigmine dose (roughly 0.5 mg IV q4-6h for 60 mg oral), or IV pyridostigmine 1/30 of oral; restart oral when she can take it; glycopyrrolate for secretions.
Disposition. Step-down or ICU with continuous monitoring and serial FVC/NIF; the floor only when she is clearly at baseline with a monitored bed available.

Long stem

Adult polytrauma with TBI for emergent craniotomy

A 58 y.o., 82 kg, 5'8" man is brought to the operating room for emergent left frontotemporal craniotomy and evacuation of an acute subdural hematoma.

HPIUnrestrained driver ejected from a motor vehicle collision approximately 90 minutes ago. EMS found him unresponsive at the scene and intubated him in the field with succinylcholine and etomidate. Brought to MGH ED where ATLS resuscitation was initiated. Two large-bore peripheral IVs in place. One unit of PRBC began infusing in the ED. CT scans completed. Now arriving in OR.

PMHMyocardial infarction 3 years ago, treated with two drug-eluting stents to the LAD. No anginal symptoms since. Hypertension. Hyperlipidemia. No prior surgeries.

MEDSAspirin 81 mg daily, atorvastatin 40 mg daily, lisinopril 20 mg daily. Last meal 5 hours prior to MVC.

PHYS EXAMHR 115; BP 95/55; assist control ventilation, FiO2 1.0; T 36.0°C; SpO2 92%. GCS 7T (E2, M4, intubated off sedation). Pupils: left 5 mm sluggish, right 3 mm reactive. Cervical collar in place. Chest auscultation: decreased breath sounds on the right. Abdomen soft. Right thigh and pubic region tender. Foley catheter in place.

CT HEADLarge left frontotemporal acute subdural hematoma with 8 mm midline shift. Effacement of the left lateral ventricle. No contralateral hemorrhage. No skull fracture.

CT C-SPINEUnstable C5-C6 ligamentous injury without fracture.

CT CHESTRight pulmonary contusion; small right pneumothorax, no chest tube; three right-sided rib fractures (4th, 5th, 6th).

CT PELVISRight superior and inferior pubic ramus fracture without retroperitoneal hematoma.

LABSHgb 9.8 gm/dL; platelets 198 K/uL; INR 1.3; K+ 3.2 mEq/L; glucose 220 mg/dL; lactate 5.2 mmol/L; creatinine 1.1 mg/dL. ABG on FiO2 1.0: pH 7.30; PaO2 88; PaCO2 38.

OR ARRIVALPatient is intubated and sedated on propofol 30 mcg/kg/min. Two 16 g peripheral IVs functioning. Arterial line not yet placed. Type and crossmatch sent; 4 units PRBC available in the OR. Surgeon is scrubbed and ready to incise.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Induction in polytrauma TBI under C-spine and ICP constraints; CPP/ICP tradeoff during ongoing hemorrhage; hyperosmolar choice when hypotensive; recognizing tension pneumothorax during an open-cranium case.

1. Initial OR management and anesthetic plan

Surgeon is scrubbed and asks to incise now. What must happen before the knife? — Field intubation: how do you confirm the tube is where it should be? — Arterial line before incision? Why/why not? — Maintenance: TIVA or volatile? Why? Volatile — how much? — Central line: now or later? Which site, with the collar on? — The right pneumothorax is small and has no tube; he is on positive pressure. Chest tube before incision? Why/why not?

Considerations and pitfalls AI draft

Before the knife. Tube confirmed, ventilation set to PaCO2 35-40, blood in the room checked, second unit hanging, MAP target set, art line going in, pupils rechecked; a minute or two of preparation is the trade, not a delay. Incising with an unconfirmed tube and no pressure trace is the flag.
Confirm ETT. Waveform capnography, bilateral breath sounds (already decreased on the right — so chest rise and a quick look at depth), and fiberoptic through the tube if any doubt; field tubes are dislodged or endobronchial more often than one thinks.
Art line. Yes — beat-to-beat pressure is the CPP monitor; place it during positioning and prep without stopping the surgeon; femoral or radial, whichever is fastest. The answer to the surgeon is a specific time, not a standoff.
Maintenance. Either defended: TIVA (propofol plus remifentanil) preserves CO2 reactivity and lowers CMRO2 and ICP; sevoflurane at ≤0.5-1 MAC is acceptable once the dura is open. Above 1 MAC vasodilates and raises ICP.
Central line. After incision, once the pressure is controlled; right IJ under ultrasound with manual in-line stabilization and the collar front removed, or subclavian; femoral is fast but the pelvic fracture is on the right, so left femoral. Not before decompression.
Chest tube. Yes — a known pneumothorax on positive-pressure ventilation with an open cranium coming is a tension pneumothorax waiting to happen, and you will not have access to the chest under the drapes. Place it now (trauma surgeon, 5 minutes) or immediately after the flap is off; a defended 'after' is acceptable, ignoring it is not.

2. Induction and hemodynamic management

Surgeon refused to wait for a chest tube; case started. Propofol to 50 mcg/kg/min and remifentanil 0.2 started; BP 75/40. Rx? — Norepinephrine or phenylephrine? Why? — End point — MAP? Why that number? — Norepinephrine 0.08, SBP 90-100 for 15 minutes. DDx? — Hgb 8.2 after 1 L crystalloid and the ED unit. Transfuse? Threshold in TBI? — Activate MTP? What decides it? — Left pupil now 6 mm and fixed. What do you do while the surgeon is still drilling?

Considerations and pitfalls AI draft

Rx. Pressor now plus the second unit of blood; hypotension is the strongest modifiable driver of secondary injury (a single SBP <90 doubles mortality).
Which pressor. Norepinephrine — alpha plus some beta, better cardiac output than phenylephrine in a tachycardic hypovolemic patient with an LAD stent; phenylephrine is acceptable as a bridge. Large crystalloid boluses without considering the coronary disease and the bleeding is a flag.
MAP. MAP ≥80 until ICP is known (assumes ICP ~20, CPP ≥60); the learner should reason from CPP, not quote a number.
Persistent borderline. Ongoing hemorrhage — pelvis (rami fractures), chest (contusion, ribs), occult abdomen — plus under-resuscitation, anesthetic depth, tension pneumothorax developing, myocardial ischemia.
Transfuse. Yes — Hgb ≥8-9 is the working target in acute TBI to protect oxygen delivery to injured brain; a 7 threshold is for stable non-brain-injured patients.
MTP. Trigger on instability with a falling Hgb and multiple bleeding sources; 1:1:1 with TXA if within 3 h (he is at ~2 h). Waiting for a crossmatch with ongoing loss is the error.
Fixed pupil. Herniation: hyperventilate briefly to PaCO2 30-32, hypertonic saline 3% 250 mL (or 23.4% 30 mL if central), head up, tell the surgeon to hurry the burr hole; keep MAP up — brain that is herniating needs pressure more, not less.

3. Hyperosmolar therapy and ICP management

Bone flap off, dura tense, surgeon asks for something to relax the brain. BP 88/50 on norepinephrine. Mannitol or hypertonic saline? Why? — Dose? — 3% or 23.4%? Why? Through what line? — Only peripheral access. 23.4% peripherally? — Hyperventilate: PaCO2 target? For how long? Why not 25? — Surgeon wants 30 degrees head up; BP falls to 78/45. Keep the head up? — Next gas: Na 149. Keep giving hypertonic?

Considerations and pitfalls AI draft

Mannitol vs HTS. Hypertonic saline — it expands intravascular volume while pulling water from the brain; mannitol's osmotic diuresis worsens hypovolemia and hypotension in a bleeding patient. Mannitol in a hypotensive polytrauma patient is the flag.
Dose. 3% saline 250 mL (or 5 mL/kg) bolus; 23.4% 30 mL; mannitol would have been 0.5-1 g/kg.
3% vs 23.4%. 23.4% is faster and lower volume but needs central access; 3% can go peripherally and gives volume, which he needs. Here 3% peripheral is the right answer until a central line is in.
23.4% peripheral. No — extravasation causes tissue necrosis and rapid infusion causes hypotension; central line only, or 3% instead.
Hyperventilation. PaCO2 30-35 as a bridge for minutes while the surgeon decompresses; below 30 vasoconstricts to the point of ischemia in already injured brain, and the effect wanes in hours. Not a maintenance strategy.
Head up with hypotension. Venous drainage helps ICP but CPP is what matters; 15-20 degrees with a pressor increase rather than flat, and keep the neck neutral in the collar — jugular compression raises ICP more than the tilt lowers it.
Na 149. Yes, continue — the target for hyperosmolar therapy is 145-155 (some go to 160); stop only above 155-160 or with serum osm >320.

4. Intraoperative tension pneumothorax

Forty-five minutes in, dura open. Over one minute PIP goes 24 to 38, SpO2 92 to 84%, BP 80/45, ETCO2 32 to 22. DDx? — First check? — Absent right breath sounds, hyperresonant, trachea midline. Dx? Rx now? — Needle decompression with the cranium open — yes/no? — Site? — Hiss of air, BP 112/70, SpO2 91%. Surgeon says the brain went slack. Why? — Chest tube: now or after closure? — Ventilator settings until the tube is in?

Considerations and pitfalls AI draft

DDx. Tension pneumothorax (known small right PTX on positive pressure), mainstem migration, mucus plug, bronchospasm, circuit obstruction, anaphylaxis; falling ETCO2 with rising PIP and hypotension is the tension picture.
First check. Hand-ventilate to feel compliance while listening to both sides and checking tube depth; then the chest. Seconds, not a chest film.
Dx / Rx. Tension pneumothorax — decompress now; call the trauma surgeon for a tube. Do not wait for imaging.
Open cranium. Yes — tension pneumothorax kills in minutes; ICP swings from a moment of decompression are survivable. Tell the neurosurgeon what is happening and go.
Site. 4th-5th intercostal space anterior axillary line with a long 14 g catheter (chest-wall thickness beats the 2nd ICS midclavicular in adults); either is acceptable if defended.
Brain went slack. Venous return restored, intrathoracic pressure fell, jugular venous pressure fell — the tension was raising ICP through venous congestion; ETCO2 and BP recovery are the proof.
Chest tube. Now — the needle is temporizing and can re-tension; a trauma surgeon places it at the right chest under the drapes while the craniotomy continues.
Ventilator until the tube. Keep it on but lower Vt and PEEP, avoid high pressures until the tube is in; the leak will persist under positive pressure.

B. POST-OPERATIVE CARE

Teaching focus. Sedation balanced with hourly neuro checks; tiered escalation of ICP control; differentiating DI from osmotic diuresis; ARDS-PEEP-ICP tradeoff in TBI; prognostic disclosure under uncertainty.

1. ICU ventilation and sedation strategy

NeuroICU, hematoma out, ICP monitor in reading 14. Extubate tonight? Why/why not? — Sedation: propofol, dexmedetomidine, or midazolam? Why? — Hourly neuro checks on propofol — how do you get an exam? — Hour 30 on propofol 50 mcg/kg/min: lactate 4.1, triglycerides 620, CK 3800, pH 7.28. Dx? Rx? — Switch to what? — Ventilator dyssynchrony, ICP 22. Paralyze? Why/why not?

Considerations and pitfalls AI draft

Extubate. No — GCS 7T before surgery, pulmonary contusion with a fresh chest tube, ICP to control, ongoing resuscitation. A learner who wants a neuro exam off the tube has the priorities inverted.
Sedation. Propofol — fast on/off for exam windows, lowers CMRO2 and ICP; dexmedetomidine allows exam but is slow to titrate and drops pressure; midazolam accumulates and clouds every exam. Adequate analgesia (fentanyl) underneath.
Neuro checks. Scheduled hold or halving of propofol for 5-10 minutes with the ICP watched; abort the hold if ICP climbs above 20-22; document what returns first.
Hour 30 labs. Propofol infusion syndrome — early, at a dose below the classic threshold (>4 mg/kg/h for >48 h), but the lactate, lipids, CK, and acidosis are the pattern. Stop the propofol now; supportive care; watch for bradycardia and renal failure.
Switch. Midazolam plus fentanyl for the short term with scheduled holds, or dexmedetomidine if pressure allows; ketamine is acceptable as an adjunct with a controlled airway and PaCO2.
Paralysis. Cisatracurium bolus then infusion is reasonable for dyssynchrony driving ICP or hypoxia; not routine — it obscures the exam and seizures; TOF-monitored, with sedation confirmed adequate first.

2. ICP elevation at 8 hours

Eight hours post-op, ICP 28 sustained for 10 minutes. First checks at the bedside? — CT: diffuse edema, no new blood, ventricles slit-like. Next, in order? — There is an EVD. Drain? How much, how fast? — 23.4% saline 30 mL: ICP 15. Na 152. Continue the 3% infusion? Target Na? Ceiling? — Two hours later ICP is 28 again. Next? — PaCO2 to 30 — for how long? — Pentobarbital: loading dose? Endpoint? — Decompressive craniectomy — when?

Considerations and pitfalls AI draft

Bedside checks. Head position and collar (jugular compression), ETT tie, PaCO2 on the gas, temperature, seizure activity, sedation depth and pain, bladder and abdominal pressure, monitor zero; then CT for a surgical lesion.
Order. Tier 1: head up 30, neutral neck, sedation and analgesia deepened, normothermia, PaCO2 35-40, CSF drainage; tier 2: hyperosmolar bolus, brief hyperventilation to 32-35, paralysis; tier 3: barbiturate coma, decompressive craniectomy, hypothermia as rescue. Less invasive first, neurosurgery involved throughout.
EVD. Yes — open at 10-15 cm H2O or drain 5-10 mL slowly; slit ventricles mean little CSF is available, and over-drainage collapses the ventricle. Not a lever that will carry him.
Na 152. Continue — target 150-155 (up to 160) while ICP is the problem; hold above 160 or serum osm >320; check Na and osm q4-6h; avoid a fall of more than 10 mEq/L per day when weaning.
Rebound to 28. Repeat the bolus (23.4% q4-6h or 3% 250 mL), confirm paralysis and deep sedation, brief hyperventilation to 30-32 as a bridge, and call neurosurgery — this is refractory ICP heading to tier 3.
PaCO2 30. Minutes to an hour at most; a bridge to the next intervention, not a setting; below 30 is reserved for impending herniation.
Pentobarbital. 10 mg/kg load over 30 min then 5 mg/kg/h for 3 h, then 1-4 mg/kg/h to burst suppression on continuous EEG; expect hypotension needing a pressor and ileus; exam is gone for days.
Craniectomy. Refractory ICP >25 despite tier 2 in a salvageable patient; earlier rather than later — it lowers ICP and mortality but not necessarily disability; a decision made with neurosurgery and the family's understanding of the trade.

3. Sodium derangement and DI

POD 1: Na 158, urine 450 mL/h for two hours. DDx? — Urine osm 200, urine Na 30, glucose 160. Which is it? Why? — DDAVP: dose, route? — Replace the urine with D5W or 0.45% saline? Rate? — How fast may the sodium come down? Why that limit in him? — Six hours later Na 141. Problem? What do you do?

Considerations and pitfalls AI draft

DDx. Central diabetes insipidus from the injury or herniation, osmotic diuresis from hypertonic saline or mannitol, hyperglycemic diuresis, diuretic, over-resuscitation with the kidney unloading it.
Which. DI — dilute urine (osm 200) in the face of a high serum osm rules out osmotic diuresis (urine osm would be >300); glucose 160 does not explain 450 mL/h. Urine osm is the discriminator; urine Na alone is not.
DDAVP. 1-2 mcg IV (or SC), repeat q8-12h to urine output and Na; or a vasopressin infusion 0.5-2 units/h if titration is needed. Overshooting is the danger.
Replacement. D5W or enteral free water to match urine output hourly while DDAVP takes effect; 0.45% saline delivers less free water and is acceptable but slower; watch glucose with D5W. Volume matters as much as tonicity — he is losing circulating volume.
Rate. No faster than 8-10 mEq/L in 24 h (0.5 mEq/L/h); in an edematous injured brain a fast fall drives water in and raises ICP — the reverse of osmotic demyelination. Both too fast and too slow harm; the ICP monitor is the guide.
141 in six hours. 17 mEq/L in 6 hours — far too fast; DDAVP plus free water overshot. Stop the free water, check ICP now, and give hypertonic saline to bring Na back up toward 150; expect ICP to have risen.

4. Worsening oxygenation on POD 2

POD 2: PaO2 90 on FiO2 0.5, PEEP 8, bilateral patchy infiltrates. P/F? DDx? — What do you check at the bedside to sort it? — ARDS it is. Tidal volume? — PEEP to 14: ICP 18 to 26. Now what? — PaCO2 50, pH 7.30, ICP 24 on 6 mL/kg. Accept the CO2 or raise the rate? — Prone? Why/why not? — Paralyze? — ECMO — offer it? Why/why not?

Considerations and pitfalls AI draft

P/F and DDx. 180 — moderate ARDS range. DDx: contusion progression, ARDS from multiple insults (trauma, transfusion, aspiration), neurogenic pulmonary edema, TACO vs TRALI, aspiration pneumonia, ventilator-associated pneumonia.
Bedside sort. Fluid balance and CVP, echo for LV function and filling, BNP, transfusion timing, secretions and Gram stain, temperature and white count; distinguishes hydrostatic from permeability edema.
Vt. 6 mL/kg predicted body weight (~450 mL for 5'8"), plateau <30, driving pressure <15 — lung protection still applies in TBI.
PEEP vs ICP. PEEP that raises ICP more than it raises PaO2 is a bad trade: back to 10-12, head up, ensure PEEP is below ICP (transmission is worst when PEEP exceeds ICP), fix the volume status, treat ICP with sedation and osmotherapy; accept a lower PaO2 (>60-65) rather than a sustained ICP >22.
CO2. Raise the rate first (to 28-30/min watching auto-PEEP); permissive hypercapnia is a direct ICP driver and is not acceptable while ICP is 24; if the rate cannot fix it, prioritize ICP and accept a higher plateau briefly. Name the conflict.
Prone. Not with ICP 24 — proning raises ICP and abdominal pressure, and the collar plus pelvic fracture complicate it; reserved for P/F <100 with ICP controlled and the neurosurgeon in agreement, with the head elevated in reverse Trendelenburg.
Paralysis. Yes if dyssynchrony or persistent hypoxemia; it also helps ICP; short course with TOF and EEG if seizures are a concern.
ECMO. VV-ECMO is technically possible but anticoagulation into a 2-day-old craniotomy with cerebral edema is the barrier; heparin-free VV runs exist but are exceptional. It is not a realistic offer at P/F 180.

5. Family communication and prognostic disclosure

POD 3, pentobarbital coma, ICP 18. His father asks: 'Did the anesthesiologist do something wrong during surgery? He was fine before.' What will you tell him? — The brother asks whether his brother is brain dead. Can that be determined today? Why/why not? — What level or interval do you need? — Ancillary test while the drug confounds? Which? — The ICU wants to lift the barbiturate to examine him. ICP goes from 18 to 30 as it lightens. Continue lightening? What now?

Considerations and pitfalls AI draft

Father. Plain: he had a severe brain injury from the crash before he ever reached the OR; the surgery removed the clot and the swelling that followed is what the injury does; nothing was done wrong; describe what is being done now; no defensiveness, no blame, no promise either way. (The one counseling beat of the case.)
Brain death today. No — pentobarbital abolishes the exam and can flatten an EEG; a brain-death exam requires no confounding sedative, normothermia, normal electrolytes, and a stable pressure; he has a working ICP monitor and drug on board.
Level. A pentobarbital level below the therapeutic range (roughly <5 mg/L) or five half-lives after stopping (days, prolonged by hypothermia and hepatic injury); then the clinical exam and apnea test.
Ancillary. Cerebral blood flow study — nuclear perfusion scan, CT angiography, or transcranial Doppler; EEG is unreliable under barbiturate. Absent flow is diagnostic regardless of the drug.
ICP 30 on lightening. Stop lightening; restore burst suppression; he is not ready for a prognostic exam and the attempt itself is causing injury. The question is when to try again (48-72 h of controlled ICP), not whether to push through. Organ-donation conversations belong to the OPO and the primary team, and only after death or a decision to withdraw — not now.

Long stem

Cervical myelopathy for posterior fusion with neuromonitoring

A 66 y.o., 78 kg, 5'3" woman is scheduled for posterior cervical decompression and instrumented fusion, C3 to C6, prone, with somatosensory and motor evoked potential monitoring.

HPIEighteen months of progressive hand clumsiness — she has stopped buttoning her own shirts — with six months of gait imbalance and two recent falls. No bowel or bladder symptoms. Symptoms progressed despite physical therapy; surgery was scheduled after new cord signal change appeared on MRI.

PMHRheumatoid arthritis for 22 years, seropositive, followed by rheumatology. Obstructive sleep apnea on nightly CPAP. Hypertension. No diabetes. No known cardiac disease; climbed a flight of stairs without chest symptoms until gait limited her.

MEDSMethotrexate 20 mg weekly with folic acid. Prednisone 7.5 mg daily for the past 6 years. Naproxen 500 mg twice daily for joint pain, last dose yesterday evening. Amlodipine 10 mg daily. Took prednisone and amlodipine this morning.

PHYS EXAMHR 76; BP 152/88; RR 14; SpO2 96% on room air; T 36.7°C. Symmetric MCP swelling and ulnar deviation of both hands with intrinsic wasting. Grip 4+/5 bilaterally. Biceps and brachioradialis reflexes brisk; Hoffmann positive bilaterally; sustained clonus at both ankles; wide-based, unsteady gait. Sensation mildly reduced in the fingertips.

AIRWAY EXAMMouth opening 3 cm. Mallampati III. Neck extension visibly limited and uncomfortable at the extremes; flexion also limited. Thyromental distance 5.5 cm. Voice normal; no stridor; teeth intact.

IMAGINGMRI cervical spine: multilevel spondylosis with severe canal stenosis C3-C6 and T2 hyperintensity within the cord at C4-5. Neutral lateral cervical radiograph: atlantodental interval 3 mm. Flexion-extension views not obtained.

LABSHgb 10.8 g/dL; MCV 84; platelets 348 K/uL; WBC 8.2 K/uL; INR 1.0; creatinine 0.9 mg/dL; K+ 4.2 mEq/L; glucose 102 mg/dL.

OR ARRIVALIONM technologist in the room; SSEP and transcranial MEP montage planned; Mayfield head clamp on the field. Two 18 g peripheral IVs; radial arterial line planned before induction. Her CPAP machine came with her belongings. Surgeon estimates 4 to 5 hours.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. The rheumatoid airway over a stenotic myelopathic cord; relaxant and anesthetic choices with MEP baselines pending; the prone flip as a monitored neurologic event; the systematic response to intraoperative MEP loss; transfusion judgment when the cord is the end-organ.

1. Airway and induction with MEPs pending

Airway — awake fiberoptic? Videolaryngoscopy with manual in-line stabilization? Which? Why? Flexion-extension films before you commit? Why/why not? Succinylcholine for this intubation? Why/why not? Rocuronium 0.6 mg/kg instead. When can the IONM team get MEP baselines? How do you shorten that? Induction agents? Doses? BP 152/88 on arrival — what BP will you hold through laryngoscopy? Why? Maintenance — TIVA? Volatile? Which? Why? Volatile ceiling, if any? Baselines — before the flip or after? Why?

Considerations and pitfalls AI draft

Airway choice. Either is defensible; the drivers are longstanding RA (possible atlantoaxial instability, TMJ disease), 3 cm opening with limited extension and Mallampati III, and a stenotic signal-changed cord that tolerates little malposition. Awake fiberoptic keeps the neck neutral and allows a post-intubation neuro check; VL with in-line stabilization is defensible if the view is expected to be workable. Want a committed, defended choice, not both listed.
Flexion-extension films. Voluntary flexion-extension films quantify atlantoaxial instability in RA (ADI >3 mm abnormal; her neutral film is at the margin) and are reasonably safe because the awake patient self-limits. Equally defensible to skip them and simply treat the neck as unstable — the anesthetic plan barely changes. Ordering them without saying what would change is worth probing.
Succinylcholine. Chronic myelopathy with UMN findings carries a theoretical receptor-upregulation hyperkalemia risk; best documented in acute denervation and disuse, uncertain in longstanding CSM. Most avoid it here because nothing forces its use; using it is defensible if defended. Fasciculations jerking a possibly unstable neck is a cited but weak secondary argument.
Rocuronium and baselines. A single intubating dose abolishes MEPs for roughly 30-60+ minutes; options are timing baselines after spontaneous recovery, sugammadex reversal before baselines, or intubating without relaxant (propofol-remifentanil, or the topicalized awake route). The learner should connect the dose given to when the IONM team can obtain usable baselines.
Induction and BP. Titrated induction with vasopressor drawn up and the arterial line in place; hypotension threatens a chronically compressed cord, and treated hypertension shifts autoregulation rightward. Hold MAP near her baseline (roughly 85-90); blunting the laryngoscopy response without buying a trough is the balance.
Maintenance. TIVA (propofol-remifentanil) is the default for reliable MEPs; volatile at or below ~0.5 MAC without N2O is sometimes workable but degrades MEP amplitude; no redosing of NMB after intubation. Committing to a technique and tying it to signal fidelity is the expected move.
Baselines. Supine before the flip, then again immediately after — the pre-turn set is the reference that makes a post-turn change interpretable.

2. The prone flip and positioning

Mayfield pins placed. Neck position for the turn? Prone on the Jackson table. First check? IONM team wants to run signals now, before incision. Let them, or wait? Why? Two minutes after the turn, BP 82/48. DDx? Rx? MAP target for the rest of the case — number? Why? Surgeon says MAP 65 is plenty. Agree? Why/why not? Eyes — how often do you check? ETT for five hours prone — what secures it? Abdomen free on the Jackson table — what does that buy her?

Considerations and pitfalls AI draft

The turn. Neck held neutral by the anesthesiologist until the Mayfield is locked to the table; a coordinated log-roll with lines and ETT guarded. Want the neck-neutral requirement stated, not 'we're careful.'
First checks. ETT depth, patency, and EtCO2; bilateral breath sounds; all lines and monitors reconnected; eyes free of pressure; face and chin clear of the frame; arms padded (ulnar nerves); breasts and abdomen free; monitoring cables intact.
Signals after the turn. Yes, immediately — positioning itself can injure a stenotic cord; comparing post-turn signals against pre-turn baselines catches a positional insult while it is still reversible by repositioning, before any surgery has happened.
BP 82/48. Venous pooling and reduced venous return from the flip on top of a vasodilating TIVA; also abdominal compression, hypovolemia, anesthetic depth. Rx: vasopressor plus volume and verify the abdomen is truly free. The compressed cord makes this urgent, not routine.
MAP target. MAP ≥85 (some accept 80) for a compressed, signal-changed cord — perfusion pressure across a stenotic segment with impaired autoregulation; her baseline MAP is ~110, which argues further against settling low. Pushing back on 65 with a stated reason is the point of the beat.
Eyes, ETT, abdomen. Pins spare the face from headrest pressure but the eyes are still checked and documented at intervals (every 15-30 minutes); the ETT is secured against prone secretions and traction with a bite block and circuit support; a free abdomen lowers epidural venous pressure — less field bleeding — and preserves ventilation compliance.

3. MEP loss during correction

Ninety minutes in, during distraction at C4-5, IONM calls a greater than 50% MEP amplitude drop in the left leg. SSEPs unchanged. Interpretation? First move? On your side — what do you check? MAP 78. Act? Target? Temp 35.4. Explains it? Technologist confirms electrodes and a control muscle are fine. What do you ask the surgeon to do — release distraction? Back out the last screw? Methylprednisolone now? Why/why not? Wake-up test? Why/why not? MAP raised to 92, distraction released; MEPs return over ten minutes. Proceed? What changes for the rest of the case?

Considerations and pitfalls AI draft

Interpretation. A unilateral MEP drop with preserved SSEPs points at the motor tracts / anterior cord — mechanical or perfusion-related from the distraction — rather than a global anesthetic effect, which depresses signals diffusely and bilaterally.
Systematic response. Run anesthetic, physiologic, technical, and surgical causes in parallel, not sequence: confirm no propofol bolus, volatile drift, or NMB; drive MAP up; check temperature, Hgb, and CO2; have the technologist verify electrodes and a control muscle; tell the surgeon immediately.
MAP. Raise promptly to ≥85-90 with vasopressor — the fastest reversible lever on cord perfusion. Watching at 78 to 'see if it recovers' is the flag.
Temperature. Hypothermia depresses evoked potentials, but 35.4 rarely explains a focal unilateral drop; warm her anyway. Blaming temperature and stopping the workup is the pitfall.
The ask to the surgeon. Specific requests: pause, release distraction, inspect the last screw trajectory, irrigate with warm solution, consider imaging the hardware. A vague 'signals are down' with no ask wastes the reversible window.
Steroids. No solid evidence supports methylprednisolone for intraoperative signal change; NASCIS-based high-dose regimens have fallen from favor with a harm signal. Some centers still give it — defensible either way if reasoned, wrong if presented as mandatory.
Wake-up test. Largely historical: slow, impractical prone in pins with a difficult airway, and MEPs already interrogate the same pathway continuously. Recognizing that it is not realistic here is the answer.
Signals return. Proceed with less correction, hold MAP ≥85, run signals more frequently, keep the anesthetic steady; document the event, timeline, interventions, and recovery contemporaneously.

4. Blood loss and the road to emergence

Three hours in. EBL 900 mL; Hgb 8.1. Transfuse now? Why/why not? Your trigger for this case — number? Surgeon says the field is oozier than expected. DDx? What do you send? Cell salvage is running. Keep it on? When does it come off the field? TXA — give it? Dose? Risk? Fluid from here — what are you following, prone? Closure begins; surgeon wants her examinable within 15 minutes of dressing. Anesthetic from now until then?

Considerations and pitfalls AI draft

Transfuse at 8.1. With ongoing surgical loss and a cord under active ischemic threat, most would transfuse — restrictive triggers validated in stable populations do not map cleanly onto an at-risk cord plus an elevated MAP goal, and she started at 10.8, so 8.1 is not a plateau. Either commitment is acceptable if the cord appears in the reasoning; a trigger around 8-9 is typical here.
Ooze DDx. Dilution, platelet dysfunction from naproxen taken through yesterday, hypothermia, epidural venous pressure (recheck the abdomen), early consumption; send platelets, coags, fibrinogen, or viscoelastic testing rather than guessing.
Cell salvage. Appropriate in instrumented fusion; keep the salvage sucker off the field while topical hemostatics and bone dust are down, and remember washed cells return no platelets or factors.
TXA. Reduces blood loss in multilevel spine surgery; typical regimen 10-30 mg/kg load then 1-2 mg/kg/h. Seizure risk is a high-dose (cardiac-range) phenomenon; no clear VTE excess at spine doses. Naming a dose is expected.
Fluid strategy. Balanced crystalloid with blood by trigger; prone position degrades dynamic indices, so follow urine output, lactate/base deficit trend, and the arterial trace with that caveat. Over-resuscitation buys facial and airway edema for the extubation decision.
Emergence plan. TIVA titrated to a prompt wake-up; no NMB since induction but recovery is still confirmed quantitatively; the goal is hands and feet moving to command before leaving the OR, analgesia layered in without burying the exam.

B. POST-OPERATIVE CARE

Teaching focus. Extubation judgment after long prone surgery; a new deficit worked up in parallel, not sequence; the post-cervical-fusion airway threat; postoperative visual loss and honest disclosure; OSA-safe analgesia with steroid and DMARD follow-through.

1. Extubation after five hours prone

Case ends: 5.5 hours prone, EBL 1.4 L, one unit PRBC, 3 L crystalloid. Supine now; face and tongue look swollen. Extubate here? What decides it? Cuff-leak test: leak present. Enough? Why/why not? She is awake, strong, following commands. Extubate over anything? Where? What is at the bedside? Tube out; she is breathing comfortably. PACU or ICU tonight? Why?

Considerations and pitfalls AI draft

What decides it. Duration prone, fluid balance, visible face and tongue edema, cuff leak, strength and work of breathing, and her OSA — the decision is a composite; no single test decides it.
Cuff leak. A present leak is modestly reassuring, not a guarantee of a patent supraglottis; an absent leak after long prone spine surgery predicts post-extubation obstruction and argues for delay with head-up positioning, diuresis toward even balance, and dexmedetomidine or propofol sedation that permits serial exams. Treating the leak as the whole answer, in either direction, is the pitfall.
How to extubate. Over an airway exchange catheter with VL and the difficult-airway cart at hand and the surgeon aware — reintubation now means a fused, immobile neck plus fresh edema, a harder airway than this morning's; do it where rescue is immediate (OR or ICU).
Disposition. ICU or a monitored unit: edema can still evolve over the next 12-24 hours, she has OSA, and hourly neuro checks are needed after a signal-change event.

2. New hand weakness in PACU

Forty-five minutes after extubation in PACU she says her hands feel dead; grip clearly weaker than her documented preop exam, both sides; legs unchanged. DDx? Exam — what separates those? First move? MAP 74. Act? Target? How? Imaging — MRI or CT? Which first? Why? Her new hardware — a problem for MRI? Methylprednisolone while you wait? Why/why not? MRI: no hematoma, cord edema at C4-5. Surgeon says no return to the OR tonight. Orders overnight?

Considerations and pitfalls AI draft

DDx. Epidural hematoma, cord ischemia or reperfusion injury (white cord), residual or new compression from graft or screw, C5 palsy (classically proximal — deltoid/biceps — and typically delayed, so acute bilateral hand weakness fits it poorly), and positioning neuropathy (bilateral ulnar reaches the hands but follows a peripheral pattern).
Bedside separation. Motor pattern by myotome (proximal vs distal, segmental vs level), a sensory level, reflex change, ulnar-territory versus diffuse hand involvement, all against the documented preop exam — a peripheral distribution reads very differently from a new cord level.
First move. In parallel, not sequence: call the surgeon now, augment MAP, keep her NPO with access in place, expedite imaging.
MAP. Augment to 85-90 with a vasopressor as for acute cord injury — the one mechanism-plausible intervention in the anesthesiologist's hands; leaving MAP at 74 while waiting for the scanner is the flag.
Imaging. MRI answers both compressive and intrinsic cord causes; modern titanium constructs are MRI-conditional with artifact, not a contraindication; CT shows hardware position only. A rapidly worsening exam can justify return to the OR without any imaging.
Steroids. High-dose methylprednisolone for perioperative cord injury is not evidence-supported and NASCIS-based practice has receded; some surgeons still request it — the learner should know the evidence is weak whichever way they commit.
Overnight. ICU with the arterial line kept, MAP ≥85 continued, serial documented exams hourly, normothermia and normoglycemia, mechanical DVT prophylaxis only, and a low threshold to re-image or re-explore if the exam worsens.

3. Neck swelling and voice change

Two hours later, still in PACU waiting for an ICU bed: the neck looks fuller, her voice is muffled, and she is anxious, sitting bolt upright. SpO2 95% on 2 L. Dx? Nebulized epinephrine? Steroids? Heliox? What does each buy? Intubate now or watch? What tips you? You commit. Awake fiberoptic or videolaryngoscopy? Where? What is open on the table? Surgeon offers to open the wound at the bedside. Does that decompress her airway? Why/why not? Tube passes; cords edematous. Orders for tonight?

Considerations and pitfalls AI draft

Concern. An evolving airway after cervical spine surgery — muffled voice and tripod posture are late-phase signs; long prone posterior cases produce pharyngolaryngeal and lingual edema from positioning and venous congestion, and deterioration is nonlinear and fast. A reassuring SpO2 is a lagging indicator. Evaluate at the bedside now — voice, stridor, work of breathing, neck exam — without letting evaluation delay the decision.
Temporizers. Nebulized epinephrine and steroids may shave mucosal edema and heliox lowers work of breathing — bridges that buy transport minutes, none of which change the trajectory; using them as a reason to defer intubation is the pitfall.
Timing. Intubate early and electively, before stridor and desaturation — once she obstructs, the same airway is attempted under the worst possible conditions.
Technique. An awake, topicalized approach preserves spontaneous ventilation in a patient with a fused immobile neck and distorted anatomy; awake VL is also workable. Do it in the OR with the surgeon scrubbed, a surgical airway set open, and a smaller tube ready.
Opening the wound. After an anterior approach, bedside wound opening directly decompresses the airway; after a posterior approach the airway threat is positional pharyngolaryngeal edema and venous congestion, so opening the posterior wound rarely rescues the airway — though evacuation may still be indicated for a hematoma itself. Reasoning the anatomy, not reciting the anterior reflex, is the point.
Tonight. Keep her intubated and head-up, treat edema, plan imaging and possible evacuation with the surgical team, and set explicit criteria for any later extubation attempt (returned leak, visibly resolving edema, awake and strong, rescue plan named).

4. Vision loss on POD 1

POD 1, 6 AM, extubated overnight after the edema settled: she reports a dark patch in the vision of her right eye since waking, painless. DDx? Exam — what separates those? Right RAPD, normal fundus, no periocular swelling. Dx? What in her course raised the risk? Ophthalmology — how urgent? Anything they can offer that changes the outcome? She asks whether it will come back. What will you tell her? What changes for her next long case?

Considerations and pitfalls AI draft

DDx. Posterior ischemic optic neuropathy (the classic lesion after prone spine surgery), anterior ION, central retinal artery occlusion from globe compression (less likely with Mayfield pins sparing the face), a cortical/occipital event, and corneal abrasion (painful and blurs rather than producing a field defect).
Exam separators. Acuity, fields, relative afferent pupillary defect (present in ION and CRAO), and fundus: pale swollen disc in AION, a normal disc early in PION, cherry-red spot with retinal whitening in CRAO, periocular trauma signs for compression; homonymous field loss with normal eyes points cortical. RAPD with a normal early fundus and no periocular signs is PION.
Risk factors here. Prone over 5 hours, EBL 1.4 L, baseline anemia, hypotensive episodes, and substantial crystalloid — the POVL registry profile — while being honest that prediction is poor and most patients with the same profile see normally.
Ophthalmology. Urgent same-morning consult; for ION there is no proven treatment (correcting anemia and blood pressure is reasonable); CRAO has time-limited maneuvers of marginal benefit. The honest position is limited therapeutic options — overpromising is the flag.
Will it come back. Prompt, plain, factual: this is a recognized complication of prone spine surgery, ophthalmology is engaged, and ION recovery is variable and often incomplete — say so without foreclosing hope; no speculation about cause, no blame, no minimization.
Next long case. Prevention evidence is thin: staging very long cases, head neutral and at or above heart level, no globe pressure, treating severe anemia and hypotension — all reasonable, none proven.

5. Analgesia, steroids, and the floor

POD 1 evening, ready to leave the ICU. Analgesia orders for a multilevel fusion in an opioid-naive OSA patient — drugs and doses? Ketorolac is on the order set; the surgeon strikes it. Agree? Why/why not? Gabapentin — add it? Why/why not? PCA basal rate? Why/why not? Where does she sleep tonight — floor, telemetry, stepdown? Monitoring? CPAP orders? Prednisone 7.5 mg for six years. Hydrocortisone for this case — yes/no? Dose? Taper? Methotrexate — hold or restart? When?

Considerations and pitfalls AI draft

Multimodal plan. Scheduled acetaminophen, low-dose ketamine as infusion or adjunct, a muscle relaxant used sparingly, and opioid via demand-only PCA; regional options for posterior cervical spine are minimal, so the systemic plan carries the load.
Ketorolac. The fusion-nonunion concern rests on retrospective and animal data and appears dose- and duration-dependent; a short low-dose course is probably safe — but it is the surgeon's fusion, and many programs avoid NSAIDs for 2-6 weeks. A reasoned conversation is right; a unilateral override is not. Her home naproxen stays held meanwhile.
Gabapentinoids. Sedation and respiratory-depression synergy with opioids in an older OSA patient — if used at all, low dose and reassessed; adding one reflexively to make the plan look multimodal is the flag.
PCA basal. No basal rate — a background opioid infusion in an opioid-naive OSA patient is the textbook setup for the overnight respiratory arrest.
Monitoring and CPAP. CPAP whenever asleep with the machine already in the hospital, continuous pulse oximetry at minimum (capnography where available), and a monitored setting for the first floor night; unmonitored q4h vitals are the failure mode.
Steroids. At 7.5 mg prednisone for 6 years, HPA suppression is plausible; for major surgery, hydrocortisone 50 mg q8h on the day of surgery with a 1-2 day taper back to the home dose, or continuing the home dose with empiric treatment of refractory hypotension, are both defensible — omitting her baseline steroid entirely is the indefensible option.
Methotrexate. Continue — trial evidence and ACR/AAHKS guidance support continuing methotrexate through elective surgery without a wound-healing penalty, while stopping risks a flare; it never needed holding, so she resumes on her usual weekly schedule.

Long stem

Isolated severe TBI, epidural hematoma for emergent craniotomy

A 34 y.o., 80 kg, 5'10" man is brought to the operating room from CT for emergent right frontotemporal craniotomy and evacuation of an epidural hematoma.

HPIFell about 12 feet from a ladder two hours ago and struck the right side of his head. Brief loss of consciousness, then talking and oriented at the scene. Over the next hour in the ED he became progressively drowsy and vomited once. The ED team took him straight from CT to the OR and asked you to secure the airway there. Ate dinner about an hour before the fall.

PMHNone. No prior surgery or anesthesia. No medications. No known drug allergies.

PHYS EXAMHR 56; BP 176/98; RR 12; SpO2 95% on a nonrebreather; T 36.4°C. Does not open his eyes to pain; moans without words; localizes to sternal rub. Pupils: right 5 mm and sluggish, left 3 mm and reactive. Right periorbital ecchymosis, blood behind the right tympanic membrane, clear fluid from the right ear. Cervical collar in place. Full dentition. Trauma survey and FAST otherwise negative.

CT HEAD3 cm right temporal biconvex epidural hematoma with 7 mm midline shift. Right temporal bone fracture extending into the skull base.

CT C-SPINENo fracture or malalignment.

LABSHgb 14.2 g/dL; platelets 240 K/uL; INR 1.0; Na+ 140 mEq/L; K+ 3.9 mEq/L; glucose 132 mg/dL; creatinine 0.9 mg/dL.

OR ARRIVALTwo 18 g peripheral IVs with normal saline running. Standard monitors on. No arterial line. The neurosurgeon is scrubbing.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Securing the airway in a full-stomach patient with signs of a skull base fracture; blood pressure and CO2 targets reasoned from cerebral perfusion; first-line treatment of herniation before decompression; anesthetic, fluid, glucose, and temperature choices that protect injured brain.

1. Airway and induction

Surgeon wants to incise in 15 minutes. Airway: RSI? Awake fiberoptic? Which? Why? Laryngoscopy with the collar on — how? Lower his BP before induction? Why/why not? Induction agent? Dose? Anything with it before laryngoscopy? What? Dose? Succinylcholine or rocuronium? Why? Dose? First laryngoscopy attempt: grade 3 view, SpO2 91% and falling. Next?

Considerations and pitfalls AI draft

RSI vs awake. Most would choose RSI here: full stomach (recent meal, vomiting), an obtunded patient who cannot cooperate, and a clock running on herniation. Awake fiberoptic in a patient who cannot follow commands invites coughing, agitation, and an ICP spike. Choosing awake without engaging those points is a flag.
Collar. Until the neck is formally cleared, treat it as possibly unstable. Many centers clear an obtunded patient on a negative high-quality CT alone, but that has not happened yet. Open or remove the front of the collar, an assistant holds manual in-line stabilization, video laryngoscope and bougie ready; expect MILS to worsen the view.
BP before induction. No. 176/98 with HR 56 in a man with a dilating pupil is the brain defending its perfusion (Cushing response). Bringing it down before decompression risks ischemia; the bigger danger at induction is hypotension. Reaching for labetalol to normalize the number is the flag.
Induction agent. Hemodynamically stable induction: reduced-dose propofol (0.5-1 mg/kg) or etomidate 0.2-0.3 mg/kg, with a pressor drawn up. Ketamine is also defensible in a combined induction. The goal is no hypotension and no hypertensive surge.
Before laryngoscopy. Fentanyl 1-3 mcg/kg before induction, or esmolol 0.5 mg/kg; lidocaine 1.5 mg/kg is commonly used though evidence is weak. Aim to blunt the surge without causing hypotension.
NMB. Either, if defended. Rocuronium 1.2 mg/kg (about 100 mg) gives RSI conditions with no ICP debate and sugammadex as backup. Succinylcholine 1-1.5 mg/kg (about 120 mg) is acceptable; any ICP rise is small and transient compared with the harm of hypoxia or hypercarbia, and he has no acute contraindication.
Grade 3, desaturating. Stop and oxygenate: two-person mask ventilation with an oral airway (no nasal airway), accepting aspiration risk because hypoxia is worse for this brain. Then a better second attempt with a bougie, an SGA as rescue, front-of-neck access if he cannot be oxygenated. Repeated attempts while SpO2 falls is the error.

2. Blood pressure after induction

Tube confirmed. Gastric tube: nasal or oral? Why? Five minutes later, BP 84/46, HR 70. Of concern? Rx? Phenylephrine? Volume? Target SBP? Why that number? Arterial line — before incision or after? Why? Level the transducer where? Why? Mayfield pins go in: BP 196/104. Rx? Lower to what?

Considerations and pitfalls AI draft

Gastric tube route. Oral. Periorbital ecchymosis, hemotympanum, and clear otorrhea point to a basilar skull fracture, and the anterior skull base cannot be assumed intact; a nasogastric tube, nasal airway, or nasal intubation risks intracranial passage through a skull base defect and meningitis. A learner who does not connect the stem signs to the route has missed the main airway hook.
Of concern. Yes, urgently. A single episode of SBP below 90 is associated with worse outcome after TBI, and with ICP likely high, cerebral perfusion may already be critically low. This gets treated now, not watched.
Rx. Pressor boluses (phenylephrine 100 mcg, or norepinephrine) and lighten the anesthetic; an isotonic bolus is reasonable. In isolated head injury this is most likely induction vasodilation plus loss of sympathetic drive; if it persists, look again for a missed source of bleeding.
Target. SBP at least 110 for his age. Without an ICP number yet, reason from CPP: assume ICP 20-25, so MAP at least 85-90 to keep CPP at least 60 (MAP 85 minus ICP 25 is 60). The learner should derive the target, not just quote one.
Arterial line. Before incision: placed right after induction while the team positions and preps, without delaying the incision. Beat-to-beat pressure is the CPP monitor in this case.
Transducer level. At the external auditory meatus, to read pressure at the level of the brain. With the head of bed raised, a heart-level transducer overstates cerebral perfusion.
Pin response. A brief, intense stimulus. Deepen the anesthetic, give an opioid bolus, short-acting agent if needed (esmolol, small labetalol doses); local at the pin sites if there is time. Long-acting antihypertensives leave him hypotensive once the stimulus passes.
Lower to what. Back to his pre-stimulus range, roughly SBP below 160 with MAP 90-100, not to normal. An uncontrolled surge risks more bleeding; an overcorrection risks ischemia.

3. Before the dura is open

ETCO2 30 on your ventilator settings. PaCO2 target? Why? Head of bed — up or flat? Why? While the field is prepped, the right pupil is now 7 mm and fixed. Of concern? Rx now? Hyperventilate? To what PaCO2? For how long? Mannitol or hypertonic saline? Which? Dose? Surgeon: 'Ten minutes to the dura.' Immediate priorities for those ten minutes?

Considerations and pitfalls AI draft

PaCO2 target. Normocapnia, PaCO2 35-40, confirmed on an ABG (ETCO2 usually reads below PaCO2). Routine hyperventilation cuts blood flow to brain that is already at risk. ETCO2 30 puts PaCO2 at roughly 32-35, at or just below the low end; get an ABG and set ventilation to the PaCO2, not the ETCO2.
Head position. Head up 15-30 degrees with the neck neutral and nothing compressing the jugular veins (collar front off, tube ties not tight), provided MAP holds; re-zero the transducer at the ear. Flat is acceptable if the surgeon needs it, but venous drainage helps ICP.
Fixed pupil. Herniation. This is an emergency; minutes matter until the clot is out.
Rx now. Tell the surgeon, keep MAP up, give an osmotic agent, and briefly hyperventilate. The definitive treatment is evacuation; everything else buys time.
Hyperventilation. Yes, briefly, to PaCO2 30-35 as a bridge to decompression, then back to normal once the bone flap is off. Its effect fades over hours and it causes ischemia if prolonged or pushed lower.
Osmotic agent. Either is defensible in a normovolemic patient. Mannitol 0.5-1 g/kg (40-80 g) over 10-15 minutes, with a Foley for the diuresis and an eye on volume. Hypertonic saline 3% 250 mL through a peripheral line, or 23.4% 30 mL only through a central line. Hypertonic saline is favored if he is hypotensive.
Ten minutes. Hold MAP at target, keep volatile at or below 1 MAC, avoid anything that raises ICP (coughing, light anesthesia, hypoxia), and have blood available. A learner who keeps stacking medical therapy and loses sight of evacuation as the treatment has the priorities backwards.

4. Maintenance, fluids, and metabolic targets

Clot out, brain slack. Sevoflurane now reads 1.4 MAC. Keep it? Switch to propofol? Why? Nitrous oxide? Why/why not? Fluid — normal saline? LR? Albumin? Which? Why? Glucose 212. Rx? Target? Temp 35.4°C. Warm him? Why/why not? EBL 900 mL, Hgb 10.1. Transfuse? Why/why not?

Considerations and pitfalls AI draft

Maintenance. Not at 1.4 MAC: above about 1 MAC, volatiles vasodilate the cerebral vessels and raise ICP. Either lower it to 1 MAC or less, or switch to propofol, which lowers cerebral metabolism and blood flow and preserves autoregulation. Both are defensible once he is decompressed; an early neuro exam is part of the reasoning.
Nitrous oxide. No. It raises cerebral metabolism and blood flow and expands trapped air after a craniotomy.
Fluid. Isotonic crystalloid. Normal saline is the usual choice; LR is mildly hypotonic and large volumes can add to edema. Avoid dextrose-containing and hypotonic fluids. Albumin has been associated with higher mortality in TBI and is avoided.
Glucose. Treat. Hyperglycemia worsens secondary injury; an insulin infusion to a target around 140-180, avoiding hypoglycemia, which is also harmful to injured brain.
Temperature. Warm gently toward 36-37°C. Prophylactic hypothermia has not improved outcome after TBI and adds bleeding and infection risk; fever is harmful too, so the goal is normothermia, not overshoot.
Transfuse. No at 10.1 with bleeding controlled. The exact threshold in acute brain injury is debated; a falling trend or ongoing loss changes the answer.

B. POST-OPERATIVE CARE

Teaching focus. Extubation and transport judgment after TBI surgery; ICP and CPP treated together; seizure prophylaxis and treatment; hyponatremia in brain injury; honest early prognosis.

1. End of the case and transport

Bone flap replaced; skin closing. Extubate in the OR? Why/why not? He stays intubated. Transport sedation: propofol? Midazolam? Which? Why? BP target en route? Transport ventilator or hand-bag? Why? Ten minutes into transport, ETCO2 52, BP 180/96. DDx? Rx?

Considerations and pitfalls AI draft

Extubate in OR. Most would keep him intubated: preoperative GCS 8, a herniation event, full stomach, and likely early CT and ICP monitoring. Extubation is defensible only if he meets clear criteria. A plan to extubate deep (full stomach, grade 3 view at induction) is a flag; so is extubating mainly to get a neuro exam when he does not meet criteria.
Sedation. Propofol infusion with an opioid: short-acting, lowers ICP, and allows an early neuro exam. Midazolam accumulates and clouds the exam for hours; acceptable only if pressure will not tolerate propofol.
BP en route. Same logic as the OR: SBP at least 110, avoid surges above about 160, pressor and antihypertensive with him.
Ventilator vs bag. Transport ventilator with continuous ETCO2, holding the PaCO2 target from the OR. Hand-bagging tends to hyper- or hypoventilate, and either moves ICP.
ETCO2 52 and hypertension. Hypoventilation (wrong transport settings, leak or disconnection, poor bagging) and light sedation or pain lead the list, but check the pupils: hypertension after evacuation can be a Cushing response to a reaccumulating clot. Hypercarbia raises ICP; check the circuit, increase ventilation, deepen sedation, and if the pupils change, go straight to CT.

2. ICU, hour 4

Neuro ICU. A parenchymal ICP monitor reads 14. Four hours later: ICP 27 for ten minutes, MAP 82. CPP? Of concern? Immediate priorities? Head up, ties loose, PaCO2 38, synchronous, afebrile. ICP 26. Rx? Ten minutes later, ICP 25. Next? Repeat CT — now or after treatment? Why? CT: mild edema, no new blood. The ICU team starts a 3% saline infusion. Sodium target? How often checked? Later, ICP 19, MAP 70. Rx?

Considerations and pitfalls AI draft

CPP. 82 - 27 = 55. Below the 60-70 target, with ICP above the treatment threshold of about 22. Two problems, not one.
Immediate priorities. Fix the simple things first: head up 30 degrees, neck neutral, tube ties and collar, ventilator and PaCO2, sedation and pain, coughing or dyssynchrony, temperature, signs of seizure, and whether the monitor is reading correctly. Jumping straight to drugs without checking these is the flag.
ICP 26, Rx. Deeper sedation and analgesia, a hyperosmolar bolus, and raise MAP to a CPP of at least 60. He has a parenchymal monitor, not a drain, so CSF drainage is not available; a learner who reaches for it has not looked at what device is in.
ICP 25, next. Call neurosurgery. If it persists despite first-line measures, escalation follows: brief paralysis, barbiturates, decompressive craniectomy, decided with neurosurgery.
CT timing. Promptly, because a sustained rise after evacuation is a reaccumulating clot until proven otherwise. Start temporizing treatment while arranging it; do not wait for the scan to treat.
Sodium target. Avoid hyponatremia above all. Many units aim for about 145-155 while giving hyperosmolar therapy, though no specific target is evidence-based; stop escalating above about 155-160 (or serum osmolality 320 with mannitol). Check sodium every 4-6 hours and avoid rapid drops.
ICP 19, MAP 70. CPP 51. The ICP is acceptable; the perfusion is not. Raise MAP (norepinephrine, or volume if he is dry) to a CPP of at least 60. Treating only the ICP number misses the point.

3. Seizure prophylaxis

Neurosurgery asks about seizure prophylaxis. Start one? Why/why not? Drug? How long? Day 1: left arm and face twitching for two minutes and continuing. Rx? Dose? Then? Twitching stops. Twenty minutes later, on a sedation hold, he no longer localizes; pupils equal and reactive. DDx? Next test? Why?

Considerations and pitfalls AI draft

Prophylaxis. Yes. In severe TBI, prophylaxis reduces early (first 7 days) post-traumatic seizures; it does not prevent later epilepsy. Levetiracetam (500-1000 mg IV every 12 hours) is commonly used; phenytoin is the classic agent. Stop at 7 days if no seizures.
Rx. A benzodiazepine first: lorazepam 0.1 mg/kg IV, up to 4 mg per dose, repeated once in 5-10 minutes if needed, or midazolam. The airway is already secure. Seizures raise cerebral metabolism and ICP, so this is treated at once.
Then. Load a second-line agent: levetiracetam 60 mg/kg (max 4.5 g), fosphenytoin 20 mg PE/kg, or valproate 40 mg/kg (max 3 g). If he is already on levetiracetam prophylaxis, a different agent or a top-up load are both reasonable. Check ICP, glucose, and sodium.
Not localizing. Postictal state, ongoing nonconvulsive seizures, a new bleed or rising ICP, residual sedation. Do not assume postictal.
Next test. Continuous EEG for nonconvulsive status, plus a CT for new blood. A learner who waits for him to wake up without an EEG may miss ongoing seizures.

4. Sodium on day 3

Day 3. Hypertonic saline stopped yesterday. Na 129, from 140 twelve hours ago. Of concern? Why? DDx? Urine output 4 L over 24 hours, urine Na 110, HR 104, weight 3 kg below admission. Most likely cause? Why? Fluid restrict? Why/why not? Rx? Which fluid? Rate? Target Na? By when?

Considerations and pitfalls AI draft

Of concern. Yes. A falling sodium shifts water into the brain, worsening edema and ICP and lowering the seizure threshold. An 11 mEq drop in 12 hours is fast.
DDx. Cerebral salt wasting, SIADH, rebound after stopping hypertonic saline, hypotonic fluids or free water in feeds.
Most likely cause. Cerebral salt wasting: high urine output and urine sodium with signs of volume loss (tachycardia, weight down). SIADH also has a high urine sodium but a normal or expanded volume. Volume status is what separates them.
Fluid restriction. No. It makes salt wasting worse, and a dry patient with injured brain is at risk of ischemia. Restriction is generally avoided in acute brain injury even for SIADH, because hypovolemia risks ischemia.
Rx. Replace volume and sodium: isotonic saline to restore volume, with hypertonic saline (3%) to raise the sodium; match ongoing urine losses; check sodium every 4-6 hours. Fludrocortisone is an option if losses continue.
Target. Back to at least 140, ideally in the 140s while ICP is still a concern. Because the drop is acute (under 48 hours) in injured brain, raise it promptly: 3% boluses (100-150 mL) for an early rise of 4-6 mEq/L, then steady correction toward target; the 8-10 mEq/L per day limit is for chronic hyponatremia. Check every 2-4 hours early to avoid overshoot.

5. Waking up

Day 5. ICP normal for 48 hours; monitor removed. Sedation off: opens eyes to voice, follows commands with the right hand, left arm weak, right pupil 4 mm and reactive. SBT today? Why/why not? SBT on CPAP 5, pressure support 5: RR 18, Vt 480 mL, copious secretions, weak cough. Extubate? Why/why not? SCDs only so far. Enoxaparin — start? Why/why not? Dose? Extubated the next day, on 2 L nasal cannula, coughing well. Oral diet today? Why/why not? His wife asks: 'Is he going to be himself again?' What will you tell her?

Considerations and pitfalls AI draft

SBT today. Yes. He follows commands, ICP is settled, and every ventilator day adds pneumonia risk. GCS alone does not decide extubation in brain injury; airway protection does.
Copious secretions, weak cough. This is the usual reason neuro patients fail extubation. Either answer is defensible: wait a day with pulmonary toilet, or extubate with aggressive suctioning and a plan for early reintubation. A learner who extubates on the SBT numbers alone has missed the secretions.
VTE prophylaxis. Yes, if neurosurgery agrees and the follow-up CT shows the hemorrhage is stable. Brain injury carries a high clot risk, and pharmacologic prophylaxis is commonly started 24-72 hours after injury or craniotomy once imaging is stable. Enoxaparin 40 mg SC daily (or 30 mg every 12 hours) or heparin 5000 units SC every 8-12 hours. Leaving him on SCDs alone on day 5 without a reason is the flag.
Oral diet. No, not before a formal swallow screen. Brain injury plus several days of intubation make silent aspiration common; a bedside dysphagia screen or speech and swallow evaluation comes first. Until he passes, keep him NPO with IV fluids or enteral nutrition. If he needs a new feeding tube, the skull base fracture still argues against blind nasal placement; place it orally or under direct visualization.
What to tell her. Honest and specific to now: he is waking up and following commands, which is encouraging; the left-sided weakness is from the injured side of the brain; how much comes back takes weeks to months and nobody can promise full recovery yet. Avoid both promising he will be fine and predicting a poor outcome on day 5. Offer what happens next (rehab, the team who will follow him).

Long stem

Posterior fossa tumor in the sitting position

A 47 y.o., 96 kg, 5'9" man is scheduled for right suboccipital craniotomy and resection of a cerebellopontine-angle tumor.

HPIEighteen months of progressive right-sided hearing loss with intermittent tinnitus. Over the past two months, headaches that are worst on waking and improve as the morning goes on. For the past several weeks he has coughed occasionally when drinking liquids, which he attributes to eating too fast. No limb weakness or numbness.

PMHHypertension, well controlled on one agent. No cardiac or pulmonary history. Never smoker. No prior surgery or anesthesia.

MEDSLisinopril 20 mg daily, taken this morning. No known drug allergies.

PHYS EXAMHR 62; BP 148/86; RR 14; SpO2 97% on room air; T 36.9°C. BMI 31. Markedly decreased hearing on the right. Subtle flattening of the right nasolabial fold. He sips water during the interview and coughs once. Mild right-sided dysmetria on finger-to-nose. Gait steady. Airway: Mallampati II, full neck range of motion.

MRI3.5 cm right cerebellopontine-angle mass extending into the internal auditory canal, consistent with vestibular schwannoma. The mass compresses the middle cerebellar peduncle and abuts and deforms the lateral pons. Mild dilation of the lateral and third ventricles with rounding of the temporal horns.

ECHOTTE: normal biventricular size and function, no valvular disease. Agitated-saline study reported as "no right-to-left shunt at rest; Valsalva not performed."

LABSHgb 15.1 g/dL; platelets 236 K/uL; INR 1.0; Na+ 139 mEq/L; K+ 4.2 mEq/L; creatinine 1.0 mg/dL; glucose 98 mg/dL.

OR ARRIVALRadial arterial line placed awake. Two 18 g peripheral IVs. The neuromonitoring team is setting up facial nerve EMG and somatosensory evoked potentials. The surgeon requests the sitting position.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. The sitting-position risk calculus against an incomplete PFO screen; VAE monitoring and aspiration-catheter placement; arterial pressure referenced to the brain; the VAE crisis sequence; brainstem-manipulation bradyarrhythmias as a monitor, not a nuisance.

1. Position decision and VAE preparation

Sitting or park-bench? Which? Why? The bubble study — enough to sit him? Why/why not? Repeat it with Valsalva, or proceed? Echo cannot come back before the case. Still sitting? Why/why not? VAE monitor — precordial Doppler? TEE? Which? Why? Multiorifice central line planned. Tip where? Confirm how? PEEP through the case? Why/why not? N2O? Why/why not?

Considerations and pitfalls AI draft

Sitting vs park-bench. Sitting gives a clean midline field, better venous and CSF drainage, less bleeding; it buys the highest VAE risk (noncollapsible venous channels above heart level), paradoxical embolism, positional hypotension, pneumocephalus, and rare midcervical flexion myelopathy. Park-bench trades some exposure for lower risk. Either is defensible if committed; not weighing the incomplete shunt screen is the flag.
Bubble study adequacy. No — a negative study at rest does not exclude PFO; right-to-left flow often appears only with Valsalva and release, and roughly a quarter of adults have a probe-patent PFO. The learner should catch the missing provocation; repeating with provocation, or a TEE bubble study after induction before positioning, is the standard fix.
Proceeding with unknown PFO. A demonstrated PFO is a strong (many say absolute) argument against sitting; leaving it unknown pushes toward completing the screen (intraoperative TEE), choosing park-bench, or accepting sitting only with TEE surveillance and meticulous prevention. A committed, defended position is the point — drifting into sitting by default is the failure.
Doppler vs TEE. TEE is the most sensitive detector (~0.02 mL/kg) and the only monitor that shows right-to-left passage of air, and it can settle the PFO question in the room; precordial Doppler (right parasternal, 3rd-6th interspaces) is the most sensitive noninvasive monitor and easier to run for hours. EtCO2 fall is less sensitive and hypotension is late. Choosing Doppler alone with the shunt question unresolved is worth challenging.
Multiorifice catheter tip. At or just below the SVC-right atrial junction for best aspiration yield; confirm with intravascular ECG (tall biphasic P wave), TEE, or radiograph. Placing the line and never confirming the tip is the classic miss.
PEEP. Avoid — PEEP does not reliably prevent entrainment, cuts venous return in a position already fighting preload, and its release can transiently reverse the interatrial gradient and favor paradoxical embolism. Jugular compression at closure is the better maneuver for finding open channels.
N2O. Avoid — it expands intravascular air and any trapped intracranial air.

2. Induction, pins, and positioning

Induction — agents? Doses? Pins next. What do you give before they go on? Dose? BP 196/108 with pin application anyway. Rx? Which agent? Why that one? Raised to sitting in stages. Transducer — zero at the arm or the external auditory meatus? Why? How many mmHg difference for him? BP at the meatus 82/46. Rx? Target MAP — number, referenced where? Surgeon asks for more neck flexion. How much do you allow? What tells you it is too much?

Considerations and pitfalls AI draft

Induction. Smooth, pressure-stable IV induction — propofol 1.5-2 mg/kg with opioid, rocuronium for intubation; the single intubating dose will have worn off before facial EMG matters. A morning ACE inhibitor on board predicts exaggerated hypotension later — worth hearing the learner say it.
Pins. Pin application is intensely nociceptive — a hypertensive surge in a man with early obstructive hydrocephalus risks intracranial hypertension. Blunt with deepened anesthetic, opioid bolus (remifentanil 0.5-1 mcg/kg), local infiltration or scalp block at pin sites, +/- esmolol just before application.
BP 196/108. Deepen, opioid, short-acting agent (esmolol 0.5 mg/kg or nicardipine 0.5-1 mg increments); the stimulus is transient — long-acting antihypertensives now compound the positional hypotension coming in minutes.
Transducer level. Zero at the external auditory meatus (circle of Willis). Sitting puts the head 20-25 cm above the heart, so brain-level arterial pressure runs roughly 15-20 mmHg below an arm-referenced number; treating the arm number as CPP overstates cerebral perfusion — the central lesson of sitting-position hemodynamics.
Hypotension on sitting up. Staged elevation, legs flexed at heart level, volume, vasopressor infusion (norepinephrine or phenylephrine); ACE-inhibitor vasoplegia may need vasopressin. Target MAP ≥60-70 at the meatus (CPP ≥60) — the learner should give a number and its reference point, not a vague 'keep it up.'
Neck flexion. Keep at least two fingerbreadths between mentum and sternum: extreme flexion obstructs jugular venous drainage (brain swelling, macroglossia, airway edema), can stretch and compress the cervical cord — midcervical flexion myelopathy, worse if hypotensive — and advances or kinks the ETT. A change in the SSEPs after flexion is the monitor's warning.

3. Venous air embolism

Mid-resection: EtCO2 falls from 33 to 21 over one minute and the precordial Doppler tone turns coarse and continuous. Dx? First move? What do you ask the surgeon to do? Aspirate the central line — what do you expect back? BP 78/40, SpO2 89% and falling. Pressor — which? Dose? Bilateral jugular compression — do it? What does it buy? Lower the head? Why? New 2 mm ST depressions in II and V5. Mechanism? Rx? Doppler quiets; BP holds at 85/50 on norepinephrine. Continue the resection? Why/why not?

Considerations and pitfalls AI draft

Dx. An abrupt EtCO2 fall with a Doppler change in a sitting craniotomy is VAE until proven otherwise; circuit disconnect, other embolism, and low cardiac output round out the list, but the paired Doppler change is nearly diagnostic.
First moves. Tell the surgeon — flood the field with saline, wax bone edges, pack; 100% O2; aspirate the multiorifice catheter; bilateral jugular compression to expose the open channel; lower the head toward heart level; support the circulation. Stopping entrainment outranks treating the numbers.
Aspiration. May retrieve air and supports the diagnosis; yield is often modest — a learner who delays field flooding to aspirate has the order wrong.
Pressors. Norepinephrine boluses (8-16 mcg) or infusion, escalating to epinephrine (10-50 mcg) as severity dictates; a large air lock in the RV outflow behaves like arrest physiology — epinephrine and CPR-style measures if pulseless.
Jugular compression / head down. Compression raises venous pressure at the wound so the surgeon can see and seal the entrainment site; lowering the head shrinks the gravitational gradient driving air in and raises venous pressure at the field.
ST depressions. With the shunt screen incomplete, think paradoxical air — coronary air embolism, with the same worry for the cerebral circulation; 100% O2, pressure support, and this is where the unfinished bubble study collects its price. A learner who never connects the two has missed the case's spine.
Continue vs abort. Resume only if the source is controlled, hemodynamics are stable, and there is no evidence of ongoing systemic embolism; recurrent or hemodynamically significant VAE argues for repositioning (lateral, head down) or staging. The defended threshold matters more than the specific call.

4. Brainstem manipulation and maintenance

Resection resumes. During dissection of tumor off the brainstem, HR falls abruptly to 38, then asystole for eight seconds. First move — surgeon's hands off, or atropine? Why? Rhythm returns when retraction is released. Each subsequent pass reproduces the bradycardia. Glycopyrrolate? Atropine? Pacing pads? Which? Why? What do you lose by giving it? EMG team reports brisk facial nerve responses. Redose rocuronium? Why/why not? Maintenance — TIVA or low-MAC volatile? Why? PaCO2 target? Why?

Considerations and pitfalls AI draft

First move. Stimulus removal — the reflex arc stops when retraction stops. 'Hands off' beats atropine for a monitored, self-terminating event; atropine given while the stimulus continues treats your monitor, not the patient, and can mask a brainstem warning.
Recurrent bradycardia. Trigeminocardiac-type reflex — trigeminal afferents at the CPA, vagal efferents — or direct traction near the vagal nuclei; the surgeon needs to hear it each time. Options: prophylactic anticholinergic (glycopyrrolate 0.2-0.4 mg gentler, atropine 0.5 mg for abrupt severe events), asking the surgeon to alter retraction, transcutaneous pacing as backup for repeated asystole. Naming the cost — losing a functional brainstem monitor — is the mark of a strong answer.
Relaxant. Facial nerve EMG requires no neuromuscular blockade beyond the intubating dose; immobility comes from anesthetic depth (remifentanil is well suited), not paralysis. Redosing rocuronium mid-case is the error.
Maintenance. TIVA (propofol + remifentanil) is the common committed answer — stable evoked potentials, no relaxant requirement, rapid predictable emergence for the early neuro exam; low-MAC volatile with opioid is also defensible. Wanting a fast, examinable wake-up after brainstem work should appear in the reasoning.
PaCO2 target. Normocapnia to mild hypocapnia (roughly 30-35 mmHg) for brain relaxation with his early hydrocephalus; aggressive hyperventilation risks cerebral ischemia for little gain.

B. POST-OPERATIVE CARE

Teaching focus. Extubation judgment against lower cranial nerve dysfunction; tension pneumocephalus after the sitting position; posterior fossa hematoma physiology and the EVD trap; aspiration and swallow evaluation; honest disclosure and tracheostomy planning.

1. Emergence and extubation

Dural closure done; stable since the air event. Extubate deep, awake, or leave the tube in? Which? Why? What must be true before the tube comes out? Cuff leak present. Enough to extubate? Why/why not? He is awake, strong, following commands; you extubate. His voice is wet and he pools secretions. Concern? Mechanism? What do you examine? PACU or ICU? Why?

Considerations and pitfalls AI draft

Deep vs awake vs stay intubated. Deep extubation is the wrong direction after CPA surgery in a man with preop swallowing trouble — airway protection is exactly what is in question. Awake extubation after demonstrated command-following and strength, versus staying intubated for a formal assessment, are the defensible poles. The preop coughing-on-liquids is the finding the learner must surface unprompted.
Before extubation. Awake and following commands, quantitative confirmation of full reversal, intact cough and gag, normothermia, stable hemodynamics, a reassuring wake-up exam after brainstem-adjacent work.
Cuff leak. No — a leak speaks to laryngeal edema after a long case with a flexed neck, not to aspiration risk, which is the question in him; knowing what the test does and does not answer is the point.
Wet voice, pooling. New or unmasked lower cranial nerve (IX/X) dysfunction after CPA retraction — high aspiration risk. Examine palate elevation, gag, volitional cough strength, voice quality; strict NPO.
Disposition. ICU — hourly neurologic checks and a watched airway after posterior fossa surgery with bulbar signs; PACU-to-floor is indefensible here.

2. Delayed decline in PACU

In PACU, 45 minutes after extubation, he becomes progressively drowsy and stops following commands; pupils 3 mm and reactive; breathing spontaneously. DDx? First bedside checks? Next study? CT: large bilateral frontal air collections compressing the frontal lobes with peaking of the frontal tips; no hematoma. Dx? Why him? Mechanism of the damage? Rx? 100% O2 — what is it doing? When does the surgeon need to act? On 100% O2 he improves to GCS 14 over two hours. Where does he go?

Considerations and pitfalls AI draft

DDx. Residual anesthetic and opioid, tension pneumocephalus (the sitting position is the classic setup), resection-bed hematoma, acute hydrocephalus, seizure and postictal state, ischemia. Reactive pupils and spontaneous ventilation lean away from catastrophic brainstem compression but exclude nothing.
Bedside and studies. Glucose, temperature, quantitative twitch monitoring, cautious opioid-reversal trial if the exam fits; immediate noncontrast head CT.
Dx. Bilateral frontal air compressing and peaking the frontal lobes (the Mount Fuji picture) is tension pneumocephalus — air under pressure with mass effect — not the near-universal, innocent postoperative pneumocephalus.
Why him / mechanism. Sitting drains CSF and the inverted-soda-bottle effect lets air fill the space; after closure the trapped air warms and expands against a ball-valve dura, compressing the frontal lobes and raising ICP — hence the decline. N2O would have expanded it further.
Rx. 100% O2 (washing nitrogen from blood steepens the gradient for resorption of the pocket), head positioning, and urgent neurosurgical decompression — burr hole or needle — if there is tension physiology or deterioration; the surgeon sees the CT now, not at rounds.
Disposition. ICU with hourly neuro checks; improvement on oxygen does not make the fossa safe for the night.

3. Rapid decline in the ICU

Four hours later the ICU calls: BP 196/92, HR 42, GCS fallen from 14 to 8. DDx? First priority? He vomits; respirations irregular. Reintubate — agents? Doses? What BP do you protect through induction? CT: 3 cm clot in the resection bed, fourth ventricle effaced, temporal horns enlarging. Dx? EVD or OR — which first? Why? Risk of the drain alone?

Considerations and pitfalls AI draft

DDx. Resection-bed hematoma and acute obstructive hydrocephalus lead; hypertension with bradycardia and a crashing GCS is Cushing physiology — brainstem compression until proven otherwise. Edema, seizure, and stroke trail well behind.
Tempo (for the examiner). A few milliliters matter: the compartment is small and rigid and contains the brainstem and fourth ventricle, so a small clot produces brainstem compression plus CSF obstruction and progresses to apnea and arrest over minutes to a few hours.
Airway. Vomiting with irregular breathing and GCS 8 demands intubation before or en route to imaging; controlled rapid-sequence induction that holds CPP (reduced propofol or etomidate, rocuronium 1.2 mg/kg, pressor drawn up), avoiding both hypotension and a hypertensive surge; hold MAP ≥80.
CT interpretation. One clot, two problems: direct brainstem compression and obstructive hydrocephalus from the effaced fourth ventricle.
EVD vs OR. Evacuation is definitive; an EVD treats the hydrocephalus and buys minutes but drained alone against a posterior fossa mass risks upward transtentorial herniation — the drain is an adjunct on the way to the OR, not a substitute. Neurosurgical attending, OR desk, and blood bank are called simultaneously; this is measured in minutes.

4. Aspiration on the first oral trial

POD 1, after re-exploration and overnight extubation: on his first trial of oral intake he coughs hard on thin liquids and desaturates to 87%; CXR shows a new right lower lobe infiltrate. Mechanism? Rx now? Reintubate — what tips you? He stabilizes on 4 L nasal cannula. Formal swallow evaluation — FEES or videofluoroscopy? What does it add? Feeding — NG? More oral trials? Antibiotics now? Why/why not?

Considerations and pitfalls AI draft

Mechanism. Aspiration through impaired glossopharyngeal and vagal function — pharyngeal weakness and an incompletely protected larynx after CPA surgery; the right lower lobe is where it lands in an upright patient. The preop coughing on liquids plus the postop wet voice predicted this; a bedside trial before formal swallow evaluation was the system failure — credit the learner who says so unprompted.
Rx now. Stop intake, sit him up, suction, supplemental O2, chest physiotherapy; bronchoscopy only for large-volume particulate aspiration or lobar collapse.
Reintubation threshold. Escalating oxygen requirement, rising work of breathing, inability to clear secretions, falling mental status — act before frank failure in a man who cannot protect his airway.
Swallow evaluation. Instrumented assessment (FEES at the bedside, or videofluoroscopy) grades the deficit and dictates diet and route; bedside screening alone already failed him once.
Feeding and antibiotics. NPO with NG (or post-pyloric) feeding until swallowing is demonstrably safe — lower cranial nerve recovery often takes weeks. Aspiration is initially a chemical pneumonitis: supportive care first, antibiotics for evolution toward infection (persistent infiltrate, fever, worsening at 48 h), not reflexively at hour zero.

5. Disclosure and planning

POD 2: right facial weakness is now obvious, and he fails the formal swallow evaluation. Facial EMG was brisk at the end of the case — what does that tell you about his face? Tracheostomy — now, or wait a week? Why? Feeding — NG or PEG? When do you decide? Diet from here? He asks whether something went wrong in the operation. What will you tell him?

Considerations and pitfalls AI draft

Facial EMG. Brisk responses at the end of the case mean the nerve is in continuity — a genuinely hopeful data point; many partial injuries improve over months. Honest uncertainty with defined follow-up, not a promise in either direction.
Tracheostomy timing. Drivers: expected duration of bulbar dysfunction, secretion burden, the aspiration event already on the record, and comfort — early tracheostomy eases secretion clearance and rehabilitation if recovery will take weeks; a defined reassessment interval (e.g., repeat instrumented swallow at 7-10 days) beats an open-ended wait.
Feeding. NG now; PEG if the instrumented reassessment still shows aspiration at 2-3 weeks; strict NPO until then.
'Did something go wrong?'. Answer the question actually asked: describe what happened, including the air embolism and the return to the OR, and why these deficits occur with this tumor in this location; no defensiveness, no speculation about blame, one consistent message shared with the surgeon. He is awake and competent — he, not just the family, gets the explanation.

Long stem

Aneurysmal SAH for craniotomy and clipping

A 52 y.o., 68 kg, 5'4" woman is scheduled for craniotomy and clipping of a ruptured anterior communicating artery aneurysm.

HPITwo days ago she had sudden onset of the worst headache of her life with vomiting, followed over the next day by increasing lethargy. In the ED, head CT showed subarachnoid hemorrhage and an external ventricular drain was placed for early hydrocephalus. Neurosurgery recommends open clipping: the aneurysm's wide neck was judged unsuitable for coiling. Nimodipine was started on admission.

PMHHypertension, poorly controlled by her own account. Active smoker, 30 pack-years. No known cardiac disease. No prior surgeries.

MEDSAmlodipine 10 mg daily at home, taken inconsistently. Nimodipine 60 mg q4h since admission.

PHYS EXAMHR 92; BP 168/92; RR 16; SpO2 96% on room air; T 37.6°C. Opens eyes to voice, confused conversation, follows commands (GCS 13: E3 V4 M6). No focal motor deficit. Nuchal rigidity. EVD at 15 cm above the tragus, open, draining xanthochromic CSF roughly 10 mL/hr.

ECGSinus rhythm at 90. Deep, symmetric T-wave inversions across the precordial leads. QTc 505 ms.

CT HEADDiffuse subarachnoid blood filling the basal cisterns and interhemispheric fissure with thick clot. Ventricular size improved after EVD placement. No infarct, no intraparenchymal hematoma.

CTA7 mm wide-necked anterior communicating artery aneurysm. No other aneurysms.

TTE (bedside, this morning)Apical hypokinesis with preserved basal function; estimated EF 40%. No significant valvular disease.

LABSNa 134 mEq/L (139 on admission); K+ 3.7; glucose 143 mg/dL; creatinine 0.8 mg/dL; Hgb 12.8 g/dL; platelets 235 K/uL; INR 1.0. Troponin T 0.42 ng/mL (elevated).

OR ARRIVALDrowsy but arousable, unchanged exam. BP 172/94. EVD clamped for transport. Two 18 g peripheral IVs; no arterial line yet. Type and screen sent. SSEP and MEP neuromonitoring planned.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Timing surgery against a stunned myocardium; transmural-pressure reasoning at induction and pinning; EVD handling with an unsecured aneurysm; brain relaxation; the intraoperative rupture crisis and BP targets before versus after the clip.

1. Proceed vs delay, induction, and pinning

Proceed with clipping this morning, or delay? Why? The ICU team asks for a cardiac cath first. Yes/no? Why? What is producing the troponin and the echo? Induction — agents? Doses? Arterial line before or after induction? Why? BP target from induction through pinning — numbers? Why that range? Pins on: BP 195/100 despite a remifentanil bolus. Rx — esmolol? Nicardipine? More propofol? Which? Why?

Considerations and pitfalls AI draft

Proceed vs delay. Proceed — rebleed risk of an unsecured ruptured aneurysm peaks in the first days and dwarfs the cardiac risk; the ECG/troponin/echo picture is neurogenic stress cardiomyopathy, which improves only as the SAH is treated. Delaying for cardiac workup is the flag.
Cath first. No — modest troponin without a coronary-territory wall-motion pattern (apical dysfunction crossing territories) argues against plaque rupture; cath adds delay, contrast, and arterial access without changing today's plan.
Mechanism. Catecholamine surge from the hemorrhage — neurogenic stunned myocardium / takotsubo physiology; typically reversible over days to weeks.
Induction. EF 40% narrows the corridor: blunt laryngoscopy without a BP overshoot (rebleed) or a trough (CPP, stunned LV). Slow titrated propofol (1-1.5 mg/kg) or etomidate with generous opioid (remifentanil 1 mcg/kg or fentanyl 2-3 mcg/kg), rocuronium; vasopressor drawn up; ketamine-driven hypertension is the wrong direction.
Arterial line. Before induction — beat-to-beat pressure through laryngoscopy and pinning is the point; the minutes spent are cheap insurance in an unsecured aneurysm.
BP target. Keep her near her running pressure and cap the peaks — commonly SBP <160 with MAP kept above the level that supports her elevated baseline CPP; both the spike and the crash are enemies (transmural pressure = MAP − ICP; a spike raises rupture stress, a trough plus open EVD drops perfusion).
Pinning spike. Pinning is the most stimulating moment before incision; 195/100 threatens rebleed. Esmolol (0.5 mg/kg) or a repeat remifentanil bolus for a brief surge; nicardipine if sustained; deepening propofol works but drips in slowly and overshoots. Pre-treat next time with local at pin sites. Committing and defending matters more than the pick.

2. EVD management and brain relaxation

The EVD — reopen before induction, or keep it clamped? Level? After positioning, the drain puts out 40 mL over ten minutes. Concern? Why? Rx? Dura open; surgeon reports a tight brain. Options? PaCO2 target? Why not 25? Mannitol or hypertonic saline? Dose? Drain CSF — how much? End point? Maintenance with SSEPs and MEPs — TIVA or volatile? Why?

Considerations and pitfalls AI draft

Reopen and level. Reopen once she is settled, at the prescribed height (15-20 cm above the tragus); a clamped drain in a hydrocephalic patient risks ICP creep, but reopening comes with a leveling check — a drain zeroed wrong after position changes silently over- or under-drains.
40 mL in ten minutes. Overdrainage with the dura closed and the aneurysm unsecured is dangerous: a sudden ICP drop raises transmural pressure across the dome (rebleed risk) and can tear bridging veins. Clamp or raise the drain, tell the surgeon, recheck the level.
Tight brain options. Head up and neutral, confirm venous drainage (tape, ties), deepen anesthesia, modest hypocapnia, CSF drainage via the EVD — the most direct lever here — plus osmotherapy.
PaCO2. 30-35 mmHg as a temporizing measure; lower buys little more relaxation and risks ischemia in a brain already primed for vasospasm.
Osmotherapy. Mannitol 0.25-0.5 g/kg or hypertonic saline (3% 150-250 mL); either defensible — she is normovolemic, so the hemodynamic argument that dominates in unstable patients is not the issue. Keep the dose modest; the EVD is doing the heavy lifting.
CSF drainage end point. Drain in small aliquots (5-10 mL) against the surgeon's report of the field, not to a number; brisk drainage before the dura is wide open repeats the transmural-pressure error.
TIVA vs volatile. With MEPs, TIVA (propofol-remifentanil, no relaxant after intubation) preserves signal quality; low-MAC volatile with SSEPs alone is defensible. The learner should tie the choice to the monitoring, not habit.

3. Intraoperative aneurysm rupture

During dissection of the dome the field fills with blood; the surgeon calls a rupture. BP 88/54, HR 122. First moves? Surgeon asks you to "bring the pressure down" to slow the bleeding. Do it? To what? Risk? Temporary clips go on both A1 segments; bleeding slows. BP target now? Why? Burst suppression — agent? Dose? End point on the EEG? Surgeon still cannot see the neck and asks for adenosine. Dose? What must be in place first? EBL 900 mL; Hgb 9.1. Transfuse? Why? Permanent clip on; temporary clips off after 9 minutes total. Concern? What do you ask the IONM team?

Considerations and pitfalls AI draft

First moves. Call for help and blood, large-bore access wide open, keep volume up — the immediate threat is exsanguination plus cerebral hypoperfusion, not ICP. Hypotension here is hemorrhage until proven otherwise.
Deliberate hypotension. Briefly and reluctantly, only if suction cannot clear the field for temporary clipping — profound hypotension in a hypovolemic patient risks global ischemia; modern practice prefers temporary clips over pharmacologic hypotension. If used: short, titrated (MAP no lower than ~50-60), with the pump primed to restore pressure.
BP after temporary clips. Normal-to-high MAP — the distal ACA territories now depend on collaterals, so pressure supports them; the rupture-pressure logic inverts the moment the clips are on.
Burst suppression. Propofol 1-2 mg/kg then infusion titrated to burst suppression on raw/processed EEG — metabolic suppression during temporary occlusion; expect pressor need and treat it rather than lightening.
Adenosine. 0.3-0.4 mg/kg rapid push through a large proximal or central line gives ~20-40 s of asystole/profound hypotension for a bloodless field. Must be pre-drawn, defibrillator pads on, surgeon and room warned, and the team agreed before it is needed — improvising it mid-crisis is the pitfall.
Transfusion. Yes — active surgical bleeding with Hgb 9.1 and an injured brain; waiting for a lower trigger during ongoing hemorrhage undershoots. In SAH most keep Hgb ≥8-9 and transfuse ahead of losses when bleeding is active.
9 minutes of temporary occlusion. Within commonly tolerated limits, especially under burst suppression, but not free — ask what the SSEPs/MEPs did during occlusion and whether they recovered; a persistent change alters the emergence plan.

4. Post-clip targets and emergence

Clip secured; ICG shows parent vessels filling and no dome fill. BP target for the rest of the case — same cap as before the clip, or different? Why? Wake her up at the end, or sedated to the ICU? Why? What must be true before you pull the tube? Analgesia — agents? Doses? At closure she bucks on the tube, BP 182/95. Lidocaine? Esmolol? Remifentanil? Which? Why? Extubated, following commands, moving all four. ICU asks for BP parameters overnight — your numbers? Why those?

Considerations and pitfalls AI draft

Post-clip target. Liberalize — the rebleed constraint died with the clip; now perfusion dominates. Avoid hypotension absolutely; most accept SBP up to ~160-180 and treat only extremes. Reciting the pre-clip cap unchanged is the flag.
Wake vs stay intubated. Wake her: preop GCS 13, monitors recovered — the early exam is the most valuable monitor she has. Staying intubated is defensible only with a reason (unrecovered MEP change, long occlusion, swelling, instability).
Before extubation. Reversal confirmed or no relaxant on board, normothermia, normocapnia, hemodynamics controlled, following commands — and a cough/hypertension plan ready.
Analgesia. Scalp block or surgeon's local plus acetaminophen 1 g and judicious short-acting opioid (fentanyl 25-50 mcg increments); loading long-acting sedation that muddies hourly neuro checks is the wrong direction.
Bucking at closure. Treat both the cough and the pressure: remifentanil or IV lidocaine 1-1.5 mg/kg for the reflex, esmolol for the surge. Pure antihypertensive without addressing the cough misses the mechanism.
ICU orders. A band, not a number — e.g., SBP 110-180, treat outside it, hourly neuro checks, nimodipine continues, daily Na. The floor matters as much as the ceiling: she is entering the vasospasm window with a stunned heart.

B. POST-OPERATIVE CARE

Teaching focus. Delayed deterioration workup including EVD failure and nonconvulsive seizure; cerebral salt wasting vs SIADH and why the treatments diverge; DCI surveillance and induced hypertension on a secured aneurysm; the heart-brain conflict when the stunned myocardium fails; seizure management and prognostic counseling.

1. Deterioration hours after handoff

POD 0, two hours after ICU handoff: she localizes to sternal rub only — she followed commands when you left. DDx? First bedside checks? The EVD has drained nothing in two hours and the waveform is dampened. Meaning? Rx? CT: ventricles larger than this morning, no new blood, clip artifact only. Dx? Rx? Drain flushed by neurosurgery and flowing; she improves but a left arm drift persists. Next study? CTA: clip well seated, vessels patent, no spasm. Next test? EEG: rhythmic epileptiform discharges. Dx? Rx — agent? Dose? Why that one?

Considerations and pitfalls AI draft

DDx. Acute hydrocephalus from EVD failure, seizure or nonconvulsive status, clip-related ischemia (ACoA perforators), hematoma at the operative site, hyponatremia or CO2 narcosis, oversedation. Early on POD 0, drain failure and seizure sit at the top; vasospasm this early is unlikely.
Bedside checks. Pupils and lateralizing exam, glucose, ABG, review sedation given, and look at the EVD — the fastest reversible causes are checked in two minutes before anyone moves to the scanner.
Dampened EVD. An occluded or malpositioned catheter — no output plus a flat waveform in a drain-dependent patient means unmeasured rising ICP, not resolution. Escalate to neurosurgery immediately; catheter-side flushing is theirs.
CT. Acute hydrocephalus from drain failure explains the exam; restore drainage (flush, revise, or replace the EVD).
Persistent drift. Focal deficit is not explained by hydrocephalus alone — image the vessels: CTA (and CT perfusion where available) for clip-related occlusion.
After a clean CTA. Nonconvulsive seizure is the remaining common cause of unexplained depressed or fluctuating exam — get EEG; a normal CT/CTA does not exclude it.
NCSE Rx. Benzodiazepine if actively seizing, then load levetiracetam ~60 mg/kg IV (max 4.5 g) — favored over phenytoin for minimal sedation, no drug interactions, and hemodynamic neutrality in a patient whose exam is the monitor.

2. Hyponatremia with high urine output

POD 2: Na 129, down from 134. Urine output 300 mL/hr overnight. Concern? Why in her, now? Urine Na 148, urine osm 610. DDx? What at the bedside separates them? The ICU resident proposes fluid restriction. Agree? Why/why not? Rx? 3% saline — bolus or infusion? Rate? Correction limit over 24 hours? Why? Fludrocortisone — add it? Dose? Next morning Na 131, urine output still 220 mL/hr. Continue? End point?

Considerations and pitfalls AI draft

Concern. Falling Na lowers seizure threshold and worsens cerebral edema — in a POD 2 SAH patient entering the vasospasm window, hyponatremia plus volume contraction is a direct DCI risk, not a lab curiosity.
Urine studies and DDx. High urine Na and osm with hyponatremia fit both cerebral salt wasting and SIADH — the urine cannot separate them; the polyuria is the hint that this is salt wasting.
Bedside separation. Volume status: CSW is hypovolemic (negative balance, falling weight/CVP, orthostatic-range tachycardia, high UOP); SIADH is euvolemic with modest output. In SAH, CSW-pattern physiology is common and the default assumption when output is high.
Fluid restriction. Disagree — restriction treats SIADH but in a volume-deplete SAH patient it stacks hypovolemia on a spasm-prone brain; the classic wrong move here. If genuinely uncertain, treat as CSW: replace salt and volume.
3% saline. Infusion (~0.5-1 mL/kg/hr) titrated to Na, with isotonic volume replacement alongside; reserve 100-150 mL boluses for symptomatic drops. Limit correction to ≤8 mEq/L per 24 h — overcorrection risks osmotic demyelination even from 129.
Fludrocortisone. 0.1-0.2 mg/day blunts renal sodium loss and shrinks the 3% requirement; reasonable adjunct in SAH salt wasting.
End point. Na stably ≥135 with matched intake-output and the natriuresis abating — taper rather than stop, and keep daily (or BID) sodium checks through the DCI window.

3. POD 5 drowsiness and new weakness

POD 5: increasingly drowsy over the morning, new left leg weakness. DDx? What does the timing tell you? First studies? TCDs: right MCA mean velocity 212 cm/s, up from 88 on POD 2. Interpretation? Act on that alone? CTA: severe bilateral ACA narrowing; perfusion shows prolonged transit anteriorly. Rx priorities? Induced hypertension — agent? Starting SBP? How high will you go? Volume goal? Hypervolemia? Why/why not? Each nimodipine dose drops her SBP by 20. Stop it? Options? Six hours at SBP 190: the leg is no better. Next?

Considerations and pitfalls AI draft

DDx and timing. Delayed cerebral ischemia from vasospasm leads on POD 5 — the classic 4-14 day window; also recheck Na, seizure, hydrocephalus, sedation. New focal deficit plus depressed level in the window is DCI until proven otherwise.
First studies. The exam is the primary monitor; TCDs and CTA/CT perfusion confirm; Na and glucose exclude mimics. Leg-predominant weakness fits ACA territory — exactly the runoff of a clipped ACoA.
TCD interpretation. Mean velocity >200 with a large rise from baseline indicates severe spasm (a high Lindegaard ratio separates spasm from hyperemia) — but TCD is insensitive for the ACA and is not, alone, the trigger; the exam plus vessel/perfusion imaging drives action.
Rx priorities. Induced hypertension on a secured aneurysm, correct volume to euvolemia, keep nimodipine, and involve neurointervention early — in parallel, not sequence.
Induced hypertension. Norepinephrine, stepwise: raise SBP in increments (160 → 180 → 200) titrated to the exam — the deficit reversing is the end point, not a number. Clipping removes the rebleed ceiling; her stunned heart, not the aneurysm, is the practical limit.
Volume. Euvolemia — triple-H is dead; deliberate hypervolemia adds pulmonary edema and cardiac strain (especially with EF 40%) without cerebral benefit.
Nimodipine hypotension. Do not discard the only agent with outcome benefit — split to 30 mg q2h, time doses against pressor titration; hold only if refractory hypotension persists despite that.
Refractory deficit. Endovascular rescue: intra-arterial verapamil/nicardipine for distal or diffuse spasm, balloon angioplasty for proximal segments — six hours of failed medical therapy with a persistent deficit is an indication, not a defeat.

4. Cardiopulmonary decompensation on induced hypertension

That night on norepinephrine, SBP 192: acute dyspnea, SpO2 84% on high-flow O2, pink frothy secretions, HR 128. Dx? First move? Repeat TTE: EF 25%, apical ballooning worse. Interpretation? Norepinephrine — up, down, or swap? Why? NIV or intubate? What decides? She cannot hold the mask and is drowsier; you intubate and sedate her. How do you follow the DCI now? Inotrope — dobutamine or milrinone? Which? Why? BP target now — number? What tells you the brain is getting enough? She stabilizes at SBP 168 on norepinephrine plus dobutamine, exam unchanged. Push back to 190? Why/why not? Angio suite tonight? Why?

Considerations and pitfalls AI draft

Dx and first move. Cardiogenic pulmonary edema from the stunned ventricle driven into a SBP-190 afterload; also volume overload, aspiration, flash ischemia. First: oxygenation — sit her up, escalate support — hypoxemia injures the ischemic brain faster than any pressure adjustment helps it.
TTE. The admission stress cardiomyopathy, now decompensating under forced afterload — the induced-hypertension strategy itself is the precipitant; a treatment complication, not a new disease.
Norepinephrine. Reduce toward the lowest pressure that holds the exam — pure alpha escalation into a failing LV worsens the edema; swapping to a pure inotrope alone abandons the DCI target. Stepwise reduction with the exam watched beat by beat.
NIV vs intubation. Mental status decides — drowsy with DCI, NIV is fragile. Intubation costs the neurologic exam, the one monitor titrating this entire strategy — substitutes are frequent sedation holidays with wake-up assessments, TCDs, imaging, and a low threshold for angio.
Inotrope. Dobutamine — raises CO with modest pressure cost and quick titration; milrinone vasodilates more and lingers (renal clearance), making an unstable pressure target harder to hold. Adding inotropy lets a lower SBP deliver the same cerebral flow.
New target and end point. The lowest pressure at which the deficit does not worsen — the exam (or its substitutes) is the end point; a fixed 190 is no longer defensible with the heart failing.
Push back to 190. No — exam unchanged at 168 means the extra 22 mmHg bought nothing and was costing the heart; re-escalate only for a new or worsening deficit.
Angio suite. Yes — when the heart caps induced hypertension, intra-arterial therapy treats the spasm directly and lets the pressure demand come down; the cardiac ceiling is itself an indication for endovascular rescue.

5. Seizure and the family conversation

POD 6, 0400, extubated the previous afternoon after angioplasty: generalized convulsion, 90 seconds, now postictal. First actions? It recurs ten minutes later — agent? Dose? What do you check right now? Na 131, glucose 128. The cause? Repeat CT? Load an antiepileptic? Which? Dose? Why that one? By morning she is back to baseline. Her husband asks whether she will get back to who she was. What will you tell him?

Considerations and pitfalls AI draft

First actions. Airway and oxygen, lateral position, suction, protect from injury, timed observation — a self-terminating 90-second convulsion needs support and workup, not reflex intubation.
Recurrence. Lorazepam 0.1 mg/kg IV (≈7 mg for her; a single dose is usually capped at 4 mg, repeatable); have a second dose and an airway plan ready.
What to check. Glucose, Na, SpO2, a lateralizing exam, and aspiration — plus a repeat CT for a new structural cause; postictal depression mimics and masks ischemic worsening for hours, and the metabolic surge is bad for a brain with active DCI.
Na 131 / glucose 128. Not the culprit — sodium has been holding on treatment; the seizure is most plausibly cortical irritation from the hemorrhage/ischemia. Do not chase the number with aggressive correction.
AED choice. Levetiracetam load (~60 mg/kg, max 4.5 g) — non-sedating, no interactions, exam-friendly; phenytoin's sedation, hypotension with loading, and interaction profile make it second choice here.
Will she get back. Honest and specific: a seizure after SAH is common and does not itself mean new permanent injury; her real determinants are the DCI course and the recovering heart. Name what is known, what is not, and the months-long timescale — no false reassurance, no foreclosure.

Long stem

Transsphenoidal pituitary resection in acromegaly with a spinal cord stimulator

A 54 y.o., 6'1", 124 kg man is scheduled for endoscopic endonasal transsphenoidal resection of a pituitary macroadenoma.

HPIFour years of enlarging hands and feet, coarsening facial features, and daily headaches. Over the past year his voice has become deeper and hoarse, and he has started bumping into door frames on both sides. IGF-1 is 3.2 times the upper limit of normal, and growth hormone did not suppress after an oral glucose load.

PMHSevere obstructive sleep apnea (AHI 52) on CPAP 14 cm H2O nightly, adherent. Hypertension. Type 2 diabetes, HbA1c 8.3%. Chronic low back and bilateral leg pain after an L4-S1 fusion 7 years ago; a spinal cord stimulator was implanted 2 years ago and he uses it continuously with partial relief. Anesthesia record from the fusion: "two-handed mask ventilation with oral airway; grade 2 view with videolaryngoscope."

MEDSOxycodone extended-release 20 mg BID and oxycodone 5 mg up to three times daily; gabapentin 600 mg TID; lisinopril 40 mg; amlodipine 10 mg; metformin 1000 mg BID; insulin glargine 30 units nightly.

PHYS EXAMHR 72; BP 162/96; RR 16; SpO2 93% on room air; T 36.8°C. Frontal bossing, prognathism, large tongue, broad hands. Bitemporal visual field loss on confrontation. Lungs clear. A palpable implanted device under a healed incision in the left upper buttock.

AIRWAY EXAMMallampati IV. Mouth opening 4 cm. Neck circumference 51 cm. Full neck range of motion. Voice hoarse; no stridor at rest.

IMAGINGMRI: 2.4 cm sellar mass with suprasellar extension elevating the optic chiasm. Thoracic spine radiograph: two percutaneous stimulator leads in the dorsal epidural space, tips at T8, tunneled to a generator in the left upper buttock.

ECHO / ECGEcho: concentric LVH; LVEF 55%; grade II diastolic dysfunction; no significant valve disease. ECG: sinus rhythm; LVH with repolarization changes.

LABSHgb 14.8 g/dL; platelets 236 K/uL; Na+ 140 mEq/L; K+ 4.3 mEq/L; creatinine 0.9 mg/dL; glucose 214 mg/dL; 8 AM cortisol 13 mcg/dL; free T4 normal.

OR ARRIVALTook oxycodone ER 20 mg and gabapentin 600 mg at 0600; lisinopril and metformin held; glargine reduced to 20 units last night. His stimulator is on; he left the controller at home. The surgeon plans an abdominal fat graft if a CSF leak is found. Radial arterial line and two 18 g IVs planned.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Getting an implanted stimulator safely off and out of the current path; the acromegalic airway; an opioid-tolerant anesthetic that still allows a fast, quiet emergence; the vasoconstrictor hypertension trap; protecting the skull base repair at emergence.

1. Before induction

Spinal cord stimulator. Leave it on? Turn it off? Which? Why? How? Magnet over the generator? Why/why not? Device rep arrives with a programmer and turns it off; the patient confirms the tingling has stopped. Hydrocortisone before incision? Why/why not? Circulator plans to put the dispersive pad on his left lateral upper thigh. Agree? Why/why not?

Considerations and pitfalls AI draft

Leave it on or off. Most manufacturers recommend the device be off before surgery, and monopolar current through an active system risks device damage, unintended stimulation, and tissue heating at the leads. Proceeding without addressing it, or cancelling outright without trying to reach the rep, are both weak answers.
How. The patient's controller, or the manufacturer's rep or the implanting pain team with a programmer. Some systems have a dedicated surgery mode rather than simply off; the rep knows which. Confirm deactivation with the patient (paresthesias gone) or the rep before proceeding. Leaving it on is the flag.
Magnet. Some systems respond to a magnet held over the generator for 10-15 seconds, but behavior varies by manufacturer and model and is not standard the way it is for a CIED. Defensible only after confirming with the manufacturer; reflexively applying one as if it were a pacemaker magnet is a flag.
Hydrocortisone. With a normal morning cortisol and an otherwise intact axis, many centers give no perioperative glucocorticoid and check postoperative cortisol; others give stress dosing to every macroadenoma. Either is defensible if the learner names the tradeoff (avoiding steroids keeps postop cortisol interpretable and spares glucose; giving them hedges against acute deficiency). Not knowing why it matters is the flag.
Pad on the left thigh. On the same side as the generator, possibly within 10 cm of it depending on where it sits, and the current path from the nose to the thigh runs the length of the trunk past the midline thoracic leads and the extension to the buttock. A strong answer: at least 10 cm from the generator, with a path from the surgical site to the pad that does not cross the system; for a head operation, the upper body (for example the right shoulder or upper arm). Padding over the generator, which he lies on supine, is a bonus point.

2. Airway and induction

Airway plan. Awake flexible bronchoscopic intubation, asleep with a videolaryngoscope, or asleep with VL plus a flexible scope? Which? Why? Assume awake flexible intubation. Route? Why? Arterial line before or after the intubation? Why? Topical agent? Max dose for him? Sedation — agent? Dose? Dexmedetomidine running; he obstructs and SpO2 falls to 85%. Rx? Scope in the trachea; a 7.5 tube hangs up at the glottis. Next? A 6.5 reinforced tube passes. Induction agent? Dose? Throat pack? Why/why not?

Considerations and pitfalls AI draft

Plan. Awake flexible intubation is well supported here: prior two-handed mask ventilation, Mallampati IV, neck circumference 51, macroglossia, severe OSA, and a new hoarse voice that suggests glottic involvement. Asleep VL is defensible only with a reason the prior grade 2 still applies, a plan for impossible mask ventilation, and a surgical airway backup. Plain direct laryngoscopy as the primary plan is a flag.
Route. Oral. Nasal is the surgical field and passes through the sphenoid approach; a learner choosing nasal has missed the operation.
Arterial line. Either is defensible. Before favors seeing the pressure response to topicalization and a hypertensive LVH heart through an awake intubation; after is reasonable to spare him discomfort. Acromegaly may compromise ulnar collateral flow and thickens the soft tissue at the wrist: assess collateral flow, expect a harder cannulation, and have brachial or femoral alternatives in mind.
Topical. Lidocaine (4% atomized or nebulized, 2% viscous for the tongue base, transtracheal or spray-as-you-go). The commonly cited ceiling for airway topicalization is about 9 mg/kg of lean body weight (roughly 700 mg for him). A learner who cannot give a ceiling, or doses by actual weight at 124 kg, is a flag.
Sedation. Dexmedetomidine 0.5-1 mcg/kg (ideal or adjusted body weight) over 10 minutes, then 0.3-0.7 mcg/kg/h, or remifentanil titrated; small midazolam doses at most. Heavy benzodiazepine or opioid boluses in severe OSA are the trap.
Obstructs at 85%. Stop or reduce sedation, jaw thrust, verbal stimulation, oxygen by high-flow nasal cannula (the nose is not yet operated on) or nasal cannula; low-flow oxygen through the scope's working channel only with the tip free in the airway. Be ready to convert. Pushing on with more sedation to get the tube in is the flag.
Hang-up. Usually the tube tip catching on the right arytenoid or the epiglottis, made worse by a big gap between scope and tube. Withdraw slightly and rotate the tube 90 degrees counterclockwise, add jaw thrust, use a softer-tipped or reinforced tube. A smaller tube both closes the scope-tube gap and fits a narrowed acromegalic glottis. Forcing it is the flag. Expect a smaller tube than body size predicts.
Induction. Propofol titrated, dosed toward lean weight, with a vasopressor drawn up. He is already intubated and hypertensive, so etomidate offers nothing here and would confound the postoperative cortisol the team may rely on to judge his axis. Rocuronium dosed on ideal body weight once the tube is confirmed.
Throat pack. Either is defensible. Many centers place one to limit blood tracking into the stomach and airway; evidence for benefit (including PONV) is weak, and a retained pack is a never-event. If placed, it is documented, counted, and removed before extubation. The tube itself goes to the left lower lip, away from the surgeon, who usually stands on the patient's right.

3. Maintenance and the nasal phase

Maintenance — TIVA or volatile? Why? Remifentanil? Ketamine? Methadone? Which? Doses? Why? Surgeon packs both nares with oxymetazoline-soaked pledgets. BP 226/122, HR 48. DDx? Rx? Labetalol? Esmolol? Why/why not? Anesthetic deepened; BP 148/84 over 5 minutes. Glucose 238. Rx? Target? MAP goal through the resection? Why?

Considerations and pitfalls AI draft

TIVA vs volatile. Both defensible. TIVA gives a quieter field in some hands and less PONV; volatile is fine at modest MAC. The key is a plan that allows a fast, cough-free emergence in a patient with severe OSA.
Opioid strategy. He takes about 80 MME/day. Ketamine 0.25-0.5 mg/kg then 0.1-0.25 mg/kg/h is a strong answer. Remifentanil gives control during intense stimulation but high doses may worsen postoperative hyperalgesia. Intraoperative methadone (0.1-0.2 mg/kg ideal body weight) reduces postop opioid use, but its long, variable half-life in a man with severe OSA who may not be able to use CPAP after surgery is a real risk; a learner who picks it must name that. His home oxycodone ER was taken this morning and covers baseline.
BP 226/122, HR 48. Alpha-agonist absorption from the pledgets, with reflex bradycardia. DDx also includes light anesthesia and stimulation, but the bradycardia points at the vasoconstrictor.
Beta-blockade. The classic trap. Beta-blockers and calcium channel blockers given for alpha-agonist hypertension from topical phenylephrine have been linked to pulmonary edema, low output, and arrest, because they remove the heart's ability to pump against a sudden afterload. The same reasoning is applied by analogy to oxymetazoline, which causes the same hypertension with reflex bradycardia. Expected answer: usually self-limited; deepen anesthesia, then a direct vasodilator or alpha-blocker if needed; avoid beta-blockers and myocardial-depressant calcium channel blockers. With HR 48, a beta-blocker is doubly wrong. Reaching for labetalol or esmolol first is the flag.
Glucose 238. Insulin infusion or IV bolus per protocol, target roughly 140-180. Hypoglycemia is the bigger short-term danger; aggressive targets below 110 are a flag.
MAP goal. Within about 20% of his baseline (roughly 95-120 mm Hg from 162/96), avoiding both surges that bleed into the field and deliberate deep hypotension, given the chiasm compression and his right-shifted autoregulation.

4. Closure and emergence

Tumor out. No CSF seen; surgeon asks for a Valsalva to check for a leak. How? Pressure? How long? CSF wells up in the sella. Surgeon will harvest fat from the right lower abdomen with monopolar cautery. Agree? Why/why not? Repair placed. Extubate in the OR or stay intubated? Why? Deep or awake extubation? Why? He bucks briefly on the tube. Rx? Following commands, TV 550 mL, RR 14. Airway exchange catheter? Why/why not?

Considerations and pitfalls AI draft

Valsalva. A sustained inspiratory hold through the ventilator or bag, commonly 30-40 cm H2O for about 10-20 seconds, which raises intracranial venous and CSF pressure so a leak becomes visible. Watch BP and SpO2 during it.
Monopolar at the fat graft. Acceptable with the device off and lowest effective power in a lower-voltage mode (cut rather than coag) with short bursts, but the upper-body pad makes the path from the right lower abdomen run up the trunk past the leads: a second pad near the harvest site (right thigh) for that phase, or confirming the path, is the strong answer. Scalpel or bipolar is preferred where the surgeon can use it; a pulsed radiofrequency device is another option that has been used safely around neuromodulation systems.
Extubate vs stay intubated. Extubation in the OR is usual and preferred, because prolonged intubation risks coughing against the fresh repair. His difficult airway calls for a deliberate at-risk extubation plan, not for staying intubated: fully awake, head up, full reversal, equipment and personnel for reintubation present, an airway exchange catheter considered. Staying intubated needs a specific reason such as ongoing instability, airway edema with no cuff leak, or failure to meet extubation criteria.
Deep vs awake. Awake and upright: difficult airway, severe OSA, and positive-pressure mask ventilation after extubation is generally avoided with a fresh skull base repair. Deep extubation in this airway is the flag.
Bucking. Coughing raises CSF pressure and threatens the graft. Lidocaine, low-dose remifentanil, or dexmedetomidine to tolerate the tube until he is awake; adequate reversal.
Exchange catheter (and before extubation). Defensible either way: a catheter keeps a route back in after a difficult awake intubation, but he must tolerate it without coughing against the repair. The examiner also listens for: throat pack out if one was placed, oropharynx and stomach suctioned (swallowed blood drives PONV), full reversal by train-of-four, head up, reintubation equipment ready. Missing a placed throat pack is the flag.

B. POST-OPERATIVE CARE

Teaching focus. Opioid-induced ventilatory impairment in severe OSA when positive pressure is off the table; restarting the stimulator and recognizing loss of therapy; analgesia for an opioid-tolerant patient; postoperative diabetes insipidus; tension pneumocephalus; new secondary adrenal insufficiency.

1. PACU, the first hour

PACU, 25 minutes after arrival. Pain 9/10; nurse gave hydromorphone 1 mg IV. Now RR 6, snoring, SpO2 84% on 6 L face mask, rouses to voice then drifts off. Rx? His CPAP is in his bag. Use it? Why/why not? High-flow nasal cannula? Why/why not? Naloxone? Dose? Why that dose? After two doses, RR 12, SpO2 95% on 4 L. Done with naloxone? Why/why not? Disposition tonight — floor, step-down, or ICU? Which? Why? Monitoring?

Considerations and pitfalls AI draft

Rx. Stimulate, sit him up, jaw thrust, oral airway if tolerated. A nasal airway is out (fresh endonasal surgery).
CPAP. Positive airway pressure is usually avoided early after transsphenoidal surgery, especially with a CSF leak and graft, because of pneumocephalus and CSF leak risk; surgeon-specific practice varies (often held for weeks). A strong learner names the risk and asks the surgeon; reflexively applying CPAP is the flag.
High-flow nasal cannula. Delivers flow and some positive pressure through the operated nose; carries similar concerns and is usually avoided early. Same expectation: name the risk.
Naloxone. 40 mcg IV increments titrated to respiratory rate, not consciousness. A full 0.4 mg in an 80 MME/day patient risks withdrawal, severe pain, hypertension, and vomiting against a fresh repair.
Done with naloxone. No: hydromorphone outlasts naloxone, so re-sedation is expected. Watch closely and be ready for repeat doses or a naloxone infusion.
Disposition. Step-down or ICU with continuous pulse oximetry and capnography: severe OSA, CPAP unavailable, opioid tolerance with escalating requirements, and a naloxone response. Sending him to an unmonitored floor bed is the flag.

2. Pain and the stimulator

Two hours later: pain 8/10, mostly his usual low back and leg pain. Stimulator still off. Turn it on now? Why/why not? Rep restores the preoperative program; he feels the tingling only in his left flank, none in his legs. Of concern? Next? Oxycodone ER — continue? Dose? Gabapentin — continue? Dose? Ketamine infusion? Dose? PCA? Why/why not? Ketorolac? Why/why not?

Considerations and pitfalls AI draft

Turn it on. Yes once he is awake enough to report sensation: reactivation and confirming the settings match the preoperative program is part of postoperative care, and it is a non-opioid analgesic he already relies on. Leaving it off until a clinic visit is the flag.
Tingling in the flank only. Loss of usual coverage after surgery means a malfunction until proven otherwise. Band-like flank tingling is the typical pattern of a lead that has shifted laterally or of contacts that have dropped out (lead damage, fracture, high impedance); a programming error is also possible. Migration is less common late after implant but cannot be assumed away. Prompt evaluation by the pain team or rep is expected, not routine clinic follow-up.
Next. Rep interrogation with an impedance check, and a thoracic spine film compared with the preoperative radiograph for lead position; turn it off if stimulation is uncomfortable or misplaced; involve the implanting team.
Oxycodone ER. Continue his baseline dose to avoid withdrawal and uncontrolled pain; acute pain is treated on top of baseline. Stopping it because of the PACU event is the flag.
Gabapentin. Continue, possibly at a reduced dose tonight, given the sedation and OSA.
Ketamine. A low-dose infusion (0.1-0.2 mg/kg/h) is a strong opioid-sparing choice in a monitored bed.
PCA. Defensible in a monitored setting without a basal infusion; a basal rate in severe OSA without CPAP is the flag.
Ketorolac. Many skull base surgeons avoid NSAIDs early because of bleeding risk at the repair; defer to the surgeon. Scheduled acetaminophen is uncontroversial.

3. POD 1, the urine output

POD 1, 0800: urine output 380, 450, and 410 mL/h over the past 3 hours. Na+ 149; glucose 172. DDx? Workup? Urine osmolality 110 mOsm/kg. Rx? Desmopressin — route? Dose? He is alert and drinking to thirst. IV fluid? Why/why not? Which? Four hours later urine output 70 mL/h, Na+ 145. Next dose — scheduled or as needed? Why?

Considerations and pitfalls AI draft

DDx. Central diabetes insipidus from posterior pituitary or stalk injury; physiologic diuresis as GH falls after acromegaly resection (urine not maximally dilute, sodium stable); mobilization of intraoperative fluid; osmotic diuresis from hyperglycemia (glucose 172 is below the usual threshold for heavy glycosuria). A rising sodium argues against the benign causes.
Workup. Urine osmolality (or specific gravity) paired with serum sodium; glucose already in hand. Dilute urine (well below 300 mOsm/kg) with a rising sodium and high output supports DI.
Desmopressin. IV or subcutaneous 1-2 mcg. Intranasal is unreliable through packing and an operated nose; oral is possible later. Giving it reflexively before confirming DI is a flag. With sodium 149 and output around 400 mL/h most would give a dose; holding it in an alert patient drinking to thirst is defensible only with sodium checks every few hours and a clear trigger to treat. Ignoring a rising sodium is the flag.
Fluids. An awake patient with intact thirst who can drink usually needs little IV fluid. If needed, hypotonic fluid to replace free water, with sodium checks every few hours. Normal saline to match urine output is a flag.
Next dose. As needed, when the polyuria returns with dilute urine and rising sodium, not scheduled. DI after pituitary surgery is often transient. It can also be the first phase of a triphasic response: an SIADH phase with hyponatremia around days 5-10, sometimes followed by permanent DI. Isolated delayed hyponatremia around day 7 also occurs without prior DI. Scheduled dosing risks severe hyponatremia.

4. POD 2, hard to wake

POD 2, 0500: nurse finds him asleep wearing his home CPAP. At 0300 he reported a new severe headache. Now opens eyes to pain, confused speech, localizes. DDx? Imaging? CT: pneumocephalus with mass effect on both frontal lobes. Rx now? 100% O2? Why/why not? Back to the OR for repair this morning. Airway — awake? Asleep? Which? Why? Mask ventilation at induction? Why/why not? N2O? Why/why not?

Considerations and pitfalls AI draft

DDx. Tension pneumocephalus from positive pressure through the skull base defect; intracranial hemorrhage; opioid or gabapentin sedation with hypercarbia; hyponatremia or hypernatremia; meningitis; seizure. The CPAP is the clue, but a learner who skips the other causes is weaker.
Imaging. Non-contrast head CT; check a blood gas, sodium, and glucose at the same time.
Rx. Remove the CPAP, head up, urgent neurosurgery; tension pneumocephalus may need needle or burr-hole decompression and repair of the leak.
100% O2. Reasonable: high FiO2 speeds nitrogen absorption from the trapped air. It does not treat tension physiology and does not delay decompression.
Airway. With a GCS of 11 (E2 V4 M5) and confusion, an awake intubation is unlikely to be feasible. RSI or a carefully titrated induction that keeps him breathing, with the first attempt optimized: videolaryngoscope plus flexible scope, a 6.5 tube ready, front-of-neck access prepared. Preoxygenate head up by face mask (no nasal high flow). Defensible alternative: if neurosurgery can decompress at the bedside first and he becomes cooperative, a topicalized, minimally sedated flexible intubation avoids apnea in a patient who is hard to mask. Whichever route, the learner must say why an apneic induction is high stakes in him.
Mask ventilation. Avoid planned positive-pressure mask ventilation, which can drive more air through the defect. If he desaturates, rescue oxygenation (gentle mask ventilation or a supraglottic airway) takes priority over the pneumocephalus. A plan that relies on bag-mask ventilation from the start is the flag.
N2O. No. It expands closed air spaces and worsens pneumocephalus.

5. Before discharge

POD 4 after the repair. 0800 cortisol 2.8 mcg/dL. BP 112/68, HR 88, fatigued, mild nausea, Na+ 135. Assume no glucocorticoid was given at either operation. Interpretation? Rx? Hydrocortisone — dose? Route? Why that dose? Discharge steroid regimen? Dose? Follow-up? He asks when he can go back on his CPAP. What will you tell him?

Considerations and pitfalls AI draft

Interpretation. A morning cortisol this low after pituitary surgery, with fatigue and nausea, is secondary adrenal insufficiency until proven otherwise; he needs replacement now, not more testing. Dismissing it as postoperative fatigue is the flag. The sodium may also reflect the SIADH phase or excess desmopressin; expect that cortisol replacement can unmask or worsen DI, so recheck sodium and urine output after hydrocortisone.
Rx. Hemodynamically stable, so oral or IV hydrocortisone at a modestly elevated dose while he recovers (for example 20 mg in the morning and 10 mg in the afternoon, or a short course at about double replacement), then down to replacement. Full stress dosing (100 mg IV, then 200 mg per 24 hours) is for hypotension, vomiting, or other instability; a learner who names that threshold is strong. Giving nothing is the flag.
Discharge regimen. Physiologic replacement (for example hydrocortisone 15-20 mg/day in divided doses) with endocrine follow-up and later reassessment of the axis. A strong answer adds: double or triple the oral dose for fever or significant illness; if vomiting or unable to keep pills down, inject hydrocortisone 100 mg IM and seek emergency care; carry a medical alert ID; tell any future anesthesia team.
CPAP counseling. A strong answer gives a plain, honest reason (pressure pushed air through the repair), says the timing is the surgeon's call and usually a matter of weeks, and covers the interim risk: until then, avoid sedatives, take opioids sparingly, sleep with the head up, and do not restart without the surgeon's approval. Telling him to stop CPAP indefinitely, or to restart at home when he feels ready, is the flag.

Short stem

Awake craniotomy for eloquent-cortex glioma

A 38 y.o. right-handed man, 5'10", 110 kg (BMI 34), is scheduled for awake craniotomy with intraoperative language mapping for a presumed low-grade glioma of the left inferior frontal region. He has had two breakthrough focal seizures in the past month despite a recent increase in his levetiracetam dose. His wife reports loud nightly snoring; he has never had a sleep study. He is markedly anxious about the operation and has asked repeatedly whether he will feel it. Mild hypertension is treated with lisinopril. His neurologic exam is intact apart from occasional word-finding pauses. MRI shows a non-enhancing 3 cm left frontal-opercular lesion without midline shift. P 84; BP 148/88; RR 14; SpO2 96% on room air; Mallampati III.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Selecting and preparing a patient for awake craniotomy: candidacy under anxiety, suspected OSA, and active seizures; seizure preparation for a mapping case; airway planning for a sedated, pinned, semi-lateral head; scalp block anatomy with toxicity arithmetic and sedation built around the airway.

1. Candidacy and psychological preparation

Awake craniotomy with language mapping is the plan. Is he a candidate? Why/why not? What would make you cancel the awake plan on the day? At the preop visit he asks again, "Will I feel it?" What will you tell him? Rehearse anything with him? What? Agree on a stop signal? What? Midazolam premed? Why/why not?

Considerations and pitfalls AI draft

Candidate. Most likely yes — anxiety is common and modifiable with preparation; his real hooks are procedural anxiety (panic mid-mapping in pins), habitus and snoring (obstruction under sedation with a hard-to-reach airway), and frequent recent seizures (stimulation-triggered seizure during mapping). True barriers are inability to cooperate or communicate, refusal after informed discussion, uncontrollable cough, or severe untreated OSA where sedation is judged unsafe. Want a commit, not a hedge; missing the anxiety or the airway is a flag.
What cancels it. Refusal or panic that preparation cannot settle, inability to lie still semi-lateral for hours, poorly controlled seizures on the day, new deficit making task performance impossible. Reasonable to frame as a joint call with the surgeon.
'Will I feel it'. An honest, specific answer beats reassurance: the scalp is blocked and the brain itself has no pain fibers; he will feel pressure, vibration, and sounds, and dural manipulation can briefly hurt and will be treated. Promising he will feel nothing sets up a mid-case crisis of trust. Preparation means walking the timeline (block, sedation, wake-up, tasks, re-sedation), the sounds and positions, and who will be talking to him.
Rehearsal and stop signal. Run the actual language tasks (naming, counting, reading) with the neuropsychologist/speech team preop to establish his baseline — his word-finding pauses make a documented baseline essential; a brief positioning trial is reasonable; an agreed verbal or hand signal for distress that will be honored, not negotiated.
Midazolam. Avoid or minimize — it depresses ventilation on top of dexmedetomidine/opioid in a suspected OSA patient and can degrade task performance during mapping; anxiolysis here comes from preparation and rapport. A small titrated dose before the block is defensible if the learner defends the trade.

2. Seizure history and mapping preparation

Two breakthrough seizures this month on an increased levetiracetam dose. Does that change how the mapping is run? How? Morning levetiracetam — give it? Send a level? Why/why not? The surgeon started dexamethasone last week. What does that change for you intraop? A seizure on the field mid-mapping — first intervention? Then? What is drawn up at the head, and to what doses?

Considerations and pitfalls AI draft

Bearing on mapping. Recent breakthrough seizures mark an irritable cortex: the risk of a stimulation-triggered seizure during mapping is real and elevated. The team may map at lower stimulation currents and use electrocorticography to watch for afterdischarges; the learner should connect the history to intraop risk, not just to home meds.
Morning levetiracetam. Give it — an omitted dose on the morning of a mapping case lowers the threshold on the day it matters most.
Level. Reasonable if adherence or recent titration is in question (his dose was just increased); not mandatory, and normal levels do not guarantee control. Either answer is defensible if reasoned.
Dexamethasone. Peritumoral edema reduction is the usual surgical rationale even in a non-enhancing lesion; for anesthesia it means hyperglycemia — check intraop glucose and treat — and insomnia/agitation that can worsen his anxiety.
Seizure on the field. Iced saline irrigated directly onto the stimulated cortex by the surgeon is the first-line abort — fastest and mapping-sparing; anesthesia owns the systemic backup and the airway. Reaching for a systemic dose first is the flag.
Rescue doses. Small aliquots: midazolam 1-2 mg, propofol in 20-50 mg increments — enough to abort a seizure without costing the airway or the rest of the mapping; suction working, airway rescue equipment sized and checked before the pins go on. Reflexively drawing a full induction dose misses the point of the case.

3. Airway evaluation for a sedated, pinned patient

Airway exam — anything extra you check for a patient who will be sedated, pinned, semi-lateral, head turned away from you? Snoring, no sleep study. Send him for polysomnography first? Why/why not? Rescue device if he obstructs and needs one in pins — LMA or ETT? Why? Aspiration prophylaxis — give any? Why/why not?

Considerations and pitfalls AI draft

Beyond the standard exam. Everything about rescue in position: mask fit, nasal patency for an airway adjunct, neck mobility with the head turned, whether he can lie semi-lateral comfortably, and how much of the airway will be physically reachable once pinned and draped. Treat the snoring as presumptive OSA: nasal airway early, low sedative doses, capnography on the nasal cannula.
Sleep study first. No — this is oncologic surgery in a patient with breakthrough seizures; weeks of delay for polysomnography that will not change the day-of plan is hard to defend. Manage him presumptively as OSA. A learner who delays surgery for the study should be pressed on what the result would change.
LMA as primary rescue. Yes — with the head fixed in pins and turned away, direct or video laryngoscopy is somewhere between awkward and impossible; an LMA can be seated from almost any position and is the realistic first rescue. The threshold at which the surgeon releases the pins should be stated in advance.
Aspiration prophylaxis. He is fasted with no reflux history — routine prophylaxis is not indicated, though an H2 blocker is a defensible personal practice for a long sedation without a secured airway. Either way, reasoned, not reflexive.

4. Technique selection, scalp block, sedation

Asleep-awake-asleep with an airway, or sedation throughout? Commit. Why? Scalp block — which nerves? Agent? Concentration? Maximum dose for him — mg? Total mL you will inject? Epinephrine in the block? Why? Sedation for the non-mapping phases — dexmedetomidine or propofol-remifentanil? Which? Why?

Considerations and pitfalls AI draft

AAA vs sedation throughout. Both are practiced; the debate should be built on HIS features. AAA secures the airway during the asleep phases — attractive with suspected OSA — but buys two airway transitions in pins. Monitored sedation keeps spontaneous ventilation and avoids the exchange, but rests everything on titration in an obstruction-prone patient. Either commit is acceptable; ignoring the snoring in the defense is the flag.
Nerves. Six per side for a hemicranium: supraorbital, supratrochlear, zygomaticotemporal, auriculotemporal, greater occipital, lesser occipital (some add greater auricular). The learner should name them, not gesture at 'a scalp block.'
Agent and concentration. A long-acting agent — ropivacaine 0.375-0.5% or bupivacaine 0.25-0.375%, with epinephrine; the block must outlast hours of surgery.
Ceiling arithmetic. Dose to lean/ideal body weight, not 110 kg: IBW roughly 73-75 kg, so ropivacaine at ~3 mg/kg gives a ceiling near 220-225 mg; 40 mL of 0.5% ropivacaine is 200 mg — near ceiling before the surgeon's pin-site and field infiltration is counted. Do the math and leave headroom (e.g., 30-40 mL of 0.375%); dosing to actual body weight is the classic error.
Epinephrine. Yes — the scalp is vascular; 1:200,000 slows absorption, lowers peak plasma levels, and prolongs the block. Watch for tachycardia/hypertensive response in a hypertensive patient.
Dexmedetomidine vs propofol-remifentanil. Dexmedetomidine preserves respiratory drive and gives arousable sedation — well matched to his airway; its costs are bradycardia/hypotension and slower offset. Propofol-remifentanil titrates fast and wakes clean, but remifentanil plus suspected OSA is an apnea setup. Many combine low-dose strategies; want a committed choice reasoned from his respiratory risk.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Running the awake phase: verification before pinning and sedation dosing; obstruction under sedation without abandoning the awake plan; stimulation-triggered seizure and mapping timing; a differential for agitation in a pinned awake patient; airway conversion in pins; emergence, first language exam, and an honest patient conversation.

1. Positioning, pinning, and early obstruction

In the room, semi-lateral, scalp block placed. Before the pins go on — what must be true? How do you test the block? Dexmedetomidine — loading dose? Over how long? Then what rate? Remifentanil — add it? Rate? Twenty minutes after pinning: RR 8, SpO2 91%, loud snoring under the drapes. First move? Then? Sedation off entirely? Why/why not? What did you set up under the drapes before this moment?

Considerations and pitfalls AI draft

Before pinning. Block working at the pin sites, patient comfortable in the final position with pressure points padded, bladder plan settled, stop signal reconfirmed, rescue drugs and airway equipment at the head — pins convert every later problem into a problem in a fixed head.
Testing the block. Sharp stimulus at each pin and incision site, not just asking if he feels numb; the surgeon supplements pin sites with local infiltration regardless.
Dexmedetomidine load. 0.5-1 mcg/kg over 10-20 minutes — dosed to lean body weight, and many drop to 0.5 mcg/kg in suspected OSA — then 0.3-0.7 mcg/kg/hr titrated to a rousable patient.
Remifentanil. Low-dose, 0.01-0.05 mcg/kg/min, for pinning and opening; the synergy of opioid plus dexmedetomidine in this airway is exactly the trap — some omit it entirely. Either answer defended is fine.
Obstruction Rx order. Remifentanil off first, verbal stimulation and command to breathe, jaw lift, O2 up, nasal airway if needed, then reduce the dexmedetomidine rate. Reaching for a device before the sedation dial, or bolusing propofol, is the flag.
Sedation off entirely. Usually not — lightening in steps preserves the awake plan; slamming everything off buys an anxious, pinned, uncomfortable patient. Calm narration as he lightens — where he is, all is well, breathe deeply — is a therapeutic tool.
Pre-draping setup. Face and airway accessible under tented, transparent drapes; nasal cannula with capnography; an arm free and visible for signals; airway cart and LMA at the head.

2. Stimulation-triggered seizure

Mapping under way. During cortical stimulation his right face twitches, then the arm — it is spreading. First move? Then? Propofol — how much? He is seizing in pins. What is the danger? What do you do about it? The seizure stops at 90 seconds; drowsy but follows commands slowly. The surgeon wants to resume mapping now. Yes/no? Why? More levetiracetam now? Dose?

Considerations and pitfalls AI draft

Immediate order. Announce it — stimulation stops; surgeon irrigates iced saline onto the cortex; support oxygenation; small propofol only if the cortical irrigation does not abort it. Jumping to a large systemic dose first is the flag.
Propofol. 20-50 mg increments — abort the seizure, keep the airway and the case. An induction-dose bolus costs both.
Protect in pins. His head cannot move and he cannot fall — the real dangers are hypoxia and limb injury: oxygen, suction ready, guard (not forcibly restrain) the limbs, watch ventilation. A learner reciting the ward-seizure script (lateral position, pad the rails) has not seen the pins.
Resuming mapping. No — postictal language errors produce false-positive mapping; a site can look eloquent because he is postictal, not because it is. Wait until he is back to his documented baseline on the rehearsed tasks, typically minutes to tens of minutes, and re-run baseline tasks before trusting new data.
Levetiracetam now. An additional IV dose (500 mg-1 g over 15 min) is reasonable after an intraoperative seizure, coordinated with the surgical team. His month of breakthrough seizures marked him; this was a known risk prepared for, not bad luck.

3. Agitation mid-mapping

Forty minutes into mapping he grows restless, works an arm loose, and reaches for the drapes. DDx? First thing you do? Nasal-cannula EtCO2 reads 52. Meaning? Rx? He says he badly needs to urinate. Options? The surgeon asks you to deepen him. A propofol bolus now — what does it cost? Urinal, coached breathing, and he settles. Continue mapping? Why/why not?

Considerations and pitfalls AI draft

DDx. Hypercapnia or hypoxia, full bladder, pain (dural traction is the classic), postictal or evolving seizure activity, anxiety/panic, positional misery after hours still. The learner generates the list; the case then confirms two of them.
First move. Ask him — the awake patient is the monitor; simultaneously check SpO2/EtCO2, glance at the field with the surgeon, and screen pain, bladder, and fear in three questions. Treating agitation as a sedation-dose problem before diagnosing it is the flag.
EtCO2 52. Nasal-cannula capnography under-reads, so the true value is higher — sedation hypoventilation is both agitating him and swelling the brain. Lighten, coach breathing; do not deepen.
Bladder. If no catheter was placed (a deliberate choice in many awake craniotomies), a urinal or condom catheter at the drapes and easing the fluids; if one is in, check it for kinks. Small, humane, and it works.
Propofol bolus costs. The language exam (confounded for many minutes), possibly the airway in this habitus, and the surgeon's remaining map; forcible restraint escalates panic in a man whose head is bolted to the table. Treat the causes first — a bolus is the last move, not the first.
When the awake part ends. When the surgeon has the map complete — or earlier, the moment patient safety or cooperation genuinely fails; the anesthesiologist makes that abort call, and the rehearsed stop signal is honored, not negotiated.

4. Conversion to general anesthesia

Mapping complete; he has held still for three hours and cannot any longer. The surgeon asks for general anesthesia for resection and closure. Pinned, semi-lateral, head turned away. Airway — LMA? Fiberoptic? Videolaryngoscopy? Which first? Why? At what point do the pins come off — say it before you induce. LMA seats; ventilating well, PIP 22. Keep it, or exchange for an ETT? Why? Exchange — how? Airway settled, resection proceeds. During closure the surgeon reports the brain is getting full. DDx? First three moves? PaCO2 target?

Considerations and pitfalls AI draft

Options. Induce and seat an LMA — the device least dependent on head position; fiberoptic intubation (through the LMA or nasally); videolaryngoscopy attempted from a compromised angle — possible but the line of approach is wrong, the mouth may face away, and neck movement is zero. Rank them for a fixed, rotated head, not a generic difficult-airway list; the learner betting on VL should be pushed.
Who unpins, when. The neurosurgeon releases the Mayfield — and the call is made at cannot-ventilate, announced as a threshold in advance, not after desaturation. Knowing the wrench's location and saying the threshold out loud is the mature answer.
Keep vs exchange. If ventilation and pressures are good and the remaining case is closure, an LMA alone is defensible; exchange to an ETT if airway pressures, brain relaxation, or duration argue for control. Want a commit tied to conditions.
How exchange. Fiberoptic through the LMA with an Aintree catheter is the standard sequence — the airway is never abandoned between devices.
Full brain DDx. Hypercapnia from the fresh conversion is the front-runner; then venous outflow obstruction from the rotated neck, nonconvulsive seizure, expanding hematoma in the cavity, volatile agent depth, head-down drift.
First three moves. Verify ventilation and drive the CO2 down, check head-up and the neck for venous kinking, deepen with propofol (or shift toward TIVA); hyperosmolar therapy after these, and tell the surgeon what you found.
Ventilation target. PaCO2 roughly 30-35 mmHg as a temporizing bridge, correlated with a gas — sustained aggressive hypocapnia trades brain volume for ischemia.

5. Emergence, first language exam, and the debrief

Closure ends. Emergence — what matters most for this head? Bucking on the airway device at emergence — how do you prevent it? First language exam — when? Against what? PACU, one hour out: naming is slower than his preop baseline, no other deficit. DDx? Next? Disposition — floor, step-down, or ICU? Why? Overnight monitoring — orders?

Considerations and pitfalls AI draft

Emergence goals. Rapid, smooth return to a testable neurologic exam without coughing, straining, or hypertension driving bleeding into a fresh resection cavity — the exam IS the monitor after this operation.
Bucking. An LMA is better tolerated at light planes and is a genuine argument for having kept it; with an ETT, opioid titration, IV lidocaine, or deep exchange to an LMA — named, not waved at.
First language exam. In the PACU within the first hour, as soon as he is awake enough — against the preop baseline tasks; anesthesia's job is to flag residual sedation as a confounder and time the exam honestly.
Slower naming in PACU. Residual sedation and post-mapping fatigue are the benign explanations; resection-cavity hematoma, edema, or ischemia in the opercular region are the ones that matter. Re-examine as sedation clears, tell the surgeon, and a low threshold for CT if it does not improve or anything else appears — attributing a new language change to anesthesia without looking is the flag.
Disposition. ICU or a dedicated neurosurgical step-down with hourly neuro checks; the intraoperative seizure, suspected OSA plus residual sedation, and the conversion each independently argue for continuous monitoring overnight; a floor bed is wrong for him.
Overnight monitoring. Continuous pulse oximetry, minimized opioids with multimodal analgesia (the scalp block is still working), lateral or head-up positioning, CPAP if he obstructs, and a low threshold to escalate — treat him as the untreated OSA patient he probably is.

Short stem

Chronic subdural hematoma for burr-hole evacuation (foundational)

A 79 y.o., 68 kg man is scheduled for burr-hole evacuation of a left chronic subdural hematoma later today. He has had two weeks of progressive confusion, headache, and gait unsteadiness after a minor fall from standing; CT shows an 18 mm left chronic subdural collection with 6 mm of midline shift. He takes apixaban 5 mg BID for atrial fibrillation and took this morning's dose before the CT result was back. A systolic murmur was worked up last year: echocardiogram showed moderate aortic stenosis with a valve area of 1.2 cm² and mean gradient 28 mmHg. He has baseline mild cognitive impairment, now worse — he repeats questions, and his daughter is at the bedside. He ate breakfast at 8 a.m. P irregular, ~88; BP 158/84; RR 16; SpO2 96% on room air. Creatinine 1.4 mg/dL; Hgb 13.1 g/dL; platelets 214 K/uL.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Timing versus reversal of a factor Xa inhibitor when the neurologic exam is slipping; what an old echo can and cannot settle before urgent surgery; capacity assessed at the bedside for this decision; choosing GA versus MAC in a frail, confused patient with aortic stenosis.

1. The apixaban problem

It is noon. Last apixaban dose was 4 hours ago, and the surgeon has posted him for 2 p.m. Proceed as posted? Why/why not? Wait instead — how many hours? Creatinine 1.4. Change your number? Why? INR returns 1.1. Reassuring? Why/why not? Apixaban-calibrated anti-Xa returns 180 ng/mL. Proceed? Reverse — with what? Dose? FFP instead? Why/why not? An hour later he is harder to rouse and the repetitions are worse. Surgeon: 'I want to go now.' Your plan?

Considerations and pitfalls AI draft

Proceed at 4 hours. 4 hours post-dose is near peak effect — the worst moment to open the skull uncovered. The tension is a slowly declining exam versus full anticoagulation; the learner should refuse to proceed with neither waiting nor reversing.
How long to wait. Apixaban half-life ~12 h; elective intracranial surgery typically waits 48-72 h off drug. The learner should see that a declining exam makes that window unavailable.
Creatinine. CrCl here is roughly 40 mL/min — clearance is prolonged, so waiting buys less than the half-life math suggests. Ignoring renal function in the timing estimate is the common miss.
INR 1.1. Proves nothing — PT/INR and aPTT are insensitive to apixaban; a learner reassured by a normal INR has missed the pharmacology.
Anti-Xa 180. An apixaban-calibrated level quantifies residual effect; 180 ng/mL is a therapeutic-range level, far above the <30-50 ng/mL many labs treat as low. Limits: calibrated assay availability and turnaround, and no validated 'safe' threshold for intracranial surgery.
Reversal agent. 4-factor PCC 25-50 units/kg (~1700-3400 units for him; many centers a fixed ~2000 units) is off-label with observational support and is what centers give before urgent surgery. Andexanet alfa, the specific antidote, was withdrawn from the US market in December 2025 after the FDA judged that its thrombotic risk outweighed its benefit. A learner who names andexanet as the answer is working from outdated knowledge, which is itself worth a conversation: how would they have found out?
FFP. Does not neutralize a direct Xa inhibitor in any useful way, and the volume load is unwelcome in aortic stenosis. 'Give FFP' is the classic wrong reflex carried over from warfarin.
Declining exam. The exam decides it: reverse (4-factor PCC per institutional pathway), confirm products and type-and-screen, and go now. Continuing to wait for a lower level while he declines is the failure mode. The learner should think one step past the reversal order — PCC in before incision, PRBC available, hemostasis rechecked with the surgeon.

2. The murmur

His echo is 13 months old. Repeat it before today's case? Why/why not? The sonographer cannot come for 6 hours. Wait, or go? Why? His daughter says he has had no fainting and no chest pain, but walks less. Change anything? Induction targets — HR? BP floor — number? Why that number? He is in AF at 88. What rhythm problem do you plan for at induction? What is drawn up? Arterial line before induction? Why/why not?

Considerations and pitfalls AI draft

Repeat echo. An echo within about a year with no interval change in symptoms is generally adequate; the real question is whether anything has changed — syncope, angina, worsening dyspnea (hard in a confused patient; ask the daughter). Reflexively re-imaging without asking what it would change is worth probing. Discovering severe AS would tighten hemodynamic discipline and lower the threshold for pre-induction pressors — it would not cancel an urgent evacuation.
6-hour delay. Waiting 6 hours for an echo while the exam declines is the wrong trade; proceed with AS-appropriate management. Bedside POCUS for a quick gradient/contractility look is a reasonable middle path if immediately available.
Daughter's history. No syncope or angina is reassuring; reduced walking is nonspecific in a man whose gait is failing from the subdural. Manage as at least moderate AS and treat him as possibly worse.
HR target. Roughly 60-80 and controlled; tachycardia shortens diastole (filling and coronary perfusion of a hypertrophied LV), profound bradycardia drops output across a fixed valve.
BP floor. His baseline is 158/84 (MAP ~110) — the floor should be set relative to that, not to a textbook 65; most would defend MAP ≥80 and act fast below it. Diastolic pressure is the coronary perfusion pressure that matters here.
Rhythm. Atrial kick is already gone, so rate is everything; the fear is RVR with induction stress or hypotension-triggered catecholamines. Phenylephrine drawn up, esmolol available, pads on and a plan for synchronized cardioversion.
Arterial line. Yes, before induction — beat-to-beat pressure in moderate AS with a reversal-dependent hemostasis plan is cheap insurance; a learner deferring it to 'after we're asleep' should defend that.

3. Capacity and consent

At the bedside he asks you what operation he is having, then asks the same question three minutes later. Can he consent? What will you ask him to find out? He says 'my head hurts — fix it.' Enough? Why/why not? What would he have to say for it to be enough? He cannot hold the risks from one minute to the next. His daughter says she is his health care proxy; no paperwork is in the chart. Proceed on her word? Why/why not? The surgeon says 'it's an emergency, just go.' Agree? Why/why not?

Considerations and pitfalls AI draft

Can he consent. Capacity is decision-specific and assessed at the bedside, not inferred from the MCI label or the repeating — some patients who repeat questions can still consent to this. The learner should go ask him, not adjudicate from the chart.
What to ask. In conversation: can he say what is wrong (blood pressing on his brain), what is proposed and its main risks, that it applies to him, weigh doing it against not, and hold a consistent choice across the conversation. The four functions (understand, appreciate, reason, express a choice) demonstrated, not recited.
'Fix it' enough. No — it expresses a choice but shows no understanding or appreciation. A learner who accepts it because it agrees with the plan is the classic pitfall: agreement is not capacity.
What would be enough. His own words back: there's a blood collection pressing on his brain, they'll drill and drain it, it could bleed or come back, and without it he'll likely get worse — held onto for more than a minute. He does not need to retain it tomorrow; he needs it for this decision.
Proxy unclear. He lacks capacity for this consent; verify — chart, PCP office, hospital records — while not letting paperwork stall an urgent case. With a declining exam, an involved daughter with no family disagreement, and surgeon concurrence, proceed per institutional surrogate/two-physician policy; ethics or administration on call if anything conflicts. Document the capacity assessment itself, who consented and on what authority, and the urgency rationale.
'Just go'. Urgent-not-emergent means there IS time to do this properly — the emergency exception (proceed with no consent at all) is not available while he's conversant and family is present. Neither wait-for-perfect-paperwork nor invoke-emergency is right.

4. GA versus MAC

GA with an ETT, or MAC with scalp local? Which? Why? Commit to MAC — sedative? Dexmedetomidine? Propofol? Nothing? Doses? Midazolam 1 mg to settle him? Why/why not? It is now 1 p.m.; he ate at 8. Wait until 4? Why/why not? MAC it is. His head will be turned and under drapes. Airway rescue — what is set up before the drapes go on?

Considerations and pitfalls AI draft

The choice. Both are done for burr-hole cSDH evacuation; either is defensible if committed and defended against HIS features. For MAC: avoids an induction in moderate AS on a freshly reversed patient, faster return to a followable neuro exam, less delirium exposure. For GA: he repeats questions and reaches — cooperation under drapes is doubtful; a still field; a secured airway you don't have to rescue head-turned under drapes. Wanting the case both ways — 'light GA, sort of' — is the flag.
Sedation strategy. Dexmedetomidine is the best fit for a delirium-prone brain — infusion ~0.2-0.7 mcg/kg/h, load omitted or given very slowly (bradycardia and hypotension both bite in AS). Propofol in small doses risks disinhibition, apnea, and hypotension in exactly this patient. Minimal-to-no sedation with a good scalp block is a legitimate answer.
Midazolam. Avoid — paradoxical agitation and delirium in the elderly, and it clouds the postoperative exam; the learner should produce the why, not just the no.
Fasting. 5 hours from a light meal in a patient whose exam is declining — the neurologic clock beats the fasting clock; waiting 3 more hours for a guideline interval he nearly meets is the wrong trade. The honest cost: if MAC, sedation depth must respect an imperfectly empty stomach; if GA, this feeds the RSI discussion.
Airway contingency. Decided before draping: head accessible or turnable, airway cart and suction in the room, video laryngoscope ready, induction drugs drawn, and an explicit word with the surgeon that the case stops if you call it. Improvising this at the moment of need is the failure.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Running a MAC safely with cautery at the head; a controlled conversion to GA in aortic stenosis; hypotension where the coronary perfusion of a hypertrophied LV is the stake; small levers for brain re-expansion and the dural reflex; a slow wake-up with a bounded differential and the anticoagulation restart conversation.

1. Conduct of MAC

You proceed with MAC and a scalp block. Monitors beyond standard? Which? Why? Oxygen — nasal cannula at 6 L? Why/why not? What flow? Cautery is about to start at the scalp. Fire risk — what do you change at the drapes? Dexmedetomidine — 1 mcg/kg load over 10 minutes? Why/why not? Infusion rate? Fifteen minutes in, he reaches toward the field, disoriented. First move? Verbal redirection fails. Agent? Dose? He settles, then reaches again 10 minutes later. Propofol 20 mg? Why/why not? At what point do you convert to GA?

Considerations and pitfalls AI draft

Monitors. Arterial line (AS, reversal-dependent hemostasis), EtCO2 sampling under the drapes for respiratory rate and apnea detection. A learner content with a pulse ox and cycling cuff is under-armed.
Oxygen and fire. Cautery near the head with open oxygen is the OR-fire setup: oxidizer pooling under drapes, ignition source, fuel. Lowest FiO2 that holds saturation — room air or nasal cannula at 1-2 L; not 6 L of open oxygen under a drape.
Drapes. Tented off the face with airway access maintained, suction under the drapes to scavenge oxygen, prep dry before cautery. Concrete requests, not vigilance in the abstract.
Dexmedetomidine. Skip or crawl the load — a standard 1 mcg/kg over 10 min invites bradycardia and hypotension in an elderly man with AS; start the infusion low (~0.3-0.4 mcg/kg/h) and titrate.
He reaches. First move is verbal — hand on his hand, reorient, warn the surgeon and pause the field. Reaching for a syringe first is the pitfall.
Next agent. A small titrated increment — dexmedetomidine bolus given slowly or 10-20 mg propofol — accepting that every increment in a disinhibited elderly brain can worsen the disorientation.
Second reach, stacked propofol. Accumulating boluses chase agitation into obstruction, apnea, and hypotension with an unsecured airway under drapes — the classic MAC death spiral.
What ends MAC. A defined line, decided now: repeated movement threatening the field, obstruction or desaturation, escalating doses without effect. Naming the tripwire in advance is the mark of judgment; drifting deeper is the flag.

2. Conversion to GA

He will not lie still. You convert to GA. Induction agent? Dose for him? RSI? Why/why not? Succinylcholine or rocuronium? Dose? With induction, BP falls to 78/42, HR 96 irregular. Phenylephrine? Norepinephrine? Ephedrine? Which first? Why in him? End point — number? Pressure recovers. Sevoflurane or TIVA for maintenance? Why?

Considerations and pitfalls AI draft

Induction agent. Etomidate 0.15-0.2 mg/kg (~10-14 mg) for hemodynamic stability, or propofol slowly titrated at reduced dose (~0.5-1 mg/kg) with a pressor already running; low-dose ketamine adjunct (~0.5 mg/kg) spares hypnotic dose but watch tachycardia in AS. Any committed, dose-reduced, pressor-supported plan passes; a standard 2 mg/kg propofol push fails him.
RSI and relaxant. He ate 5 hours ago, is agitated, and just got sedative increments — a modified RSI is reasonable: rocuronium ~1 mg/kg or succinylcholine ~1-1.5 mg/kg (no contraindication here). The learner should connect the fasting history from A4 to the airway plan, not treat this as an elective induction.
Pressor first. Phenylephrine (or norepinephrine) — raises diastolic pressure and coronary perfusion of the hypertrophied LV without tachycardia, and reflex slowing is welcome. Ephedrine is the wrong reflex: tachycardia shortens diastole and raises demand across a fixed valve.
End point. Back toward his own baseline — MAP ≥80, not a generic 65; in AS the cost of running low is subendocardial ischemia, not just a number on the screen.
Maintenance. Either sevoflurane at modest MAC with pressor support or a TIVA is defensible for burr holes; vasodilation from deep volatile is the thing to own either way. Wanting a followable early postoperative exam argues for a light, short-acting technique.

3. Hypotension mid-case

Thirty minutes in: BP 82/45 on 0.7 MAC sevoflurane, HR 92 irregular. Rx? Target — number? Why that number in him? Turn the sevoflurane down to 0.4 MAC, or start a norepinephrine infusion? Which? Why? Rhythm becomes narrow and regular at 130 for 40 seconds, then irregular at 95 again. Rx now? Esmolol? Why/why not? It comes back at 140, sustained, BP 70/40. Now? Energy?

Considerations and pitfalls AI draft

Of concern. A diastolic of 45 in a hypertrophied, pressure-loaded LV is a coronary perfusion problem — the LV that most needs diastolic pressure is getting the least. Treating this as routine anesthetic hypotension is the miss.
Target. Anchored to HIS baseline of 158/84 — the learner should reason to 'higher than my usual target' (MAP ≥80, diastolic recovered), not recite MAP 65.
Lighten vs pressor. 0.7 MAC is already modest, so the bigger lever is vasoconstriction — phenylephrine or norepinephrine infusion; cutting the volatile below amnestic levels to chase pressure trades one problem for another.
Transient regular 130. Likely atrial flutter with conduction or an SVT run — brief, self-terminated, but a warning: this heart tolerates 130 poorly (diastole collapses). Fix pressure, depth, volume, magnesium and potassium, oxygenation first; no beta-blockade on top of hypotension and volatile — negative inotropy at the wrong moment. Reaching for a drug before the triggers is the pitfall.
Sustained 140 with BP 70/40. Unstable — synchronized cardioversion now, 100-200 J biphasic, pads already on from the induction plan; amiodarone 150 mg over 10 min or small titrated esmolol only if he were perfusing.

4. Re-expansion, the dural reflex, and emergence

Cavity open, surgeon irrigating: 'He's draining slowly — can you help the brain come up?' What do you change? PaCO2 target? Head position? How much re-expansion do you expect from that? With the next irrigation, HR falls to 42, BP 96/50. Cause? First move? Atropine? Why/why not? It recurs with each pass of irrigation. Rx? Closure begins. What does 'back to baseline' look like for him at emergence? Extubate him at that exam? Criteria?

Considerations and pitfalls AI draft

Small levers. Allow PaCO2 to drift up to ~45-50 (more cerebral blood volume), level or slightly lower the head, a gentle sustained inspiratory hold to raise venous pressure — all real, all modest. Hyperventilating a brain you want to expand is the active mistake to catch.
Expectations. A chronically compressed, atrophic 79 y.o. brain re-expands over days, not minutes — the honest answer to the surgeon is 'small levers, mostly time.' Overpromising here is a flag.
Bradycardia with irrigation. Trigeminocardiac/dural traction reflex — the stimulus is the cause, so the first move is 'stop irrigating,' not a syringe. HR recovers when the stimulus stops.
Atropine. Not for a self-resolving reflex with adequate pressure; if recurrent and hemodynamically significant, glycopyrrolate 0.2 mg or atropine 0.4 mg before further irrigation is reasonable, plus warmed irrigant and a gentler hand.
Back to baseline. Defined by the daughter's description — oriented to himself, conversant but repeating questions — not a normal mental status exam he never had. Chasing a crisp exam with more time or stimulation misreads the patient.
Extubation criteria. The physiologic criteria stand — awake to voice, airway reflexes, regular spontaneous ventilation, full reversal confirmed (TOF ratio ≥0.9), warm, hemodynamically stable — but 'follows commands' is graded against his baseline; a patient at his own confused baseline with intact airway reflexes can be extubated.

5. Slow to wake in PACU

Forty minutes into PACU he opens his eyes to voice but follows no commands — slower than you expected. DDx? First three things you do? ABG: pH 7.31, PaCO2 61. Rx? Thirty minutes later PaCO2 is 42 and he is no more awake. CT? What are you looking for? CT shows a small residual collection, no new bleed, no pneumocephalus. Next test? The surgeon asks when the apixaban can restart. Your answer? What decides the day? His daughter asks why he isn't waking up. What will you tell her?

Considerations and pitfalls AI draft

DDx. Bounded to this case: residual sedative sensitivity in a 79 y.o. brain, hypercapnic narcosis, nonconvulsive seizure, reaccumulation or tension pneumocephalus, stroke, and the quick metabolic checks (glucose, sodium, temperature).
First three actions. Look at him (pupils, symmetry, lateralizing signs), support ventilation and get a gas, send glucose and sodium — cheap, fast, and they sort half the list before anyone calls for a scan.
ABG. PaCO2 61 with pH 7.31 — hypercapnia from residual sedation is at least contributing; stimulate, support ventilation, reassess. The trap is stopping here: hypercapnia found is not the workup finished if he doesn't wake once corrected.
CT decision. Normocapnic and still not waking → CT now; looking for reaccumulation, tension pneumocephalus, and stroke. Waiting another cycle 'to see' on a reversed-anticoagulant fresh subdural is the miss.
Clean CT. EEG — nonconvulsive seizure after subdural evacuation is real and invisible without it; MRI for stroke if EEG is unrevealing.
Apixaban restart. Not a number to recite — a joint call with neurosurgery and cardiology weighing his AF stroke risk against rebleed into a fresh subdural cavity (and chronic SDH recurs). Typically days to a couple of weeks with imaging stability; interim mechanical prophylaxis and a documented plan. The learner's job is to name the competing risks and the right owners.
The daughter. Plain and honest: he is slower to wake than expected, the likely reason (medications and carbon dioxide in an older brain), what has been checked, what happens next, and when she'll hear more — no false reassurance, no catastrophizing.

Short stem

Elective supratentorial tumor craniotomy (foundational)

A 61 y.o., 80 kg, 5'7" woman is scheduled for elective right frontal craniotomy for resection of a 4 cm meningioma with surrounding vasogenic edema. For two weeks she has had headaches on waking with nausea, and she reports her left hand has become clumsy; in clinic her outstretched left hand drifts. One week ago she was started on dexamethasone 4 mg BID and levetiracetam 500 mg BID. Type 2 diabetes treated with metformin; her home glucoses have run 180-240 since starting the dexamethasone. GERD, asymptomatic on daily omeprazole; hypertension treated with amlodipine. P 76; BP 152/88; RR 14; SpO2 98% on room air; T 36.9°C. Airway exam: Mallampati II, full neck extension, good mouth opening.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Recognizing the symptomatic supratentorial mass from its parts; the steroid and antiepileptic slate with its glucose consequence; aspiration-risk judgment in controlled GERD; lines, monitors, and blood planning for an elective craniotomy.

1. How sick is this brain

Her two-week story: morning headache with nausea, and a new drifting left hand. What is going on physiologically? Why worse in the morning? Her MRI is on the screen. Before you induce, what do you want off that scan? The report: 4 mm midline shift, edema through the right frontal white matter, tumor abutting the superior sagittal sinus anteriorly. Which of those changes your anesthetic? How? The scan is three weeks old and the nausea is now daily. Re-image, or go? She is anxious in holding. Midazolam 2 mg? Why/why not?

Considerations and pitfalls AI draft

Two-week story. Morning headache with nausea plus a new focal motor sign is the raised-ICP-with-mass-effect cluster; the learner should assemble it and name it themselves. Treating this as a routine elective without engaging the symptoms is the flag.
Mechanism. A 4 cm mass plus vasogenic edema raises ICP; symptoms worse on waking from recumbency and nocturnal CO2 rise increasing CBF; the drift is focal compression of right motor cortex — an early localizing sign, not just 'clumsiness'.
What to look for on MRI. Degree of midline shift, edema extent, ventricular effacement or trapped ventricle, cisterns, and relationship to the superior sagittal sinus — each changes how much reserve she has under anesthesia.
Sinus proximity. Parasagittal/sinus-abutting meningiomas raise blood-loss and sinus-injury stakes and can obstruct venous outflow; mostly this drives blood availability and tighter hemodynamic discipline, not cancellation.
Old scan, progressing symptoms. Progression since imaging matters more than the calendar date; call the neurosurgeon — the answer may be re-image, move the case up, or steroid adjustment. Silently proceeding on a stale scan with a changing exam is the pitfall.
Midazolam. Either answer is defensible if reasoned: a small titrated dose in a monitored setting for real anxiolysis, versus withholding because sedation-induced hypoventilation raises PaCO2, CBF, and ICP in a patient with reduced compliance. Reflexive premedication without engaging the ICP physiology is the flag.

2. The medication slate

Dexamethasone this morning — give it? Why/why not? Why is she on it at all? Her glucoses have run 180-240 since it started. Does that matter for the case? Why? Intraop glucose target — number? How will you run insulin? Metformin the morning of — give or hold? Why? Levetiracetam this morning — give it? Why? Amlodipine — give it? Why?

Considerations and pitfalls AI draft

Dexamethasone morning-of. Give it. Missing doses risks rebound peritumoral edema on the day you most need a slack brain. Steroids shrink vasogenic (not cytotoxic) edema around the tumor, often improving symptoms within days — it is why her drift may even be better than two weeks ago. Abrupt stop risks rebound edema plus some HPA suppression after a week; many give an additional intraop dose at the surgeon's request.
Glucose concern. Steroid-induced hyperglycemia on top of T2DM; hyperglycemia worsens outcome after brain injury and ischemia, so it is not cosmetic here.
Target and insulin. Roughly 140-180 mg/dL intraop; check in holding, then hourly; IV insulin by small boluses or infusion. Tight control is the opposite error — undetected hypoglycemia under anesthesia is catastrophic for the brain.
Metformin. Hold the morning of surgery per routine; it provides no fasting benefit and simplifies the insulin plan. Lactic acidosis risk is largely historical concern but holding is standard.
Levetiracetam. Give it — she has a cortical supratentorial lesion; an intraop or emergence seizure is exactly what prophylaxis is for.
Amlodipine. Continue. Calcium channel blockers do not cause the refractory induction hypotension associated with ACEi/ARBs, and arriving at 152/88 rather than 190/100 makes the smooth induction easier.

3. Aspiration risk and the airway

She has GERD, asymptomatic on omeprazole. RSI or a standard titrated induction? Which? Why? She mentions she vomited once this morning. Change your plan? Why? You choose a standard IV induction — any aspiration prophylaxis beyond her PPI? Succinylcholine for her — any hesitation? Why? Twitch monitor — right arm or left? Does the side matter? Why?

Considerations and pitfalls AI draft

RSI for controlled GERD. Most would not: asymptomatic on a daily PPI, fasting, normal airway — a standard titrated induction is defensible and avoids trading a controlled induction for a marginal aspiration benefit. RSI is also defensible; the learner must commit and own the tradeoff rather than reflexively RSI everyone with the word 'reflux'. Symptoms, not the diagnosis label, drive the decision — active regurgitation, large hiatal hernia, gastroparesis, recent intake, obstruction.
Morning vomiting. The wrinkle: her nausea/vomiting is likely ICP-driven, not gastric outlet pathology — but vomiting on the morning of surgery still means a stomach of unknown contents; gastric ultrasound or a pragmatic tilt toward RSI both show good reasoning.
Prophylaxis. She is already on a PPI; nonparticulate antacid or famotidine add little in a fasting patient but are low-cost; metoclopramide reasonable if gastric concern persists.
Succinylcholine. Acceptable if needed. Its transient ICP rise is clinically minor with an adequate induction, and a two-week mild upper-motor-neuron drift is not a meaningful hyperkalemia risk — but the learner should show they considered both rather than never having heard of either.
Twitch monitor side. Prefer the unaffected (right) arm. A paretic limb upregulates acetylcholine receptors and looks resistant to nondepolarizers, so its twitches overestimate recovery. With a drift this mild the effect is small — the principle, not the panic, is the point.

4. Monitors, access, and blood

Arterial line — before or after induction? Why? What would flip you to placing it awake? Central line for this case — yes/no? Why? Peripheral IVs — how many, what gauge? Her arms will be tucked. Does that change what you do before draping? The surgeon wants MEPs. What changes in your anesthetic? Type and screen, or crossmatch? Why?

Considerations and pitfalls AI draft

Art line timing. Either is defensible for an elective, stable patient. Pre-induction gives beat-to-beat pressure across laryngoscopy — the highest-risk minutes for both spike and trough. Post-induction is quicker and reasonable with frequent NIBP cycling. A committed, defended choice is the point; more shift, labile hypertension, cardiovascular disease, or difficult access tips toward awake placement.
Central line. Not needed for this supine craniotomy — not a sitting-position VAE setup, no expected vasoactive infusions. Placing one 'because craniotomy' is worth challenging.
PIVs and tucked arms. Two IVs, at least one 16-18 g, tested and secured before tucking; after the drapes go up you cannot get to them.
Neuromonitoring. Often none for a frontal meningioma; with her motor findings the team may want MEP/SSEP or motor mapping — ask the surgeon before the plan is set, because MEPs preclude ongoing muscle relaxant and cap volatile depth (favoring a TIVA).
Type and screen vs crossmatch. Meningiomas are vascular tumors, and hers abuts the sagittal sinus — most would crossmatch 2 units rather than screen only. A small convexity lesion far from the sinus is where screen-only is defensible; the learner should tie the answer to the imaging.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. An induction bracketed against both spike and trough; maintenance choices that respect a swollen brain; a stepwise response to intraoperative brain bulk; steady judgment through osmotic diuresis, hyperglycemia, and temperature drift; an emergence engineered for the neuro exam.

1. Induction

Time to induce. BP limits through laryngoscopy — numbers? Why those in her? Propofol dose for her 80 kg? Opioid — which, how much? Rocuronium or succinylcholine? Why? To blunt laryngoscopy — fentanyl, esmolol, or lidocaine? Pick one, and dose it. Two minutes after intubation, BP 85/50, HR 72. Of concern? Why? Phenylephrine, ephedrine, or volume? Which first? Target BP — number? Why that number?

Considerations and pitfalls AI draft

Goals. The learner should produce both directions themselves: no hypertensive spike (surges CBF into a poorly autoregulating tumor bed — edema, hemorrhage) and no trough (CPP = MAP minus ICP, and her ICP is already up, so 'normal' MAPs buy less perfusion). Naming only one failure mode is the incomplete answer.
Doses for 80 kg. Propofol ~1.5-2.5 mg/kg (120-200 mg) titrated; fentanyl 2-3 mcg/kg (160-240 mcg) or a remifentanil-based technique; either works if deliberately timed against laryngoscopy.
Relaxant. Rocuronium 0.6-1 mg/kg is the usual elective choice; succinylcholine defensible if rapid control were needed (see A3). Want a reason, not a habit.
Blunting. Any committed, dosed choice: fentanyl timed ~3 min before laryngoscopy, esmolol 0.5 mg/kg, lidocaine 1-1.5 mg/kg. Inducing deeply and hoping is the pitfall.
BP 85/50. Yes, of concern — MAP ~62 against an elevated ICP is a real CPP cut, and the injury from hypotension is silent until the postop exam. Treat promptly.
Rx and target. Phenylephrine suits propofol vasodilation with HR 70s; ephedrine if bradycardic; volume runs in the background but is too slow alone. Target near her ward baseline — she lives at 152/88 (MAP ~110), so a MAP in at least the 80s-90s, not a textbook 65.

2. Maintenance, fluids, and mannitol

Maintenance — TIVA or volatile? Commit. Why? You choose volatile; the resident runs sevoflurane at 1.5 MAC. Acceptable? Why/why not? Add N2O? Why/why not? PaCO2 target before the dura opens — number? After it opens — same, or lower? Which crystalloid runs? What is off the list? Why? The surgeon asks for mannitol as the dura is about to open. Dose for her? Over how long? What do you watch for the next 30 minutes?

Considerations and pitfalls AI draft

TIVA vs volatile. Either is defensible for an elective supratentorial case with a modest ICP picture: volatile at or below ~1 MAC leaves CO2 reactivity and CBF near normal; propofol lowers CMRO2 and CBF and is favored when the brain is tight. Challenge whichever they pick — the reasoning is the target.
Sevo 1.5 MAC. No — above ~1 MAC, dose-dependent cerebral vasodilation outruns metabolic suppression and autoregulation degrades; exactly the wrong direction for a swollen brain.
N2O. Most avoid it here: a cerebral vasodilator that raises CMRO2, and it expands closed gas spaces — a pneumocephalus concern at and after closure.
PaCO2. Low-normal to mildly hypocapnic (~33-35) as the working target, trimming toward 30 when the surgeon needs a slacker brain with the dura open. Prophylactic aggressive hyperventilation is not a resting state — vasoconstriction has an ischemia price.
Fluids. Isotonic crystalloid (normal saline or a balanced solution). Off the list: anything glucose-containing (she is already 180-240, and hyperglycemia worsens ischemic injury) and hypotonic fluids (free water goes straight to brain water). Large-volume LR is worth a caveat as mildly hypotonic.
Mannitol. 0.25-1 g/kg; commonly ~0.5 g/kg = 40 g for her, infused over 10-15 min rather than slammed.
What to watch. A transient rise in intravascular volume as mannitol osmotically pulls water in — increased preload a limited heart would feel, and a rapid infusion can transiently drop BP — then the intended brisk osmotic diuresis; so track volume status and the Foley, and check Na/K and osmolality if dosing repeats. The diuresis you asked for becomes hypovolemia if ignored.

3. The tight brain

Dura open. Surgeon: 'the brain is bulging.' Before any drug, what do you check at the head of the bed? EtCO2 reads 31. Satisfied? Why/why not? You are on sevoflurane at 1.0 MAC. Change the agent? To what? Why? More mannitol, or hypertonic saline? Pick one. What do you check before redosing? Another dose of dexamethasone — does it buy you anything in the next ten minutes? Ten minutes later it is no better. What is left to try?

Considerations and pitfalls AI draft

First moves. The free, fast physical checks: confirm head-up tilt, neutral head position, no ETT tie or tape compressing the jugulars, no circuit problem stacking pressure, minimal PEEP. Reaching for drugs before checking the table is the classic miss.
EtCO2 31. Not sufficient — EtCO2 underestimates PaCO2 by a variable gradient; send an ABG. A 'hyperventilated' patient by capnograph can be sitting at PaCO2 38.
Depth and agent. Converting from volatile to a propofol-based technique lowers CBF while keeping depth, the one agent change that helps the brain directly; deepen if light, since light anesthesia raises CBF and CMRO2.
More osmotherapy. Either an additional mannitol dose (toward ~1 g/kg total, after checking osmolality/osm gap) or a hypertonic saline bolus is reasonable; want a committed choice with a check-before-redose reflex.
Dexamethasone now. Works on vasogenic edema over hours to days — give it, but it rescues nothing in the next ten minutes; counting it as an acute measure is the flag.
Telling the surgeon. A plain accounting: what has been done, what is pending (the ABG), what is left — deeper propofol to burst suppression, PaCO2 transiently toward 28-30, more osmotherapy, ventricular drainage from the field, and a surgical conversation about rapid internal decompression of the tumor. No preexisting CSF drain exists to open in this supratentorial crani; the surgeon can drain from the field. The team decides together; silence at the head of the bed is the failure.

4. The quiet middle

Resection underway, brain now slack. Urine output 400 mL over the past hour. Expected, or a problem? What else could drive it? No labs are back yet — how do you tell them apart at the bedside? Replace the urine? With what, how much? Glucose returns 260. Treat? To what target? How, and when do you recheck? Temp 35.2°C and drifting down. Does it matter here? Why? Warm her — how, mid-craniotomy with a pinned head?

Considerations and pitfalls AI draft

400 mL/hr. Expected osmotic diuresis after 40 g of mannitol — the timing is the tell. The learner should also surface diabetes insipidus on their own, then argue against it: DI is rare mid-case outside pituitary/hypothalamic surgery, and mannitol diuresis tapers over a few hours while DI is sustained and relentless.
Bedside sorting. Timing relative to mannitol, trajectory (tapering vs escalating), and urine appearance are the no-lab clues; if it persists, send serum Na and urine osmolality — dilute urine against a rising serum Na is DI.
Replace. Partial replacement with isotonic crystalloid guided by hemodynamics. Chasing it 1:1 defeats the purpose of the mannitol; ignoring it entirely buys hypovolemia and hypotension. Middle path, watching the art line.
Glucose 260. Treat — IV insulin in small boluses (e.g., 4-6 units) or an infusion, recheck within the hour, target 140-180. The paired error to name: overshooting into hypoglycemia in an anesthetized patient who cannot declare symptoms.
Temp 35.2. The mild-hypothermia-for-neuroprotection question is settled — no outcome benefit in aneurysm surgery (IHAST) and none established here, while real costs accrue: coagulopathy in a bleeding field, infection, shivering on emergence raising O2 demand, and a slower wake-up muddying the exam. Maintain normothermia.
Warming logistics. Forced-air over the lower body, fluid warmer, warm the room a notch — all compatible with a pinned head and open cranium.

5. Emergence

Closing begins. How do you want her to wake up? Why? Your plan — remifentanil through emergence? Lidocaine before suctioning? Dose? What antihypertensive is drawn up before the wake-up, and why that one? Extubation criteria for her? During the head dressing, BP 178/95. Rx now? Why does it matter so much this hour? Agent, dose? She is extubated and awake, but the left side moves less than this morning. DDx? When do you image? PACU orders — BP ceiling? What triggers a call to you?

Considerations and pitfalls AI draft

Goals and the collision. The learner should produce the tension themselves: a rapid, clean wake-up so the surgeons get an early neuro exam — against no coughing, bucking, or hypertension on the tube, because venous and arterial spikes bleed into a fresh resection cavity. A slow, smooth wake-up and a fast, violent one each fail a different goal.
Specific plan. Low-dose remifentanil continued through emergence and tapered after the pins are out; lidocaine 1-1.5 mg/kg before suctioning; minimal-stimulation extubation; antihypertensive in hand before the wake-up begins, not fetched after the spike.
Which antihypertensive. Labetalol in 5-10 mg increments or nicardipine (boluses or infusion) — effective without dilating cerebral vessels; esmolol for a rate-dominant picture. Pure vasodilators like nitroprusside/nitroglycerin raise CBF and are the wrong tools.
Extubation criteria. Awake and following commands (the exam is the point of the wake-up), intact airway reflexes, full reversal (TOF ratio ≥0.9), normothermic, adequate gas exchange.
BP 178/95. Treat now — postoperative hematoma clusters in the first hours and tracks with emergence hypertension; most surgeons want SBP held under ~140-160. Labetalol 10 mg IV and re-dose to effect is a reasonable concrete answer.
Left side slower. Residual anesthetic can unmask or exaggerate a pre-existing deficit (differential awakening) — and she started with a drift. But the alternatives are the ones that kill: hematoma, edema, seizure with a postictal (Todd's) paresis. Trajectory over 30-60 min with serial exams decides; any worsening, new deficit beyond baseline, or falling arousal buys an immediate CT rather than more watching. Give the PACU her baseline, the current exam, the BP ceiling, and explicit thresholds for calling and imaging. A vague 'watch her neuro status' is the failed version.

Long stem

Morbid obesity, OSA, prior failed neuraxial, repeat cesarean with placenta accreta

A 36 y.o. G3P2 at 39 weeks gestation, 152 kg, 5'4" (BMI 58), is scheduled for repeat cesarean delivery, her third. Obstetric ultrasound raises concern for placenta accreta over the prior cesarean scar.

HPIFirst cesarean under uncomplicated spinal at an outside hospital. Second cesarean at age 31: 90 minutes of attempted epidural placement, ultimately converted to general anesthesia after surgical incision under inadequate block; required two attempts at intubation. She recalls feeling pulling during the second cesarean but reports no nightmares or avoidance. On home CPAP at 14 cm H2O for severe OSA (AHI 65), uses it nightly. Has been doing prenatal pool exercise. BMI was 48 prior to pregnancy.

PMHClass III obesity. Severe OSA on CPAP. Gestational diabetes on insulin. Chronic hypertension on labetalol. Mild iron-deficiency anemia. GERD on PPI.

MEDSLabetalol 200 mg PO BID; insulin lispro sliding scale; omeprazole 40 mg PO daily; low-dose aspirin 81 mg; prenatal vitamins.

PHYS EXAMHR 88; BP 142/88; RR 18; SpO2 94% on room air; T 37.0°C. Neck circumference 47 cm. Mallampati IV, restricted neck extension, mouth opening 3 fingerbreadths, thyromental distance 4 cm. Redundant soft tissue over the lumbar back; bony landmarks not palpable on exam.

LABSHgb 10.5 g/dL; platelets 195 K/uL; INR 1.0; glucose 110 mg/dL; creatinine 0.7 mg/dL. Type and screen positive antibody (anti-E); four units crossmatched.

IMAGINGObstetric ultrasound suggestive of placenta accreta spectrum (lower segment, prior scar adherence). MRI confirms placenta percreta with bladder involvement. Cardiology TTE: LV hypertrophy, mild diastolic dysfunction, EF 65%, RVSP 38 mmHg.

FETALEstimated fetal weight 4200 g. FHR baseline 140 with appropriate variability.

OR ARRIVALBariatric OR table with ramp pillows in place. After multiple attempts a single 18 g IV in the right forearm. Right radial arterial line attempted twice unsuccessfully. Ultrasound brought into the room. NICU and gynecologic oncology team notified for the accreta. IR notified for possible postpartum embolization.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Modality choice when neuraxial is technically hard and GA airway is hard too; ultrasound-guided block in the morbidly obese; awake fiberoptic intubation versus optimized RSI; physiology of ventilation and position in the patient with BMI ~58; managing accreta hemorrhage with massive transfusion.

1. Modality decision

Neuraxial or a planned GA for this percreta cesarean hysterectomy? Which? Why? You choose neuraxial — spinal, slow epidural, or CSE? Which? Why? Ultrasound to place it — useful in her? Why? You expect placement to take 30-40 minutes; OB wants to start. Change your plan? Why?

Considerations and pitfalls AI draft

Neuraxial vs GA. Two defensible paths: neuraxial avoids a predicted difficult airway but is technically challenging in her; many accreta centers plan a controlled GA to avoid a crash conversion mid-hemorrhage (which this case then depicts). The drivers she brings: OSA, obesity ventilation limits, predicted difficult airway AND difficult neuraxial, percreta with high bleeding risk, prior failed regional and recall. Commit and defend either; wanting it both ways is the flag.
Spinal vs slow epidural vs CSE. CSE allows immediate surgical anesthesia plus a prolonged catheter for a long accreta case; single-shot spinal may be too brief if dissection extends. Commit and own the tradeoff.
Ultrasound. Very useful in obesity to identify midline, depth, and interspace; reduces attempts and time.
Time pressure. Engage OB on timing and pre-position before delivery when possible; the counter-argument is that a long, uncertain placement in a bleeding-risk case argues for a controlled GA from the start. Either is defensible if reasoned.
GA dangers. Difficult airway (MP IV, TMD 4 cm, neck 47 cm, restricted extension, prior 2-attempt intubation), rapid desaturation from reduced FRC, aspiration risk, and prior recall — a full-stomach hard airway in a percreta hemorrhage is the nightmare.

2. Backup airway plan

You plan a CSE with GA backup. If you must convert, awake fiberoptic or asleep with video laryngoscopy? Which? Why? Awake fiberoptic — walk your topicalization. Sedation during it — agent? Dose? You complete the CSE, surgical anesthesia at T4. As OB enters, BP 80/45, SpO2 90% on 4 L NC. DDx? Rx? Head-up or flat now? Why?

Considerations and pitfalls AI draft

Awake vs asleep. With a predicted difficult airway (MP IV, restricted extension, prior 2-attempt intubation, rapid desaturation), an awake technique is the safe default if conversion is elective/semi-elective; asleep VL as first attempt is defensible only if she is already anesthetized and stable with the airway team and fiberoptic ready. Naming decision points is the mark of judgment.
Awake fiberoptic. Atomized topicalization of tongue, oropharynx, and trachea (nebulized/atomized lidocaine, superior laryngeal and transtracheal supplements if comfortable), antisialagogue, patient upright; commit to the sequence.
Sedation in OSA. Minimal, short-acting; dexmedetomidine preferred over stacked opioids/benzodiazepines because it preserves airway tone and drive; over-sedating a difficult airway is the trap.
BP fall + SpO2 90%. Sympathectomy from the CSE plus supine atelectasis and aortocaval compression at BMI 58; aggressive left uterine displacement, phenylephrine or norepinephrine, fluid bolus, FiO2 to 1.0; restore pressure first, then head-up to recruit.

3. Ventilation, position, accreta finding

OB confirms percreta with bladder involvement; the plan is cesarean hysterectomy. She is awake under the CSE, SpO2 92% on 6 L. Head-up? How far? What pressors and inotropes are drawn up and labeled before incision? Calcium — where is it? Which blood products are in the room before the uterus is opened? OB: 'she's bleeding briskly.' Rx now?

Considerations and pitfalls AI draft

Position. Ramped, head-up, aggressive left tilt; expect tidal volumes to fall further as the abdomen is packed and she bleeds.
Pressors/inotropes. Multiple agents drawn up and labeled, calcium ready, norepinephrine running or immediately available, vasopressin available.
Blood ready. PRBC, FFP, platelets, cryo or fibrinogen concentrate in room; calcium and TXA at hand; rapid transfuser primed.
Brisk bleeding. Activate MTP, get a second large-bore line if not already in (she has a single 18 g), start the rapid transfuser, and pace resuscitation with the surgical steps — do not fall behind the loss.

4. Massive transfusion and coagulopathy

EBL 4 L and climbing. BP 75/40 on norepinephrine 0.3 and vasopressin 0.04. Product ratio — what are you giving? Calcium — how often, and why here? Cryoprecipitate or fibrinogen concentrate? Which? Why? TXA — yes/no? Dose? By when? The CSE was working. She becomes restless, then unresponsive. What happened? Rx? You convert to GA — induction agent and dose in this hypovolemic patient? Tube in. Ventilator — tidal volume, how many mL? PEEP? Plateau ceiling? She had recall last time. Hypnotic plan for the next 20 minutes — agent? Dose? Monitor?

Considerations and pitfalls AI draft

Product ratio. 1:1:1 as the default while goal-directed testing catches up; fibrinogen replacement specific and early; calcium repleted frequently; trend lactate and ionized calcium.
Calcium. Recheck ionized calcium every few units — citrate from rapid transfusion chelates calcium, and hypocalcemia both worsens coagulopathy and drops cardiac output. Give calcium chloride/gluconate to keep iCa normal.
Cryo vs fibrinogen concentrate. Either — fibrinogen concentrate delivers a known dose in small volume and fast; cryoprecipitate is the traditional source. Replace to keep fibrinogen above ~150-200 in obstetric hemorrhage; commit.
TXA. 1 g IV over 10 minutes, ideally within 3 hours of the bleed onset (WOMAN trial); repeat once if bleeding continues. Early, not an afterthought.
Restless then unresponsive. Hemorrhagic shock with cerebral hypoperfusion — she is dying, not lightly anesthetized; secure the airway and control the resuscitation. Reading this as inadequate block alone is the miss.
Conversion to GA. She needs a secured airway and reliable anesthesia; reduce the induction dose for hypovolemia — ketamine 0.5-1 mg/kg or low-dose etomidate — with a full RSI-dose paralytic (rocuronium 1.2 mg/kg or succinylcholine); pressors up. A standard induction dose here arrests her.
Ventilator. Low tidal volume by predicted (not actual) body weight (~6-8 mL/kg PBW, roughly 300-400 mL for 5'4"); modest PEEP 8-10 to offset the atelectasis of a heavy chest and abdomen; plateau ≤30; rate to PaCO2. Zero PEEP in her collapses dependent lung; sizing volume to 152 kg is the common error.
Keeping her unaware. The tension the case sets up: a hypovolemic brain tolerates little hypnotic, yet she had prior recall. Use the lowest effective hypnotic plus a benzodiazepine (midazolam) and scopolamine as tolerated, a processed-EEG monitor if available, volatile as pressure allows, and document the plan and her history. Chasing full MAC into arrest, or giving nothing and accepting awareness, are the paired failures.

B. POST-OPERATIVE CARE

Teaching focus. Extubation judgment in the BMI-58 OSA patient after massive transfusion; postop respiratory failure and noninvasive support; multimodal analgesia that respects OSA; VTE prophylaxis in the high-risk postpartum; disclosure when the patient had a prior bad anesthetic and another hard course.

1. Extubation

Hysterectomy done, EBL 5 L, given 10 PRBC, 8 FFP, 2 platelets, 10 cryo, TXA. BP 100/60 on norepinephrine 0.05. Extubate in the OR? Why/why not? If you extubate, what criteria must be met first? Position for extubation? CPAP in PACU — apply when? Why? She is extubated; SpO2 falls to 85% on 6 L within 20 minutes. DDx? Rx? At what point do you reintubate? Disposition?

Considerations and pitfalls AI draft

Extubate or not. Many would leave her intubated after 5 L blood loss with class III obesity, severe OSA, and a massive transfusion — she is at high risk for post-extubation failure and reintubation would be a hard airway. Defensible either way only if the criteria are named and honestly met.
Criteria. Adequate gas exchange, full reversal confirmed (TOF ≥0.9), normothermia, hemodynamic stability off or on minimal pressor, surgical hemostasis, awake and following commands.
Position and CPAP. Head-up, ramped; apply CPAP within minutes of extubation given severe OSA — do not wait for her to obstruct.
Post-extubation hypoxemia DDx. Obesity atelectasis, residual neuromuscular block, opioid effect, pulmonary edema (TACO or TRALI after massive transfusion), aspiration — reach for the most likely (atelectasis/residual) while scanning for TACO/TRALI given the transfusion volume.
Rx and reintubation. CPAP/BiPAP, head-up, recruit, treat the specific cause; reintubate for rising CO2 with declining mental status or refractory hypoxemia — do not let a hard airway crash on the ward.
Disposition. ICU.

2. Postoperative respiratory failure

POD 1: hypoxic on CPAP, RR 30, P/F 180, PaCO2 climbing. DDx? Most likely in her? A BiPAP trial — set EPAP and IPAP where, relative to her home 14? What tells you NIV is failing? She becomes obtunded with a rising CO2. Reintubate now, or keep trying NIV? Why? Her airway is difficult — how do you set up this intubation differently from a routine floor tube?

Considerations and pitfalls AI draft

DDx. Atelectasis from positioning and obesity, mucus plugging, pulmonary edema, aspiration, opioid-induced hypoventilation — most likely atelectasis with an obesity-hypoventilation contribution.
NIV settings. BiPAP with EPAP at or above her home 14 cm H2O to splint the airway, IPAP set higher to augment tidal volume; titrate to exhaled volumes and CO2.
NIV failure. Worsening gas exchange, rising CO2, declining mental status — do not ride a failing trial into an arrest.
Reintubate. An obtunded patient with a rising CO2 needs the airway now; delaying invites a crash induction on a hard airway. Bring the difficult-airway cart, video laryngoscope and fiberoptic, a second skilled operator, ramp and preoxygenate/apneic-oxygenate, and pick the technique deliberately — this is not a routine floor tube.
Bronchoscopy. For suspected plugging or to assess aspiration once the airway is secured.

3. Multimodal analgesia in OSA

Pain plan for her — what is scheduled around the clock? Acetaminophen — yes/no? NSAID — yes/no? Why? IV opioid for breakthrough — agent, dose, and what monitoring? A PCA — yes/no in severe OSA? Why? Gabapentinoid — yes/no? Why? TAP or QL block? Which? Why?

Considerations and pitfalls AI draft

Scheduled. Multimodal, opioid-sparing by default: acetaminophen scheduled, an NSAID if renal function and hemostasis allow (caution after 5 L loss), plus a truncal block.
Breakthrough opioid. Small, monitored doses only, with continuous pulse oximetry and capnography; every opioid dose stacks on an OSA baseline.
PCA in OSA. High risk for respiratory depression; not a default — if used at all, only in a monitored setting with capnography and conservative settings. This is the answer to give OB: a basal-rate or generous-demand PCA in severe OSA after this course is how these patients die overnight.
Gabapentinoid. Controversial in OSA — sedation and respiratory-depression risk with modest analgesic benefit; not a routine add here.
Block choice. TAP or quadratus lumborum — either reasonable; QL may give somewhat better visceral coverage. CPAP whenever she sleeps is part of the analgesic safety plan, not separate from it.

4. VTE prophylaxis

POD 1: hemostasis good, drains low. Start pharmacologic VTE prophylaxis now, or wait? What decides the timing? Agent? How do you dose it at 152 kg? Until it starts, what protects her? POD 2: new unilateral leg swelling. Concern? Workup? It confirms DVT. Therapeutic anticoagulation now — yes/no? Why? If not, what instead?

Considerations and pitfalls AI draft

When to start. As bleeding risk allows — typically within 12-24 h postpartum after cesarean hysterectomy once hemostasis is secure; a plan agreed with OB. She is very high risk (obesity, cesarean hysterectomy, immobility, postpartum).
Agent and dose. Enoxaparin commonly, dosed for her weight (weight-based or anti-Xa-guided rather than a flat prophylactic dose in class III obesity).
Mechanical. Sequential compression from the start; it is the bridge while pharmacologic prophylaxis is held for bleeding risk, and matters most in exactly this delayed-anticoagulation high-risk patient.
New leg swelling. DVT is the primary concern; also cellulitis and hematoma. Duplex ultrasound; D-dimer is of limited use postpartum.
Therapeutic anticoagulation. Weigh confirmed DVT against re-bleeding risk days after a percreta hysterectomy; an IVC filter is a bridging option if anticoagulation is truly contraindicated. A multidisciplinary call (OB, hematology, the surgical team), not a unilateral one.

5. Disclosure and follow-up

POD 3. She asks why she had to be put to sleep this time. What will you tell her? She took her CPAP off overnight; the nurse reports SpO2 88% on room air while she slept. Rx? What goes in her record for the next anesthesiologist? Her next anesthetic — awake intubation? ICU bed? What do you recommend in writing?

Considerations and pitfalls AI draft

Why asleep. An honest account: the bleeding became life-threatening and she lost consciousness from blood loss, so the airway had to be secured and general anesthesia given; what was done to prevent recall this time.
CPAP off, SpO2 88%. Desaturation while asleep off CPAP in severe OSA with opioids on board — CPAP back on whenever she sleeps, continuous oximetry/capnography, review the opioid orders; explain the why rather than simply reordering it.
Summary letter. A portable anesthesia record: the difficult intubation and technique used, products received, complications, and explicit recommendations for future care.
Next anesthetic. Straight recommendations, not a threat: a predicted difficult airway with an awake intubation option, difficult neuraxial (ultrasound, early placement), an ICU bed, CPAP perioperatively, and a multimodal analgesic plan.

Long stem

Severe rheumatic mitral stenosis with new AF, planned cesarean

A 33 y.o. G2P1 at 36 weeks gestation, 58 kg, 5'3", is admitted for planned cesarean delivery tomorrow morning for known severe rheumatic mitral stenosis with progressive symptoms.

HPIProgressive exertional dyspnea since week 28, now NYHA class III to IV; orthopnea and paroxysmal nocturnal dyspnea for the past week. Two triage visits in 10 days for shortness of breath. Today walking from the parking lot left her breathless. No chest pain. Immigrated from Vietnam at age 19; first child delivered uneventfully at 24.

PMHChildhood rheumatic fever. Severe rheumatic mitral stenosis with mitral valve area 0.85 cm² and mean gradient 18 mmHg on echo this month. New-onset atrial fibrillation four weeks ago, rate-controlled. Mild gestational hypertension. No prior anesthetics other than uncomplicated spinal for first cesarean.

MEDSMetoprolol 50 mg PO BID; furosemide 20 mg PO daily; therapeutic-dose enoxaparin 1 mg/kg SC BID for AF (last dose 24 hours ago); prenatal vitamins.

PHYS EXAMHR 92 (atrial fibrillation, controlled); BP 118/72; RR 22; SpO2 95% on 2 L NC; T 36.8°C. Loud opening snap, low-pitched mid-diastolic murmur at the apex with presystolic accentuation lost in AF. Bibasilar crackles to the mid-zone. JVP elevated to the angle of the jaw. Mild pitting edema. Airway: Mallampati II, full mouth opening, full neck extension.

ECGAtrial fibrillation at 92 with diffuse repolarization changes; no ischemic features.

LABSHgb 10.2 g/dL; platelets 195 K/uL; INR 1.2; creatinine 0.7 mg/dL; BNP 1240 pg/mL; anti-Xa drawn this morning (~24 h after last dose) 0.5 IU/mL. Type and screen positive for anti-K antibody (notified blood bank, two crossmatched units on hold).

IMAGING / TTE todayMitral valve area 0.85 cm², mean gradient 18 mmHg; estimated RVSP 60 mmHg; RV mildly dilated with preserved function; LV ejection fraction 60%; biatrial enlargement; no thrombus seen. CXR with cephalization and small bilateral pleural effusions.

FETALFHR baseline 140 with appropriate variability and accelerations.

OR ARRIVALTwo 16 g peripheral IVs and a right radial arterial line in. Cardiology and cardiac surgery on standby. NICU team present. Epidural cart in the room. ECMO consult notified the day before.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Hemodynamic goals for fixed mitral stenosis with new AF in late pregnancy; neuraxial choice when slow ascent of level governs the technique; managing the post-delivery autotransfusion in a patient who cannot accept the volume; rate control and pulmonary pressures intraoperatively.

1. Pre-induction goals and monitoring

Hemodynamic targets for her — HR? Rhythm? Preload? SVR? PVR? Why each? Beyond the arterial line she has, what monitoring do you want? A CVP — will it help you here? Why/why not? On the table she is anxious and her rate jumps to 118 in AF. Rate or anxiety first? Esmolol, metoprolol, dexmedetomidine, or magnesium? Which? Why that one?

Considerations and pitfalls AI draft

Goals. Keep HR ~70-90 (diastolic filling time is everything across a fixed valve), maintain rate control in AF, avoid falls in preload and SVR, avoid rises in PVR (no hypoxia, hypercarbia, or light-anesthesia sympathetic surges).
Monitoring. Arterial line already in; TEE intraop has a role if the question becomes volume and RV function; a PA catheter is debated in fixed MS and many avoid it; CVP has limited utility with severe MS and AF (poor surrogate for LV filling).
Anxious tachycardia at 118. Treat it before anything else — the tachycardia collapses diastolic filling and can precipitate pulmonary edema; addressing anxiety is part of the hemodynamic plan, not a sideshow.
Agent. Esmolol (titratable, short) or low-dose metoprolol for rate; dexmedetomidine calms her while preserving rate control; magnesium is an adjunct. Defend on time course and hemodynamics; avoid anything that drops SVR abruptly.

2. Modality decision and neuraxial technique

Single-shot spinal, slow-titration epidural, or continuous spinal for her? Which? Why? Last enoxaparin was 24 hours ago and her anti-Xa this morning is 0.5 IU/mL. Neuraxial now — proceed, or wait? Why? An epinephrine-containing test dose in a patient in AF — use it, or omit it? Why? What sensory level do you want for incision? How fast do you let the block climb? Why?

Considerations and pitfalls AI draft

Modality. Slow-titration epidural or continuous spinal over single-shot spinal in severe MS — a rapid sympathectomy drops preload and SVR that a fixed valve cannot compensate for. A reflexive single-shot spinal here is a flag.
Anticoagulation timing. Therapeutic LMWH wants a 24-hour interval before neuraxial; she is right at that boundary. An anti-Xa of 0.5 IU/mL at ~24 h is higher than expected for a patient truly cleared — it suggests residual effect. Consider a further delay or a modified plan; the number informs but does not by itself license the block.
Epinephrine test dose. An epinephrine-laced test dose can raise the rate in AF and is hard to interpret as a marker of intravascular placement (baseline rate already irregular); tachycardia is also exactly what you are trying to avoid. Many omit epinephrine and rely on incremental dosing with aspiration; defensible.
Target level. T4 for cesarean, reached slowly through a titrated catheter so her circulation compensates for each increment; abrupt sympathectomy is the danger.

3. Intraoperative rate, rhythm, and BP swings

Level is T5. As the surgeon enters the peritoneum, HR jumps to 130 in AF and BP falls to 88/52. DDx? Do you fix the rate or the pressure first? Why? Rate control — which agent? She is already on metoprolol; does that change your choice? A phenylephrine bolus for the pressure — helpful or harmful here? Why? Esmolol in: HR 95, BP 96/58. Another phenylephrine bolus, or a 500 mL fluid bolus? Which? Why?

Considerations and pitfalls AI draft

Tachycardia DDx. Anxiety, inadequate block for the stimulus, surgical manipulation, volume shift, sympathetic response — and the rate itself is now driving the hypotension.
Rate vs pressure. Rate is the lever in MS: slowing the rate lengthens diastolic filling and usually restores the pressure; pure vasoconstriction without rate control leaves the gradient and filling problem unsolved.
Rate control. Short-acting beta blocker (esmolol) titrated is preferred over a large bolus of a long agent; her home metoprolol does not preclude more, but titrate to effect and treat the trigger too.
Phenylephrine. Raises SVR and coronary perfusion but also raises PVR — use a cautious dose; it supports pressure but does not fix the underlying tachycardia-driven filling failure.
Pressor vs fluid. With the rate controlled, a modest phenylephrine bolus — she arrived congested (crackles to the mid-zone, JVP at the jaw, BNP 1240), so a 500 mL bolus is the wrong lever and can flash pulmonary edema; volume goes in small, watched aliquots only for measured loss. Reflexive fluid for neuraxial hypotension is the trap in MS.

4. Post-delivery autotransfusion and uterotonics

Baby out. The surgeon asks for oxytocin. Bolus or slow infusion? Why? Dose? Atony at 5 minutes. Methylergonovine — yes/no in her? Why? Carboprost — yes/no? Why? Misoprostol — yes/no? She becomes acutely dyspneic: SpO2 89%, HR 140 AF, BP 90/55. What has happened? Rx? Furosemide now — yes/no? Why now?

Considerations and pitfalls AI draft

Oxytocin. Slow dilute infusion, never an IV push — bolus oxytocin causes vasodilation, reflex tachycardia, and a pulmonary-pressure spike, all poorly tolerated in severe MS with pulmonary hypertension.
Methylergonovine. Avoid — raises SVR and PVR; a hazard with her RVSP 60.
Carboprost. Avoid — raises PVR and can worsen her pulmonary hypertension; relatively contraindicated here.
Misoprostol. The uterotonic of choice among the drugs here (800-1000 mcg), alongside early mechanical and surgical management, because it spares the pulmonary and systemic vasculature.
Post-delivery dyspnea. Uterine contraction autotransfuses ~500 mL into a circulation with a fixed valve — the preload surge overwhelms the stenosis and flashes pulmonary edema; the tachycardia compounds it. Rx: control the rate, sit up, oxygen/NIV, diurese now that the baby is out (this is the moment diuresis is right), consider milrinone for RV support with caution for its vasodilation. Get cardiology to the bedside early — this is the predicted crisis of the case.

B. POST-OPERATIVE CARE

Teaching focus. Postpartum hemodynamics in fixed mitral stenosis; resuming anticoagulation in the immediate postpartum period; recognizing when temporizing fails and definitive valve intervention is needed; counseling on future pregnancies after a near-miss.

1. Immediate postpartum ICU course

Arrives in ICU on 4 L NC, HR 100 AF, BP 105/65, SpO2 93%, mild crackles. First priorities? Diurese — to what endpoint? Restart anticoagulation — when, which agent, what dose? OB is worried about uterine bleeding. Does that move your timing? Metoprolol — IV or PO tonight? Pulmonary edema returns 2 hours in. Rx?

Considerations and pitfalls AI draft

Priorities. Rate and rhythm control, gentle diuresis, oxygen, and vigilance for recurrent pulmonary edema as fluid mobilizes over the next 24-72 h.
Diuresis endpoint. Respiratory comfort and improving oxygenation while preserving enough filling for the stenotic valve — perfusion and symptom endpoints, not a target weight; over-diuresis drops preload below MS tolerance.
Anticoagulation timing. Balance AF stroke risk against postpartum hemorrhage: mechanical compression immediately, resume pharmacologic anticoagulation ~12-24 h postpartum once hemostasis is secure.
Agent. A heparin infusion early (titratable and reversible if she bleeds or needs a procedure), transitioning to LMWH once bleeding risk falls.
Recurrent edema. More diuresis, NIV, tighten rate control, and consider milrinone with careful pressure support if RV function flags.

2. AF with RVR and hemodynamic decompensation

POD 1: HR 150 AF, BP 78/45, SpO2 88% on NIV, lactate 4. She is unstable. First move? Synchronized cardioversion — indicated now? Energy? She has been off anticoagulation since delivery — does that stop you? Why/why not? After she stabilizes, rate control — agent and dose? Amiodarone in fixed MS — reasonable? Why? Cardiology says she needs balloon mitral valvuloplasty. Transport to the cath lab — intubate first, or go as she is? Why?

Considerations and pitfalls AI draft

Priorities. She is unstable — hypotension, hypoperfusion, rising lactate from uncontrolled RVR across a fixed valve; immediate synchronized cardioversion is the lead while you support perfusion.
Cardioversion. Synchronized, start ~100-200 J biphasic; instability overrides the usual anticoagulation-before-cardioversion caution — the thromboembolic risk is accepted because she is decompensating now. Decide with cardiology but do not delay for a stable patient's rules.
Rate control after. Only once perfusing, and cautiously in fixed MS: IV beta blocker or diltiazem to effect; nodal agents alone will not rescue an unstable patient — that is what the shock is for.
Amiodarone. Reasonable for rhythm control here; watch BP acutely and pulmonary/thyroid effects over the longer term.
BMV logistics. Transport with full hemodynamic monitoring, rescue drugs drawn, and an anesthesia team present in the cath lab; agree the airway plan and vascular access before moving her.

3. Postpartum hemorrhage in the cardiac patient

POD 1 evening: heavy lochia, Hgb 8.4 to 6.8 over 4 hours, BP 95/60, HR 130 AF. What worries you most in her specifically? OB asks for a uterotonic. Which, and which do you refuse? Volume — what fluid, how fast? BP 82/50 after two units. Pressor? Why that one? Transfusion threshold in her — higher or lower than usual? Why? Her heparin was running — what do you do with it?

Considerations and pitfalls AI draft

Concerns. She tolerates neither the hypovolemia of the bleed nor the volume of aggressive resuscitation — a fixed valve punishes fluid shifts in both directions; and the tachycardia from hypovolemia itself worsens filling.
Uterotonic. Oxytocin by slow infusion and misoprostol; refuse methylergonovine and carboprost (SVR/PVR effects); escalate to mechanical and surgical control earlier than usual rather than leaning on drugs.
Volume. Slow, titrated, small aliquots with the lungs watched — resuscitate the loss without flooding a fixed valve; blood over crystalloid as she needs replacement.
Pressor. Norepinephrine or vasopressin to support pressure without a big chronotropic hit; avoid pure beta agonists that drive the rate up across the stenosis.
Transfusion threshold. Transfuse at a higher hemoglobin than a healthy postpartum patient — her oxygen delivery is margin-limited by the valve and pulmonary hypertension; the exact number is contextual but err toward earlier replacement.
Heparin. Hold it for active bleeding, keep mechanical compression on, and restart once hemostasis is secure — a reversible agent is exactly why an infusion was chosen early.

4. Balloon mitral valvuloplasty postpartum

Cardiology proceeds with balloon valvuloplasty. Sedation or GA for the case? Why? What monitoring goes in first? Anticoagulation during the procedure — what, and what is your reversal plan? During balloon inflation her BP suddenly drops. DDx? Rx? Post-procedure echo: residual gradient 6, no significant new MR. Where does she go? Does the result change her anticoagulation?

Considerations and pitfalls AI draft

Sedation vs GA. Sedation preferred when she tolerates it — avoids the preload/SVR drop and PVR rise of induction across a fixed valve; keep a GA plan and airway ready for collapse.
Monitoring. Arterial line and full monitoring before instrumentation; rescue drugs drawn; a clear backup plan for hemodynamic collapse.
Anticoagulation. Procedural heparinization with a reversal (protamine) plan if bleeding.
Hypotension on inflation. Transient occlusion of the valve during balloon inflation is expected and brief; a persistent drop suggests tamponade (from transseptal/perforation), acute severe MR from a torn leaflet, or arrhythmia — differentiate fast and treat (pericardiocentesis, support, cardiology).
Post-procedure. A residual gradient of 6 with no significant MR is a good result; ICU or step-down monitoring; anticoagulation continues for her AF, and both heparin and warfarin are breastfeeding-compatible if she nurses.

5. Counseling and future pregnancy

POD 4, doing well. She asks whether she can safely have another baby. What will you tell her? She wants to breastfeed and asks for a DOAC instead of injections. Yes/no? Why? What can she take? What written summary do you make sure goes home with her for her next anesthetic?

Considerations and pitfalls AI draft

Future pregnancy. High-risk — pregnancy nearly decompensated her; the message is preconception cardiology, likely definitive valve intervention before another pregnancy, and shared decision-making. The learner supports rather than owns this conversation with cardiology and OB; an honest account of how severe this episode was is part of it.
Breastfeeding and anticoagulation. Her AF is valvular (rheumatic MS), which contraindicates DOACs regardless of lactation — her options are warfarin or heparin/LMWH; both warfarin and heparin are compatible with breastfeeding. Defer dosing specifics to cardiology and lactation resources.
Documentation. A portable anesthesia summary: the valve disease and RVSP, the intraoperative course and pulmonary edema, the valvuloplasty details, anticoagulation, and explicit recommendations for any future anesthetic.

Long stem

Postpartum hemorrhage after vaginal delivery with a labor epidural in place

A 33 y.o. G3P3, 5'5", 88 kg, delivered vaginally 40 minutes ago after an induction of labor. You are called to her labor room for bleeding.

HPIInduced at 41 weeks 1 day for post-dates: misoprostol, then oxytocin for 22 hours. Labor epidural placed at L3-4 14 hours ago; sensory level T10 bilaterally and comfortable throughout. Temp 38.3°C four hours before delivery; ampicillin and gentamicin started for suspected intraamniotic infection. Three-hour second stage. Spontaneous vaginal delivery of a 4,250 g boy at 0410 with a second-degree laceration, repaired. Placenta delivered at 0425 and reported intact. Clear liquids only during labor.

PMHTwo prior uncomplicated vaginal deliveries, both with epidurals; the last 2 years ago. Mild intermittent asthma since childhood: albuterol a few times a year, last used 2 months ago, never hospitalized or intubated. No other medical history. No prior surgery.

MEDSPrenatal vitamin. Albuterol inhaler as needed. Ampicillin and gentamicin IV since this afternoon. No known drug allergies.

PHYS EXAMOn admission: BP 118/72; BP 112-126/68-78 throughout labor. Mallampati III, full dentition, thyromental distance three fingerbreadths, normal neck extension. Lungs clear.

LABSOn admission: Hgb 11.6 g/dL; platelets 196 K/uL. Type and screen: O positive, antibody screen negative.

AT THE BEDSIDE (0450)The nurse is massaging the fundus and reports a quantified blood loss of 1,100 mL. Postpartum oxytocin 30 units/500 mL running at 125 mL/h since delivery. HR 118; BP 96/58; RR 22; SpO2 98% on room air; T 38.1°C. Awake and anxious; says she feels cold and lightheaded. One 18 g IV. Epidural catheter in place; last PCEA bolus 30 minutes ago.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Recognizing how much a parturient has really lost and getting ahead of it; uterotonics chosen against her history and their contraindications; TXA timing; extending a labor epidural versus converting to GA for exploration and a balloon in a bleeding patient; running a massive transfusion to fibrinogen, calcium, temperature, and end points.

1. Called to the bedside

Bleeding continues. Immediate priorities? Access — what? Size? Labs — which? Blood — how many units? Crossmatched or uncrossmatched? Why? The QBL — trust it? Why/why not? How much has she actually lost? What tells you? DDx for the bleeding? How do you sort it at the bedside? OB: uterus soft, fundus above the umbilicus; laceration intact and dry. Interpretation? Crystalloid while blood is on the way? How much? Why?

Considerations and pitfalls AI draft

Immediate priorities. More hands, a second large-bore IV, labs, blood to the room, and uterotonic escalation alongside the OB, with QBL recounted every 5-15 minutes. Oxygen, warmed fluids, a pressure cuff cycling every few minutes. A learner who stays at the head of the bed waiting for the next number is behind.
Access. One 18 g is not enough. A second large-bore peripheral (16 g or larger, or a rapid infusion catheter) now, before she clamps down further; ultrasound guidance or an intraosseous line if peripheral attempts fail. A central line is not the first move in a bleeding patient with veins.
Labs. CBC, fibrinogen, PT/INR, aPTT, a fresh type and crossmatch sample, ABG with lactate and ionized calcium; a viscoelastic test if available. Fibrinogen is the most useful early lab: a level below about 200 mg/dL early in PPH predicts progression to severe hemorrhage. A learner who sends only a hemoglobin has missed this.
Blood. 2-4 units of PRBC now, with a cooler in the room. Her admission screen was negative, so crossmatched (or electronically crossmatched) units come quickly if the sample is still current. If she becomes unstable before they arrive, uncrossmatched units go in; waiting on a crossmatch in a patient who is deteriorating is the error.
Trust the QBL. Only partly. Quantified loss means weighing pads, sponges, and drapes (1 g is about 1 mL) minus their dry weight, plus calibrated under-buttocks drapes, subtracting amniotic fluid collected before the placenta. It beats a visual estimate, which runs low and more so as volume rises, but even a good QBL lags: blood pooled in the uterus and vagina has not been counted yet.
How much lost. Probably more than the count. A healthy parturient holds her BP until late; tachycardia, a narrowing pressure, feeling cold and lightheaded are hypovolemia. Shock index (HR divided by SBP) is about 1.2; above roughly 0.9-1.0 it tracks with need for transfusion. Fever, pain, and anxiety add to the HR, but none of them should be used to explain it away. Reassurance from an SBP in the 90s is the flag.
DDx. Tone (atony, the most common cause), trauma (laceration extension, cervical or vaginal tear, hematoma, inversion, rupture), tissue (retained placenta or membranes), thrombin (coagulopathy, dilutional or consumptive). Sort it by palpating the fundus, inspecting the lower tract under good light, rechecking the placenta, and watching whether the blood clots. Prolonged oxytocin, intraamniotic infection, a large baby, and a long second stage all point to atony; a placenta "reported intact" does not rule out a missing fragment.
Interpretation. Atony until proven otherwise: a soft, high uterus with an intact, dry repair. Retained tissue and coagulopathy can coexist with it, so the placenta check and the clotting labs still matter.
Crystalloid. Warmed isotonic crystalloid as a bridge, roughly 1-2 L, then blood. Large crystalloid volumes dilute clotting factors, worsen coagulopathy and edema, and buy little. Liters of saline while waiting for blood is the flag.

2. Uterotonics

Uterus still soft despite bimanual massage. Oxytocin — increase? Bolus? Dose? Why that dose? Five minutes later, no better. Second agent: methylergonovine? Carboprost? Misoprostol? Which? Why? Dose? Route? Carboprost? Why/why not? TXA? Dose? Timing? A second dose — when?

Considerations and pitfalls AI draft

Oxytocin. Reasonable to turn up the infusion and give a small IV bolus, 1-3 units over at least 30 seconds (10 units IM is an alternative). Rapid large IV boluses (5-10 units pushed) cause vasodilation, hypotension, tachycardia, and ST changes, which this hypovolemic patient cannot afford.
Five minutes later, no better. After 22 hours of oxytocin, the receptors are desensitized and more oxytocin buys little. The point is to move to a second agent early. Escalating oxytocin dose after dose while the uterus stays soft is the flag.
Second agent. Methylergonovine 0.2 mg IM is a sound choice: she is normotensive throughout labor with no coronary disease. It can be repeated every 2-4 hours. It is contraindicated in hypertension, preeclampsia, and coronary disease; side effects are nausea, vomiting, and hypertension.
Route. Methylergonovine IM, not IV: an IV bolus can cause severe hypertension, coronary vasospasm, and stroke. Carboprost IM or intramyometrial. Misoprostol oral, sublingual, or rectal.
Carboprost. 250 mcg IM (or intramyometrial), repeated every 15-90 minutes, up to 8 doses (2 mg). It is contraindicated in asthma: it can cause bronchospasm and hypoxemia. Her asthma is mild, but other agents are available, so most would not use it. If it ever comes to a last resort, it is given with a bronchodilator ready and the airway watched. A learner who gives it without mentioning her asthma has missed a hook.
Misoprostol. 600-1000 mcg (oral, sublingual, or rectal) is a reasonable adjunct, but its onset is slow and it is weaker than the injectables, so it is not the second agent to rely on. Fever and shivering are common and will muddy her infection picture.
TXA. Yes, now: 1 g IV over 10 minutes, as early as possible and within 3 hours of birth; the benefit falls with every delay and it is not started after 3 hours. Delivered at 0410, she is well inside the window. A second 1 g if bleeding continues after 30 minutes or restarts within 24 hours. It treats fibrinolysis, not atony, so it does not replace uterotonics. Avoid a rapid push (hypotension).

3. To the operating room

0500. Assume methylergonovine and TXA are in. QBL 1,800 mL; HR 126, BP 88/50; second unit of PRBC running. OB wants the OR for an exam under anesthesia, manual exploration, and a balloon. Go now or stabilize first? Why? Extend the epidural or convert to GA? Why? Assume the epidural. Agent and volume? In the OR, block T8 bilaterally; BP 80/46. Rx? A retained fragment is removed. While the balloon goes in: QBL 2,600 mL, BP 72/38, HR 140; she is confused and retching. GA now? Why/why not? Induction and NMB: drugs and doses? Airway plan?

Considerations and pitfalls AI draft

Go now. Yes, and resuscitate on the way. The OR gives light, exposure, positioning, a rapid infuser, and room to convert. "Stabilizing" in the labor room before the source is controlled loses time. Blood travels with her and massage continues.
Epidural vs GA. Either is defensible at this point. Extending a working epidural avoids an airway in a Mallampati III parturient with a full stomach, and is reasonable if she is mentating and responding to volume. But a dense block takes away sympathetic tone her pressure depends on, and with ongoing hemorrhage and a shock index above 1 some will go straight to GA. Flags: a large single bolus into a hypovolemic patient, or reflexive GA without weighing the airway.
Agent and volume. 3% chloroprocaine 10-15 mL (fastest onset) or 2% lidocaine 10-15 mL, with or without epinephrine and bicarbonate, given in 5 mL increments with BP every 1-2 minutes, not as one large bolus. The dilute labor infusion will not give a dense enough block; 0.5% bupivacaine is too slow here. A T10 level with dense sacral coverage is often enough for manual exploration; many aim for T8-T6 for intrauterine manipulation and balloon placement. A cesarean-level T4 is not needed and adds hypotension.
BP 80/46. Hypovolemia plus the new sympathectomy. Blood is the treatment; a pressor bridges. Phenylephrine 50-100 mcg or norepinephrine 5-10 mcg boluses are reasonable with HR 126; ephedrine adds tachycardia and is slow. Run blood fast through a warmer and keep the uterotonics going. A pressor alone to fix the number is the flag.
GA now. Yes. Confusion means her brain is not perfused and she cannot protect her airway; retching adds aspiration risk; more neuraxial local anesthetic is off the table in profound shock. Holding off until she arrests is the error.
Induction and NMB. RSI. Ketamine 0.5-1 mg/kg (about 45-90 mg, lower end in shock) or etomidate 0.2-0.3 mg/kg (about 18-26 mg). Ketamine also bronchodilates, which suits her asthma, but in a patient whose catecholamines are spent its direct myocardial depression can show. A standard propofol dose is the flag. Succinylcholine 1-1.5 mg/kg actual weight (about 90-130 mg) or rocuronium 1.2 mg/kg (about 70 mg on ideal weight, up to about 105 mg on actual weight) with sugammadex available; either, if defended. Pressor in hand, head-up position, preoxygenate as well as her confusion allows.
Airway plan. Video laryngoscope, smaller tube (6.0-6.5), bougie, a second-generation SGA as rescue, front-of-neck access kit open, suction running (retching). Pregnancy airway edema plus Mallampati III means the first attempt has to be the best one. Gastric tube after the airway is secure.

4. Resuscitation in the OR

Assume she is intubated on the first pass. Labs from 0455 return: Hgb 9.4, platelets 151, INR 1.2, fibrinogen 168. Reassured? Why/why not? Massive transfusion — activate? Why/why not? Ratio? Fibrinogen — replace now? Why/why not? With what? Dose? Target? Maintenance: sevoflurane? Propofol? Why? After 6 units of PRBC: iCa 0.86 mmol/L, K+ 5.3. Rx? Agent? Dose? Temp 35.2°C. Of concern? Rx? Balloon at 400 mL; drain output 40 mL in 15 minutes. Transfusion end points now?

Considerations and pitfalls AI draft

Reassured. No. The labs are 30 minutes old and were drawn early. Hemoglobin lags acute loss until volume is replaced; a 9.4 says nothing about the last liter. The fibrinogen is the worrying number: low for term pregnancy (where it usually runs 350-650 mg/dL) and below 200 this early.
Massive transfusion. Yes. Ongoing bleeding past 2.5 L, hemodynamic instability, and early low fibrinogen. Activation gets products flowing in packs without unit-by-unit orders. Waiting for the next lab is the flag.
Ratio. Empiric, approaching 1:1:1 (PRBC:plasma:platelets, one apheresis platelet unit per about 6 units of PRBC), until labs or viscoelastic results can guide it. Obstetric hemorrhage uses up fibrinogen early, so it gets replaced early rather than waiting for plasma to do it.
Fibrinogen. Cryoprecipitate 10 units (two 5-unit pools) or fibrinogen concentrate about 2-4 g; target above 200 mg/dL, then recheck. Plasma raises fibrinogen slowly and only with large volume. A viscoelastic fibrinogen assay, if available, can guide repeat dosing faster than the lab.
Maintenance. Volatiles relax the uterus in a dose-dependent way, so keep sevoflurane low (about 0.5 MAC or less), supplemented with opioid, ketamine, or midazolam; propofol TIVA avoids the uterine effect but drops pressure in shock. Either, if defended. Shock and low anesthetic doses mean awareness risk: processed EEG and an amnestic. Running a full MAC of volatile with an atonic uterus is the flag.
iCa and K+. Citrate in the products binds calcium; low calcium worsens clotting, myocardial contractility, and uterine tone. Calcium chloride 1 g through a large, well-running line (central preferred), or calcium gluconate 3 g; repeat to keep iCa above about 1.1 mmol/L. K+ 5.3: calcium protects the myocardium; watch the ECG, trend it, and treat with insulin and glucose if it climbs. An arterial line for sampling is worth placing now if it is not in.
Temperature. Yes. Hypothermia slows clotting enzymes and impairs platelets, and the lethal triad (hypothermia, acidosis, coagulopathy) feeds itself. Warmer on every line, forced-air warming, warm room; target above 36°C.
End points. Once bleeding slows, stop the fixed ratio and transfuse to numbers: Hgb about 7-8 (higher if still bleeding or unstable), platelets above 50 (above 75 while bleeding), fibrinogen above 200, INR below about 1.5, iCa above 1.1, temperature above 36°C, pH above 7.2, lactate falling. Continuing to hang massive transfusion packs after hemostasis invites volume overload.

B. POST-OPERATIVE CARE

Teaching focus. Extubation and disposition after an obstetric massive transfusion; hypoxemia after resuscitation; when the labor catheter can safely come out and when VTE prophylaxis can start; oliguria and nephrotoxins after shock, with breastfeeding-safe analgesia; a postpartum headache in a patient on prophylactic LMWH; what to tell her about the next pregnancy.

1. End of the case

Bleeding controlled with the balloon at 400 mL; OB plans to leave it 12-24 hours. Totals: QBL 3,400 mL; 6 PRBC, 6 FFP, 1 apheresis platelets, 10 units cryoprecipitate, 2 g calcium chloride, 2.5 L crystalloid, TXA 2 g. Off pressors; BP 116/70, HR 96, T 36.3°C. ABG on FiO2 0.5: pH 7.31, PaCO2 39, PaO2 204, lactate 3.4. Extubate in the OR? Why/why not? What do you check first? Assume she is extubated awake. Disposition — postpartum floor? PACU? ICU? Why? Monitoring for the next 6 hours — what? How often? Oxytocin — continue? How long? Analgesia — what? NSAID? Why/why not?

Considerations and pitfalls AI draft

Extubate. Reasonable if she meets criteria: bleeding controlled, stable off pressors, normothermic, acidosis and lactate improving, awake and following commands, full reversal confirmed with quantitative monitoring (gentamicin can potentiate neuromuscular blockade). Staying intubated is also defensible if the airway is swollen, the lactate is climbing, or bleeding may restart. Extubating deep with a full stomach is the flag.
Check first. Airway and facial edema after about 6 L of products and fluid on a pregnant airway: look, and do a cuff leak test. Suction the stomach through the gastric tube. Extubate fully awake, head up, with the difficult-airway setup still in the room.
Disposition. ICU or an obstetric high-dependency unit with ICU-level nursing: a balloon that can fail, a massive transfusion with lung injury or overload still possible over the next hours, coagulopathy labs, and hourly urine output. A regular postpartum bed is the flag.
Monitoring. Continuous ECG and SpO2, frequent BP (arterial line if in), Foley with hourly urine output, fundal checks and balloon drain output every 15-30 minutes at first, temperature. Repeat CBC, fibrinogen, coagulation, iCa, and lactate within 1-2 hours, then every 4-6 hours.
Oxytocin. Continue while the balloon is in, typically 12-24 hours. Prolonged high-dose oxytocin has an antidiuretic effect; with large volumes, watch sodium.
Analgesia. Scheduled acetaminophen with opioid as needed for balloon cramping and the perineum. Hold NSAIDs for now: platelets and coagulation are still recovering and her kidneys have just been through shock. Routine ketorolac tonight is the flag.

2. Two hours in the ICU

Two hours after ICU arrival: SpO2 87% on 4 L nasal cannula, RR 32, BP 156/94, HR 110, T 37.4°C. Bilateral crackles. CXR: bilateral perihilar opacities, small effusions. DDx? Most likely? Why? How do you sort them at the bedside? Rx? Furosemide? Why/why not? Dose? Thirty minutes later: SpO2 90% on a nonrebreather, RR 28, talking in full sentences. CPAP? High-flow? Reintubate? Which? Why?

Considerations and pitfalls AI draft

DDx. Transfusion-associated circulatory overload (TACO), transfusion-related acute lung injury (TRALI), aspiration pneumonitis (she was retching before induction), pulmonary edema from postpartum preeclampsia (new BP 156/94: check urine protein, platelets, liver enzymes, symptoms), cardiogenic edema from another cause such as peripartum cardiomyopathy, atelectasis. PE does not explain crackles and bilateral opacities.
Most likely. TACO. Hypertension, tachycardia, effusions, and a large positive balance: roughly 6 L in against 3.4 L out, plus the volume returned to the circulation as the uterus contracts. TRALI comes on within 6 hours with fever and hypotension more typical and no volume overload. Aspiration can coexist and is often worst in dependent segments.
Sorting them. Fluid balance; point-of-care ultrasound (B-lines, a full IVC, LV function, effusions); BNP or NT-proBNP (high favors TACO, though postpartum values vary); and the response to a diuretic. An echo also screens for unexpected LV dysfunction.
Rx. Sit her up, oxygen, stop or slow any running fluids and products, furosemide 20-40 mg IV. Quick improvement supports TACO. Diuresing a hypotensive TRALI patient is the error, which is why the BP matters.
CPAP, high-flow, or reintubate. She is awake, protecting her airway, and partly responding. A trial of CPAP or high-flow nasal oxygen with close watching is reasonable after more diuretic. Reintubate for fatigue, a falling mental status, worsening gas exchange, or hemodynamic decline. A two-hour-old extubation with a full stomach argues for a low threshold, not for avoiding support.

3. The epidural catheter overnight

By midnight, SpO2 96% on 2 L. Midnight labs: platelets 72, INR 1.6, fibrinogen 210. Remove the epidural catheter now? Why/why not? What values do you want first? Postpartum day 1, 0600: platelets 79, INR 1.3, fibrinogen 255; balloon out, bleeding minimal. Remove now? Why/why not? After removal — what do you monitor? How often? VTE prophylaxis — mechanical? Pharmacologic? Agent? Dose? First dose — when? Why?

Considerations and pitfalls AI draft

Midnight. No. Catheter removal carries a hematoma risk comparable to placement, and an INR of 1.6 after a fresh coagulopathy is too high. Leave it capped (or use it for analgesia) and recheck. Pulling it because the case is over is the flag.
Values. Platelets about 70,000 or higher (the obstetric consensus threshold for neuraxial procedures) and stable or rising, INR below about 1.5, normal aPTT and fibrinogen, no anticoagulant on board. A catheter left longer slightly raises infection risk; inspect the site.
0600. Yes. Coagulation has recovered, platelets are rising, bleeding is controlled, and no LMWH has been given yet. Confirm the motor block from the OR dosing has fully resolved before removal; a block that has not worn off is itself a warning sign.
After removal. Leg strength and sensation, new back pain, bowel or bladder change, every few hours (for example every 2-4 hours) for at least 12-24 hours. Any new deficit means an emergent MRI and neurosurgery; outcome depends on decompression within hours.
VTE prophylaxis. Yes, both. She is high risk: postpartum, massive transfusion, infection, BMI about 32, and limited mobility. Compression devices now; pharmacologic prophylaxis once bleeding is controlled. Enoxaparin 40 mg SC daily (weight-adjusted dosing is an alternative) or heparin 5,000 units SC every 8-12 hours.
First dose. At least 4 hours after the catheter comes out (ASRA, once-daily low-dose LMWH). The catheter should not be pulled within 12 hours of a low-dose LMWH dose, which is why removal comes before the first dose. Holding all pharmacologic prophylaxis for days without a reason is the flag.

4. Postpartum day 1, low urine output

Postpartum day 1, 1400. Urine output 15-20 mL/h for 4 hours. Creatinine 1.4, from 0.6 on admission. BP 108/64, HR 94, afebrile. Hgb 7.6, from 7.9 last evening; fundus firm, pad count minimal. DDx? First step at the bedside? Fluid bolus? Why/why not? How much? Transfuse? Why/why not? Gentamicin is still ordered. Continue? Why/why not? Ketorolac 30 mg IV every 6 hours started this morning. Continue? Why/why not? Analgesia instead? She is breastfeeding. Any of your analgesics a problem? Which?

Considerations and pitfalls AI draft

DDx. Prerenal (relative hypovolemia after yesterday's diuresis), ischemic tubular injury after shock, nephrotoxins (gentamicin, ketorolac), and a kinked or blocked Foley. A creatinine that has more than doubled with oliguria is AKI and needs attention today, not a recheck tomorrow.
First step at the bedside. Flush or check the Foley first; then volume status by exam and ultrasound (IVC, lungs), and a review of every drug on the MAR.
Fluid bolus. A small, reassessed challenge (250-500 mL of balanced crystalloid), guided by ultrasound of the IVC and lungs, because she had overload yesterday. Repeated liter boluses to chase urine output is the flag; so is refusing volume to someone who is dry.
Transfuse. Most would hold. The hemoglobin is stable, the fundus is firm, she is not bleeding, and she had transfusion-associated overload yesterday; another unit adds that risk for little gain. Transfuse for ongoing bleeding, hemodynamic instability, symptoms, or Hgb below about 7. A learner who transfuses to the number without connecting it to yesterday's overload has missed the point.
Gentamicin. Stop it, or switch with OB to a non-nephrotoxic agent if antibiotics are still needed. After a vaginal delivery, antibiotics for intraamniotic infection usually stop at delivery unless there is ongoing infection, and she is afebrile. Continuing an aminoglycoside into AKI without a level is the error.
Ketorolac. Stop it: AKI, recent thrombocytopenia, and a uterus that bled yesterday.
Analgesia. Scheduled acetaminophen, ice and local measures for the perineum, low-dose oxycodone as needed. Acetaminophen, ibuprofen (once kidneys recover), and short courses of low-dose oxycodone are compatible with breastfeeding; codeine and tramadol are avoided because ultra-rapid metabolizers can expose the infant to high opioid levels.

5. Postpartum day 2, headache

Postpartum day 2, 1000. Creatinine 0.9; afebrile since the morning of delivery. Headache for 20 hours, frontal and occipital: 8/10 sitting, 2/10 lying flat. BP 118/74. Neuro exam normal. DDx? Most likely? Why? Imaging? Why/why not? Rx? Blood patch? Why/why not? Platelets 108, INR 1.1. Enoxaparin 40 mg last given yesterday at 1100; next dose due at 1100 today. Patch now? Why/why not? Next enoxaparin — when? She asks whether she will bleed like this with her next baby. What will you tell her?

Considerations and pitfalls AI draft

DDx. Post-dural puncture headache from an unrecognized dural puncture, postpartum preeclampsia (can present days to weeks after delivery; BP normal now but recheck), cerebral venous thrombosis (postpartum, TXA, massive transfusion), posterior reversible encephalopathy, subarachnoid hemorrhage or reversible vasoconstriction (thunderclap onset), meningitis (recent infection plus neuraxial), caffeine withdrawal, migraine, sleep deprivation.
Most likely. PDPH: positional, fronto-occipital, starting within a day or two of a neuraxial procedure, with a normal exam and BP. No wet tap was recognized, but an unrecognized puncture by the needle or the catheter happens.
Imaging. Not for a classic positional headache with a normal exam and BP. MRI with venography if the headache loses its positional pattern, or with focal signs, seizure, confusion, fever, or failure of a blood patch. Given her clot risk, a learner who never mentions venous thrombosis has missed a hook.
Rx. Fluids, acetaminophen, and caffeine help little and do not fix it. An epidural blood patch is the definitive treatment. A sphenopalatine ganglion block is a minor option. Bed rest neither prevents nor treats PDPH.
Blood patch. Reasonable. The headache is severe upright, has lasted 20 hours, and is stopping her from caring for a newborn. Her infection risk has settled (afebrile for more than two days); the coagulation question comes next.
Patch now; next enoxaparin. Yes. Platelets 108 and INR 1.1 are adequate, and the last low-dose dose was 23 hours ago, past the 12-hour minimum. Hold the 1100 dose; give the next dose at least 12 hours after the patch, this evening (ASRA timing for once-daily low-dose LMWH after neuraxial needle placement). Giving the 1100 dose and then patching is the flag.
What to tell her. Honest and specific: her risk is higher than average next time, but most women who bleed like this do not bleed like this again. The epidural did not cause the bleeding, and an early epidural next time helps if she needs a procedure. What helps: an early visit with the anesthesia team, delivering where blood and a massive transfusion can be given, large-bore IV and a crossmatch on admission, anemia corrected before delivery, active management of the third stage, TXA and uterotonics ready. Offer a debrief of what happened and follow-up; traumatic stress after a hemorrhage is common.

Long stem

32-week parturient after MVC with hemorrhagic shock and fetal distress

A 27 y.o. G2P1 at 32 weeks gestation, 70 kg, 5'6", is brought to the trauma bay 30 minutes after a head-on motor vehicle collision. Trauma surgery plans emergent exploratory laparotomy for a positive FAST and hemodynamic instability; obstetrics is scrubbed for possible cesarean if fetal status worsens.

HPIRestrained driver, head-on collision at approximately 45 mph, airbag deployed, brief loss of consciousness, complains of left chest and diffuse abdominal pain. Bleeding from a forehead laceration. Last meal was a granola bar and coffee 2 hours ago.

PMHUnremarkable. One prior uncomplicated vaginal delivery three years ago. No prior anesthetics.

MEDSPrenatal vitamins, no other medications.

PHYS EXAMHR 128; BP 92/58; RR 26; SpO2 95% on 4 L NC; T 36.4°C. Cervical collar in place. Airway: Mallampati II, full mouth opening, full neck extension behind collar. Obvious left chest wall ecchymosis with crepitus; decreased breath sounds at the left base. Diffuse abdominal tenderness, gravid uterus tender to palpation. Pelvis stable. 5 cm forehead laceration packed.

ECGSinus tachycardia at 128, no ischemic features.

LABSHgb 11.5 g/dL (12.4 at 26 weeks; hemoglobin lags acute blood loss); platelets 180 K/uL; INR 1.1; fibrinogen 280 mg/dL; lactate 4.2; base deficit minus 7; creatinine 0.8; type and screen with anti-K antibody, two units crossmatched, MTP activated.

IMAGINGFAST positive for free fluid in the right upper quadrant and pelvis. CT not yet performed. Portable CXR: left rib fractures 4-7, small left pneumothorax, no widened mediastinum.

FETALEstimated fetal weight 1900 g. FHR baseline 165 with reduced variability and recurrent late decelerations over the past 20 minutes.

OR ARRIVALTwo large-bore peripheral IVs in upper extremities. No arterial line yet. C-collar maintained. Patient with 15° left tilt on the OR table. Trauma, OB, NICU teams present; cardiothoracic surgeon notified for chest tube and possible thoracotomy.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Trauma resuscitation modified for late pregnancy; airway, ventilation, and lines in the pregnant patient with chest trauma; the intraoperative obstetric decision and how anesthesia supports it; massive transfusion in the bleeding gravid patient.

1. Pre-induction priorities

She is on the table. Trauma wants to cut in five minutes. Chest tube before you induce, or induce now and tube after? Why? Arterial line before induction — yes/no? Why? Induction agent? Dose? Paralytic? Dose? Laryngoscopy with the collar on — how, exactly? Cricoid — yes/no? Why? Keep the left tilt through induction with the collar on? Why?

Considerations and pitfalls AI draft

Pneumothorax first. Positive pressure turns a small pneumothorax into a tension pneumothorax in a patient already in shock; a chest tube (or at minimum a finger thoracostomy or needle decompression with the tube kit open) goes in before or during induction. Inducing with no plan for the chest is a flag.
Arterial line. Yes if it takes one attempt while the chest tube goes in; it does not delay the incision. Place it after induction if the first attempt fails.
Induction agent. Ketamine 0.5-1 mg/kg or etomidate 0.1-0.2 mg/kg, dose-reduced for hemorrhagic shock; full-dose propofol here is a flag. Expect the pressure to fall regardless once sympathetic tone is removed; have push-dose pressor drawn.
Paralytic. Succinylcholine 1-1.5 mg/kg or rocuronium 1.2 mg/kg; sugammadex 16 mg/kg available if rocuronium.
Collar. Open the front of the collar, an assistant holds manual in-line stabilization, video laryngoscope first pass, bougie ready. MILS worsens the view; expect it and do not lift against it.
Cricoid. Defensible either way; if applied, release it the moment it degrades the view.
Tilt. Left uterine displacement stays. At 32 weeks the supine position can cut cardiac output by a third in a patient who has none to spare. If spine precautions forbid tilting the board, displace the uterus manually.

2. Ventilation, volatile, and uterine relaxation

Intubated first pass on VL. Chest tube in: 200 mL of blood and a persistent air leak. Tidal volume — how many mL? PEEP? Plateau ceiling? Peak pressure climbs to 42, SpO2 91%. DDx? Next? Volatile — which agent, and what MAC? Why that number? OB is scrubbed and asks whether they should deliver now while trauma explores. Can the fetus wait? What tells you it can? What tells you it cannot?

Considerations and pitfalls AI draft

Tidal volume. 6-8 mL/kg predicted body weight; PBW for a 5'6" woman is ~59 kg, so 350-450 mL. Sizing to 70 kg actual weight is the common error.
PEEP and plateau. PEEP 5-8, plateau ≤30; watch peak pressures with an air leak and fractured ribs.
Peak 42. Right mainstem (the diaphragm is high and the tube migrates), kinked or blocked chest tube with re-accumulating pneumothorax, hemothorax, aspirated blood or gastric contents, bronchospasm. Check depth and breath sounds, suction, look at the chest tube, ultrasound the chest.
Volatile. Sevoflurane at 0.5-0.7 MAC; MAC is reduced ~30% in pregnancy, and she is in shock, so tolerance is low. Above ~1 MAC the uterus relaxes and atony after delivery gets worse. Supplement with ketamine or opioid rather than pushing the vaporizer; awareness risk is real and is addressed in the next probe.
Deliver now?. The fetus is hypoperfused because the mother is; maternal resuscitation is fetal resuscitation. Delivery is indicated if the tracing does not recover with maternal pressure and oxygenation restored, if the uterus obstructs surgical control of the bleeding, or if the mother is deteriorating and the uterus is a volume sink. A resident who says 'deliver' or 'wait' without naming the tracing, the maternal pressure trend, and hemorrhage control is guessing.

3. Intraoperative C/S decision

Trauma finds a grade IV liver laceration; packs are in. EBL 1.5 L. FHR 60s for four minutes. OB will deliver now. BP 80/45 with 4 units in. Anything you want before the uterine incision? Baby out, 1900 g, to NICU. Oxytocin — bolus or infusion? Dose? Uterus boggy at three minutes and the field fills. Methergine, carboprost, or misoprostol — which? Why? Volatile at 0.5 MAC to spare tone. Awareness — how do you cover it? SpO2 88% with the packs in and the retractor up. Rx?

Considerations and pitfalls AI draft

Before uterine incision. Uterotonics drawn, second suction, blood checked and hanging, calcium in hand, rapid infuser primed; tell the room she will bleed from two places at once.
Oxytocin. Infusion, not a bolus, in a hypotensive patient; a 3-5 IU bolus drops SVR and can crash her. Start ~3 IU over a minute or straight to an infusion of 10-40 IU/L and titrate.
Second-line agent. Carboprost 250 mcg IM or methergine 0.2 mg IM are both acceptable (no asthma, no hypertension); misoprostol is slow and belongs as an adjunct, not the rescue. Commit and give it now; a bimanual uterus from OB at the same time.
Awareness. Midazolam 1-2 mg, ketamine (which also holds pressure), opioid, processed EEG if available; tell her afterward what was done and why. Turning the vaporizer down with nothing in its place is the trap.
SpO2 88%. Packs and retractors push the diaphragm up: FRC falls, the tube can go mainstem. FiO2 1.0, confirm tube depth, ask the surgeon to ease the retractor, recruit, check the chest tube is swinging (recurrent tension is on this list), ultrasound for hemothorax.

4. Massive transfusion and coagulopathy

EBL 3.5 L. 6 PRBC and 4 FFP in. BP 75/40, HR 140, norepinephrine 0.2 mcg/kg/min. Lactate 7. Ratio from here? Ionized calcium 0.8. Dose? Recheck how often? Ninety minutes since the crash. TXA — yes/no? Dose? Fibrinogen returns 120. Cryo or concentrate? How much? Target? Cell saver from the abdominal field — yes/no? Why? The bank says her anti-K leaves two matched units and they need 40 minutes for more. What do you ask for? Temp 34.8. Rx? Packs in and the field still oozes. What number tells you to stop chasing it and push for damage control?

Considerations and pitfalls AI draft

Ratio. 1:1:1 empirically until viscoelastic data arrive, then goal-directed. Platelets are the component most often forgotten at this volume.
Calcium. Calcium chloride 1 g IV now, roughly 1 g per 2-4 units of citrated product, ionized Ca checked every 30 minutes. Citrate toxicity plus hypothermia plus acidosis is the coagulopathy that products alone cannot fix.
TXA. Yes: 1 g over 10 minutes, then 1 g over 8 hours; within 3 hours of injury, so the trauma indication holds.
Fibrinogen 120. Already dangerously low for a parturient (term normal 350-600; her 280 at arrival was the first signal of consumption). Cryo 10 units (~2 g) or fibrinogen concentrate 4 g; target ≥200 while bleeding. Waiting for a value below 100 is the error.
Cell saver. Amniotic contamination is a theoretical concern that leukoreduction filters address; the real contraindication is bowel injury and gross contamination of the field. If the bowel is intact, use it.
Anti-K. ~91% of donors are K-negative, so K-negative uncrossmatched units are readily available; ask for them by name and do not wait 40 minutes. Anti-K also matters for the neonate (HDFN); NICU needs to know.
Temp 34.8. Warm every line, forced air on everything not in the field, warm the room; below 35 the clotting cascade slows and platelets stop working regardless of the counts.
Damage control. When the rate of loss exceeds the rate of replacement and the lactate keeps rising despite products: pack, temporary closure, ICU for rewarming and correction, then IR or a planned re-look. The resident should name lactate trend, base deficit, temp, and ionized calcium as the numbers that call it.

B. POST-OPERATIVE CARE

Teaching focus. ICU management of the postpartum trauma patient; pulmonary contusion evolving to ARDS; analgesia in chest trauma; VTE prophylaxis after trauma and surgery; mental health and psychosocial follow-up after an event with risk for lasting harm.

1. ICU arrival and initial plan

ICU: intubated, abdomen packed and temporarily closed, norepinephrine 0.05, baby alive in NICU. Tidal volume and PEEP now? Sedation — propofol, dexmedetomidine, or a benzodiazepine infusion? Which? Why? Ribs 4-7 on the left. Block tonight, or wait until she is extubating? Which block? Why that one? INR 1.4, platelets 90 after the resuscitation. Paravertebral catheter tonight — yes/no? Why? Ketorolac — give it? Why/why not?

Considerations and pitfalls AI draft

Vent. 6 mL/kg PBW, PEEP 8-10 with contusion and a large transfusion, plateau ≤30, driving pressure ≤15.
Sedation. Propofol infusion for a patient who is going back to the OR and has an open abdomen; dexmedetomidine as an adjunct for opioid sparing; avoid benzodiazepine infusions (delirium, prolonged ventilation).
Block now. Early; contused, splinting lungs get worse each hour. Erector spinae plane catheter is the pragmatic choice: superficial, compressible, not constrained by coagulopathy.
Paravertebral tonight. No. ASRA treats paravertebral like neuraxial; with INR 1.4 and platelets 90 after massive transfusion, wait for correction. Thoracic epidural is also off the table for now.
Ketorolac. No: fresh massive transfusion, a packed liver, platelets 90, and an undefined creatinine after shock. Acetaminophen scheduled; NSAID later.

2. Worsening hypoxemia on POD 1

POD 1: FiO2 0.7, PEEP 10, P/F 130, plateau 28, bilateral infiltrates worse on the left, Hgb 8.9 and stable. DDx? She received 14 units yesterday. TACO or TRALI — which does this look like? What at the bedside separates them? Vent change now — what specifically? Prone — yes/no? Why? Paralyze — yes/no? Why? Furosemide 40 mg — give it? What tells you? Peak pressure jumps to 50, SpO2 82%, BP 70/40. Dx? Rx?

Considerations and pitfalls AI draft

DDx. Pulmonary contusion progressing, ARDS, TRALI, TACO, aspiration at induction, atelectasis, early pneumonia. Contusion plus transfusion is the likeliest combination.
TACO vs TRALI. TACO: hypertension, raised JVP, positive balance, BNP up, improves with diuresis. TRALI: fever, hypotension, onset within 6 hours of product, no overload, does not respond to diuretics. Both give bilateral infiltrates.
Vent change. Tidal volume to 6 mL/kg PBW (~350 mL), PEEP titrated up with attention to driving pressure, permissive hypercapnia acceptable.
Prone. P/F <150 on FiO2 ≥0.6 despite optimization meets the criterion; the open abdomen with packs is the real problem and is a relative contraindication. Discuss with trauma; a decision either way must name that trade-off.
Paralysis. Only for dyssynchrony or refractory hypoxemia, not routine.
Furosemide. Yes if she is volume-overloaded (fluid balance, IVC, JVP, echo); no if pressors are climbing or the picture is TRALI. Examine before dosing.
Peak 50, hypotension. Tension pneumothorax with a clotted chest tube until proven otherwise; also mainstem migration or mucus plug. Disconnect from the vent, bag by hand, check the tube, decompress, replace the chest tube.

3. Pain and regional anesthesia

POD 2: off norepinephrine, abdomen closed at re-look, INR 1.2, platelets 110. Enoxaparin 40 mg was given at 0600. Rib pain limits her tidal volumes on pressure support. Thoracic epidural, paravertebral catheter, ESP catheter, or intercostal blocks? Which? Why? How many hours after the 0600 dose can you place it? Next enoxaparin dose — how long after placement? Catheter in and working. Scheduled non-opioids — what and what dose? Ketorolac now — yes/no? Why? She extubates that afternoon. PCA hydromorphone — yes/no? What monitoring? Ketamine infusion — rate?

Considerations and pitfalls AI draft

Choice. Thoracic epidural or paravertebral catheter gives the best analgesia for four contiguous fractures; ESP catheter is the compromise that sidesteps the anticoagulation timing. Any is defensible if reasoned; intercostal blocks alone are too short-lived.
Enoxaparin timing. Prophylactic dose: neuraxial or paravertebral placement ≥12 hours after the dose (so 1800 or later), next dose ≥12 hours after placement (ASRA), and ≥4 hours after catheter removal. ESP has no such constraint.
Non-opioids. Acetaminophen 1 g q6h scheduled; gabapentinoid optional; lidocaine infusion if no epidural.
Ketorolac. Still no: packed liver 48 hours ago with re-bleed risk, creatinine after shock. Revisit in days.
PCA. Yes, with continuous pulse oximetry and capnography; a patient with rib fractures who is undertreated hypoventilates just as surely as one who is oversedated.
Ketamine. 0.1-0.2 mg/kg/h.

4. VTE prophylaxis after trauma in postpartum

POD 3: enoxaparin 40 mg once daily, SCDs on. Is 40 mg daily the right dose for her? Your dose? Why? That evening: HR 135, SpO2 86% on 4 L, BP 98/60, RR 30. DDx? First test at the bedside? Echo: dilated RV, flat septum, no effusion, lungs without B-lines. Next test? Can she travel to CT? CT: saddle embolus. Heparin in a patient whose liver was packed 72 hours ago — yes/no? Bolus? BP 72/40. Lytics — yes/no? Why? What instead?

Considerations and pitfalls AI draft

Dose. Postpartum plus major trauma plus surgery plus transfusion puts her in the highest-risk group; many trauma protocols use enoxaparin 30 mg BID or 40 mg BID, or weight-based 0.5 mg/kg BID, with anti-Xa monitoring. Once-daily 40 mg under-doses her.
DDx. PE first, then sepsis, recurrent hemorrhage, tension pneumothorax, progressing ARDS.
Bedside. Point-of-care echo and lung ultrasound, ECG, ABG; a dilated RV with a flat septum and dry lungs in this context is PE until proven otherwise.
CT. Yes if she can be moved with a physician, pressor in hand, and airway equipment; the diagnosis changes the treatment, so it is worth the trip.
Heparin. Yes, unfractionated infusion without a bolus (or a reduced bolus), because it is titratable and reversible; discuss with trauma but do not withhold anticoagulation from a hemodynamically significant PE.
Lytics. Systemic thrombolysis is contraindicated within roughly 10-14 days of major surgery and hemorrhage; hers was 72 hours ago. Catheter-directed therapy, surgical embolectomy, or VA ECMO as a bridge; IVC filter only if anticoagulation truly cannot be given.

5. Disclosure and mental health follow-up

POD 5: extubated, awake, oriented. She asks what happened and where her baby is. What will you tell her? She says she remembers voices and pressure on her belly during the operation. Next? How do you find out whether that was awareness? You decide it probably was. Who does she need to see, and when? Sedation and analgesia plan for the next few days — what changes? What goes in her anesthesia record for the next team?

Considerations and pitfalls AI draft

What happened. Plain and honest: the crash, the bleeding, the operation, that her baby was delivered and is alive in the NICU, and that the team will bring the full picture together with OB and trauma. Do not defer the fact that the baby is alive; do not invent prognostic certainty.
Memories. Take it seriously; a structured interview (modified Brice) in a quiet room, no argument about whether it could have happened. Ketamine and low volatile in a shocked patient make awareness plausible.
Referral. Psychiatry or psychology within days, not at discharge; awareness and trauma both carry PTSD risk, and early support changes outcome. Social work alongside for the NICU course.
Sedation and analgesia. Minimize sedatives, keep her lucid enough to participate and see the baby, protect sleep, treat pain with the block and non-opioids so she is not fogged.
Record. Awareness episode and the circumstances, anti-K antibody and transfusion history, massive transfusion, difficult-airway status (not difficult; say so), blocks placed; a letter she carries.

Long stem

Idiopathic pulmonary arterial hypertension in active labor at term

A 26 y.o. G1P0 at 36 weeks gestation, 62 kg, 5'5", presents in active labor at 6 cm cervical dilation. She has known idiopathic pulmonary arterial hypertension and was scheduled for elective cesarean at 37 weeks but went into spontaneous labor today, a few days before the planned date.

HPIIdiopathic PAH diagnosed at age 22 after presyncope and progressive dyspnea on exertion; right-heart catheterization at that time showed mean PA pressure 56 mmHg, PVR 9 Wood units. Initial improvement on dual oral therapy. Pregnancy proceeded despite counseling; she elected to continue.

PMHIdiopathic PAH (WHO Group 1, functional class II to III). Multidisciplinary plan with cardiology, OB, and anesthesia for delivery at 37 weeks by elective cesarean. No prior surgeries, no prior anesthetics.

MEDSSildenafil 20 mg PO TID; selexipag 1600 mcg PO BID; low-dose aspirin 81 mg daily; prophylactic enoxaparin 40 mg SC daily (last dose 14 hours ago); prenatal vitamins.

PHYS EXAMHR 102, sinus; BP 110/68; RR 22; SpO2 92% on room air; T 37.0°C. Loud P2, parasternal RV heave. JVP elevated to 8 cm. Trace edema. Airway: Mallampati II, full mouth opening, full neck extension.

ECGSinus tachycardia, RV hypertrophy, right-axis deviation, T-wave inversions V1-V3.

LABSHgb 12.4 g/dL; platelets 220 K/uL; INR 1.0; BNP 980 pg/mL; creatinine 0.7 mg/dL; type and screen negative.

TTE (recent)RVSP estimated at 78 mmHg; RV moderately dilated with preserved function; septal flattening; moderate tricuspid regurgitation; reduced RVOT VTI; LV ejection fraction 60%.

IMAGINGCXR with enlarged central pulmonary arteries, no acute infiltrate.

FETALEstimated fetal weight 3500 g. FHR baseline 145 with appropriate variability, no decelerations.

OR ARRIVALAdmitted to L&D 90 minutes ago. Cardiology and adult cardiac anesthesia notified. ECMO team aware. 18 g antecubital IV. No arterial line yet. OB asks whether anesthesia is comfortable with assisted vaginal delivery versus moving to cesarean now.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Labor analgesia and modality choice in fixed pulmonary hypertension; lines and monitoring that earn their cost; RV-protective hemodynamic goals through delivery; recognizing and treating an intrapartum PH crisis.

1. Modality and plan

OB asks: assisted second stage under an epidural, or cesarean now? Which? Why? Enoxaparin 40 mg 14 hours ago. Neuraxial now — yes/no? Why? Arterial line before the epidural — yes/no? Central line — before the block or after? Why? PA catheter — yes/no? Why? Targets for the rest of labor: MAP? HR? SpO2? PaCO2? Why each number? Oxygen by nasal cannula now — yes/no? Why?

Considerations and pitfalls AI draft

Mode of delivery. Either is defensible if reasoned. Assisted vaginal delivery under a dense epidural with a shortened second stage avoids surgical stress, blood loss, and a GA she may not tolerate; planned cesarean gives a controlled setting with the full team. She is at 6 cm with a reassuring tracing, so a well-managed vaginal delivery is reasonable; a resident who reflexively chooses cesarean 'because she is sick' should be asked what the cesarean protects her from.
Enoxaparin. Prophylactic dose; ASRA asks for ≥12 hours; 14 hours is fine. Document the time and hold the next dose until ≥4 hours after placement.
Arterial line. Yes, before the block, radial; every hemodynamic decision in the next 24 hours depends on beat-to-beat pressure.
Central line. Before the block, right IJ under ultrasound; she will need titrated vasopressors and possibly inotropes, and placing it during a crisis is the wrong time.
PA catheter. Most PH-experienced teams avoid it: arrhythmia and PA rupture risk in a dilated, hypertensive pulmonary tree with limited decision value; TTE/TEE gives the RV picture. A yes is defensible only with a stated reason.
Targets. MAP ≥70 (RV coronary perfusion depends on aortic pressure exceeding RV pressure), HR 80-100 in sinus (the dilated RV needs time to fill; loss of atrial kick is catastrophic), SpO2 ≥95%, PaCO2 low-normal for pregnancy (~30-35). Hypoxia, hypercarbia, acidosis, and pain each raise PVR.
Oxygen. Oxygen is a pulmonary vasodilator; at 92% she is on the steep part of the curve where a contraction or a dose of opioid tips her. Start it now.

2. Neuraxial technique

Epidural, CSE, or single-shot spinal for labor? Which? Why? Test dose — 3 mL of lidocaine 1.5% with epinephrine 15 mcg? Yes/no? Why? Loading — what solution, how many mL at a time, how far apart? After 10 mL of bupivacaine 0.0625% with fentanyl 2 mcg/mL: BP 92/58 from 110/68, HR 112, SpO2 90%. Rx? Phenylephrine 100 mcg, norepinephrine 8 mcg, or vasopressin 1 unit — which? Why? Fluid — how much before you reassess? BP 108/66 on norepinephrine 0.04. Infusion rate for the epidural? OB wants forceps. Top-up — what solution? How many mL at a time? Target level?

Considerations and pitfalls AI draft

Technique. Slow epidural or a CSE with intrathecal opioid only (no intrathecal local); a single-shot spinal produces the abrupt sympathectomy a fixed-PVR patient cannot compensate for. Committing to a spinal here is a flag.
Test dose. Omit the epinephrine: 15 mcg intravascular produces tachycardia that she tolerates badly and that you cannot distinguish from labor. Aspirate, dose incrementally, watch for the block.
Loading. Dilute bupivacaine 0.0625-0.1% with fentanyl in 3-5 mL increments every 5 minutes with the arterial line watched; no 10-15 mL loads.
Hypotension. Expected sympathectomy on top of a preload-dependent RV; treat the pressure before it becomes an RV ischemia spiral. Norepinephrine 4-8 mcg boluses or vasopressin 0.5-1 unit; phenylephrine works but raises PVR at higher doses and produces reflex bradycardia. Any of the three is defensible; the reasoning about PVR is what you are listening for.
Fluid. 250 mL boluses with reassessment (IVC, JVP, SpO2), not a liter; an over-distended RV pushes the septum into the LV and drops output further.
Infusion and second stage. Standard low-concentration infusion or PIEB; for instrumental delivery, dose the existing catheter in 3-5 mL increments of a stronger solution (lidocaine 2% or bupivacaine 0.25%) with pressor running, aiming for a sacral and perineal block, not a T4 surgical level.

3. Sudden intrapartum hypoxia and hypotension

Two hours later, 8 cm. SpO2 84% on 4 L, HR 130 sinus, BP 82/45, she is anxious and short of breath. DDx? One bedside test — what? TTE: RV dilated, septum flat, IVC plethoric, no effusion, no clot in transit. Dx? Rx in order? Inhaled — iNO or epoprostenol? Dose? Pressor — norepinephrine or vasopressin? Dose? Milrinone — start it? Why/why not? SpO2 80% and she is drowsy. Intubate? Why/why not? Induction agent and dose? Once intubated: tidal volume? PEEP? PaCO2 target?

Considerations and pitfalls AI draft

DDx. PH crisis with acute RV failure, pulmonary embolism, pulmonary edema, occult hemorrhage, amniotic fluid embolism, sepsis. Bedside echo sorts most of it in two minutes.
Dx. Acute RV failure from a PH crisis: labor catecholamines, pain, hypoxia, and a partially blocked patient add up to a PVR surge the RV cannot overcome.
Order. Oxygen to 100%, restore MAP (norepinephrine first: RV coronary perfusion), inhaled vasodilator, treat pain and anxiety (top up the epidural, small opioid), then inotrope; call cardiac anesthesia and the ECMO team now, not later.
Inhaled. INO 20-40 ppm or inhaled epoprostenol 50 ng/kg/min; both are selective pulmonary vasodilators with no systemic drop; whichever the unit can deliver in five minutes.
Pressor. Norepinephrine 0.05-0.2 mcg/kg/min; vasopressin 0.02-0.04 units/min added because it raises SVR without raising PVR. Using both is common.
Milrinone. Inodilator that supports the RV and lowers PVR but drops SVR; start 0.25-0.5 mcg/kg/min without a bolus and only with a pressor already running. Reasonable once MAP is restored; wrong as the first drug.
Intubation. Last resort, when oxygenation or mental status fails despite the above; induction drops SVR and positive pressure raises PVR and cuts preload, and this is where PH patients arrest. Most experienced operator, pressor running, inhaled vasodilator through the circuit, etomidate 0.1-0.2 mg/kg (ketamine acceptable), no propofol bolus.
Ventilation. 6-8 mL/kg PBW, PEEP 5, plateau low, normocapnia or mild hypocapnia (PaCO2 30-35); hypercapnia and high intrathoracic pressure both push PVR up.

4. Conversion to C/S and uterotonics

Intubated. SpO2 94% on FiO2 0.8, epoprostenol running, norepinephrine 0.1, vasopressin 0.04, MAP 72. FHR 90 for six minutes; OB calls cesarean. Maintenance — volatile and how much? What else? Baby out. Oxytocin — bolus or infusion? Dose? Atony at five minutes, 800 mL in the suction. Methergine, carboprost, misoprostol, TXA — which? Why not the others? Placenta out, uterus contracting, bleeding slowing. Fluid for the next ten minutes — give or hold? Furosemide — draw it up now? Why? BP 85/55, HR 130, SpO2 88%, RV worse on TEE. Rx? Epinephrine or milrinone? Which? Why? ECMO — call now? What tells you?

Considerations and pitfalls AI draft

Maintenance. Sevoflurane ≤0.5-0.7 MAC with opioid (remifentanil infusion or fentanyl) carrying the anesthetic; volatile depresses the RV and lowers SVR, and high MAC relaxes the uterus. Nitrous is out (raises PVR).
Oxytocin. Infusion only, started slowly (for example 1-2 IU over minutes, then a low-rate infusion); a bolus drops SVR, raises HR, and spikes PA pressure. A resident who gives 3-5 IU IV push has not engaged the disease.
Atony. Misoprostol 800-1000 mcg buccal or rectal, TXA 1 g, bimanual compression, early Bakri or surgical measures. Methergine raises PVR and SVR (contraindicated); carboprost is a pulmonary vasoconstrictor and bronchoconstrictor (contraindicated). Naming either without a flag is a fail.
Autotransfusion. ~500 mL returns from the contracting uterus and caval compression is relieved; the RV takes a preload hit within minutes. Have the diuretic drawn, keep fluid restrictive, watch CVP and the RV on TEE, and do not add volume for the bleeding until the echo says she needs it.
RV decompensation. Raise MAP first (norepinephrine up, vasopressin), increase the inhaled vasodilator, then epinephrine 0.03-0.05 mcg/kg/min for inotropy; milrinone here drops the SVR she is already losing. Correct acidosis and hypercarbia.
ECMO. Call as pressors escalate and the RV keeps dilating; VA ECMO is the support for RV failure with hypoxemia. The team should be cannulating in a controlled setting, not during CPR. Rising lactate, falling SpO2 on maximal support, and progressive RV dilation are the triggers.

B. POST-OPERATIVE CARE

Teaching focus. The first 24-72 hours postpartum carry the highest mortality risk in PH; surveillance and titration of pulmonary vasodilators; resuming targeted PH therapy; postpartum hemorrhage and anticoagulation in the cardiac patient; counseling on lactation and future pregnancy.

1. Immediate postpartum ICU plan

ICU: intubated, norepinephrine 0.15, vasopressin 0.04, epoprostenol 50 ng/kg/min. BP 100/65, HR 110 sinus, SpO2 96% on FiO2 0.6, RV improved on TEE. MAP target? Why that number? PaCO2 target? Sedation — propofol or dexmedetomidine? Why? Sildenafil and selexipag — restart when? Route? They were last given 16 hours ago. Pharmacy says the tube formulations cannot come until morning. Accept that? Why/why not? Enoxaparin — restart when? Dose? She is 3 L positive. Diurese tonight? What tells you?

Considerations and pitfalls AI draft

MAP. 65-75; the RV is perfused during systole only when aortic pressure exceeds RV pressure, so hypotension is RV ischemia.
PaCO2. 35-40, no hypercarbia; avoid hyperventilation to the point of high airway pressures.
Sedation. Dexmedetomidine or low-dose propofol; the goal is no sympathetic surges (PVR spike) and no hypotension; adequate analgesia matters as much.
Targeted therapy. Restart now via the gastric tube; sildenafil and selexipag have short half-lives, and a gap of 24 hours risks rebound pulmonary hypertension. IV sildenafil exists if the gut is not working.
Enoxaparin. Prophylactic 40 mg daily restarted at 12-24 hours once hemostasis is confirmed; she is at high VTE risk and a PE would be fatal. Mechanical compression until then.
Diuresis. Yes if the RV is distended and she is oxygenating poorly; no if she is pressor-dependent with a small IVC. Echo before the furosemide; the RV is both preload-dependent and preload-intolerant, and the window is narrow.

2. Wean and extubation

POD 1: FiO2 0.4, epoprostenol weaned off over six hours, norepinephrine 0.03, sildenafil and selexipag restarted PO. Breathing trial — yes/no? What must be true first? On the trial: HR 115 → 128, RR 28, SpO2 93%, BP 100/60. Continue or stop? Why? Rested, retried, passes. Extubate to nasal cannula, high-flow, or NIV? Why? Two hours after extubation: HR 130, RR 32, SpO2 88% on high-flow at 50 L. DDx? Rx? Epoprostenol again — how do you give it to an extubated patient? Reintubate — what tells you?

Considerations and pitfalls AI draft

Before the trial. Pressor at minimal dose, inhaled vasodilator off for hours without deterioration, oral therapy on board, no bleeding, awake, normal lactate.
HR 128, RR 28. Stop. A rising heart rate and respiratory rate on a trial is the RV failing to keep up; pushing through is how these patients arrest. Rest, and retry in a few hours.
Extubate to. High-flow nasal oxygen or NIV; some PEEP and a guaranteed FiO2 avoid the desaturation that spikes PVR. Plain nasal cannula is a flag.
Deterioration. Recurrent PH crisis, pulmonary edema after the autotransfusion, PE, atelectasis. Oxygen to 100%, NIV, restart the inhaled vasodilator (epoprostenol nebulized through the NIV or high-flow circuit; iNO via nasal delivery in some units), echo.
Reintubation. Earlier rather than later: rising work of breathing, falling SpO2 on NIV, hypotension, or mental status change. A crash reintubation of a PH patient carries far more risk than an elective one in the ICU with cardiac anesthesia present.

3. Postpartum hemorrhage in PH

POD 1 evening, extubated and on high-flow: heavy lochia, Hgb 8.4 → 6.5 over four hours, BP 95/55, HR 130, lactate 3.1. Uterotonic — what? Why not the others? Crystalloid bolus or blood first? How much before you reassess? Transfusion target — what Hgb for her? Why? Pressor while blood is on the way — which? Enoxaparin was given six hours ago. Reverse? OB wants to go to the OR for exam and a Bakri. The epidural came out this morning. Spinal, GA, or sedation with local? Which? Why?

Considerations and pitfalls AI draft

Uterotonic. Oxytocin infusion at a low rate and misoprostol; methergine and carboprost remain contraindicated; TXA 1 g.
Volume. Blood, not crystalloid: she needs oxygen-carrying capacity without dilution and without volume the RV cannot take. Transfuse unit by unit with echo or CVP between units.
Target. Higher than a healthy parturient, around 8-9 g/dL; a fixed-PVR RV with reduced output depends on oxygen content.
Pressor. Norepinephrine or vasopressin as a bridge to blood, not a substitute for it.
Enoxaparin. Prophylactic dose six hours ago: protamine partially reverses LMWH and is reasonable for life-threatening bleeding, but a single 40 mg dose is rarely the problem; hold the next dose, correct the surgical bleeding.
Anesthetic for the OR. Spinal is the wrong answer (abrupt sympathectomy in a hypovolemic PH patient); GA with a controlled induction and cardiac anesthesia present is the safe default; sedation with paracervical local is possible for a brief exam and balloon but not if the surgeon may need more. Commit and defend.

4. Acute crisis on POD 2

POD 2, 0600: BP 70/40, HR 140, SpO2 82% on 6 L, lactate 5. TTE: RV severely dilated, LV underfilled. DDx? What at the bedside separates PE from another PH crisis? Enoxaparin has been held since the bleed. Heparin now — yes/no? Why? Rx while the ECMO team mobilizes? Norepinephrine 0.3, vasopressin 0.04, epinephrine 0.1, inhaled running, MAP 50. Cannulate for VA ECMO — yes/no? Why? On ECMO, pulse pressure narrows to 5 mmHg and the aortic valve is not opening on echo. Dx? Rx?

Considerations and pitfalls AI draft

DDx. PE (postpartum, held anticoagulation, immobile), recurrent PH crisis, sepsis, recurrent hemorrhage, tamponade; the echo already excluded effusion.
PE vs crisis. Clot in transit or RV thrombus on echo, McConnell sign, DVT on compression ultrasound of the legs; CTPA only if she can travel. The hemodynamics are identical; the treatment differs.
Heparin. Yes: empiric unfractionated heparin without a bolus if the bleeding has stopped, because a PE in this patient is fatal untreated and UFH is reversible.
Bridge. MAP first (norepinephrine and vasopressin up), inhaled vasodilator up, epinephrine for RV inotropy, oxygen, intubation only if unavoidable and only with ECMO cannulating.
VA ECMO. Yes; three pressors with MAP 50 and a rising lactate is the definition of failing conventional support. VA ECMO unloads the RV and oxygenates; catheter-directed therapy or surgical embolectomy follows if PE is confirmed.
LV not opening. LV distension from retrograde VA flow against a stunned LV; reduce ECMO flow slightly, add inotrope, consider an IABP or Impella vent, and keep the lungs ventilated to avoid a hypoxic upper body.

5. Counseling — lactation and future pregnancy

POD 6: decannulated, extubated, off pressors, on her oral regimen. She asks whether she can have another baby. What will you tell her? Contraception — an estrogen-containing pill? Why/why not? What instead? Breastfeeding on sildenafil and selexipag — yes/no? Enoxaparin — how long postpartum? Dose? Anesthesia follow-up — when, and what goes in the letter she carries?

Considerations and pitfalls AI draft

Another pregnancy. Honest: maternal mortality in PAH pregnancy is roughly 10-25% even in expert centers, and a second pregnancy after RV failure and ECMO is higher; the standing recommendation is against future pregnancy. Say it plainly, say it with cardiology and OB present, and leave room for her to ask. Deferring the whole conversation is a flag; so is delivering it alone at the bedside without her team.
Contraception. Estrogen is contraindicated (thrombosis, fluid retention); progestin-only implant or levonorgestrel IUD, or sterilization when she is ready to decide.
Lactation. Sildenafil transfers minimally and is generally considered compatible; selexipag has no human lactation data and most PH programs advise against breastfeeding on it. Involve the PH pharmacist and lactation team rather than answering off the cuff.
Enoxaparin. At least 6 weeks postpartum at prophylactic dose; longer, or therapeutic, if the PE was confirmed.
Letter and follow-up. PH severity and catheterization data, the crisis, the ECMO run, drugs that helped and drugs that are contraindicated (methergine, carboprost, oxytocin bolus, single-shot spinal), airway status, and a contact for any future anesthetic; one clinic visit with anesthesia within weeks.

Long stem

RUQ pain and abnormal labs in the third trimester (HELLP with hepatic rupture)

A 29 y.o. G1P0 at 33 weeks gestation, 68 kg, 5'4", is admitted to labor and delivery for right upper quadrant pain, malaise, and decreased fetal movement. The obstetricians are asking whether she can go for urgent cesarean delivery.

HPIProgressive RUQ and epigastric pain for 24 hours with nausea and anorexia. Vague headache and brief blurred vision yesterday. Denies fever, contractions, vaginal bleeding. Prenatal visit one week ago: BP 138/86 (baseline 110/70 first trimester), trace proteinuria; she was scheduled for repeat assessment but presented earlier due to symptoms.

PMHUnremarkable. No prior surgeries or anesthetics. No history of viral hepatitis, no recent travel, no alcohol use.

MEDSPrenatal vitamins, no other medications.

PHYS EXAMAppears uncomfortable. HR 104; BP 162/98; RR 20; SpO2 97% on room air; T 37.2°C. Mild scleral icterus. Tender to deep RUQ palpation without rebound. Three-plus pitting edema to the thighs. Brisk reflexes with clonus. Airway: Mallampati II, full mouth opening, full neck extension.

LABSHgb 9.8 g/dL (11.5 one week ago); platelets 92 K/uL (175 one week ago); AST 380, ALT 410; LDH 980; total bilirubin 2.2; INR 1.2; fibrinogen 220 mg/dL; creatinine 1.3 mg/dL; uric acid 8.5 mg/dL; haptoglobin 12; peripheral smear with schistocytes; urine protein 3+. Type and screen sent, no antibodies.

IMAGINGRUQ ultrasound: hepatic capsule irregularity with a small subcapsular fluid collection; gallbladder normal; no biliary dilation. Obstetric ultrasound: estimated fetal weight 1900 g, posterior placenta, no abruption identified.

FETALFHR baseline 130 with reduced variability, no decelerations.

OR ARRIVAL18 g peripheral IV in the antecubital fossa, lactated Ringer's running. No magnesium yet. Obstetric team scrubbed for cesarean; the surgeon asks whether you are ready.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Working a DDx for the parturient with abdominal pain, abnormal labs, and an evolving picture; modality choice when coagulation and hepatic findings constrain neuraxial; recognizing and responding to intraoperative bleeding and hepatic rupture; uterotonic and pressor choice when the patient is already compromised.

1. Abdominal pain and abnormal labs

The surgeon asks if you are ready. Yes/no? What must happen first? Working Dx? What else is on the list? BP 162/98 on the table. Treat before you start? Agent? Dose? Target? Magnesium — load now? Dose, over how long? Rate after, with a creatinine of 1.3? OB asks for a CT of the liver before they cut. Yes/no? Why? Second IV — what size? Blood in the room — how many units, and which products?

Considerations and pitfalls AI draft

Not ready. She needs blood pressure control, magnesium started, a second large-bore IV, blood in the room, and an arterial line; all of that takes fifteen minutes and none of it should take longer. Saying yes because the surgeon is scrubbed is a flag; so is an hour of workup with a fetus showing reduced variability.
Dx and DDx. HELLP with a subcapsular hepatic hematoma is the working diagnosis (hypertension, proteinuria, hemolysis by LDH/haptoglobin/schistocytes, platelets halved, transaminitis, capsular finding). The list must include acute fatty liver of pregnancy, TTP, HUS, viral hepatitis, cholecystitis, and abruption. A resident who says only HELLP should be asked what would make it AFLP or TTP.
BP. Labetalol 20 mg IV, doubling every 10 minutes to 80 mg, or hydralazine 5-10 mg IV; target below 160/110 before laryngoscopy or a block, roughly 140/90, not normal. Overshooting drops placental perfusion.
Magnesium. 4-6 g IV over 20 minutes, then 1 g/h rather than 2 g/h with a creatinine of 1.3; do not delay delivery for the load to finish. It runs through the case.
CT. No; the ultrasound already shows the capsule and the collection, CT adds transport time and a contrast load to a deteriorating patient, and the treatment (delivery, then surgical control if it ruptures) does not change.
Access and blood. Second 16 g or 14 g IV, arterial line, rapid infuser primed; 4 PRBC, 4 FFP, platelets, and cryo in the room. Fibrinogen 220 is already low for pregnancy and will fall fast if she bleeds.

2. Modality decision under coagulopathy

Spinal or GA? Which? Why? What number, or what else, would flip you? A TEG can be back in 15 minutes. Wait for it? Why/why not? You choose GA. Induction agent? Dose? Sux or rocuronium? Dose? Why that one? Laryngoscopy at her pressure — pretreat with what? Dose?

Considerations and pitfalls AI draft

Modality. GA is the expected commit: platelets halved in a week with active hemolysis, a falling fibrinogen, a rising INR, and a hepatic hematoma that may rupture and turn this into a massive hemorrhage under a spinal. A spinal at 92 K is defensible in a stable HELLP; the trajectory is what argues against it. Either answer must engage both the count and the trend.
Threshold. Most accept neuraxial at ≥70-75 K when stable and rising or steady; a count falling this fast has no safe number. What would flip toward spinal: a stable repeat count, normal TEG, no hematoma. What would flip harder toward GA: clinical bleeding, fibrinogen <200, INR >1.5.
TEG. Useful and cheap, but not worth a 15-minute delay in a patient with a hematoma and a non-reassuring fetus; send it and proceed. The answer changes the products, not the modality.
Induction. Propofol 2 mg/kg (she is hypertensive, not hypovolemic yet) with attention to pressure; ketamine raises BP and is the wrong choice here.
Paralytic. Succinylcholine 1.5 mg/kg is not meaningfully potentiated by magnesium and gives the fastest conditions; rocuronium 1.2 mg/kg works but magnesium prolongs and deepens the block, so monitor TOF and expect a long recovery. Sugammadex 16 mg/kg if needed.
Laryngoscopy. Labetalol 20-40 mg IV, plus remifentanil 1 mcg/kg or fentanyl 2 mcg/kg; a hypertensive surge at laryngoscopy in a preeclamptic is a stroke risk. Warn NICU about the opioid.

3. Intraoperative bleeding and surgical findings

Intubated first look, BP 148/90 after the fentanyl. OB opens and reports 800 mL of free blood and a ruptured hepatic capsule with active bleeding. BP 88/52, HR 130. First three things? MTP — activate now? Ratio? Pressor while the blood hangs — which? Dose? OB asks: deliver the baby first or pack the liver first? Which? Why? Baby out. Oxytocin — dose and how? Methergine — yes/no? Why? HPB surgery is 15 minutes away. What do you ask OB to do with the liver right now? Ionized calcium 0.85. Dose? TXA — dose? Cell saver — yes/no? Why?

Considerations and pitfalls AI draft

First three. Call for help and a second anesthesiologist, activate MTP, open the rapid infuser on the second line; tell the room the diagnosis so OB packs rather than explores.
MTP and ratio. Yes, now; 1:1:1 until viscoelastic data arrive, with fibrinogen replaced early because HELLP consumption plus dilution drives it below 200 quickly.
Pressor. Hemorrhagic shock is treated with blood; norepinephrine 4-8 mcg boluses or phenylephrine 100 mcg as a bridge while the first units run. A resident who titrates a pressor and does not name the products has the priorities inverted.
Baby or liver first. Deliver first: it takes two minutes, removes uteroplacental blood flow demand, lets the uterus contract, and gives OB room to pack the liver with the abdomen open; then pack. Packing first while the fetus is hypoperfused and the uterus is in the way is the wrong order.
Oxytocin. Infusion, no large bolus in a hypotensive patient; 3 IU slowly then an infusion. Methergine is contraindicated in severe hypertension and preeclampsia regardless of the current pressure; naming it without a flag is a fail. Carboprost is acceptable.
Liver now. Pack it with laparotomy pads and hold pressure (Pringle maneuver if the surgeon can); no attempts at repair by OB. Packing buys the 15 minutes.
Calcium. Calcium chloride 1 g IV now, recheck every 30 minutes through the resuscitation.
TXA. 1 g over 10 minutes, then 1 g over 8 hours; within 3 hours of onset.
Cell saver. Yes, with a leukoreduction filter; amniotic contamination is a theoretical concern. It is the hepatic blood that is worth salvaging.

4. Post-delivery course and the liver

Liver packed, HPB in. EBL 4 L; 8 PRBC, 8 FFP, 2 platelets, 10 cryo in. BP 90/55 on norepinephrine 0.15, HR 120, temp 35.2, lactate 6.2, pH 7.21. Labs: platelets 45, fibrinogen 150, INR 1.6. Products now — what and how much? Targets? Still hypotensive on 0.15 after all that blood. DDx? What do you check? HPB wants to leave her packed and open. Close the fascia? Why/why not? Magnesium — still running? Rate? Transport to ICU — what comes with you? What sends her back to the OR tonight? Name the numbers.

Considerations and pitfalls AI draft

Products. Platelets 1 apheresis unit (target ≥50 K, higher if bleeding), cryo 10 units or fibrinogen concentrate 4 g (target ≥200), FFP 2-4 units or PCC for INR ≥1.5 with ongoing bleeding; recheck in 30 minutes.
Persistent hypotension. Ongoing surgical bleeding under the packs, hypocalcemia, hypothermia and acidosis, tension from abdominal packing, transfusion reaction, the magnesium; check ionized calcium, temperature, a TEG, bladder pressure, and ask HPB to look under the packs before you increase the pressor.
Fascia. Leave it open: a packed, coagulopathic, acidotic, edematous abdomen will develop compartment syndrome if closed; temporary closure and a planned re-look at 24-48 hours.
Magnesium. Continue at 1 g/h; creatinine 1.3 and a massive transfusion both reduce clearance; check a level in the ICU and reflexes every hour.
Transport. Intubated and sedated, vasoactives on pumps, blood products and calcium in hand, airway kit, monitor with the arterial line, a second person, the ICU called ahead.
Back to the OR. Rising drain or pack output, a falling hemoglobin after correction, rising pressor requirement with a normal calcium and TEG, or bladder pressure >20; name the numbers, not 'if she gets worse.'

B. POST-OPERATIVE CARE

Teaching focus. ICU management of the postpartum patient with hepatic injury and coagulopathy; recognizing and treating ongoing bleeding when source is hidden; ventilatory support and extubation judgment in a marginal patient; postpartum eclampsia surveillance and disclosure when recovery diverges from the expected course.

1. ICU arrival and initial plan

ICU: intubated, packed, open abdomen under a vacuum dressing, norepinephrine 0.1. Arterial line and two large peripherals in. You place a central line — which site? Why? Vent — tidal volume? PEEP? Sedation — propofol, dexmedetomidine, or midazolam? Which? Why? Magnesium — rate? Level target? Reflexes how often? One hour in: Hgb 7.9, platelets 55, fibrinogen 180. Transfuse now? Which products? Name the goals for six hours from now — the numbers.

Considerations and pitfalls AI draft

Central line. Right IJ under ultrasound; a subclavian in a coagulopathic patient is non-compressible; femoral is under the abdominal dressing and dirty.
Vent. 6-8 mL/kg PBW (PBW ~52 kg, so 350-400 mL), PEEP 5-8 with attention to abdominal pressure transmitted to the chest, plateau ≤30.
Sedation. Propofol infusion for a patient going back to the OR; dexmedetomidine as an adjunct once pressors allow; no midazolam infusion. Opioid for the abdomen; fentanyl, not morphine, with liver and kidney injury.
Magnesium. 1 g/h, level 4-7 mg/dL, reflexes hourly; hold and check a level if reflexes disappear or RR falls once she is spontaneously breathing. Continue at least 24 hours postpartum, longer if hypertension and neurologic signs persist.
Transfuse. Fibrinogen 180 with an open packed liver: cryo or concentrate now to ≥200; platelets to ≥50 K, so a unit if any bleeding; Hgb 7.9 is acceptable if stable, transfuse if trending down.
Six-hour goals. MAP ≥65 on falling pressor, lactate halved, temperature ≥36, ionized calcium ≥1.1, fibrinogen ≥200, platelets ≥50 K, INR <1.5, urine output ≥0.5 mL/kg/h, stable hemoglobin, bladder pressure <20.

2. Ongoing coagulopathy

Six hours in: drains 800 mL serosanguinous, INR 1.8, fibrinogen 140, platelets 48, Hgb 7.8, temp 36.2, ionized Ca 1.05. Bleeding or oozing? What tells you? Products — what, how much? Targets? Cryo or fibrinogen concentrate? Dose? Next hour: another 400 mL in the drains, Hgb 6.5. Back to the OR, IR, or more products and wait? Which? Why? Enoxaparin — first dose when? Dose?

Considerations and pitfalls AI draft

Bleeding or oozing. The volume says bleeding; the hemoglobin holding at 7.8 says the drains may be diluted. Coagulopathy from consumption plus dilution is certain; surgical bleeding is not excluded. Correct the coagulopathy and see whether the output falls.
Products. Cryo 10 units or fibrinogen concentrate 4 g (target ≥200), platelets 1 unit (target ≥50 K, ≥75 K if actively bleeding), FFP 2-4 units (INR <1.5), calcium chloride 1 g. Recheck in 30-60 minutes; empiric repeat dosing without labs is a flag.
Cryo vs concentrate. Concentrate is faster, smaller volume, and dosed precisely (70 mg/kg raises fibrinogen ~100 mg/dL); cryo is cheaper and widely available. Either is right; ask for the dose.
400 mL and Hgb 6.5. Surgical bleeding until proven otherwise: back to the OR for re-exploration and re-packing, or IR for hepatic artery embolization if she is stable enough to travel and the surgeon prefers it. Waiting with products is the wrong answer once the hemoglobin drops with corrected labs.
Enoxaparin. Not until 24-48 hours after bleeding has clearly stopped and the surgeon agrees; sequential compression until then. Postpartum HELLP with massive transfusion is a high VTE-risk state; starting it too late is also an error.

3. Worsening liver function on POD 1

POD 1: AST 1200, ALT 1400, bilirubin 4.8, INR 2.4 despite 4 FFP overnight, ammonia 95, glucose 62 on D10 at 50 mL/h. What does an INR climbing through FFP tell you? DDx now? Glucose 62 — Rx? What rate? Ammonia 95 — Rx? Lactulose with an open abdomen — yes/no? N-acetylcysteine — give it? Why? Plasma exchange — yes/no? When? Hepatology says she may need to be listed. What do you have to protect to keep her a candidate?

Considerations and pitfalls AI draft

INR through FFP. Synthetic failure: the liver is not making factors. This is acute liver failure, not consumption alone; transient correction with FFP followed by drift is the signature.
DDx. AFLP (hypoglycemia, hyperammonemia, coagulopathy out of proportion to bleeding), HELLP with hepatic infarction or necrosis, ischemic hepatitis from the hemorrhagic shock, drug injury. A resident anchored on HELLP should be asked what the glucose and ammonia mean.
Glucose. D10 at a higher rate or D20 via the central line, hourly glucose, target >70; hypoglycemia in liver failure is a marker of severity and injures the brain.
Ammonia. Lactulose is safe via the NG tube even with an open abdomen (ileus permitting); rifaximin as an adjunct; avoid sedatives that confound the exam; ammonia >150 raises the intracranial pressure concern.
NAC. Reasonable; non-acetaminophen acute liver failure has a transplant-free survival signal with NAC in early-grade encephalopathy, and the risk is low.
Plasma exchange. For refractory HELLP/AFLP with multi-organ failure after delivery; not first line, but it is on the table within 24-48 hours if the trajectory continues.
Candidacy. No uncontrolled sepsis, no irreversible brain injury (ICP management, avoid over-sedation, head up, sodium 145-150 if encephalopathy deepens), hemodynamic support that keeps the other organs alive; early transfer to a transplant center rather than waiting to be sure.

4. Postpartum eclampsia and pulmonary edema

POD 2: sedation lifted for a neuro check, and she has a tonic-clonic seizure on the ventilator. SpO2 84%, peak pressure 45. First? Magnesium is running at 1 g/h. Bolus? Dose? Still seizing at three minutes. Next drug? Dose? Seizure stops. DDx? Magnesium level returns 3.2 mg/dL. Rate now? CT head now, or wait? Why? CT negative. Back in the ICU: SpO2 88% on FiO2 0.8, PEEP 8, bilateral crackles, pink secretions. DDx? Echo: LV hyperdynamic, IVC full, B-lines everywhere. Rx? Furosemide dose? PEEP — up to what? Refractory — next?

Considerations and pitfalls AI draft

First. She is intubated: FiO2 1.0, hand-ventilate if pressures allow, protect the lines and the abdomen, confirm the tube; then treat the seizure.
Magnesium. 2 g IV over 5 minutes as a re-bolus on top of the running infusion; a full 4-6 g load in a patient with a creatinine of 1.3 already on magnesium risks toxicity. Check a level.
Refractory. Lorazepam 2-4 mg IV or midazolam 2-5 mg; then levetiracetam 1-2 g load; propofol bolus is available since she is intubated. Do not keep pushing magnesium.
DDx. Postpartum eclampsia first, then intracranial hemorrhage (coagulopathic, hypertensive), cerebral venous sinus thrombosis, hypoglycemia, hyponatremia, hepatic encephalopathy, PRES.
Level 3.2. Sub-therapeutic; increase to 2 g/h with hourly reflexes and a repeat level in 4 hours, still watching the creatinine.
CT. Now, once she is stable enough to move: a coagulopathic hypertensive patient with a seizure needs hemorrhage excluded before anything else is assumed; MRI/MRV later for PRES or CVST.
Pulmonary edema. Preeclamptic capillary leak plus volume overload from resuscitation, TACO, TRALI, cardiogenic (peripartum cardiomyopathy is on the list until the echo is read); the echo here says overloaded with a good LV.
Rx. Furosemide 20-40 mg IV and repeat by effect, PEEP up to 10-14 with attention to abdominal and RV pressures, FiO2 1.0, strict restriction, BP controlled; if refractory, paralysis, prone with an open abdomen is nearly impossible, so early ECMO consultation or CRRT for fluid removal.

5. Disclosure and ongoing course

POD 4: she opens her eyes and follows commands on a sedation hold; abdomen still open. Her husband asks if she will live. What do you say? Analgesia and sedation for the coming days with a failing liver and a creatinine of 1.9 — what do you use? What do you avoid? Why? Acetaminophen — yes/no? Aspirin next time — dose, from when? Her letter — what goes in it?

Considerations and pitfalls AI draft

Will she live. Honest uncertainty, no false reassurance, no despair: she has survived the bleeding, her liver and kidneys are the question, the transplant team is involved, and the next 48-72 hours will tell. Say what is being done, name who will update him and when. Vagueness and false certainty are both flags.
Analgesia. Fentanyl or hydromorphone in small doses (no morphine with renal failure, no meperidine), ketamine infusion, dexmedetomidine for sedation, regional (TAP catheters) once coagulation allows; avoid NSAIDs (kidney, platelets), avoid benzodiazepines and gabapentinoids that accumulate and cloud the neuro exam.
Acetaminophen. Hold while the liver is failing; when it recovers, ≤2 g/day is acceptable.
Aspirin. 81-162 mg daily from 12-16 weeks in any future pregnancy; preconception counseling with maternal-fetal medicine.
Letter. HELLP with hepatic rupture, massive transfusion and any antibodies formed, acute liver failure course, eclampsia, easy airway, the drugs that were held and why, and a request that future anesthetic teams plan early neuraxial with platelet trend in hand.

Long stem

Severe preeclampsia with thrombocytopenia and morbid obesity, emergent cesarean

A 32 y.o. G2P1 at 35 weeks gestation, 110 kg, 5'5" (BMI 41), is brought from L&D to the OR for stat cesarean delivery for non-reassuring fetal tracing.

HPIAdmitted six hours ago with severe headache, scotomata, and right upper quadrant pain. BPs in the severe range since arrival despite labetalol boluses. Magnesium sulfate running at 2 g/h after a 4 g load. Obstetricians now report category III tracing with persistent late decelerations and minimal variability.

PMHChronic hypertension. Gestational diabetes on insulin. Obstructive sleep apnea on home CPAP, fair adherence. Two prior wet taps with epidurals during her first delivery, ultimately uncomplicated. No prior anesthetic complications she can recall.

MEDSLabetalol 200 mg PO BID, nifedipine ER 60 mg daily, insulin glargine 24 units qHS, magnesium sulfate gtt running, prenatal vitamins.

PHYS EXAMAnxious. HR 108; BP 174/108; RR 22; SpO2 94% on room air; T 37.0°C. Airway: Mallampati IV, thyromental distance 5 cm, neck circumference 44 cm, restricted neck extension from edema. Brisk reflexes with sustained clonus at the ankles. Pitting edema to the thighs and over the hands.

LABSHgb 11.2 g/dL; platelets 78 K/uL (was 142 K/uL one week ago); INR 1.0; fibrinogen 410 mg/dL; AST 112, ALT 138; creatinine 1.1 mg/dL; urine protein 4+; type and screen, no antibodies, two units PRBC on hold.

FETALEstimated fetal weight 2400 g. FHR baseline 95 with recurrent late decelerations and minimal variability over the past 25 minutes.

OR ARRIVAL18 g peripheral IV running LR with magnesium piggyback. Foley draining tea-colored urine. CPAP brought from the floor. Pt positioned with 15° left tilt. Obstetric team scrubbed; surgeon asking how long until incision.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Modality choice under thrombocytopenia and severe-range hypertension; airway plan for the morbidly obese parturient on magnesium; managing BP swings around induction and emergence; recognizing and treating refractory uterine atony when uterotonics interact with the magnesium and the heart.

1. Modality and neuraxial decision

The surgeon asks how long until incision. Spinal or GA? Which? Why? What number, or what else, flips you the other way? A TEG is 20 minutes away. Wait for it? Why/why not? Her epidural history — does it change the call? Treat the pressure before the block or the induction? Agent? Dose? Target? You go spinal. Bupivacaine dose? Adjuncts? Needle?

Considerations and pitfalls AI draft

Modality. Either is defensible if both risks are engaged. The airway is what makes GA dangerous (Mallampati IV, TMD 5 cm, neck 44 cm, edema, OSA, BMI 41, magnesium); the platelet trajectory is what makes the spinal uncomfortable. With INR 1.0 and fibrinogen 410, a single-pass spinal with a 25 g needle by the most experienced operator is the choice most would make. A reflexive GA without naming the airway, or a reflexive spinal without naming the trend, is a flag.
Threshold. Most accept ≥70-75 K when the count is stable; hers has halved in a week, so the question is whether it is 78 now or 60 by the time the needle goes in. Clinical bleeding, petechiae, a fibrinogen falling, or a repeat count below 70 would push to GA; a stable repeat count reassures.
TEG. No; a category III tracing does not wait 20 minutes for a test that changes the products more than the modality. Send it and proceed.
Wet taps. They predict a technically harder back (obesity, edema) and a higher PDPH risk; they are not a contraindication. Ultrasound the spine first; the most experienced hands go first.
BP. Yes, before either: labetalol 20-40 mg IV (she is already on it), or hydralazine 5-10 mg; target <160/110, roughly 140-150/90-100, not normal. A hypertensive surge at laryngoscopy or a hypotensive collapse after a spinal are both worse on an untreated 174/108.
Spinal dose. Hyperbaric bupivacaine 10-12 mg (obesity is not a reason to drop below 10 mg for a cesarean), fentanyl 15 mcg, morphine 100-150 mcg; 25 g pencil-point needle, sitting, ultrasound-marked midline. Phenylephrine or norepinephrine infusion running from the moment she lies down.

2. GA induction in the obese, preeclamptic, magnesium-loaded parturient

Two spinal attempts, no CSF, FHR 80. Convert to GA. Position — how do you ramp 110 kg in two minutes? Preoxygenation — technique, and what end-tidal O2 tells you to go? Induction agent? Dose — on what weight? Sux or rocuronium? Dose? Why that one? VL or DL first? Why? BP 190/115 as you reach for the syringe. Give what? Dose? Target? Grade 3 view on VL, one attempt, SpO2 96%. Next? Bougie passes, tube in, ETCO2 present. Volatile — which and what MAC?

Considerations and pitfalls AI draft

Ramp. Shoulder and head blankets or a commercial ramp to bring the tragus level with the sternal notch, reverse Trendelenburg 20-30°; every minute of ramping is worth it, and it can be done while the surgeon preps.
Preoxygenation. Tight mask, 100% oxygen, head up, CPAP 5-10 or her own CPAP circuit, high-flow nasal oxygen under the mask for apneic oxygenation; go at end-tidal O2 ≥80%, or after 3 minutes if the tracing does not allow more. Expect desaturation in under a minute in this body habitus.
Induction. Propofol 2 mg/kg on lean body weight (~60-65 kg, so 120-150 mg), with the pressure treated first; ketamine is wrong here (hypertensive, headache, scotomata).
Paralytic. Succinylcholine 1-1.5 mg/kg on total body weight (fastest, shortest, minimally affected by magnesium, and the one to choose in a predicted difficult airway); rocuronium 1.2 mg/kg with sugammadex 16 mg/kg ready is acceptable, but magnesium prolongs and deepens it and blunts sugammadex reversal. A resident who dose-reduces rocuronium 'because of the magnesium' has it backwards.
VL. Video laryngoscope first pass: it is the best chance at first-pass success in a Mallampati IV with a short thyromental distance; DL as backup, not the other way round. A second-generation supraglottic and a scalpel on the tray.
BP 190/115. Labetalol 20-40 mg IV plus remifentanil 1 mcg/kg or fentanyl 2 mcg/kg or esmolol 1 mg/kg before laryngoscopy; target below 160/110 for the laryngoscopy; nitroprusside as a first move is a flag. Tell NICU the opioid went in.
Grade 3 view. Bougie under the epiglottis with the VL still in place, external laryngeal manipulation, one more attempt with a different blade or a hyperangulated blade; if that fails, supraglottic airway and ventilate. Repeated laryngoscopy in an edematous preeclamptic airway converts a difficult airway into a lost one.
Volatile. Sevoflurane at 0.5-0.75 MAC until delivery (MAC is reduced in pregnancy, magnesium adds CNS depression, and higher MAC relaxes the uterus); supplement with opioid after the cord is clamped.

3. Intraoperative BP swings and emergence

Tube in on the second look with a bougie. Baby out at six minutes, Apgars 4 and 7. Two minutes after delivery, BP 78/40, HR 115. DDx? Rx? Phenylephrine, ephedrine, or norepinephrine? Which? Dose? OB reports atony. Oxytocin — dose? Bolus or infusion? Atony persists. Methergine — give it? Why/why not? Carboprost — give it? Why/why not? Closing: BP 195/118, HR 120, end-tidal sevo 0.5%. DDx? Drug and dose? Target? Magnesium has run at 2 g/h through the case. Stop it at emergence, or continue? How long?

Considerations and pitfalls AI draft

Post-delivery hypotension. Loss of aortocaval compression alone does not do this; oxytocin bolus, bleeding from atony, volatile depth after the sympathetic surge, the magnesium, and residual induction drug. Look at the field before you choose the drug.
Pressor. Phenylephrine 100 mcg or norepinephrine 8 mcg boluses for a vasodilated drop; ephedrine is acceptable but adds tachycardia. Phenylephrine is not contraindicated in obstetrics; a resident who says so should be corrected.
Oxytocin. Infusion rather than a large bolus in a hypotensive patient: 1-3 IU slowly, then 10-40 IU/L infusion. A 5-10 IU IV push here is a flag.
Methergine. Contraindicated in severe hypertension and preeclampsia regardless of the current pressure: it will produce a hypertensive crisis in twenty minutes. Naming it without a flag is a fail.
Carboprost. No asthma, so it is allowed; give 250 mcg IM, repeat every 15 minutes up to 8 doses, with the caveat that it raises pulmonary and systemic pressure and causes bronchospasm and diarrhea. Misoprostol 800-1000 mcg rectal or buccal alongside; TXA 1 g.
Hypertensive surge at closing. Light anesthesia at 0.5% end-tidal with the incision being closed, pain, hypercarbia, bladder; also preeclampsia itself. Deepen (opioid, propofol), then labetalol 20-40 mg IV or hydralazine 5-10 mg or a nicardipine infusion; target <160/110 before extubation. Nitroprusside as a reflex is a flag.
Magnesium. Continue through emergence and for at least 24 hours postpartum; a brief hold for 'weakness at extubation' without a restart is how postpartum eclampsia happens. Assess strength with the magnesium running, not by stopping it.

4. Refractory atony and massive hemorrhage

Atony persists after oxytocin, carboprost x2, and misoprostol. EBL 2500 mL. BP 70/35, HR 138. MTP — activate? Ratio? First units hanging. Calcium — dose? How often? OB asks: Bakri, B-Lynch, IR embolization, or hysterectomy. Can she tolerate 40 minutes in IR? What tells you? Labs: fibrinogen 142, INR 1.7, platelets 54. Products — what and how much? Targets? TXA — dose? It was 25 minutes ago; give it again? Temp 35.1. Rx? Magnesium at 2 g/h for eight hours. Stop it now? Why/why not? What number tells you the resuscitation is winning?

Considerations and pitfalls AI draft

MTP. Yes, now; 1:1:1 until viscoelastic data arrive; a second large-bore line and a rapid infuser; call for a second anesthesiologist.
Calcium. Calcium chloride 1 g IV now, repeat roughly every 2-4 units of citrated product, ionized calcium every 30 minutes.
Can she go to IR. No: BP 70/35 on no products with an open abdomen is not a patient who travels. Bakri or B-Lynch now with the abdomen open; hysterectomy if those fail. IR is for the stable patient with ongoing bleeding. The resident's job is to say plainly whether she has 40 minutes; hand-waving to the surgeon is a flag.
Products. Cryo 10 units or fibrinogen concentrate 4 g (target ≥200 while bleeding), platelets 1 unit (target ≥50 K, ≥75 K if still bleeding), FFP or PCC for INR ≥1.5; recheck in 30 minutes.
TXA. 1 g over 10 minutes; a second 1 g if bleeding continues after 30 minutes. If it was not given already, it is late but not too late (within 3 hours).
Temp 35.1. Warm all lines, forced air on the exposed patient, warm the room; hypothermic coagulopathy will not respond to products.
Magnesium. Reduce or briefly hold while she is in hemorrhagic shock; magnesium lowers vascular tone and worsens atony, and clearance falls with hypoperfusion. Restart as soon as she is stable; the eclampsia window does not close. Stopping without a plan to restart is the error.
Winning. Lactate trending down, base deficit closing, MAP ≥65 with falling pressor, urine output returning, ionized calcium ≥1.1, fibrinogen ≥200, a firm uterus; not a single hemoglobin.

B. POST-OPERATIVE CARE

Teaching focus. Extubation judgment after massive transfusion in an obese parturient on magnesium; recognizing and treating postpartum eclampsia; working up postpartum oliguria when AKI, preeclamptic injury, and ATN compete; the POD 2 endpoints (magnesium off, VTE prophylaxis, oral antihypertensives, insulin) before the floor; honest disclosure when the postpartum course did not match the patient's expectations.

1. Extubation

Case done. EBL 4 L; 8 PRBC, 6 FFP, 2 platelets, 10 cryo, 2 g TXA. BP 100/60 on norepinephrine 0.04. Magnesium restarted at 1 g/h. Temp 36.1. Extubate in the OR? Why/why not? What must be true? Sugammadex 4 mg/kg given, TOF ratio 0.95, head lift 3 seconds. Good enough with the magnesium? Why? You extubate. Twenty minutes later: SpO2 88% on 6 L, RR 28, crackles both bases. DDx? Bedside test? Echo: LV vigorous, IVC full, B-lines throughout. Rx? Her own CPAP — yes/no? Furosemide — dose? SpO2 84% on CPAP and she is drowsy. Reintubate — now? Plan for this airway the second time?

Considerations and pitfalls AI draft

Extubate or not. Leaving her intubated is the safer answer: massive transfusion, a pressor still running, magnesium, a difficult airway, OSA, and a leaky preeclamptic vasculature that will get worse over the next 12 hours. Extubation is defensible only if every criterion is met and the airway team is prepared to reintubate. Extubating to free up the OR is a flag.
Criteria. Awake and following commands, TOF ≥0.9 with sustained head lift, normothermic, pressor off or minimal, no ongoing bleeding, acceptable gas exchange on low FiO2, BP <160/110.
Magnesium and strength. Magnesium weakens the neuromuscular junction independently of the rocuronium and blunts sugammadex reversal; a TOF of 0.95 is reassuring but a 3-second head lift is marginal. A 5-second head lift and a strong grip carry more weight than the monitor here; if in doubt, wait.
Hypoxemia DDx. Pulmonary edema (preeclamptic, TACO, TRALI), atelectasis in obesity, residual weakness, opioid and magnesium respiratory depression, OSA obstruction, aspiration. Bedside echo and lung ultrasound sort most of it.
Rx. Sit her up, CPAP (her own machine is fine if the mask fits and she is awake enough), furosemide 20-40 mg IV, restrict fluids, control BP; TACO and preeclamptic edema both respond, TRALI does not.
Reintubation. Now, before she arrests: falling saturation on CPAP with drowsiness is a failing trajectory. Same ramp, VL first with the bougie in hand, most experienced operator, supraglottic and surgical airway ready, and this time no rush. Waiting for a lower number is the error.

2. Postpartum seizure

POD 0, 8 hours postop in the ICU, extubated on CPAP. The primary team stopped the magnesium two hours ago. Tonic-clonic seizure. First moves? Magnesium — dose? Why that dose? Still seizing at three minutes. Next drug? Dose? Seizure stops. She is post-ictal, SpO2 90% on a non-rebreather, snoring loudly. Intubate? Why/why not? DDx for the seizure? CT head — now, or after she settles? CT normal. Magnesium — rate now? For how long?

Considerations and pitfalls AI draft

First moves. Lateral, oxygen, suction, protect her from injury, confirm the IV, call for help; do not force anything into her mouth.
Magnesium. 2 g IV over 5 minutes, up to 4 g total; she stopped only two hours ago and has residual on board, and her creatinine is 1.1. A full 4-6 g load risks toxicity. Stopping magnesium early postpartum is the error that led here and should be named.
Refractory. Lorazepam 2-4 mg IV or midazolam 2-5 mg; then levetiracetam 1-2 g; be ready to intubate when the benzodiazepine goes in.
Intubate. A difficult airway, OSA, post-ictal obstruction, and SpO2 90% on a non-rebreather: yes, in a controlled fashion now with the full airway team, rather than after the next seizure or an aspiration. Watchful waiting is defensible only with the airway team at the bedside and improving saturations.
DDx. Postpartum eclampsia first (it occurs up to days out, especially when magnesium is stopped early); intracerebral hemorrhage in a hypertensive thrombocytopenic patient, CVST, PRES, hyponatremia, hypoglycemia (insulin, NPO), local anesthetic is not on the list (no epidural).
CT. As soon as she is stable enough to move: hemorrhage must be excluded in this patient; MRI/MRV later for PRES or CVST if the CT is negative and the picture does not fit.
Magnesium after. 1-2 g/h for 24 hours after the seizure, adjusted to creatinine, with hourly reflexes and a level; do not stop it again for a soft reason.

3. Oliguria and rising creatinine

POD 1: urine output 12 mL/h for four hours. Cr 1.8 (baseline 0.9), BUN 32, K 5.1. BP 112/72 off pressors. DDx? What do you examine and check first? Foley flushes clear, bladder pressure 14, bladder ultrasound empty. Fluid bolus — yes/no? How much? What tells you? 500 mL in, urine output unchanged. Furosemide — yes/no? Dose? Why? Magnesium running at 1 g/h with this creatinine. Rate now? Reflexes are gone and RR is 9. Dx? Rx? Dose? She is now short of breath, SpO2 91%. DDx? Rx?

Considerations and pitfalls AI draft

DDx. Preeclamptic AKI, ATN from hemorrhagic shock and pigment (she had tea-colored urine at the start), hypovolemia from under-resuscitation, abdominal compartment syndrome after massive resuscitation, obstructed Foley, TTP/HUS if platelets fall again. Anchoring on one is a flag.
First. The Foley, the abdomen (bladder pressure), volume status (IVC, JVP, lung ultrasound, balance), a urine sodium and sediment.
Fluid. A small bolus (250-500 mL) only if the exam says she is dry (collapsing IVC, dry lungs); a preeclamptic vasculature leaks, and 'a liter for oliguria' produces the pulmonary edema in the next beat. No response to 500 mL means stop giving fluid.
Furosemide. Yes if she is full (IVC plethoric, B-lines) to protect the lungs; it does not treat the AKI, and a dose that produces urine does not mean the kidney is better. 20-40 mg IV.
Magnesium. Renally cleared; at a creatinine of 1.8 reduce to 0.5-1 g/h with a level every 4-6 hours, or hold while the level is checked.
Reflexes gone, RR 9. Magnesium toxicity (loss of reflexes ~10 mEq/L, respiratory depression above ~12); stop the infusion, calcium gluconate 1 g IV over 3 minutes, support ventilation, send a level; dialysis if she is anuric and the level is very high.
Dyspnea. Pulmonary edema (preeclamptic, TACO), magnesium-related hypoventilation, atelectasis, PE; lung ultrasound and echo, then CPAP and diuresis or ventilation as the picture dictates. Renal consultation now for oliguria refractory to optimization, rising potassium, and a possible dialysis need.

4. POD 2: magnesium endpoint, VTE prophylaxis, and the floor regimen

POD 2, 24 hours after the seizure. Magnesium at 0.75 g/h, level 5.8, reflexes 1+, creatinine 1.5, urine 45 mL/h, BP 158/98. Stop the magnesium now? Why/why not? Magnesium off. Three hours later BP 168/104. Treat? Agent? Dose? Target? Oral regimen for the floor: nifedipine, labetalol, or both? Doses? Enalapril — yes/no? Why? Platelets 88 and rising, Hgb 7.8, no bleeding, BMI 41. Enoxaparin — yes/no? Dose? When? Heparin instead? Why? Hgb 7.8, asymptomatic. Transfuse? IV iron? Glucose 140 before dinner. Glargine 24 units tonight — give it? Dose? Transfer to the floor — what must be true?

Considerations and pitfalls AI draft

Stop magnesium. Yes — 24 h beyond the seizure with a therapeutic level, no clonus, and a kidney that is clearing it slowly (creatinine 1.5) is the endpoint; continuing indefinitely accumulates toward toxicity, which she has already had once. Persistent severe symptoms (headache, visual change, clonus) would extend it; a BP of 158/98 alone does not.
BP 168/104. Severe-range, treat within 30-60 min: labetalol 20 mg IV (escalating 40, 80), hydralazine 5-10 mg IV, or nifedipine IR 10 mg PO; target 140-150/90-100, not normal — a rapid drop is its own harm.
Oral regimen. Nifedipine ER 30-60 mg daily first (effective postpartum, once daily, compatible with breastfeeding), labetalol 200-400 mg TID added if needed; she was on both before delivery so restart both. Enalapril is breastfeeding-compatible and a good postpartum agent, but with an evolving AKI at creatinine 1.5 hold it until the kidney recovers.
VTE prophylaxis. Yes — cesarean, BMI 41, preeclampsia, massive transfusion, ICU stay: high risk. Platelets >50 and rising with no bleeding and no neuraxial catheter: start now. Enoxaparin weight-based (about 0.5 mg/kg BID, ~60 mg BID at 110 kg) if creatinine clearance is above 30; unfractionated heparin 5000-7500 units TID is the alternative while the creatinine is moving, and it reverses fast if she rebleeds. Withholding prophylaxis for the platelet count is the error.
Hgb 7.8. No transfusion — asymptomatic, no ongoing bleeding; IV iron (e.g., ferric carboxymaltose or iron sucrose) for a faster recovery than oral; transfuse for symptoms or Hgb <7.
Glargine. Hold or halve — insulin sensitivity returns within hours of delivery and gestational diabetes usually resolves; a full 24 units into a postpartum patient eating poorly produces overnight hypoglycemia. Check fasting glucoses and reassess at the postpartum visit.
Floor. BP <160/110 on oral agents for 12-24 h, magnesium off with reflexes and mental status normal, off NIV with oxygen requirement stable, urine output improving on a falling creatinine, a VTE plan written, CPAP nightly with continuous oximetry on the floor given OSA and opioids.

5. Disclosure and counseling

POD 3: extubated, creatinine 1.4 and falling, on the floor. She asks why she ended up in the ICU and whether she nearly lost her uterus. What will you tell her? She also has a headache since yesterday, worse sitting up, better lying flat. BP 150/95. DDx? What do you check? Blood patch on POD 3 with platelets 95 — yes/no? Why? What goes in her letter for a future anesthetic? Aspirin next pregnancy — dose, from when? CPAP at discharge — anything different?

Considerations and pitfalls AI draft

What to tell her. Plain and complete: severe preeclampsia, why the baby had to come out fast, why the spinal failed and she was put to sleep, the bleeding from a uterus that would not contract, the transfusion, that the surgeons used measures to keep her uterus and that a hysterectomy was the next step had they failed, the seizure, the kidney injury. No minimizing, no blame, and the OB and ICU teams told the same account before she hears it. Offering a partial version and referring the rest to OB is a flag.
Headache DDx. PDPH after two spinal attempts (positional pattern), but preeclampsia is still active at 150/95, and CVST, PRES, and subdural are on the list after eclampsia. Neurologic exam, BP trend, platelets, and a low threshold for MRI/MRV; the positional pattern alone is not enough here.
Blood patch. Not yet: platelets 95 on POD 3 is acceptable for a patch, but with an unexplained seizure three days ago and hypertension, image first and exclude CVST and hemorrhage; a patch into a patient with an intracranial process is the error. Once imaging is clean, a patch at 24-48 hours from symptom onset is reasonable.
Letter. Difficult airway (grade 3 on VL, bougie), failed spinal and the reason, HELLP-range labs, massive transfusion, postpartum eclampsia, magnesium toxicity episode, AKI, OSA; and a recommendation for early neuraxial planning with a platelet trend and an airway team present in any future pregnancy.
Aspirin. 81-162 mg daily from 12-16 weeks; preconception planning with maternal-fetal medicine, BP optimization, and recurrence risk of preeclampsia around 15-25%, higher with chronic hypertension.
CPAP. Nightly, adherence reinforced; postpartum fluid mobilization and opioids make the first weeks a high-risk window, and a sleep medicine follow-up for retitration after the weight and edema settle.

Short stem

Stat cesarean in laboring parturient with epidural, conversion to general

A 28 y.o. G3P2 at 39 weeks gestation, 5'7", 78 kg, has been in active labor for 11 hours with a continuous lumbar epidural infusion of bupivacaine 0.1% with fentanyl 2 mcg/mL, placed six hours ago without difficulty. Her first delivery was a cesarean complicated by a 1.5 L postpartum hemorrhage that required a Bakri balloon; her second was an uncomplicated vaginal birth. She has well-controlled asthma on albuterol prn and mild iron-deficiency anemia (Hgb 10.4). Her last meal was four hours ago, a sandwich and orange juice. Mallampati II at admission; HR 96; BP 128/76; RR 18; SpO2 99% on room air. The obstetric team has managed a prolonged second stage with intermittent variable and late decelerations. She is requesting a top-up because the obstetricians plan a forceps trial at the bedside.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Assessing a laboring epidural at the bedside; situating a parturient's airway and aspiration risk under labor physiology; reactive airway considerations in pregnancy; anemia and resuscitation preparation when the case may convert.

1. Bedside epidural assessment

She reports cramping suprapubic pain, 6/10 with each push; legs feel normal. Pump at 10 mL/h, two patient boluses in the last hour. Level to ice T10 bilaterally, Bromage 0. Is this epidural working? Why/why not? Level and density you want before a forceps trial? Top-up agent — bupivacaine 0.25%? Lidocaine 2%? Chloroprocaine 3%? Which? How many mL? Test dose first, six hours in? Why/why not? Ten minutes after 10 mL: level T8 to ice, still 5/10 with each contraction, no sensation change over the perineum to ice. What is this? Another bolus, or replace the catheter? Why? OB wants to start forceps in 5 minutes. At the bedside with this block, or move her to the OR? Why?

Considerations and pitfalls AI draft

Is it working. T10 to ice bilaterally with new suprapubic and pushing pain is a block losing density and sacral coverage in second stage, not a dead catheter; the flag is reaching for a top-up before checking level, symmetry, motor, and pump history.
Level for forceps. T10 with dense sacral (S2-4) coverage for low/outlet forceps; a surgical block (T4-T6) only if the plan is cesarean. Something denser than 0.1% bupivacaine either way.
Top-up agent. Bupivacaine 0.25% 8-10 mL for forceps coverage; lidocaine 2% with bicarbonate and epinephrine 8-10 mL if cesarean may follow (fast, extendable); chloroprocaine 3% for the fastest onset. Any is defensible if committed and matched to the likely path.
Test dose. Yes in some form: catheter position changes over six hours of labor; either a formal 3 mL lidocaine 1.5% with epi 1:200,000 or the top-up in 5 mL increments with aspiration and a 3-minute check. Pushing 10 mL in one pass is the error.
Perineum unchanged. Sacral sparing: the large S1-2 roots resist dilute solutions and a catheter that has crept cephalad. Sit her up, larger-volume less-dilute bolus; if a second bolus fails, replace the catheter now rather than discover a non-surgical catheter at a stat cesarean.
Bedside vs OR. With a marginal block, prior 1.5 L PPH, and a nonreassuring tracing, the OR (trial of forceps with the option to cut) is the stronger answer; bedside forceps is defensible only if she names what she gives up (full monitoring, blood, immediate conversion).

2. NPO and aspiration risk

Sandwich and orange juice four hours ago. Full stomach? Why/why not? The top-up goes in; ten minutes later she is nauseated and retching. BP 92/58, HR 104. Cause? Rx? Pressor — which? Dose? BP 118/70, nausea gone. She may go to the OR within the hour. Antacid now — which? Sodium citrate — how many mL? How long does it last? Famotidine — give it? Why/why not? Metoclopramide — dose? She vomits undigested sandwich on the way to the OR. Does that empty her stomach for you? What does it change about induction?

Considerations and pitfalls AI draft

Full stomach. Yes; labor, pain, and epidural fentanyl slow gastric emptying; the four-hour interval buys nothing. Every laboring patient is a full stomach for induction purposes.
Nausea with BP 92/58. Sympathectomy from the top-up with hypotension; nausea is the symptom of the BP. Treat the BP: LUD, fluid bolus, phenylephrine 100 mcg IV or ephedrine 5-10 mg if HR is low; nausea resolves with the pressure.
Sodium citrate. 30 mL of 0.3 M within 20-30 minutes of induction; effect lasts about an hour, so redose if the OR is delayed.
Famotidine. 20 mg IV; onset 30-60 minutes, so it will not help an induction in 10 minutes but does cover a later one and the PACU. Giving it because the case may convert is the point.
Metoclopramide. 10 mg IV; promotes emptying and raises LES tone; modest effect.
Vomiting. Does not empty the stomach reliably; she remains RSI. Ondansetron 4 mg treats the symptom and changes no aspiration risk.

3. Asthma in the parturient

Albuterol prn. What do you ask her? Two puffs twice this week for a cold, last night. Chest clear now, SpO2 99%. Albuterol neb before the OR? Why/why not? GA is the backup. Propofol or ketamine? Which? Dose? Sux or roc? Why? Volatile — sevoflurane or desflurane? Why? Atony after delivery in her — carboprost? Why/why not? What replaces it? Ketorolac after cesarean — yes/no? Why?

Considerations and pitfalls AI draft

History. Rescue frequency, recent URI, night symptoms, prior ED visits, intubations, steroid courses, triggers. Two uses in a week with a URI is mild; a recent steroid course would change the plan.
Pre-emptive neb. Reasonable before GA in any asthmatic with recent symptoms (albuterol 2.5 mg neb or 4-8 puffs MDI); low cost. Not required for a neuraxial case.
Induction agent. Propofol 2-2.5 mg/kg attenuates airway reflexes; ketamine 1-1.5 mg/kg bronchodilates and supports BP; either. Etomidate is neutral and not preferred. Reduce the dose if hypotensive.
Relaxant. Sux 1-1.5 mg/kg; roc 1.2 mg/kg is equivalent for RSI with sugammadex available. No asthma reason to avoid either; avoid histamine-releasing agents.
Volatile. Sevoflurane; desflurane is airway-irritant and increases resistance in reactive airways.
Carboprost. Contraindicated in asthma (bronchospasm); methergine (no severe HTN here) and misoprostol replace it. Say this to OB before the case, not during the hemorrhage.
Ketorolac. Fine unless aspirin-exacerbated respiratory disease; ask about NSAID reactions. Withholding NSAIDs from every asthmatic is a common overcaution.

4. Anemia and resuscitation prep

Hgb 10.4; T&S on admission, antibody screen negative. Crossmatch now? How many units? Why? One 18 g IV from the floor, positional. Adequate? What do you want? Prior 1.5 L PPH with a Bakri. Before the forceps trial, what is in the room? Uterotonics drawn up — which? Doses? Cell saver — set up? Why/why not? TXA — give it now, prophylactically? Why/why not?

Considerations and pitfalls AI draft

Crossmatch. Yes; prior PPH plus prolonged second stage plus possible operative delivery is a hemorrhage risk profile; 2 units crossmatched, blood bank aware. Hgb 10.4 leaves less reserve than the number suggests.
Access. A positional 18 g is not adequate; two reliable large-bore (16-18 g) IVs before the trial, not after the bleed starts.
In the room. Warmed fluids, rapid infuser available, uterotonics drawn, blood ordered, a plan for OR transfer stated to OB.
Uterotonics. Oxytocin infusion ready (e.g., 30 U/500 mL); methergine 0.2 mg IM; misoprostol 800-1000 mcg; no carboprost (asthma).
Cell saver. Supported in obstetric hemorrhage with a leukoreduction filter; reasonable to have ready given her history; not mandatory for a vaginal trial.
TXA. 1 g IV within 3 hours of hemorrhage onset once bleeding is established; routine prophylaxis before vaginal delivery is not standard. Either answer needs the reasoning.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Recognizing block failure under time pressure and committing to conversion; airway and induction in the parturient with a full stomach and a labor airway; troubleshooting hypoxemia and awareness intraoperatively; managing postpartum hemorrhage when uterotonic choice is constrained.

1. Stat C/S call and modality

You moved her to the OR. FHR drops to 60 and stays. OB calls stat C/S. Epidural in, level T8. Decision-to-delivery target? Top-up agent — lidocaine 2% with bicarb and epi? Chloroprocaine 3%? Bupivacaine 0.5%? Which? Why? How many mL? Test dose first? Why/why not? After 10 mL: BP 80/45, HR 118, she says she cannot get a full breath. DDx? Rx? Pressor — which? Dose? Level checks T4 to ice, grip strong, speaking full sentences. Give the rest of the top-up? Why/why not?

Considerations and pitfalls AI draft

Target. Category 1: delivery as fast as safely possible, commonly quoted as within 30 minutes but the real target is minutes; state aloud what you need.
Top-up. Lidocaine 2% with bicarbonate and epinephrine, 15-20 mL in increments, onset 5-10 min; chloroprocaine 3% is faster but short and antagonizes later neuraxial opioid; bupivacaine 0.5% too slow. Commit.
Test dose. A formal test dose costs 3 minutes she may not have; incremental 5 mL doses with aspiration and monitoring is the accepted compromise. Either is defensible if reasoned; a single 20 mL push is not.
BP 80/45, cannot get a full breath. Sympathectomy from rapid extension with a nonreassuring tracing on top; high or total spinal from a migrated catheter is the must-exclude. Strong grip, full sentences, and a T4 level make this sympathectomy, not a high spinal. Do not assume LAST without signs.
Rx. Stop injecting, LUD, phenylephrine 100 mcg boluses or norepinephrine, fluid, oxygen; recheck level and respiratory effort.
Give the rest. No; T4 is the target. More lidocaine buys nothing but a higher block. Proceed to incision.

2. Inadequate block, decision to convert

Prep and drape. Pinch test at the incision line: nothing on the left, sharp on the right; ice T4 left, T10 right. FHR 60. Options? Another 5 mL? Surgeon infiltrates? Ketamine? GA? Which? Why? How many minutes will you give this block? What sets that number? Ketamine — dose? OB makes the skin incision and she screams and grabs the drape. Now?

Considerations and pitfalls AI draft

Unilateral block after full dose. A catheter problem (lateral, in a paravertebral gutter); redosing 5 mL rarely fixes a unilateral block after 15 mL and delays the baby. Commit to a path.
Adjuncts. Ketamine 0.25-0.5 mg/kg (20-40 mg), surgeon local, IV fentanyl bridge a patchy block for minutes, not a hemi-block. Naming them as a substitute for a surgical block is the flag.
Time budget. A persistent FHR of 60 gives essentially no time; state a number (2-3 min) and what forces the move: fetal deterioration and maternal pain.
She screams. Convert to GA now. Chasing a failed block with boluses while she suffers and the baby is bradycardic is the error. Tell OB to stop cutting until she is asleep.

3. GA conversion

You call GA. You last looked at this airway 11 hours ago, Mallampati II. Look again? What do you expect to find? Position on the table — how? Preoxygenation — how long? Why that long? Propofol dose? Sux or roc? Dose? Cricoid — yes/no? Why? DL: large tongue, edematous oropharynx, epiglottis only, Cormack-Lehane 3. Next move? Second attempt — same blade? SpO2 92% and falling. Now?

Considerations and pitfalls AI draft

Airway change. Labor airway: mucosal edema, weight gain, pushing, fluids; Mallampati commonly advances a grade or two over labor. Look again and prepare for a worse airway than admission.
Position. Ramped, head-up 20-30 degrees, left tilt or LUD; check that the table can tilt before induction.
Preoxygenation. As long as the FHR allows; 3 minutes tidal breathing or 8 vital-capacity breaths on a tight mask; high-flow nasal oxygen during laryngoscopy if available. Pregnant FRC and O2 consumption make her desaturate in about a minute.
Drugs. Propofol 2-2.5 mg/kg (about 150-180 mg; reduce if hypotensive); sux 1-1.5 mg/kg or roc 1.2 mg/kg with sugammadex drawn.
Cricoid. Standard in most OB practice; release if it obstructs the view. Either defensible if argued.
CL 3. Optimize: external laryngeal manipulation, head lift, bougie under the epiglottis; second attempt with video laryngoscopy, not the same blade. Two attempts then SGA; ventilate between attempts.
SpO2 92% falling. Stop looking, mask ventilate with two hands and an oral airway, cricoid on, SGA if mask fails; the sequence is oxygenation, not the tube. Front-of-neck access if cannot ventilate.

4. Awareness, hypoxemia, and delivery

VL on the second attempt, Cormack-Lehane 2, tube in, ETCO2 confirms, SpO2 back to 97%. Volatile — which? MAC before delivery? Why that number? Baby out at 2 minutes, Apgars 3 and 7. BP 75/40, HR 140; surgeon reports a boggy uterus. DDx? Rx? Oxytocin — dose? How fast? Still boggy at 3 minutes. Methergine — yes/no? Dose? OB asks for carboprost. Your answer? Why? Misoprostol — dose? Route? Sevoflurane at 1 MAC. Turn it down? To what? Awareness — how do you cover it?

Considerations and pitfalls AI draft

Maintenance. Sevoflurane about 0.7-1 MAC before delivery; enough to prevent awareness, low enough to limit uterine relaxation; N2O 50% can supplement.
BP 75/40 with a boggy uterus. Atony plus volatile-induced relaxation, hemorrhage, and the aortocaval load coming off; amniotic fluid embolism if it does not respond. Oxytocin now.
Oxytocin. 3 U IV bolus over 30 s (repeat once or twice at 3-minute intervals), then infusion; a 10 U push causes hypotension. Or a 30 U/500 mL infusion run fast.
Methergine. Yes: 0.2 mg IM (or slow IV in some practices); no hypertension here. Repeat at 2-4 h.
Carboprost. No, asthma; state it plainly and offer misoprostol instead. Bronchospasm in an intubated asthmatic mid-hemorrhage is the trap.
Misoprostol. 800-1000 mcg rectal or sublingual; slower onset; adjunct.
Volatile and awareness. Drop to 0.5 MAC or convert to propofol infusion; cover with midazolam 2 mg, fentanyl, ketamine; processed EEG if available; document. Volatile at 0.5 MAC alone with no supplement is the awareness setup.

5. Persistent atony and emergence

Oxytocin, methergine, misoprostol in. EBL 2.0 L and climbing; BP 85/50, HR 135. OB wants 20 minutes to place a Bakri and compression sutures before deciding on hysterectomy. Can she tolerate 20 minutes? What tells you? Products — what, and in what ratio? Calcium — when? Fibrinogen 160. Rx? Target? TXA — dose? Bakri holds. EBL 2.8 L; 4 PRBC, 4 FFP, 2 g fibrinogen in; BP 108/66 off pressor, lactate 3.2, T 35.6. Extubate in the OR? Why/why not? What do you need to see? Next morning she tells you she remembers hearing voices and feeling pressure before the baby came out, and asks whether that was real. What will you tell her?

Considerations and pitfalls AI draft

Can she tolerate 20 minutes. The anesthesiologist's call to make and state: rate of loss, pressor requirement, product availability, pH/lactate, coagulation. Rising pressor need and loss outpacing replacement means no. Inform the decision without owning the surgical choice.
Resuscitation. Activate massive transfusion; PRBC:FFP:platelets near 1:1:1 until guided by labs; calcium with every 2-4 units (ionized Ca target >1.1); fibrinogen is the first factor to fall in obstetric hemorrhage: cryoprecipitate or concentrate to keep it >200 mg/dL; point-of-care testing if available.
TXA. 1 g IV over 10 min, repeat once at 30 min if bleeding continues.
Extubation. Hemostasis confirmed, warm (>36), lactate falling, no pressor, reversal confirmed, awake with full strength, airway not worse than at induction (it was CL 3 before edema and fluids). After a difficult airway and 2.8 L, keeping her intubated to a monitored bed is the conservative and defensible answer; extubating over an exchange catheter is a middle path.
Reported recall. Credible awareness: light pre-delivery anesthesia, a difficult airway, and hemorrhage. Tell her it is real and possible, that it was not her imagination, and apologize; do not minimize. Explain why she was put to sleep and what happened with her airway; document, arrange follow-up and psychological support; give her a letter about the difficult airway for future anesthetics.

Short stem

Opioid use disorder on buprenorphine in labor

A 30 y.o. G2P1 at 39 weeks gestation, 5'4", 72 kg, presents in active labor at 5 cm cervical dilation. She is on buprenorphine-naloxone 16 mg sublingual daily for opioid use disorder, with two years of stable treatment in recovery. She also takes sertraline for depression and uses cannabis two to three times per week. Smokes five cigarettes daily. Hgb 11.4; platelets 165; vital signs normal; Mallampati II; visible track marks bilaterally on the antecubital fossae.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Pre-op assessment of the parturient in stable opioid recovery; whether to continue buprenorphine through labor and delivery; labor analgesia matched to a partial-agonist baseline; planning for the breakthrough pain that buprenorphine will not cover; IV access in the patient with poor peripheral options.

1. Buprenorphine through labor

Continue her buprenorphine through labor? Why/why not? Hold it and cover with a full agonist instead — advantages? Disadvantages? She asks you to stop it today because she is worried about the baby. What will you tell her? Her addiction provider calls back. What do you ask? Neonatology — what do they need to know before delivery?

Considerations and pitfalls AI draft

Continue. The expected commit; holding risks withdrawal, relapse, and worse pain control with no offsetting benefit.
Full-agonist switch. Rarely indicated; buprenorphine occupies receptors for days regardless, and the switch destabilizes a stable regimen.
Her worry about the baby. NAS risk is real on either path; stopping today does not protect the neonate and puts her recovery at risk; the plan is collaborative and she has a voice in it.
Addiction provider. Current dose and timing, recent stability, split-dosing preference, postpartum plan, support resources.
Neonatology. Maternal buprenorphine dose; NAS monitoring and supportive care; rooming-in and breastfeeding are usually supported.

2. Labor analgesia plan

Labor analgesia plan? Epidural now at 5 cm, or wait? Why? Local anesthetic and concentration? Fentanyl in the epidural — useful in her? Why/why not? Epidural is in, level T10 bilaterally, pain still 8/10. DDx? Rx? Pain persists after a bolus. IV fentanyl? Ketamine? Nitrous? Which? Why? PCA fentanyl for the rest of labor — yes/no? Why?

Considerations and pitfalls AI draft

Early epidural. Yes; reduces stress and systemic opioid exposure; no reason to wait.
LA. Dilute bupivacaine or ropivacaine plus opioid; standard.
Epidural fentanyl. Still works locally but effect is blunted by receptor occupancy; expect less benefit; clonidine or a higher LA concentration can supplement.
Pain despite T10. Missed segment, patchy block, visceral pain, opioid-induced hyperalgesia; assess before redosing.
Adjuncts. IV fentanyl has little to add on top of buprenorphine; subdissociative ketamine or nitrous are more useful; commit and defend.
PCA fentanyl. Poor choice here; favor neuraxial and non-opioid adjuncts.

3. IV access and preparation

One 20 g IV placed after four attempts. Adequate? What do you want? Ultrasound-guided peripheral or central line — which first? Why? Second ultrasound attempt fails. Central line now — site? Why? Type and screen sent. Enough, or crossmatch? Why? Her drug history — what on exam would change your plan before placing an epidural?

Considerations and pitfalls AI draft

Access. One marginal 20 g is not adequate for a laboring patient who may bleed; two reliable large-bore lines.
Ultrasound first. Yes; track-mark anatomy makes landmark attempts low-yield.
Central line. Place early rather than during a hemorrhage; internal jugular under ultrasound is the usual pick.
T&S vs crossmatch. T&S suffices at baseline risk; crossmatch when a risk factor appears.
Exam. Murmur, fever, or stigmata of endocarditis from prior IV drug use; a new murmur warrants an echo before proceeding electively.

4. Plan for conversion

OB says cesarean is likely. Post-cesarean pain plan — what is scheduled? Regional adjunct — TAP, QL, or neuraxial morphine? Which? Why? Buprenorphine on the day of surgery — usual dose, split dosing, or hold? Why? Breakthrough opioid — agent? How does the dose compare to an opioid-naive patient? Ketamine infusion — start in the OR or reserve for PACU? Why?

Considerations and pitfalls AI draft

Scheduled. Acetaminophen and NSAID if no contraindication; opioid only as supplement.
Regional. Neuraxial morphine if the catheter is used for the case; TAP or QL as adjunct or if no catheter; either defensible.
Buprenorphine. Continue; many programs split into TID dosing peripartum for steadier analgesia; never hold.
Breakthrough opioid. Expect roughly 2-3x naive morphine-equivalents because of receptor occupancy; titrate with monitoring.
Ketamine. Starting in the OR is reasonable given predictable high requirements; reserving it is defensible if the regional plan is strong.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Modality choice when GA could cost her recovery; managing intra-operative and PACU breakthrough pain under partial-agonist receptor occupancy; PACU respiratory safety as opioids stack on a buprenorphine baseline; the one recovery-protecting conversation before she leaves anesthesia care.

1. Stat cesarean and modality

FHR drops to 70 and stays. OB calls stat C/S. Epidural in. Top-up agent? Dose? Target level? Level T4, BP 95/60. Surgeon enters the peritoneum and she reports sharp pain. DDx? Rx? IV fentanyl 100 mcg, no effect. Next? Ketamine — dose? Two more minutes and she is still in pain. Convert to GA? Why/why not?

Considerations and pitfalls AI draft

Top-up. Lidocaine 2% with bicarbonate and epinephrine, ~15-20 mL incrementally, to T4-T6.
Pain despite T4. Visceral pain not covered, patchy block, opioid-induced hyperalgesia.
Fentanyl fails. Expected in her; escalate to ketamine 0.25-0.5 mg/kg, surgeon local, anxiolysis.
GA. If pain is uncontrolled and she is suffering, convert; chasing a failed block with repeated boluses is the error. GA in an opioid-tolerant patient is not a relapse risk in itself.

2. Post-delivery: atony and neuraxial morphine

Baby out. BP 90/55, HR 110. Atony at 5 min. Uterotonic — first agent? Second? Methergine? Carboprost? Why? Bleeding controlled, EBL 900 mL. Neuraxial morphine through the catheter before it comes out — yes/no? Dose? Monitoring afterward — what, and for how long?

Considerations and pitfalls AI draft

Uterotonics. Oxytocin infusion first; methergine acceptable (no severe HTN); carboprost acceptable (no asthma); misoprostol adjunct.
Neuraxial morphine. Yes; buprenorphine does not preclude it; standard dose (e.g., 2-3 mg epidural).
Monitoring. Continuous pulse oximetry and capnography for 24 h; opioids stacked on a partial-agonist baseline can still cause delayed hypoventilation.

3. Breakthrough pain in PACU

PACU: pain 8/10 despite acetaminophen, ketorolac, her morning buprenorphine, neuraxial morphine, and a TAP block. Next? Hydromorphone — dose? How does that compare to an opioid-naive patient? Ketamine — bolus dose? Infusion rate? Pain is 9/10 an hour later and the incision is firm and tender. Now? Who do you call?

Considerations and pitfalls AI draft

Next. Treat the pain; undertreating a tolerant patient risks her recovery. Do not read high requirements as drug-seeking.
Hydromorphone. Titrate in larger increments than naive dosing (roughly 2-3x); monitor.
Ketamine. Bolus 0.25-0.5 mg/kg then 0.1-0.3 mg/kg/h.
Firm tender incision. Exclude hematoma or evolving surgical complication before adding more opioid; call OB.
Consults. Acute pain service and addiction medicine early.

4. Respiratory depression and reversal

Two hours later: RR 8, SpO2 91% on 2 L, arousable to voice. Cause? Rx now? Naloxone — yes/no? Dose? Why that dose? She wakes fully after 80 mcg and is now sweating, vomiting, and writhing. What happened? Rx? Capnography — continue how long? Where does she go tonight?

Considerations and pitfalls AI draft

Cause. Stacked opioid effect (neuraxial morphine plus IV hydromorphone) on a partial-agonist baseline.
Rx now. Stimulate, oxygen, support ventilation, hold further opioid.
Naloxone. Small titrated doses (40 mcg increments); buprenorphine's high receptor affinity makes reversal partial and a full dose can precipitate withdrawal.
Sweating, vomiting, writhing. Precipitated withdrawal; stop naloxone, supportive care, reassess the regimen with addiction medicine; do not restart full-agonist opioid reflexively.
Monitoring. Continuous capnography until reliably awake and ventilating; monitored bed overnight.

5. Handoff and recovery

She is ready to leave PACU. Buprenorphine tomorrow — dose? Split it? Why? Monitoring on the floor — continuous SpO2? Capnography? How long? Naloxone at the bedside — yes/no? The floor nurse asks whether to hold buprenorphine if she gets IV hydromorphone. Hold it? Why/why not?

Considerations and pitfalls AI draft

Buprenorphine tomorrow. Home dose confirmed with addiction medicine; splitting into TID doses peripartum gives steadier analgesia; never stopped.
Monitoring. Continuous pulse oximetry and capnography for 24 h after neuraxial morphine and a respiratory-depression event; step down only after a clean interval.
Naloxone. Yes at the bedside, with the 40-80 mcg titration written in the order so the floor does not push 0.4 mg.
Nurse's question. No; buprenorphine continues alongside full agonists; holding it invites withdrawal and relapse.

Short stem

Active asthma flare in labor at term

A 31 y.o. G2P1 at 38 weeks gestation, 5'5", 74 kg, presents in active labor at 5 cm cervical dilation. She has steroid-dependent asthma with two prior ICU admissions and one intubation in the past three years; current peak flow is 60% of her personal best with audible wheezing, and she has been progressively short of breath over the past 24 hours. Aspirin sensitivity and penicillin allergy. Took prednisone 20 mg PO this morning per her chronic regimen. P 108; BP 132/82; RR 24; SpO2 93% on room air; Mallampati II.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Bedside pulmonary assessment in active labor; matching labor analgesia plan to a fragile reactive airway; stress steroid coverage in the chronically treated patient; planning the airway and uterotonic choices that the rest of the case will turn on.

1. Pulmonary assessment

Let her labor as she stands, or treat first? Why? At the bedside: short phrases, accessory muscles, diffuse expiratory wheeze both fields. Rx now, in order? Albuterol — dose? Ipratropium? Magnesium — dose? She took prednisone 20 mg this morning. Hydrocortisone on top? Dose? Why? ABG — yes/no? Why? ABG on 2 L: pH 7.38, PaCO2 40, PaO2 68. Interpretation? After 2 hours: peak flow 75%, SpO2 96% on 2 L, RR 20, full sentences. Where does she labor — L&D room or ICU? Why?

Considerations and pitfalls AI draft

Treat first. An active flare with a prior intubation in a term parturient; labor pain and catecholamines will worsen it. Treat now, in the L&D room, while the epidural is set up.
Bedside Rx. Oxygen to SpO2 >95%; albuterol 2.5-5 mg neb, repeat q20 min or continuous; ipratropium 0.5 mg neb x3; magnesium 2 g IV over 20 min; hydrocortisone 100 mg IV; continuous SpO2 and fetal monitoring.
Hydrocortisone. Two reasons: her flare needs systemic steroid beyond 20 mg prednisone, and chronic prednisone 20 mg/day suppresses the HPA axis, so labor and possible surgery need stress-dose coverage: hydrocortisone 100 mg then 50 mg q8h for 24 h.
Magnesium. Bronchodilator; it is also a tocolytic and will contribute to atony later; note it and move on.
ABG. Yes: she is tachypneic with SpO2 93% and a history of intubation. A normal PaCO2 of 40 in a laboring pregnant woman whose baseline is 28-32 is relative hypercapnia: fatigue, not reassurance. PaO2 68 on oxygen is poor.
Where. L&D with continuous SpO2, one-to-one nursing, pulmonology and ICU aware; transfer if she fails to improve or PaCO2 rises. An improving patient does not need the ICU, but the threshold to move is low.

2. Labor analgesia plan

Epidural now at 5 cm, or wait? Why? Local anesthetic and concentration? Test dose with 15 mcg epinephrine — give it? Why/why not? Epidural dosed; level T10 to ice; pain 2/10. Twenty minutes later she says she cannot catch her breath; wheeze louder; SpO2 91% on 2 L; BP 98/60; HR 120. DDx? First move? Level rechecks T8 to ice, grip full strength, no numbness in the hands. High block? Why/why not? Rx? Albuterol given, SpO2 95%, BP 108/68, still wheezing. Keep the epidural running? Why?

Considerations and pitfalls AI draft

Early epidural. Yes: pain and hyperventilation drive bronchospasm; an epidural lowers catecholamines and minute ventilation demand and gives a surgical option that is not a GA airway.
LA. Bupivacaine 0.0625-0.1% with fentanyl 2 mcg/mL; keep the level low (T10) to preserve accessory muscles.
Epinephrine test dose. 15 mcg epinephrine in an asthmatic is not harmful (it bronchodilates); the confounder is her baseline HR of 108. Give it, or dose incrementally with aspiration; either defensible.
Dyspnea at 20 minutes. Worsening flare, high block reducing accessory muscle recruitment, sympathectomy with hypotension and anxiety, allergic reaction, pulmonary edema (magnesium, fluids). Check level and hands first.
High block. T8 with full grip and no hand numbness is not a high block; the dyspnea is her lungs plus mild sympathectomy. A rising level (T4 or above, weak grip, numb hands) would change the answer to ventilatory support.
Rx. Albuterol, oxygen, phenylephrine for BP, sit her up, continue the flare regimen; reassess PaCO2 if not improving.
Keep it. Yes; the epidural is not the cause and the alternative if she needs a cesarean is a GA airway in an actively flaring asthmatic.

3. Aspirin sensitivity and uterotonic implications

Aspirin sensitivity — what do you ask her? Flushing and severe wheeze after ibuprofen twice; nasal polyps. Diagnosis? Ketorolac after delivery — yes/no? Why? Acetaminophen — fine? Atony after delivery in her — first agent? Dose? Second agent — methergine? Carboprost? Misoprostol? Which? Why? Carboprost — under any circumstance in her? Why? Two agents in and still boggy — next?

Considerations and pitfalls AI draft

History. The reaction (wheeze, flushing, angioedema vs GI upset), timing, which NSAIDs, nasal polyps, chronic rhinosinusitis.
Dx. Aspirin-exacerbated respiratory disease (Samter's triad: asthma, nasal polyps, NSAID reactions); all COX-1 inhibitors are contraindicated, ketorolac included. Not an IgE allergy.
Acetaminophen. Fine at standard doses (high doses have weak COX-1 activity but are tolerated).
First agent. Oxytocin 3 U IV over 30 s or an infusion, repeat once; then infusion.
Second agent. Methergine 0.2 mg IM (BP 132/82 is acceptable) or misoprostol 800-1000 mcg rectal/sublingual; both are asthma-safe. Commit to an order and say why.
Carboprost. Absolute contraindication in severe asthma; life-threatening bronchospasm. Say this to OB before delivery so it is not requested in the moment.
Refractory. Mechanical and surgical early: bimanual compression, Bakri, compression sutures, uterine artery ligation, IR embolization; TXA 1 g; she has one fewer drug than most patients, so escalate sooner.

4. Plan for conversion

OB warns she may need a stat C/S. Neuraxial or GA — what do you want? What would force GA? GA is the backup. Albuterol before induction — how, and when? Propofol or ketamine? Which? Dose? Sux or roc? Why? Volatile — which? Hydrocortisone — you gave 100 mg at admission. More for surgery? When? Penicillin allergy: hives as a child. Cefazolin for surgical prophylaxis? Why/why not? Her husband asks whether she will end up on a ventilator again. What will you tell him?

Considerations and pitfalls AI draft

Modality. Extend the epidural; GA only for a failed block under time pressure or maternal respiratory failure. Saying so to OB now buys minutes later.
Albuterol before induction. 4-8 puffs by MDI or a neb in the 15-30 minutes before induction; blunts intubation-triggered bronchospasm.
Induction. Ketamine 1-1.5 mg/kg bronchodilates and holds BP; propofol 2 mg/kg blunts airway reflexes; either, committed. Lidocaine 1.5 mg/kg IV before laryngoscopy is a reasonable add. Avoid desflurane; sevoflurane is the volatile.
Relaxant. Sux 1-1.5 mg/kg or roc 1.2 mg/kg with sugammadex; no asthma reason to avoid either; avoid atracurium/mivacurium (histamine).
Steroid. She is covered for the day by the 100 mg; continue 50 mg q8h; an additional dose at induction is reasonable. Missing it invites refractory hypotension.
Cefazolin. Yes; childhood hives with penicillin is not a contraindication; cefazolin has a distinct side chain and cross-reactivity is under 1%. Reflexive clindamycin or vancomycin gives worse prophylaxis.
Husband. The one counseling beat: a plain answer that a ventilator is possible if her lungs fail or if surgery under GA is needed, that everything being done now is aimed at avoiding it, and what she will see if it happens. Not false reassurance.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Modality choice when GA risk is high; recognizing and treating intraoperative bronchospasm; supporting hemodynamics in a patient with a sympathectomy and a reactive airway; uterotonic and analgesic constraints around delivery; extubation judgment in the asthmatic.

1. Stat C/S decision

FHR drops to 80 and stays. OB calls stat C/S. Level T10 to ice on the left, T12 on the right. Top-up agent? How many mL? After 10 mL lidocaine 2% with bicarb and epi over 3 minutes: T8 left, T10 right, FHR 70. Continue dosing or GA? Why? You call GA. Albuterol — how? Induction — agent and dose? Cricoid — yes/no? VL: Cormack-Lehane 2, tube in, ETCO2 present. Peak pressure 42, tidal volume 250 mL, SpO2 94%. DDx? First move? Capnogram: sloped upstroke, no plateau. Meaning? Rx?

Considerations and pitfalls AI draft

Top-up. Lidocaine 2% with bicarbonate and epinephrine, 15-20 mL in 5 mL increments; the asymmetric baseline warns the catheter may not deliver.
Continue or GA. An asymmetric block still short of T6 after 10 mL with FHR 70: GA. In her, GA is the higher-risk path, but a hemi-block with a bradycardic fetus is not a path at all. Chasing the block is the flag.
Induction. Albuterol 8 puffs via mask before induction; ketamine 1.5 mg/kg (about 110 mg) or propofol 2 mg/kg (150 mg); sux 1.5 mg/kg (110 mg); cricoid per practice; lidocaine 100 mg IV is reasonable.
Peak pressure 42. Bronchospasm vs mainstem intubation vs kinked or obstructed tube vs light anesthesia vs circuit; check depth and breath sounds first.
Capnogram. Shark-fin: expiratory obstruction; bronchospasm.
Rx. 100% O2, hand-ventilate with long expiration, deepen (sevoflurane up, propofol bolus 50 mg), albuterol 8-10 puffs into the ETT, ketamine 50 mg, epinephrine if not responding; tell OB to proceed.

2. Intraoperative bronchospasm

Sevoflurane 1.5 MAC, albuterol 10 puffs, propofol 50 mg: peak pressure 50, SpO2 88%, ETCO2 60, BP 95/55. Still bronchospasm, or something else? How do you check? Suction catheter passes freely, breath sounds equal, no rash, no swelling. Next drug? Epinephrine — route? Dose? Magnesium — dose? Over how long? Ventilator — rate? Tidal volume? I:E? PEEP? What PaCO2 will you accept? Baby not yet out; the surgeon is at the uterus. Sevoflurane up or down? Why?

Considerations and pitfalls AI draft

Something else. ETT obstruction or mainstem (pass a suction catheter, auscultate), anaphylaxis (rash, hypotension, edema), pneumothorax, breath-stacking from a fast rate. Free catheter, equal sounds, no rash: refractory bronchospasm.
Epinephrine. 10-20 mcg IV boluses, escalating; infusion 0.02-0.1 mcg/kg/min if repeated boluses; bronchodilator and pressor in one. Terbutaline 0.25 mg SC is a slower alternative.
Magnesium. 2 g IV over 10-20 min (second dose today; she had 2 g at admission); it will add to atony after delivery; accept that.
Ventilator. Rate 8-10, tidal volume 6 mL/kg, I:E 1:3-1:4, PEEP 0-5, disconnect briefly to release trapped gas if hypotensive; permissive hypercapnia to PaCO2 60-70 while pH >7.2; fetal acidosis argues for delivery, not high pressures.
Volatile before delivery. Up: bronchospasm is the immediate threat and the uterus can be treated once the baby is out; tell OB that atony is coming and to deliver quickly.

3. Post-delivery hypotension and atony

Baby out. BP 75/40, HR 130, SpO2 92%, peak pressure 36. Surgeon reports atony. DDx for the pressure? Pressor — phenylephrine? Norepinephrine? Epinephrine? Which? Dose? Oxytocin — dose? How fast? Uterus still boggy at 3 minutes. OB asks for carboprost. Your answer? Methergine — BP now 95/55 on pressor. Give it? Dose? Misoprostol — dose? Route? Sevoflurane at 1.5 MAC. Up for the lungs or down for the uterus? What number? What replaces it? Awareness — how do you cover it?

Considerations and pitfalls AI draft

DDx. Volatile-induced atony with hemorrhage, magnesium, aortocaval load gone, dynamic hyperinflation lowering venous return, ongoing bronchospasm, oxytocin bolus effect, AFE if unresponsive.
Pressor. Epinephrine 10-20 mcg boluses or infusion does both jobs (bronchodilation and pressure); norepinephrine if bronchospasm is improving; phenylephrine is a poor sole choice with HR 130 and bronchospasm.
Oxytocin. 3 U IV over 30 s, repeat at 3 min, then infusion 30 U/500 mL; not a 10 U push at BP 75/40.
Carboprost. No, and say why in one sentence; offer methergine and misoprostol. Yielding to the surgeon's request is the trap in the case.
Methergine. Yes: 0.2 mg IM; BP 95/55 is not hypertension. Misoprostol 800-1000 mcg rectal or sublingual as adjunct.
Volatile. Down to 0.5 MAC once bronchospasm is improving (peak 36 from 50); cover bronchodilation with epinephrine infusion, ketamine, magnesium; cover awareness with propofol infusion or midazolam 2 mg plus fentanyl; processed EEG if available.

4. Refractory atony with limited options

Oxytocin, methergine, misoprostol in. EBL 1.8 L, BP 80/45 on epinephrine 0.05 mcg/kg/min, HR 135. OB wants 15 minutes for a Bakri and compression sutures before hysterectomy. Can she tolerate 15 minutes? What tells you? Products — what first? Ratio? Fibrinogen 150. Rx? How much? TXA — dose? Calcium — when? How much? Crystalloid — you have given 2 L. More? Why/why not? She needs more pressor. Add what? Why that one?

Considerations and pitfalls AI draft

Can she tolerate it. Rate of loss vs replacement, pressor trajectory, lactate/pH, coagulation; say yes with a stated stop rule (rising pressor, loss faster than products) rather than defer. Inform the surgical call; do not own it.
Products. Massive transfusion activated; PRBC:FFP:platelets near 1:1:1 until labs guide; warm everything.
Fibrinogen 150. Below the obstetric target of 200: cryoprecipitate 10 units (or fibrinogen concentrate 2-4 g) now; fibrinogen falls first in obstetric hemorrhage.
TXA and calcium. TXA 1 g IV, repeat once at 30 min; calcium chloride 1 g per 2-4 units or to ionized Ca >1.1; citrate load plus magnesium worsens hypocalcemia and atony.
Crystalloid. Stop at 2 L; inflamed asthmatic lungs plus magnesium and low oncotic pressure invite pulmonary edema; volume comes as products.
Pressor. Escalate epinephrine (it is treating both problems) and add vasopressin 1-2 U bolus or 0.04 U/min for vasoplegia; norepinephrine acceptable. Pressors are a bridge to hemostasis, not a substitute.

5. Extubation and pain plan

Bakri holds; hysterectomy avoided. EBL 2.5 L; 4 PRBC, 4 FFP, 1 platelet, cryo, TXA. Peak pressure 22, ETCO2 38, SpO2 97% on 50%, BP 110/70 off pressor, T 35.4, lactate 2.8, faint expiratory wheeze. Extubate in the OR? Why/why not? What do you need to see first? Awake or deep? Why? Wheeze on emergence — what is drawn up? Epidural catheter still in. Morphine through it — dose? Pain plan — what is scheduled? What is out? PCA — basal? Why/why not? Where does she go tonight? Steroid tomorrow — dose?

Considerations and pitfalls AI draft

Extubate. Not yet: T 35.4, lactate 2.8, residual wheeze, and a 2.5 L hemorrhage; warm, confirm hemostasis and reversal (TOF), repeat gas; then extubate awake in the OR or ICU. Immediate extubation to prove a point is the flag; so is reflex overnight ventilation in a patient who meets criteria an hour later.
Awake vs deep. Awake with full reversal and a suctioned airway; deep avoids coughing but leaves a full-stomach parturient unprotected; lidocaine IV 1 mg/kg and albuterol before emergence reduce the cough-bronchospasm risk.
Drawn up. Albuterol MDI, epinephrine 10 mcg/mL, ketamine, propofol; a plan to reintubate stated.
Neuraxial morphine. Epidural morphine 2-3 mg before the catheter comes out; respiratory monitoring (continuous SpO2, capnography) 24 h; she is an asthmatic with a fresh flare, so monitoring is not optional.
Scheduled and out. Acetaminophen 1 g q6h, neuraxial morphine, TAP blocks if the neuraxial dose was not given; NO ketorolac or any NSAID (AERD); ketamine infusion 0.1-0.2 mg/kg/h reasonable.
PCA. Demand-only hydromorphone after neuraxial morphine; no basal.
Disposition and steroid. ICU or high-acuity step-down with continuous SpO2 and scheduled nebs; hydrocortisone 50 mg q8h for 24 h, then her prednisone 20 mg or a flare burst (40-60 mg) per pulmonology.

Short stem

Sickle cell disease in active labor after recent vaso-occlusive crisis

A 24 y.o. G1P0 with hemoglobin SS sickle cell disease at 37 weeks gestation, 5'3", 58 kg, is in active labor at 4 cm dilation. She was discharged five days ago after a vaso-occlusive crisis requiring four days of IV hydromorphone PCA. She has bilateral femoral head avascular necrosis and chronic back pain, for which she takes oxycodone 10 mg every 6 hours at home. Hgb 7.6 g/dL (baseline 8.0), reticulocytes 18%, LDH 920. P 102; BP 118/72; RR 22; SpO2 95% on 2 L NC; mild crackles at bases; Mallampati II.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Sickle cell physiology in late pregnancy and labor; matching labor analgesia to chronic opioid exposure; transfusion thresholds and acute chest surveillance; preparing for conversion when the patient and the system are already running close to the line.

1. Sickle cell in labor

The crackles — worried? DDx? Workup now? CXR: no infiltrate, small bibasilar atelectasis. T 37.2, no chest pain. Working diagnosis for now? What are you watching for through labor, and how often do you look? Fluids — which? Rate? Why that rate? Oxygen — SpO2 target? Why? Temperature — target? How do you hold it? Her hemolysis labs this morning — meaning? Transfuse before labor goes further? Why/why not?

Considerations and pitfalls AI draft

Worried. Yes: crackles, oxygen requirement, and tachypnea five days after a VOC is early acute chest syndrome until proven otherwise; also atelectasis, volume overload, pneumonia, PE, peripartum cardiomyopathy.
Workup. CXR, CBC with retic, type and screen with antibody history, ABG if she worsens, lactate, blood cultures if febrile; hematology called now, not at the cesarean.
Working Dx. Atelectasis with a mild oxygen requirement, but acute chest evolves over hours and the CXR lags; repeat exam, SpO2, and RR every 1-2 h with a low threshold to re-image.
Fluids. Isotonic crystalloid at about 1-1.5x maintenance (100 mL/h) to euvolemia; hypovolemia sickles, but she has crackles and sickle cardiomyopathy is common: no liberal boluses.
Oxygen and temperature. SpO2 at or above 95%, never tolerate desaturation; normothermia 36.5-37.5 with warmed fluids and a warm room; hypothermia and shivering trigger sickling.
Labs. Hgb below her baseline with retic 18% and LDH 920 is active hemolysis, not just dilution; reserve is thin and any further loss is poorly tolerated. Not yet a transfusion trigger by number alone.

2. Labor analgesia and opioid tolerance

Epidural now at 4 cm? Why? Local anesthetic and concentration? Epidural opioid — fentanyl? Hydromorphone? None? Which? Why? Her oxycodone 10 mg q6h — continue it while the epidural runs? Why/why not? Test dose with epinephrine — give it? Why/why not? Epidural dosed; T10 to ice bilaterally; contraction pain 2/10 but she reports 7/10 pain in both hips and the lower back. Is the epidural failing? DDx? Rx? Hydromorphone IV — dose? How does it compare to a naive patient?

Considerations and pitfalls AI draft

Early epidural. Yes: labor pain and catecholamines drive sickling; the epidural lowers oxygen demand, supports rest and hydration, and gives a cesarean option without GA.
LA and opioid. Bupivacaine or ropivacaine 0.0625-0.1% with fentanyl 2 mcg/mL; fentanyl is standard and still adds analgesia in a tolerant patient; hydromorphone is an alternative; opioid-free epidural is defensible but wastes a lever.
Home oxycodone. Continue it: the epidural covers labor, not her AVN pain or her baseline requirement; stopping it invites withdrawal and uncontrolled pain, both crisis triggers.
Epinephrine test dose. Reasonable; no sickle-specific contraindication; baseline HR 102 confounds the read, so watch BP too or dose incrementally.
Hip and back pain with a good T10 block. Not epidural failure: AVN and chronic back pain, an evolving VOC, or bone pain from the labor stress; missed segments if the pattern is dermatomal. Treat systemically; do not redose the epidural for pain the block does not cover.
Hydromorphone. Expect 2-3x naive requirements; 0.5-1 mg IV titrated with SpO2 and RR monitored; hydromorphone PCA (her recent regimen) is reasonable alongside the epidural. Undertreating pain in SCD is the error, not overtreating.

3. Transfusion and acute chest surveillance

Hematology calls back. Transfuse before delivery — yes/no? Why? What Hgb would make it yes? Simple or exchange? Why? What would make it exchange? Antibody screen: anti-E and anti-C. What do you order? How many units? How long will the blood bank need? What will you accept in an emergency if matched blood is not ready? Cell saver for a cesarean — set up? Why/why not?

Considerations and pitfalls AI draft

Transfuse now. Not by the number: Hgb 7.6 near her baseline with no symptoms of anemia; simple transfusion for Hgb below about 7 or a fall of more than 2 g from baseline, symptoms, or evolving acute chest. Prophylactic transfusion in pregnancy is program-dependent; either answer with the reasoning.
Simple vs exchange. Simple for anemia; exchange for severe acute chest, stroke, multiorgan failure, or when raising Hgb without raising viscosity matters (target HbS below 30%, Hgb not above 10). A simple transfusion to Hgb 11-12 raises viscosity and can precipitate crisis.
Order. 2 units sickle-negative, leukoreduced, antigen-matched for C, E, and Kell at minimum (and antigen-negative for her alloantibodies); crossmatch takes hours with alloantibodies, so order now.
Emergency. If exsanguinating, uncrossmatched or incompletely matched blood is given and the hemolytic risk accepted; the point is to have matched units ready so that choice is never forced.
Cell saver. Salvaged cells sickle and hemolyze under processing and may be reinfused as sickled cells; most centers avoid it in SS disease or use it only with hematology agreement. Antigen-matched allogeneic blood is the plan.

4. Plan for conversion

OB warns a cesarean may be needed. Neuraxial or GA — which do you want? Why? Hypotension under the block — phenylephrine? Norepinephrine? Ephedrine? Which? Why? Lowest SBP you will accept? Why that number? Oxytocin — how fast? Carboprost — yes/no? Why? FiO2 in the OR — target? Room temperature — set to what? Postop analgesia — neuraxial morphine or TAP blocks? Which? Why?

Considerations and pitfalls AI draft

Modality. Extend the epidural; GA adds atelectasis, hypoventilation, and postoperative pulmonary complications in a patient already at risk of acute chest. GA only for a failed block or maternal collapse.
Pressor. Norepinephrine or phenylephrine infusion titrated to baseline; ephedrine acceptable for bradycardia; the sickle-specific point is no tolerance of hypotension: hypoperfusion and stasis sickle. SBP within 10-20% of baseline (about 100).
Uterotonics. Oxytocin as an infusion or slow small bolus; a 10 U push drops SVR. Carboprost is not contraindicated by SCD, but with evolving pulmonary findings it raises pulmonary artery pressure and bronchospasm risk; methergine (no HTN) and misoprostol first.
FiO2 and temperature. Supplemental oxygen to SpO2 at or above 95% throughout; warm room, forced air, warmed fluids; a cold OR is a crisis trigger.
Postop analgesia. Neuraxial morphine 100-150 mcg intrathecal or 2-3 mg epidural if the catheter is used, plus TAP blocks as adjunct; multimodal; expect high opioid needs on top.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Modality choice when both neuraxial and GA carry sickle-specific risk; recognizing and treating evolving acute chest intraoperatively; managing the opioid-tolerant patient through delivery; emergence, disposition, and immediate crisis surveillance.

1. Stat C/S and modality

FHR drops to 70 and stays. OB calls stat C/S. Epidural in, level T10. Top-up agent? How many mL? Target level? After 10 mL lidocaine 2% with bicarb and epi: BP 88/50, HR 130, SpO2 90% on 4 L NC. DDx? Rx now? Pressor — which? Dose? Level T6 to ice; BP 100/60 on norepinephrine; SpO2 91% on a non-rebreather. Continue under the block or convert to GA? Why?

Considerations and pitfalls AI draft

Top-up. Lidocaine 2% with bicarbonate and epinephrine 15-20 mL in 5 mL increments to T4-T6.
BP 88/50 with SpO2 90%. Sympathectomy from the rapid extension in a patient with thin reserve; the hypoxemia is the lungs (evolving acute chest, atelectasis) unmasked by the drop in perfusion, or a high block. Check level and hands.
Rx. LUD, norepinephrine or phenylephrine to SBP near 110 promptly (hypotension sickles), oxygen by non-rebreather, sit head up, modest fluid; recheck level.
Continue or GA. Continue: the block is at T6 and pressure is controlled; SpO2 91% on NRB with a stat fetus is not yet an indication to intubate; state the trigger for GA (SpO2 falling below about 90 on NRB, rising work of breathing, obtundation) and have the airway ready.

2. Intraoperative hypoxia, fever, new infiltrate

Level T4. As OB preps: SpO2 88% on the non-rebreather, RR 30, crackles now diffuse, T 38.6. Working diagnosis? What else? First move? Intubate now, or deliver under the block first? Why? Antibiotics — which? Blood bank — what do you call for now? Exchange transfusion now, in the OR — yes/no? Why? Albuterol — give it? Why?

Considerations and pitfalls AI draft

Working Dx. Acute chest syndrome: new hypoxemia, fever, tachypnea, and diffuse crackles in a sickle patient in labor. Also pneumonia, aspiration, pulmonary edema, PE, AFE, transfusion reaction if products have run.
First move. FiO2 to 1.0 (NRB is already maximal; add high-flow nasal or CPAP if available), sit head up, tell OB the maternal status, call for help and the ICU.
Intubate or deliver. Deliver under the block: the fetus is bradycardic and delivery relieves the maternal load in minutes; intubation of a hypoxemic SCD patient under time pressure adds risk. Intubate if she cannot maintain SpO2 above about 88-90 on maximal oxygen, obtunds, or tires. Either is defensible with a stated trigger.
Antibiotics. Third-generation cephalosporin plus a macrolide (ceftriaxone 1-2 g and azithromycin 500 mg) for typical and atypical organisms; cefazolin surgical prophylaxis is not coverage for acute chest.
Blood bank and hematology. Release the antigen-matched units now; exchange transfusion is the treatment for severe acute chest but is not done in the OR: ask hematology to set up exchange in the ICU immediately after delivery, and give simple transfusion of 1-2 matched units in the OR as a bridge if Hgb falls.
Albuterol. Yes; bronchospasm accompanies acute chest in a substantial fraction and albuterol is low-cost; not a substitute for oxygen, transfusion, and antibiotics.

3. Post-delivery hemodynamics and hypoxia

Baby out. SpO2 86% on the non-rebreather, RR 34, BP 80/45, HR 135; uterus boggy. Intubate now? Why/why not? Induction — agent? Dose? Sux or roc? Tube in; FiO2 1.0, PEEP 8, SpO2 93%. Oxytocin — dose? Rate? Uterus still soft. Next agent? Carboprost — yes/no? Why? Volume — crystalloid or blood? How much? Pressor? She was awake and talking 3 minutes ago. Awareness — how do you cover it? Ketamine — help or harm here? Why?

Considerations and pitfalls AI draft

Intubate. Yes: SpO2 86% on maximal oxygen with rising work of breathing after delivery is respiratory failure; the delivery did not rescue her. Waiting for arrest is the error.
Induction. Ketamine 0.5-1 mg/kg or etomidate 0.2 mg/kg for a hypotensive hypoxemic patient (propofol only at a reduced dose); sux 1.5 mg/kg or roc 1.2 mg/kg; norepinephrine running; preoxygenation is already maximal, so expect rapid desaturation.
Uterotonics. Oxytocin 3 U slow bolus then infusion; methergine 0.2 mg IM (no HTN); misoprostol; carboprost no: acute chest with hypoxemia is pulmonary vascular disease in the moment and carboprost raises PA pressure and bronchospasm.
Volume and pressor. Matched blood as the volume: Hgb was 7.6 before bleeding began; 1-2 units now, crystalloid modestly, norepinephrine to SBP 100; do not let her sit hypotensive while waiting for products.
Awareness. She was conscious moments ago; midazolam 2 mg, volatile at 0.5 MAC or propofol infusion once BP allows, fentanyl; processed EEG if available; document.
Ketamine. Helps: hemodynamic support, bronchodilation, and analgesia in an opioid-tolerant patient; 0.5 mg/kg then 0.2 mg/kg/h. The pulmonary vasoconstriction concern is small at these doses.

4. Immediate pain control in the opioid-tolerant SCD patient

Case closed. She stays intubated, FiO2 0.6, SpO2 94%, on norepinephrine 0.08 mcg/kg/min; epidural catheter still in. Morphine through the catheter before she leaves the OR? Dose? Or keep the catheter running — with what, and for how long? Her home oxycodone — when does it restart? What covers it until then? Hydromorphone IV — starting dose in her? Compared to a naive patient? Ketamine infusion — continue? Rate? Ketorolac — yes/no? Why? Acetaminophen — dose? Route?

Considerations and pitfalls AI draft

Neuraxial morphine or infusion. Epidural morphine 2-3 mg is reasonable even intubated (respiratory depression is monitored); keeping the catheter with bupivacaine 0.1% plus fentanyl for 24-48 h is the better answer for a patient who will need high-dose systemic opioid anyway: it spares opioid and ventilation. Remove with attention to anticoagulation timing.
Home oxycodone. Restart via the OG tube as soon as she can take enteral medication, or sooner as scheduled IV hydromorphone; her baseline 40 mg/day oxycodone must be replaced, not paused.
Hydromorphone. 0.4-1 mg IV boluses, 2-3x naive requirements; scheduled or PCA once awake; continuous SpO2 and capnography. Undertreatment is a crisis trigger.
Ketamine. Continue 0.1-0.2 mg/kg/h; reduces opioid need and hyperalgesia in SCD crisis pain.
Ketorolac. No for now: fresh hemorrhage, possible renal injury from hypoperfusion and sickle nephropathy; revisit when stable. NSAIDs are otherwise a mainstay of SCD pain.
Acetaminophen. 1 g IV q6h.

5. Emergence and disposition

ICU overnight; exchange transfusion at 02:00, HbS now 25%, Hgb 9.2. Morning: FiO2 0.4, PEEP 5, SpO2 96%, awake, follows commands, RSBI 50, T 37.8, off norepinephrine. Extubate? Why/why not? What else do you want first? Extubated. Two hours later: SpO2 91% on 4 L, RR 26, chest pain she calls her usual crisis pain. Take her at her word? Why/why not? Next? She asks what happened in the OR and why she woke up with a tube. What will you tell her?

Considerations and pitfalls AI draft

Extubate. Yes if she passes a spontaneous breathing trial, cuff leak present, secretions manageable, hemostasis confirmed, and the exchange has done its work; a repeat CXR and gas first. Conservative bias is fine, but keeping a patient who meets criteria intubated for another day adds pneumonia and deconditioning.
Chest pain after extubation. No: in SCD, chest pain plus a new oxygen requirement is acute chest recurrence, PE, atelectasis, or splinting; repeat CXR, gas, incentive spirometry, oxygen, and analgesia; the patient's label of usual pain does not close the differential.
Next. Incentive spirometry every hour awake (prevents acute chest), oxygen, treat pain fully, hematology for a second exchange if worsening; ICU stay until off oxygen and pain controlled.
What you tell her. A plain account: her lungs failed during the cesarean, she needed a breathing tube and an exchange transfusion, the baby's status, and what to expect next; answer questions; document; note for future anesthetics that acute chest followed delivery.

Short stem

Elective cardioversion of atrial fibrillation with LVEF 30%

A 67 y.o., 5'10", 100 kg man is scheduled in the cardiology procedure suite for elective electrical cardioversion of atrial fibrillation, first noted 6 weeks ago with palpitations and worsening dyspnea. New heart failure: LVEF 30% on echo 3 weeks ago, normal coronaries on catheterization; he now sleeps on two pillows. Meds: apixaban 5 mg BID (he says he missed "a few doses" last week), metoprolol succinate 50 mg daily, sacubitril-valsartan, furosemide 40 mg daily, and metformin for type 2 diabetes. Nothing to eat since midnight; black coffee at 6:30 AM. Procedure booked for 8 AM. HR 118 irregular; BP 104/68; RR 20; SpO2 94% on room air. Bibasilar crackles; Mallampati III; K 3.4; Mg 1.6; Cr 1.3.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Pre-procedure evaluation for elective cardioversion outside the OR: anticoagulation status and the need for TEE; whether a decompensating low-EF patient is ready for sedation and which drugs he takes or skips; fasting, aspiration risk, sedation depth, and the airway plan for a shared-airway procedure in a patient with a difficult-looking airway; oxygen, monitoring, and rescue drugs.

1. Anticoagulation before cardioversion

Cardiology asks whether a TEE is needed first. Cardiovert without one? Why/why not? He clarifies: two missed evening doses, eight days ago. Changes your answer? Why/why not? This morning's apixaban: give it, or hold it for the TEE? Why? Before the probe goes in, anything in his history to check? He denies dysphagia, GI bleeding, or esophageal surgery. Anticoagulation after the shock: how long? Why, if he leaves in sinus rhythm? Long term: stop apixaban if he stays in sinus? Why/why not?

Considerations and pitfalls AI draft

Cardiovert without TEE. AF present 6 weeks is well beyond 48 h, so cardioversion needs either at least 3 weeks of uninterrupted therapeutic anticoagulation or imaging that excludes left atrial and appendage thrombus. A DOAC has no level to confirm adherence, so the history is the only evidence. Proceeding on "he's on apixaban" misses this.
Two missed doses. Still a gap inside the 3-week window. With a half-life around 12 h, two missed doses leave him unprotected for a day or more. TEE stays. A learner who negotiates the number of missed doses down to "close enough" is a flag.
Morning dose. Give it. He must be anticoagulated at the moment of cardioversion and continuously afterward. TEE carries a small bleeding risk that does not justify a gap in the highest-risk window.
History before TEE. Dysphagia or odynophagia, stricture, varices, prior esophageal or gastric surgery, upper GI bleeding, chest radiation, limited neck mobility. Anticoagulation raises the cost of mucosal injury but is not a contraindication.
Duration after. At least 4 weeks regardless of stroke-risk score. Atrial mechanical function (stunning) lags electrical conversion by days to weeks, and thrombus can form after a successful shock; most post-cardioversion strokes occur in the first weeks.
Long term. The long-term decision rests on stroke risk, not on the current rhythm. His CHA2DS2-VASc is 3 (heart failure, age 65-74, diabetes), so anticoagulation continues indefinitely. AF recurrence is often silent. Stopping because he is in sinus is the error.

2. Dyspnea and crackles on the morning of cardioversion

Proceed today, or diurese first? Why? Supine for the TEE: will he tolerate it? What tells you? BNP? Repeat TTE? Why/why not? Electrolytes: any Rx before the shock? Why? Targets? Route? The cardiology fellow wants diltiazem 20 mg IV now to slow the rate. Agree? Why/why not? Alternative? His morning meds: which does he take today? Why?

Considerations and pitfalls AI draft

Proceed. The rhythm is likely driving the decompensation, so restoring sinus is often the treatment and mild congestion alone is not a reason to cancel. He is not unstable (no shock, ischemia, or altered mentation), so this is not an emergency shock either. A short delay for diuresis is defensible when orthopnea or hypoxemia would make supine sedation unsafe. Either commit is acceptable if the learner names what would change it.
Supine. Sedation removes his compensation; orthopnea predicts rapid desaturation and loss of reserve once he is sedated and positioned for the probe. Ask how he tolerates lying flat now; plan head-up positioning as far as the study allows.
BNP / TTE. Neither changes today's plan. He had an echo 3 weeks ago and the TEE will image the heart. Ordering tests that do not alter management is a mild flag.
Electrolytes. Hypokalemia and hypomagnesemia raise the risk of ventricular arrhythmia after the shock and of early AF recurrence. Common targets are K at least 4.0 and Mg at least 2.0, rechecked before the shock. A rough guide is 10 mEq of potassium per 0.1 mEq/L rise, so about 60 mEq here: oral 40 mEq plus IV at about 10 mEq/h peripherally, roughly 3 h in all; furosemide this morning will pull K down. IV magnesium 2 g over 15-30 min or longer. Delaying for a K of 3.4 is a judgment call: the evidence that mild hypokalemia alone causes harm is weak, but with low EF, a loop diuretic, and a planned shock, most would replete first.
Diltiazem. Decline. IV non-dihydropyridine calcium channel blockers are harmful with LVEF under 40%: negative inotropy can tip him into cardiogenic shock. This is a contraindication, not a caution.
Alternative. Small IV metoprolol doses if BP allows; amiodarone (rate control plus a chance of conversion, safe in low EF); digoxin is slow and needs K corrected first. With the shock less than an hour away, no rate drug at all is also reasonable.
Morning meds. Metoprolol: take it (withdrawal causes rebound tachycardia). Sacubitril-valsartan: holding the morning dose is reasonable with BP 104/68 and sedation-induced vasodilation ahead; continuing is defensible if he is not hypotensive; restart after. Furosemide: giving it treats the congestion, holding it for the procedure is also defensible. Taking or holding everything by reflex is the flag. Metformin: hold the morning dose while he is fasting; resume when he is eating.

3. Fasting, sedation depth, and airway plan

Cardiology wants to start at 8 AM to hold the schedule. Agree? Why/why not? Earliest start? More history before sedation? What? He denies nausea, bloating, early satiety, or reflux. Aspiration risk: low? High? Why? TEE, then the shock. Moderate sedation? Deep sedation? GA? Which? Why? Natural airway? LMA? ETT? Which? Why? Assume deep sedation with a natural airway. Mask ventilation if he obstructs: easy or hard? Why? Airway equipment at the bedside: what?

Considerations and pitfalls AI draft

Start at 8. No. Black coffee is a clear liquid, and ASA fasting guidance is 2 h for clear liquids, so the earliest start is 8:30. The case is elective and the delay is 30 minutes. Starting early to hold the schedule is the flag. If the learner already delayed for K and Mg repletion in A2, the timing is moot but the reasoning still counts.
Earliest start. 8:30 AM for the coffee. With milk or creamer, many institutional policies apply the 6 h rule for nonhuman milk, which would push the start to 12:30.
More history. Symptoms of delayed gastric emptying from diabetic gastroparesis (nausea, bloating, early satiety, vomiting), reflux or hiatal hernia, prior aspiration, recent opioids. Diabetes can slow emptying even when fasting is met. Obesity alone is debated: fasted obese patients have gastric volumes similar to lean patients, though reflux is more common.
Aspiration risk. Fasting met once 8:30 passes and no gastroparesis symptoms, so not a full stomach. Raising it: diabetes, deep sedation removing airway reflexes, supine positioning, and a probe that provokes gagging and retching; obesity matters more for the airway than for gastric content. Most would call it low to moderate. Calling him a full stomach that mandates RSI, or ignoring the factors altogether, are both weak answers.
Depth. Probe passage and the shock are both stimulating; the shock is brief but painful. Deep sedation (unresponsive to voice, spontaneous breathing) is the usual target, with readiness to convert to GA. Moderate sedation often fails and leaves him gagging on the probe.
Airway. A natural airway is common when fasting is met and the airway is manageable. The probe occupies the oropharynx, so an LMA cannot be used with the probe in. GA with an ETT is defensible if the learner judges aspiration risk high or expects to lose the airway, accepting induction risk with LVEF 30%. A strong learner names what would make them intubate: regurgitation, repeated obstruction, failure to oxygenate.
Mask ventilation. Expect it to be hard: Mallampati III, BMI about 32, age, and a probe in the mouth that prevents a seal and an oral airway. Ask about snoring or OSA, a beard, and neck mobility. Orthopnea and low reserve mean desaturation comes fast.
Equipment. Suction on and within reach; oral and nasal airways; face masks and a circuit or bag for positive pressure; bite block; LMA for use once the probe is out; video laryngoscope, ETTs, and stylet; an induction drug and a neuromuscular blocker immediately available for RSI if he regurgitates.

4. Oxygen, monitoring, and rescue drugs

Assume deep sedation with a natural airway. Oxygen: nasal cannula? Face mask? High-flow nasal? Which? Why? Arterial line: yes/no? Why? Pressor drawn up: which? Dose? Why that one? Ventilation monitoring with a bite block in: how? Pads on: before induction, or after the TEE? Why?

Considerations and pitfalls AI draft

Oxygen. High-flow nasal oxygen extends apnea tolerance, useful in a borderline-hypoxemic heart failure patient; its small PEEP effect is largely lost with the mouth open around the probe. Nasal cannula is acceptable. A face mask will not stay on with the probe in.
Arterial line. Not required for brief sedation; defensible for beat-to-beat pressure with LVEF 30% and BP 104/68. If no line, NIBP every 1-2 min through induction and the shock.
Pressor. Phenylephrine 50-100 mcg or norepinephrine 4-8 mcg boluses. Ephedrine adds chronotropy he does not need in AF with a fast ventricular rate. Atropine and epinephrine ready as well.
Capnography. Required for moderate and deep sedation; a nasal cannula with a sampling port, or a bite block with a CO2 port.
Pads. Before induction, in the vector chosen for the shock, so cardioversion or pacing is immediate if he deteriorates at any point.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Agent choice and dosing for brief deep sedation with LVEF 30%; the shared airway during TEE; synchronized cardioversion technique and a failed first shock; bradycardia and hypotension after conversion; recovery, disposition, and the medication plan.

1. Induction for TEE

Assume K and Mg repleted. 11 AM: K 4.0, Mg 2.2. HR 110 in AF, BP 102/66, SpO2 95% on room air. Assume TEE first, then the shock, under deep sedation with a natural airway. Agent: propofol? Etomidate? Ketamine? Which? Why? Dose? Midazolam first: yes/no? Why? Fentanyl: yes/no? Dose? Assume propofol. After 50 mg: BP 76/44, HR 108, still AF. Of concern? Rx? Phenylephrine? Ephedrine? Fluid bolus? Which? Why? BP 96/60. More propofol for the probe: how much? Topical lidocaine to the oropharynx: yes/no? Why?

Considerations and pitfalls AI draft

Agent. No single right answer. Etomidate preserves hemodynamics but causes myoclonus that can disturb the ECG and the study, and nausea. Propofol gives the best conditions but lowers SVR and contractility, so it must be titrated with a pressor ready. Ketamine raises HR and myocardial oxygen demand, which is unwelcome in fast AF, and is a direct myocardial depressant if catecholamines are depleted. Combinations are defensible.
Dose. Etomidate 0.1-0.15 mg/kg (10-15 mg); propofol in 0.25-0.5 mg/kg increments (25-50 mg); ketamine 0.5-1 mg/kg (50-100 mg). A full induction dose of propofol (1.5-2 mg/kg, 150-200 mg) in LVEF 30% is the error.
Midazolam. 1-2 mg adds amnesia and anxiolysis at the cost of a slower recovery; either way is fine.
Fentanyl. 25-50 mcg blunts probe stimulation and reduces propofol need; it adds to apnea risk.
Hypotension. Propofol vasodilation and myocardial depression in a ventricle that has already lost atrial kick. Restore pressure promptly: coronary perfusion is at stake.
Rx. A pressor bolus first (phenylephrine 100 mcg or norepinephrine 4-8 mcg). Ephedrine raises the rate in fast AF. Fluid only in small amounts (250 mL) given his congestion. Target MAP at least 65 or near his baseline.
More propofol. 10-20 mg increments to probe tolerance, watching respiration and BP after each.
Topical lidocaine. Reduces gag and the propofol needed. Count the dose; benzocaine is avoided (methemoglobinemia). Nothing by mouth until the gag returns.

2. Desaturation with the probe in

Probe passes on the second attempt. SpO2 falls from 96% to 86%; capnogram flat. DDx? First move? Assume sedation stopped and jaw thrust with the probe in: SpO2 82%. Next? Pull the probe? Why/why not? Nasal airway? Why/why not? Probe out, two-hand mask with an oral airway: chest rises, CO2 returns, SpO2 94%. Probe back in: how do you prevent a repeat? Study: dense spontaneous echo contrast in the left atrium, no thrombus in the appendage, appendage emptying velocity 22 cm/s. Proceed to cardioversion? Why/why not?

Considerations and pitfalls AI draft

DDx. Upper airway obstruction (tongue and soft tissue, probe pushing the epiglottis), central apnea from propofol, laryngospasm from probe stimulation, regurgitation and aspiration, a displaced sampling line. A flat capnogram with falling SpO2 is not a monitor problem until proven.
First move. Stop sedation, increase O2 flow, jaw thrust or chin lift, stimulate, and ask the echocardiographer to pause.
Next. Probe out, then two-hand mask with an oral airway; LMA if mask ventilation fails; ETT if he cannot be oxygenated or regurgitation is seen. Inspect and suction the oropharynx for gastric content.
Pull the probe. Yes when jaw thrust fails. The probe prevents a mask seal and an oral airway; oxygenation outranks imaging. Persisting with the study while SpO2 falls is the flag.
Nasal airway. Possible with lubrication and gentle technique, but he is on apixaban and epistaxis into a sedated airway is a real cost. Not the first choice here.
Prevent a repeat. Smaller increments, jaw support during insertion, high-flow nasal oxygen, lateral position, the most experienced operator passing the probe. Repeated obstruction is a reason to secure the airway with an ETT.
Proceed. Yes. Spontaneous echo contrast and low appendage velocity mark stasis and higher thromboembolic risk but are not thrombus and do not cancel the shock. They reinforce uninterrupted anticoagulation afterward. A thrombus would cancel it.

3. Synchronized shock

Probe out. Pads anterolateral. Keep that placement, or change? Why? Mode? Energy? Why? Sync markers are landing on the T waves in lead II. Of concern? Rx? More sedation before the shock: agent? Dose? 200 J synchronized: AF persists. Next? Why? Amiodarone first, or shock again? Why? Charging for the second shock. Mode? Why?

Considerations and pitfalls AI draft

Placement. Anterolateral and anteroposterior are both acceptable; the goal is a vector through the atria. Some prefer anteroposterior in obesity; the evidence on which is better is mixed. Changing the vector is a tool held for a failed shock.
Mode and energy. Synchronized, so the shock lands on the R wave and avoids the vulnerable period of the T wave, which can induce VF. Current AHA guidance favors a first biphasic shock of at least 200 J for AF; lower first energies fail more often.
T-wave sensing. A tall T wave read as an R wave risks a shock on the T and VF. Switch to a lead with a tall R and small T, adjust the gain, and confirm a marker on every QRS before charging.
Sedation. The shock is painful; confirm he is unresponsive; propofol 10-20 mg just before is usual. Awareness of the shock is a preventable harm.
Failed shock. Change the vector (anteroposterior), press firmly on the pads to lower transthoracic impedance, and check pad contact. Raise the energy if the device allows; many biphasic defibrillators top out at 200 J, so on those the next shock repeats maximum energy with a new vector. Repeating the same shock unchanged is the flag.
Amiodarone or shock again. Amiodarone is the antiarrhythmic of choice with low EF and can aid the next attempt, though it takes time; ibutilide's torsades risk is higher with low EF and is best avoided. Most teams shock again first with the changes above.
Mode for the second shock. Many defibrillators revert to unsynchronized after each shock. Reselect sync and confirm the markers again. An unsynchronized shock in AF is the error this beat is checking.

4. After the second shock

Second shock, anteroposterior: sinus rhythm at 40, a 5-second pause, then sinus at 36. BP 68/40. Of concern? Cause? Rx? Atropine: dose? After atropine: HR 40, BP 70/42. Next? Epinephrine? Dopamine? Pacing? Which? Why? Assume transcutaneous pacing. Rate? Output? How do you confirm capture? Paced at 70, capture confirmed, BP 98/60. He grimaces and reaches for his chest. Rx? Ten minutes later, intrinsic sinus at 62. Pacing off now? Why/why not?

Considerations and pitfalls AI draft

Cause. Sinus node dysfunction unmasked once AF stops (the tachy-brady picture), added to beta-blockade, residual propofol, and vagal tone. Hypotension follows from a rate-dependent cardiac output in a ventricle with LVEF 30%, plus propofol.
Atropine. 1 mg IV, repeated every 3-5 min to a 3 mg total. Stop further sedation; pressor bolus as a bridge.
Next. Epinephrine infusion 2-10 mcg/min, dopamine 5-20 mcg/kg/min, or transcutaneous pacing. Pads already on make pacing fast; epinephrine also supports contractility. Any is defensible if defended; waiting on repeated atropine while BP stays near 70/40 is the flag.
Pacing settings. Demand mode, rate 60-80; raise the output until each spike is followed by a wide QRS and a T wave (electrical capture), then set it a margin above that threshold.
Confirm capture. A pulse oximeter or arterial waveform at the paced rate, or a femoral pulse. A carotid pulse is confounded by the muscle twitch from pacing.
Grimace. Transcutaneous pacing hurts. Small doses of fentanyl, ketamine, or midazolam, titrated against the BP.
Pacing off. Turn the rate below his intrinsic rate and leave the pads on in standby; keep atropine and epinephrine ready. Removing the pads because the rate looks good is the flag: the node already paused once.

5. Recovery after cardioversion

Recovery area, 30 minutes: awake, oriented; sinus 64; BP 104/66; SpO2 92% on room air; occasional cough. DDx? Chest x-ray: yes/no? Why? At 1 hour, SpO2 95% and lungs at baseline. Discharge home today? Why/why not? Cardiology admits him to telemetry. Metoprolol tomorrow morning: same dose? Why/why not? Apixaban tonight? Why/why not? He asks why he can't go home now that his heart is back in rhythm. What will you tell him?

Considerations and pitfalls AI draft

DDx. Aspiration (probe, sedation, the obstruction episode), atelectasis, residual sedation and hypoventilation, worsening pulmonary edema, blunted cough and gag from topical lidocaine. Compare his lung exam, RR, and work of breathing with his baseline.
Chest x-ray. If there are new focal findings, persistent hypoxemia, or a new O2 requirement; not required routinely. Suspected aspiration is observed, not treated with prophylactic antibiotics or steroids.
Discharge. Not today. A 5-second pause and symptomatic bradycardia that needed pacing point to sinus node dysfunction; he needs telemetry and cardiology or EP review for a possible pacemaker. After an uneventful cardioversion, same-day discharge is usual once he is back to baseline, tolerating fluids after the topical wears off, with an adult escort and no driving for 24 h.
Metoprolol. Hold or reduce tomorrow's dose and decide with cardiology. Restarting the full dose on autopilot after symptomatic bradycardia is the trap; abrupt withdrawal also risks rebound tachycardia and AF recurrence.
Apixaban. Yes, on schedule. The TEE and shocks are not reasons to hold; the weeks after cardioversion are the highest-risk period.
What to tell him. Plain language: his heart's own pacemaker slowed and paused after the shock; he needs monitoring overnight to see if it happens again and whether he needs a pacemaker; the blood thinner continues. No false reassurance that the rhythm problem is fixed.

Short stem

Urgent ERCP under propofol sedation in a patient with severe OSA and obesity

A 71 y.o., 5'4", 105 kg woman is scheduled for urgent ERCP with sphincterotomy and stone extraction for choledocholithiasis in the GI endoscopy suite. She was admitted 36 hours ago with RUQ pain, fever, and jaundice and has received 3 L of lactated Ringer's and piperacillin-tazobactam; NPO since midnight. Severe OSA on CPAP at 14 cm H2O nightly; hypertension treated with amlodipine. T 38.1 C; HR 104; BP 118/70; RR 20; SpO2 93% on room air. Neck circumference 45 cm; Mallampati IV. Total bilirubin 4.6 mg/dL; WBC 13.4; platelets 176. The endoscopist plans to do the procedure prone.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Readiness and resuscitation when the procedure is the source control; sedation versus GA with an ETT in severe OSA and obesity, and the GA plan if chosen; the oxygen and monitoring plan for deep sedation; what an off-site room must have before anyone is sedated.

1. Timing and readiness

It is 0800; GI has her booked for 1400. Proceed today, or delay to optimize? Why? Labs before she comes down? Which? More fluid now? How much? To what end point? Arterial line? Why/why not? Lactate 2.9 at noon, up from 2.1 at 0800. Of concern? Move the case earlier? Why/why not?

Considerations and pitfalls AI draft

Proceed vs delay. Ongoing cholangitis with a stone in the duct; biliary drainage is the treatment, so resuscitation runs alongside it over hours, not days. Postponing until fever and WBC normalize is the error; so is sending her down under-resuscitated.
Labs. BMP (K+, creatinine, glucose), repeat CBC, INR (biliary obstruction can prolong it, and a sphincterotomy is planned), lactate, blood cultures if not already drawn, type and screen.
Fluid. Still febrile and tachycardic after 3 L. Check volume responsiveness (passive leg raise, urine output trend, POCUS if windows allow) and give 500 mL boluses of LR to an end point: HR trending down, MAP 65 or more, urine output about 0.5 mL/kg/h by ideal body weight (about 25-30 mL/h), lactate clearing. Reflex liters in a 71 y.o. with severe OSA who will be semi-prone are not free.
Arterial line. Defensible either way. Points for one: a cuff on a large conical arm is often unreliable, cycling a cuff every 2-3 minutes in a semi-prone patient is hard to read, and she is septic and will get propofol. A strong answer names the cuff-fit problem rather than reciting BMI.
Lactate 2.9. Rising, not clearing: ongoing infection or hypoperfusion. More resuscitation and an earlier slot if GI can do it; drainage moves up, not back. If she progressed to pressor-dependent shock, the location and technique might change, but the need for drainage would not.

2. Sedation or general anesthesia

Anesthetic plan: propofol deep sedation with a natural airway, or GA with an ETT? Which? Why? The endoscopist prefers sedation and says intubating adds 20 minutes per case. Changes your plan? Why/why not? Position — prone, semi-prone, or supine? Why? Assume GA with an ETT. Prone then? Why/why not? Induction — RSI? Why/why not? Awake or asleep intubation? Why? Backup if the first attempt fails?

Considerations and pitfalls AI draft

Sedation vs GA. Both are defended in practice; the learner has to weigh them for this patient. For GA with an ETT: severe OSA, BMI about 40, neck 45 cm, Mallampati IV, SpO2 93% on room air at baseline, a shared airway she will lie on, a possibly long procedure with a difficult cannulation, and an off-site location far from help. For sedation: avoids induction hypotension in a septic patient, faster turnover, no airway trauma from intubation. A plan for sedation that does not include a rescue plan and a low threshold to convert is a flag.
Endoscopist's preference. Turnover time does not set the airway plan. A strong answer stays on the patient's risk and states what would make the plan change; giving in, or arguing, without a clinical reason both miss.
Position. Prone gives the endoscopist the best duodenal view but is the worst position for this patient's airway and the hardest to rescue from; semi-prone (left lateral with the right side rolled up) keeps the face and mouth more reachable; supine ERCP is feasible, technically harder for the endoscopist, and makes airway rescue and intubation easiest.
Prone with an ETT. More acceptable once the airway is secured: tube taped well, position and breath sounds checked after the turn, face and eyes padded on a prone headrest, and enough people to turn 105 kg safely. Semi-prone or supine is still a reasonable choice.
RSI. Reasonable and defensible: acute illness, obesity, and pain with opioids raise aspiration risk despite NPO since midnight. The cost is the short safe apnea time in obesity and OSA, so preoxygenate head-up (ramped) with CPAP, NIV, or high-flow oxygen and keep oxygen flowing during apnea; gentle low-pressure mask ventilation during an RSI is defensible here.
Awake vs asleep. Asleep with a video laryngoscope after good preoxygenation is reasonable if mask ventilation and a supraglottic airway are expected to work; awake flexible-scope intubation is defensible given Mallampati IV, a large neck, and severe OSA. Either choice needs a reason.
Backup. A named sequence before induction: second-generation supraglottic airway, two-person mask, call for help, and a front-of-neck kit open in the room.

3. Oxygen and monitoring under sedation

Assume your attending elects propofol sedation, semi-prone. Midazolam premedication? Why/why not? Oxygen delivery — standard nasal cannula, high-flow nasal oxygen, or a nasal CPAP mask? Which? Why? Ventilation — how will you monitor it? Target SpO2 during the case? Her CPAP machine is on the ward. Bring it down? Why/why not? Under what circumstances would you convert to GA?

Considerations and pitfalls AI draft

Midazolam. Little benefit and real cost in severe OSA at 71: it adds to the airway obstruction and the residual sedation in recovery. Small dose or none.
Oxygen. High-flow nasal oxygen or a nasal CPAP mask splints the upper airway and buys time to desaturation better than a standard cannula; they make the capnography waveform smaller and less reliable (washout), which the learner should anticipate. A standard cannula alone is a weak choice here.
Ventilation monitoring. Continuous capnography is expected for deep sedation, sampled at the nares or mouth; plus direct observation of chest and abdominal movement and SpO2. SpO2 lags apnea, especially on high-flow oxygen.
Target SpO2. About 92% or higher. A high SpO2 on high-flow oxygen buys time but can hide hypoventilation for minutes; the capnogram and chest movement give the early warning, not the oximeter.
Home CPAP. Yes: the mask fits her and the pressure is known, so it is ready for recovery, and some teams use it or a nasal CPAP mask during the case. Waiting for it after she desaturates in recovery is the avoidable delay.
Converting to GA. Persistent obstruction despite jaw thrust and a nasal airway, desaturation that does not reverse quickly, regurgitation, escalating pressor needs, or a long, difficult cannulation with rising propofol requirements. Naming the thresholds in advance is the point; 'I will convert if things go badly' is not a threshold.

4. Setting up the GI suite

The GI suite is one floor below the main ORs. The room has wall oxygen, wall suction, and a monitor with SpO2, ECG, and NIBP. Enough to start? What is missing? Anesthesia machine for a sedation case — yes/no? Why? Backup oxygen source? Which? Airway equipment at the head of the bed — which items? The C-arm and the endoscopy tower sit at her head and left side. Access to the airway — how? Second anesthesia provider present at the start — yes/no? Why? Getting her supine from semi-prone — how many people? How long?

Considerations and pitfalls AI draft

Not enough. Missing capnography, a second suction set up for the anesthesia team (the endoscopist's suction is not yours), a self-inflating bag that can deliver high FiO2, airway equipment, emergency drugs, an emergency cart with a defibrillator, a working phone to call for help, and adequate light and space to reach the head.
Anesthesia machine. Yes in this patient: conversion to GA is likely enough that the machine, circuit, and ventilator should be checked and in the room, not down the hall. A sedation case in a low-risk patient might reasonably go without one.
Backup oxygen. A full E-cylinder with a regulator, checked; wall supply can fail and high-flow oxygen draws a lot.
Airway equipment. Masks in several sizes, oral and nasal airways, second-generation supraglottic airways in the right size, video laryngoscope, bougie, ETTs, and a front-of-neck kit; drugs drawn up for intubation, including a paralytic.
C-arm and tower. Agree before the start where the C-arm parks and how fast it moves away; position so the face and mouth can be seen and reached. The learner should not accept a set-up where the airway is under equipment.
Second provider. Reasonable to have one present at the start or immediately available; two-handed mask ventilation in severe OSA and obesity needs a second person on the bag, and help from the main ORs is a floor away in an emergency.
Supine. Agree on the plan before sedation: number of people (usually four or more for 105 kg), a slide sheet, the stretcher or procedure table flat and alongside, and who moves the scope. It should take under a minute.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Running propofol sedation semi-prone in severe OSA: dosing, reading the capnogram, rescuing obstruction and desaturation away from the OR, converting to GA after regurgitation, ventilating after aspiration, and recovery and disposition after an off-site airway event.

1. Starting the sedation

Assume semi-prone, high-flow nasal oxygen at 50 L/min with FiO2 0.6, bite block in. Propofol — bolus? Dose? Infusion rate? Dosed to what weight? Ketamine? Fentanyl? Which, if either? Why? The scope passes; she coughs and reaches for the bite block. Deeper? How? Ten minutes in, BP 84/48, HR 96. Rx? Agent? Dose? BP 80/46 after two doses. Next?

Considerations and pitfalls AI draft

Propofol. Small titrated boluses (10-20 mg at a time, judged by effect, not a fixed mg/kg load), then an infusion started low, about 50-75 mcg/kg/min, and titrated up; deep sedation for ERCP often needs 100 mcg/kg/min or more, but start low at 71 and septic. Bolus scalar: lean body weight, about 53 kg here (her ideal weight, 55 kg, gives nearly the same number, which is expected in obese women; total weight does not). Infusion scalar: adjusted weight (about 75 kg) is a common choice; some sources use total weight for maintenance, so either is defensible if titrated to effect. Dosing a bolus on 105 kg risks apnea and hypotension, more so at 71.
Adjuncts. Low-dose ketamine (10-20 mg increments) adds analgesia and reduces propofol needs with less respiratory depression; fentanyl adds to apnea in severe OSA, so small doses or none. Either choice needs a reason.
Coughing and reaching. Deepen by small propofol increments or a ketamine dose; topical pharyngeal local anesthetic helps; a large bolus to stop movement is how apnea starts. Some movement under deep sedation is expected.
BP 84/48. Propofol vasodilation in sepsis, on top of amlodipine; reduce the propofol rate if depth allows, phenylephrine 100 mcg or ephedrine 5-10 mg, and a fluid bolus if she is still volume-responsive.
No response to two doses. Start a norepinephrine infusion; recheck the cuff fit and place an arterial line if not already in; lighten the propofol and lean on ketamine. Rising pressor needs mean worsening sepsis or too deep a plane, and bring forward the decision to convert to GA with a secured airway.

2. Change on the capnogram

Twenty minutes in, the capnogram goes flat. SpO2 97%, HR 88. DDx? First move? Jaw thrust; snoring returns with a small waveform, then flat again. SpO2 90%. Next? Nasal airway? Size? Ask the endoscopist to stop? Why/why not? SpO2 back to 96%. The endoscopist wants to continue. Same propofol rate? Why/why not?

Considerations and pitfalls AI draft

DDx. Apnea (central, from propofol), complete upper-airway obstruction, or a sampling problem (line kinked, dislodged, or washed out by high-flow oxygen). A normal SpO2 does not exclude apnea; on high-flow oxygen it will lag by minutes.
First move. Look and feel: chest and abdominal movement, a hand near the mouth; check the sampling line; stimulate and jaw thrust; reduce or pause the propofol.
SpO2 90%, recurrent obstruction. Obstruction under too much propofol: stop or reduce the infusion, sustained jaw thrust, raise the high-flow rate, place a nasal airway.
Nasal airway. About 6.0-7.0 mm for an adult woman, well lubricated, placed gently; epistaxis is the main risk and is not a reason to withhold it.
Stop the procedure. Yes, briefly, while the airway is restored; the scope in the duodenum and ongoing insufflation make it worse. A strong learner asks for the pause rather than working around it.
Continue. Lower propofol rate, more reliance on ketamine and topical, and a clear threshold for converting to GA. Restarting at the same rate means repeating the event.

3. Retching and desaturation semi-prone

Forty-five minutes in, cannulation is still difficult and the duodenum is distended. She retches; bilious fluid pools in her mouth and around the bite block. SpO2 86% and falling. First actions? Turn her supine now, or manage semi-prone? Why? SpO2 74%, HR 52. Mask ventilation — can you get a seal? How? Two-person mask, poor chest rise. Next? Supraglottic airway or intubation? Which? Why? Intubation drugs — hypnotic? Dose? Paralytic? Dose? Dosed to what weight?

Considerations and pitfalls AI draft

First actions. Call for help; scope out with suction through the scope to decompress the stomach and duodenum; head down and turned so fluid drains out of the mouth; suction the oropharynx; 100% oxygen; stop the propofol.
Supine or semi-prone. A semi-prone or lateral head-down position helps drainage while suctioning; for mask ventilation and intubation she needs to be supine and ramped, so move quickly once the mouth is cleared. This is why the turn was planned before sedation.
SpO2 74%, HR 52. Bradycardia from hypoxemia; oxygenation is the treatment. Atropine without oxygenation does not fix it.
Mask seal. Two-person technique with oral and nasal airways, head ramped and jaw thrust; the regurgitation risk does not outweigh oxygenating a patient at 74%.
SGA or ETT. A second-generation supraglottic airway is a fast bridge to oxygenation if the mask fails, but with active regurgitation and an aspiration event the definitive airway is an ETT; intubate.
Drugs. She already has propofol on board and is hypoxemic and hypotension-prone: little or no further hypnotic, or a small dose of ketamine (about 0.5 mg/kg by lean weight, about 25 mg) or etomidate (about 0.1-0.15 mg/kg by lean weight, about 5-8 mg). Paralytic for rapid sequence: succinylcholine 1-1.5 mg/kg by total body weight (about 105-160 mg; atropine at hand given the bradycardia) or rocuronium 1.2 mg/kg by ideal or lean weight (about 65 mg); onset on ideal weight is slower, and some dose rocuronium on adjusted weight for speed. Video laryngoscope and bougie at hand.

4. Ventilation after intubation

Tube in; bilious fluid suctioned from the tube, no particulate. FiO2 1.0, SpO2 91%. Tidal volume? PEEP? Peak pressure 44, plateau 30. DDx? Rx? Wheezes bilaterally. Rx? Agent? SpO2 94%, peak 34. Bronchoscopy now? Why/why not? Steroids? Antibiotics — change? Why/why not? The endoscopist asks to finish the stone extraction. Proceed? Why/why not?

Considerations and pitfalls AI draft

Settings. Volume control at 6-8 mL/kg predicted body weight (about 55 kg, so about 330-440 mL), PEEP 8-10 or more given obesity and aspiration, rate to a normal pH, FiO2 weaned to SpO2 above 92%. Dosing tidal volume to 105 kg is the classic error.
Peak 44, plateau 30. A 14 cmH2O peak-to-plateau gap points to airway resistance (bronchospasm, secretions, kinked or bitten tube, tube in a mainstem); the high plateau reflects low compliance from the obese chest wall, a gas-distended abdomen, and position. Disconnect and hand-bag, pass a suction catheter, check tube depth and breath sounds, ask the endoscopist to suction the remaining gas out of the bowel.
Wheezes. Aspiration-triggered bronchospasm: deepen the anesthetic, albuterol through the circuit; small epinephrine doses only if severe.
Bronchoscopy. For particulate matter or persistent lobar collapse; with clear bilious fluid and improving gas exchange, not required now.
Steroids and antibiotics. No steroids for aspiration pneumonitis. She is already on piperacillin-tazobactam, which covers aspiration flora; no change for the aspiration alone.
Finish the procedure. Yes, if oxygenation and hemodynamics are stable: the infected duct still needs drainage, and she now has a secured airway. Continue supine, or semi-prone or prone with the tube secured and checked after the turn; if gas exchange worsens, the endoscopist places a stent and stops.

5. End of procedure and recovery

Sphincterotomy done, stones cleared. SpO2 95% on FiO2 0.5, PEEP 10. Extubate in the GI suite, or transport intubated? Why? Neuromuscular recovery — how do you confirm it? She is extubated and in PACU. Forty minutes later SpO2 89% on 4 L nasal cannula, RR 24, dozing between breaths. Rx? Disposition tonight? Why? Three hours later: epigastric pain radiating to the back, HR 116, lipase 2,600. DDx? Rx? She asks what happened during the procedure. What will you tell her?

Considerations and pitfalls AI draft

Where to extubate. Either is defensible if reasoned: extubating in the GI suite means a reintubation, if needed, happens away from help; transporting intubated to PACU or the OR to extubate there is reasonable after an aspiration. If extubated, she must be fully awake, sitting up or ramped, with full reversal and an oxygen plan ready.
Neuromuscular recovery. Quantitative train-of-four ratio of 0.9 or more; clinical signs alone are not enough. This applies whichever paralytic was used in B3; after rocuronium, sugammadex is dosed by actual (total) body weight per the label.
PACU desaturation. OSA with residual sedation and opioid, atelectasis, aspiration pneumonitis. CPAP now at her home 14 cmH2O (or titrated), sitting up, minimize opioids; a chest radiograph. If her machine did not come down, use the PACU's device; waiting for hers is a delay to fix, not a reason to skip CPAP.
Disposition. A monitored bed (ICU or step-down) with continuous pulse oximetry, ideally capnography, and CPAP: severe OSA, an aspiration with a new oxygen requirement, and resolving cholangitis. Not an unmonitored floor bed.
Pain and lipase 2,600. Post-ERCP pancreatitis is most likely (difficult cannulation is a risk factor); also perforation after sphincterotomy, worsening cholangitis, or bleeding. CT if the picture is atypical, with peritoneal signs, or she deteriorates.
Rx. Goal-directed LR (moderate, not aggressive, given her lungs and OSA), multimodal analgesia with acetaminophen and carefully monitored opioid, early oral feeding as tolerated, GI aware.
What to tell her. Plainly: she vomited during sedation, some went into her lungs, her oxygen dropped, and a breathing tube was placed to protect her lungs and finish the procedure; the stones were removed; what is being watched now (breathing, pancreas), and that a future procedure will plan for this. Document and disclose; no hedging or minimizing.

Short stem

Fistulogram under MAC in a dialysis patient with stable angina and limited revascularization options

A 64 y.o., 5'10", 88 kg man presents for a fistulogram of his left upper-arm AV fistula after it bled for 20 minutes following a full run of hemodialysis yesterday. History includes HTN, HLD, T2DM, ESRD on hemodialysis MWF, and CAD s/p CABG x3 ten years ago. He reports reproducible crushing chest pain when he walks more than about 100 feet, relieved within a few minutes by rest; he is mostly sedentary at baseline. Meds: carvedilol, amlodipine, isosorbide mononitrate, SL nitroglycerin, aspirin, atorvastatin, insulin glargine. A prior right forearm AV graft is thrombosed. BP 162/88, HR 68, SpO2 96% on room air. Hgb 9.6, K 5.1.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Whether a patient with exertional angina and limited revascularization options should proceed with a low-risk but time-sensitive access procedure; what data actually change the decision; the dialysis patient's bleeding, potassium, volume, and contrast questions; morning medications and anemia; technique and monitoring when both arms are spoken for.

1. Today, or optimize first?

IR wants him on the table this morning. Proceed today, or delay? Which? Why? What data would most change your call? Why that? Cath 8 months ago: all three grafts patent; ungrafted native disease in D1, D2, and OM1. Stress test the same month: reversible ischemia in the mid-to-apical anterior and anteroseptal walls. Of concern? Why? TTE last month: LVEF preserved, RV function low-normal, no significant valve disease. Change your call? Why/why not? SL nitroglycerin about once a week, the same as six months ago; no pain at rest. Proceed today? Why/why not? His cardiologist, reached by phone, suggests a two-week delay to reconsider PCI. Agree? Why/why not? Doses: carvedilol 25 mg BID, isosorbide mononitrate 120 mg daily, amlodipine 10 mg daily. Increase carvedilol? Add ranolazine? Neither? Which? Why?

Considerations and pitfalls AI draft

Proceed vs delay. The tension is a low-risk, time-sensitive procedure (a bleeding, failing access he needs to dialyze tomorrow) against a fixed ischemic burden. Either commit is defensible if reasoned. Red flags: reflexive cancellation for 'cardiac clearance,' or proceeding without asking whether the angina is stable.
Data that would change the call. ACC/AHA perioperative guidance: test only when the result would change management independent of the procedure. A recent cath, stress test, and echo are worth far more than anything new; an ECG compared with a prior is reasonable. A strong learner asks for what already exists (and for the trajectory of his symptoms) rather than ordering a new stress test.
Cath and stress. Residual ischemic burden despite patent grafts. Anterior-wall ischemia fits the ungrafted diagonals (D1, D2). The anteroseptal component is LAD septal-perforator territory, not one of the named ungrafted vessels; it implies septals poorly supplied despite the LAD graft (for example, septals arising proximal to the anastomosis off a diseased native LAD). The ungrafted OM1 (lateral wall) shows no reversible ischemia, so it is likely small or collateralized. Net: a narrow margin for supply-demand mismatch. Tachycardia is the main enemy, with hypertension and diastolic hypotension close behind; this sets up the intra-op goals.
TTE. Preserved LV function shifts the concern from pump failure to ischemic threshold. Low-normal RV function is worth noting (less reserve for volume shifts, head-down positioning, or a protamine or pulmonary insult) but is not a reason to delay.
Stable pattern. Weekly SL nitroglycerin unchanged for months, exertional only, no rest or crescendo symptoms reads as stable angina. But angina at about 100 feet is CCS class III despite uptitrated therapy: older (2007) ACC/AHA guidance treated that as an active cardiac condition and current guidance does not, so proceeding with a low-risk procedure is defensible. Severe stable angina is also an independent reason to discuss revascularization for symptoms, which makes delay a defensible answer too. Unstable features (rest pain, new pattern, increasing NTG use) are the clear reason to delay.
Cardiologist's two-week delay. Fistula thrombosis or hemorrhage, missed dialysis (hyperkalemia, volume overload), and a tunneled catheter with its infection and central-stenosis risk. Prophylactic revascularization did not improve outcomes even before elevated-risk surgery (CARP, elective major vascular surgery), and in advanced CKD and dialysis patients with stable CAD an invasive strategy did not reduce death or MI (ISCHEMIA-CKD). Current ACC/AHA guidance: revascularize before noncardiac surgery only when indicated independent of the surgery. PCI also adds DAPT that complicates the access procedures to come. Agreeing with the cardiologist is defensible if the learner names what the delay costs.
Further optimization. There is room on carvedilol (maximum 50 mg BID above 85 kg), limited by resting HR and BP, and uptitration takes days to weeks, not hours. Ranolazine is generally avoided in dialysis patients (acute renal failure reported at CrCl <30; pharmacokinetics not studied in dialysis). Anemia is the other lever (A3). 'Neither, today' is defensible; a weak answer says 'optimize' with nothing specific in mind.

2. Bleeding, potassium, volume, contrast

Assume no further optimization is possible and he goes today. DDx for yesterday's prolonged bleeding? Labs before he goes? Which? Why? INR 1.0, PTT normal, platelets 190. Bleeding risk for the case? DDAVP? Yes/no? Why? Treat his potassium before the case? Why/why not? Yesterday's run ended 1.5 kg above target when he cramped; this morning he is 2 kg above dry weight; lungs clear, no orthopnea, no edema. Can he lie flat for the procedure? Why/why not? Contrast load. Concern in him? Why/why not? He still makes about 400 mL of urine a day. Change your answer? Why/why not?

Considerations and pitfalls AI draft

DDx. Outflow (venous) stenosis causing access hypertension is the leading cause of prolonged post-cannulation bleeding and the reason for the fistulogram; residual heparin from the run, uremic platelet dysfunction, aspirin, and cannulation technique also contribute. A strong learner links the bleeding to the lesion IR is looking for.
Labs. Potassium, Hgb, and a basic coagulation screen are reasonable. A weak answer orders nothing in a dialysis patient or a large panel with no question attached.
Bleeding risk and DDAVP. Low for a percutaneous procedure with normal coags. Uremic platelet dysfunction is improved after dialysis; dialysis heparin has worn off by today. DDAVP (0.3 mcg/kg) is a treatment for clinical uremic bleeding, not routine prophylaxis here.
Potassium. A mildly elevated value the morning after a full run reflects rebound and is acceptable for a short MAC. Pitfalls: succinylcholine, hypoventilation, acidosis, or a prolonged case that pushes it higher. Check the ECG for peaked T waves; recheck if plans change.
Volume. Short of dry weight means little tolerance for fluid boluses if he becomes hypotensive; clear lungs and no orthopnea mean he can lie flat for a short case. This shapes the B3 hypotension decision.
Contrast. In an anuric patient contrast nephropathy is moot; contrast is cleared with dialysis. Residual urine output is worth preserving (associated with better outcomes on dialysis), so minimizing contrast is reasonable, but it is not a reason to delay. Fistulograms use modest volumes.

3. Morning medications and anemia

He took carvedilol and isosorbide this morning and held amlodipine. Right calls? Why? Aspirin today? Why/why not? Transfuse before the case? Why/why not? Transfusion threshold in him? Number? In holding, during IV placement: chest pressure 5/10. Rx? Nitroglycerin? Route? Dose? Pain resolves in 3 minutes; ECG unchanged from baseline. Proceed today? Why/why not? Anxiolysis before he goes back? Why/why not? Agent? Dose?

Considerations and pitfalls AI draft

Morning meds. Continue the beta-blocker (withdrawal raises ischemic risk; the error is starting one de novo, not continuing one) and the nitrate. Holding amlodipine is reasonable in a patient prone to hypotension after dialysis; taking it is also defensible given today's BP.
Aspirin. Continue: secondary prevention after CABG, and bleeding risk for this procedure is low.
Transfuse?. No for a short, low-blood-loss procedure at this Hgb. In preexisting cardiovascular disease the best-supported restrictive threshold is about 8 g/dL (FOCUS; AABB 2023), with symptoms as a trigger. MINT (acute MI) found a nonsignificant trend toward worse outcomes with a restrictive strategy; it does not apply directly to stable CAD, though his active angina makes symptom-triggered transfusion a fair discussion. Transfusion in ESRD carries volume overload, potassium load, and HLA sensitization that can hurt future transplant candidacy, a point strong learners raise.
Holding-area angina. SL nitroglycerin 0.4 mg. Brief, typical pressure provoked by anxiety and IV placement, resolving promptly with no ECG change, is consistent with his stable pattern. A strong learner asks whether this felt different from usual; delaying is defensible if it did. Ignoring it is the error.
Anxiolysis. Reasonable to blunt catecholamine-driven tachycardia: midazolam 0.5-1 mg titrated. Note the active glucuronide metabolite accumulates in renal failure; small doses, monitored.

4. Technique, monitoring, and the arms

IR: 'Fistulogram, probably a venoplasty, local only, 20 minutes.' Enough to choose a technique? Why/why not? What else do you need from IR? Why? IR adds: supine, left arm out on a board, local at the puncture site; balloon inflation is the painful step; heparin if they intervene; if the fistula clots and thrombectomy fails, a tunneled dialysis catheter today. Local alone? MAC? GA? Which? Why? Assume MAC. Propofol? Dexmedetomidine? Fentanyl? Ketamine? Which? Why? Arterial line? Why/why not? Site? BP cuff: right arm with the thrombosed graft? Leg? Which? Why? Holding placed a 20 g IV in the right antecubital fossa. Acceptable? Why/why not?

Considerations and pitfalls AI draft

What else from IR. 'local only, 20 minutes' undersells a venoplasty. A strong learner asks about position and whether he can lie flat, which steps hurt (venous balloon inflation is very painful), heparin, possible thrombectomy or stent, expected contrast, what happens if the vein ruptures, and the plan if the fistula clots (a catheter under the same anesthetic, with the neck under drapes). This is the 'verify with IR' content; a weak answer asks nothing and picks a technique.
Technique. MAC with local is typical and defensible; GA is defensible if he cannot lie still or the plan may expand to a neck line. Local alone risks pain-driven tachycardia and ischemia during inflation. GA trades that for induction and emergence swings. The defense should be built around avoiding tachycardia and hypertension.
Agents. Propofol and fentanyl titrate well; avoid morphine and meperidine in ESRD. Dexmedetomidine offers sympatholysis but adds bradycardia and hypotension on top of carvedilol and is slow to titrate for a 30-minute case. Ketamine alone raises HR and BP, a poor fit. Short-acting analgesia timed to balloon inflation (fentanyl or a small remifentanil bolus) is the key move.
Arterial line. Not mandatory for a short MAC; standard monitors with a 5-lead ECG are acceptable. Defensible given his ischemic margin and painful stimulation. The real problem is the site: arm arteries matter for future access, so a femoral or dorsalis pedis site, or no line, are the usual arguments.
BP cuff. Never on the fistula arm. The right arm with a thrombosed graft is often used but some avoid it; a leg cuff reads differently from the arm. No single right answer; the red flag is not thinking about it.
IV site. Vein preservation for future access argues against antecubital and upper-arm veins; hand or lower-extremity veins are preferred. Keeping an already-working IV for a short case is defensible if the learner names the trade-off and avoids further arm venipuncture.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Explicit heart rate and blood pressure targets in fixed coronary disease; treating stimulation-driven ischemia in the right order; extending a case under the same anesthetic when the access fails; hypotension in a beta-blocked patient above his dry weight; interpreting troponin in ESRD; regional anesthesia for the next access operation.

1. Hemodynamic targets

MAC under way, sheath in, he is calm. BP 150/80, HR 66. Target HR? Why that number? Target BP? Upper and lower limits? Why? 5-lead ECG. Precordial lead: where? Why? Supplemental O2? Why/why not? Target SpO2? IR is about to inflate the balloon. Fentanyl? Remifentanil? Esmolol? Nothing? Which? Dose?

Considerations and pitfalls AI draft

HR target. Roughly 55-70: slower rates lengthen diastole and lower demand; tachycardia is the main driver of demand ischemia across fixed lesions.
BP targets. Keep near his baseline, roughly within 20%; avoid hypertension (wall stress, demand) and avoid diastolic hypotension (coronary perfusion pressure). A strong learner names numbers and ties the lower limit to diastolic pressure.
Leads. Lead II plus a precordial lead. V5 is the classic choice; V3-V4 is at least as sensitive in perioperative data (Landesberg) and defensible here. Demand ischemia shows as ST depression, which does not localize to the culprit territory, so the stress-test territory is not by itself a reason to move the lead. A strong learner names a lead and a sensitivity rationale.
Oxygen. Enough to keep normal saturation (about 94-98%) via nasal cannula with capnography; hyperoxia adds nothing and may cause coronary vasoconstriction.
Before inflation. Pre-emptive short-acting analgesia timed to inflation (fentanyl 25-50 mcg a few minutes ahead, or a remifentanil bolus about 0.25-0.5 mcg/kg just before), with esmolol drawn up. Giving nothing before a known painful stimulus in this patient is the pitfall.

2. Balloon inflation

Balloon inflated across the outflow stenosis. He groans and pulls at his arm. HR 104, BP 192/100. Rx? 2 mm ST depression in your precordial lead. Interpretation? Deflate the balloon now? Why/why not? Fentanyl? Esmolol? Which first? Dose? Balloon down; HR 76, BP 148/82; ST depression now 1 mm; chest pressure 3/10. Nitroglycerin? Why/why not? Route? Dose? Five minutes later: ST back to baseline, pain-free. Two more inflations planned. Proceed? Why/why not? Anything different before the next inflation? Remifentanil? Esmolol? Propofol bolus? Which? Dose?

Considerations and pitfalls AI draft

Rx. Remove the stimulus, analgesia, then rate and pressure control, with oxygen.
Interpretation. Demand (subendocardial) ischemia driven by tachycardia and hypertension, presumed to be in his known territory from the stress test; ST depression itself does not localize. A 12-lead after the event helps; lead or position artifact is less likely given the clinical picture.
Deflate. Yes; removing the stimulus is the fastest anti-ischemic intervention available. Pushing through the inflation is the error.
Agents. Fentanyl 25-50 mcg or a small remifentanil bolus for pain; esmolol 10-20 mg increments (or 0.5 mg/kg) for rate. Order matters: analgesia, then rate.
Nitroglycerin. IV 25-50 mcg boluses or an infusion started low (about 0.25-0.5 mcg/kg/min) and titrated, or SL 0.4 mg; watch for reflex tachycardia and diastolic hypotension.
Next inflation. Reasonable to proceed now that ST and pain have resolved, but with more than before: a larger or better-timed analgesic dose (remifentanil bolus or fentanyl), esmolol given before inflation rather than after, a small propofol bolus if he cannot tolerate it, and shorter inflations if IR can accept them. Recurrent or persistent ST change means stop the procedure, 12-lead, troponin, cardiology.

3. The fistula clots

IR completes the venoplasty without further ST change. Minutes later the fistula thromboses. IR gives 5000 units of heparin, attempts thrombectomy, fails, and wants to place a tunneled right IJ dialysis catheter now so he can dialyze tomorrow. Proceed under the same anesthetic? Why/why not? Head-down tilt for the IJ. Tolerable in him? How much? Protamine before tunneling? Why/why not? Face draped; he coughs and moves as the dilator goes in. Deepen sedation? Convert to GA? Which? Why? Moments later: BP 82/44, HR 58. DDx? Breath sounds equal, no blood on aspiration, no new ST change. Phenylephrine? Ephedrine? Fluid? Which? Why?

Considerations and pitfalls AI draft

Proceed. Reasonable if the ST changes have resolved and he is stable: one anesthetic, monitoring already in place, and he needs dialysis tomorrow. If ischemia is ongoing, a non-tunneled temporary catheter or deferring to a more controlled setting is defensible.
Head-down. Modest Trendelenburg (10-15 degrees) for venous distension and air-embolism prevention; briefly increases preload and wall stress. Usually tolerable for the minutes it takes; minimize duration.
Protamine. Not routinely needed for a tunneled catheter after a single 5000-unit dose; IR may also want heparin effect to persist after a failed thrombectomy. The established risk factors for protamine reactions are NPH or other protamine-containing insulin, fish allergy, other drug allergy, and a prior protamine reaction. Glargine contains no protamine, and evidence that an uneventful CPB exposure ten years ago raises risk is weak. The reaction to fear in him is catastrophic pulmonary vasoconstriction with RV failure, given his low-normal RV. A strong learner weighs a small benefit against hypotension and reaction risk.
Deepen vs GA. With his face draped and the operative field at the neck, airway access is poor; deepening sedation risks obstruction under the drapes. Brief, careful deepening or converting to GA with a secured airway are both defensible; the red flag is deepening without a plan for the airway.
Hypotension DDx. Sedation or anesthetic deepening (propofol vasodilation) on beta-blockade, and the loss of preload when leveled from head-down, plus complications of IJ access (carotid puncture, pneumothorax, hemothorax, air embolism) and ischemia. Strong learners include the access complications; the negatives given narrow but do not exclude them.
Rx. Phenylephrine 50-100 mcg restores diastolic pressure but may slow HR further; ephedrine 5-10 mg supports HR but its beta effect is blunted by beta-blockade. Carvedilol also blocks alpha-1, so the alpha response to both may be attenuated; small vasopressin doses are an option if the response is poor. A small fluid bolus (250 mL) is acceptable but limited by his volume status. Target the diastolic pressure, not just the number.

4. PACU troponin

PACU: pain-free, BP 146/78, HR 70, ECG back to baseline. hs-troponin T 98 ng/L; 72 ng/L at a clinic visit three months ago. Interpretation? Repeat it? When? What change would matter? Repeat at 3 hours: 104 ng/L. Home today, observation, or admission? Which? Why? Cardiology before he leaves? Why/why not? Dialysis tomorrow through the new catheter. Any change to his usual run? What? Why?

Considerations and pitfalls AI draft

Interpretation. Chronically elevated troponin is common in ESRD; the comparison with his own baseline and the serial trend matter more than the absolute value. A rise from his prior baseline after documented intra-op ischemia is suspicious for perioperative myocardial injury.
Repeat. Yes, at 1-3 hours per the assay protocol, and again later (6-12 hours or next morning), since the PACU draw came hours after the intra-op event and may already be on the upslope. A dynamic change of more than about 20% relative, or a meaningful absolute delta for the assay, supports acute injury; rule-in algorithms are not validated in ESRD.
3-hour value. 98 to 104 is a 6 ng/L (about 6%) rise: stable relative to the PACU draw. Against the clinic value of 72 it is a 26-32 ng/L (36-44%) rise, but a three-month-old value in a dialysis patient is a weak baseline. Genuinely ambiguous: either observation with a later troponin or admission is defensible; discharging without a plan or follow-up is not.
Cardiology. Reasonable to involve before discharge given documented ischemia and a troponin above baseline; perioperative myocardial injury carries real 30-day mortality even when asymptomatic.
Tomorrow's run. Intradialytic hypotension during ultrafiltration can provoke ischemia in him: a strong learner suggests a gentler ultrafiltration goal (accepting he stays above dry weight for a run or two), cooler dialysate or holding antihypertensives before the run, and flags the new catheter's heparin lock.

5. Three weeks later: new access

Three weeks later he is back for a left brachiobasilic fistula with basilic vein transposition, about 2 hours. Angina unchanged; dialyzing through the catheter. Repeat stress testing first? Why/why not? GA? Brachial plexus block with sedation? Which? Why? The surgeon prefers GA. Change your plan? Why/why not? Assume a block. Supraclavicular? Infraclavicular? Axillary? Which? Why? Local anesthetic? Volume? Dose? Incision extends up the medial upper arm. Adequate coverage? Why/why not? As you finish the block, he asks whether this operation could cause a heart attack like last time. What will you tell him?

Considerations and pitfalls AI draft

Stress test. Repeat stress testing is not indicated: symptoms unchanged, recent testing on file. But a strong learner asks what cardiology concluded about last month's ischemia and troponin rise; if it was called a type 2 MI, ACC/AHA guidance has long advised waiting about 60 days before elective noncardiac surgery. That must be weighed against the infection and central-stenosis risk of staying on a catheter. Proceeding and a short delay are both defensible; not asking is the error.
Technique. Regional with light sedation avoids airway and induction swings and produces sympathectomy-mediated vasodilation. Randomized evidence shows better early fistula patency with brachial plexus block than with local anesthesia (Macfarlane, Lancet 2021); evidence against GA is weaker (small trials, observational data), and none is specific to basilic transposition. GA is defensible but should be defended.
Surgeon prefers GA. A strong learner engages on the merits (patency, hemodynamics, duration, positioning) rather than simply deferring or overruling.
Approach. Supraclavicular gives dense upper-arm coverage but carries phrenic nerve palsy risk; infraclavicular or axillary avoid the phrenic nerve. Axillary may miss the musculocutaneous nerve without a separate injection.
Local anesthetic. E.g. ropivacaine 0.5% 20-30 mL; ESRD patients may be at higher toxicity risk (acidosis, hyperkalemia, altered protein binding), so stay well within the maximum dose.
Medial upper arm. The intercostobrachial nerve (T2) is not part of the brachial plexus; a subcutaneous field block across the medial upper arm is needed.
What will you tell him. Honest and specific: a small heart strain was detected during a painful moment last time, was treated, and the plan this time (block, steady medications, close monitoring) is designed to reduce that stress; the risk is low but not zero. False reassurance or a frightening list of numbers are both weak answers.

Long stem

Hip fracture on apixaban in an older woman with mild cognitive impairment

An 84 y.o., 64 kg, 5'4" woman is scheduled for urgent left hip cemented hemiarthroplasty for a displaced femoral neck fracture.

HPIFell at about 2200 last night walking to the bathroom; her daughter found her on the floor at 0630. She says she tripped on the rug but cannot recall the details. Left hip pain, 8/10 with any movement despite hydromorphone 0.5 mg IV twice in the ED. Last ate at 1800 yesterday. Orthopedics has an OR at 1300 today.

PMHAtrial fibrillation. Hypertension. Mild cognitive impairment diagnosed 2 years ago; lives with her daughter, walks to the mailbox and back daily with a cane, independent in self-care; her daughter manages her medications. No chest pain or fainting that her daughter has noticed. Cataract surgery under sedation 3 years ago, uneventful.

MEDSApixaban 5 mg twice daily, last dose 0800 yesterday (evening dose missed). Metoprolol succinate 50 mg daily and lisinopril 20 mg daily, both last taken 0800 yesterday. Donepezil 10 mg at bedtime. No known drug allergies.

PHYS EXAMHR 92, irregular; BP 148/82; RR 18; SpO2 94% on room air; T 37.1°C. Oriented to person and place, not to date; attentive and answers questions appropriately. Irregularly irregular rhythm; no murmur. Dry mucous membranes. Lungs clear. Left leg shortened and externally rotated; distal pulses intact. Mallampati II; upper and lower dentures.

IMAGINGHip X-ray: displaced left subcapital femoral neck fracture. CT head (ED): no acute findings; chronic small vessel changes.

ECGAtrial fibrillation, ventricular rate 94; no acute ST changes.

LABSHgb 10.9 g/dL; platelets 210 K/uL; INR 1.3; aPTT 34 s; Na+ 134 mEq/L; K+ 4.6 mEq/L; BUN 32 mg/dL; creatinine 1.2 mg/dL (0.9 three months ago); glucose 128 mg/dL.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Timing of hip fracture surgery against optimization; residual DOAC effect and the neuraxial decision; block choice under anticoagulation; induction and post-induction hypotension in an older, dry patient; recognizing and treating cardiovascular collapse at cementing; blood, depth, temperature, and reversal choices that set up a clear-headed emergence.

1. Timing and anesthetic technique

0900 in the ED; OR booked for 1300. Proceed today? Why/why not? Tripped or fainted? What tells you? Echo before the OR? Why/why not? Apixaban effect gone by now? How do you tell? Spinal at 1300? Why/why not? Wait until tomorrow morning for a spinal? Why/why not? PCC to make a spinal possible today? Why/why not?

Considerations and pitfalls AI draft

Proceed today. Most would go today. Surgery within 24-48 hours of a hip fracture is linked to less pain, fewer complications (pneumonia, pressure injury, delirium, VTE), and lower mortality; delay should be reserved for a correctable problem that would change risk (severe electrolyte derangement, decompensated heart failure, uncontrolled ventricular rate, sepsis). Use the morning: IV fluid for the long lie and rising creatinine, a block for pain, a plan for the apixaban. A learner who delays for routine tests or 'to optimize' without naming what will be fixed is the flag.
Tripped or fainted. Unclear, and it matters. An unwitnessed fall she cannot recall, AF, and two antihypertensives keep syncope on the table. A strong learner asks the daughter about prodrome, palpitations, and prior near-falls, and looks at orthostatics if feasible, the ECG, glucose, and electrolytes. The goal is not a full syncope workup before surgery but deciding whether something reversible or dangerous is hiding.
Echo. Not for most. No murmur, no heart failure symptoms or signs, and she walks daily; an echo would not change the anesthetic plan and risks costing the OR slot. A focused echo is reasonable when it can be done without delay and there is a new murmur, heart failure, or a fall that looks cardiac. Postponing surgery by a day to wait for a formal study is the error.
Apixaban effect. Not reliably, and the INR does not answer it. PT/INR is insensitive to apixaban: a near-normal value does not exclude meaningful drug effect, and her 1.3 could reflect apixaban, poor intake, or nothing. Her creatinine clearance by Cockcroft-Gault is about 35 mL/min ((140-84) x 64 / (72 x 1.2) x 0.85), so apixaban's half-life (about 12 hours normally) runs longer; at 25-29 hours she is only about two half-lives out and a quarter or more of peak effect may remain. Only an apixaban-calibrated anti-Xa level (or drug level) estimates residual drug.
Spinal at 1300. No for most. At 1300 she is 29 hours from a treatment-dose apixaban; ASRA recommends at least 72 hours before a neuraxial block at treatment doses unless a drug-specific level is low (apixaban below 30 ng/mL, a threshold that has not been clinically validated). General anesthesia does not need a drug-free interval; operating today with blood available is reasonable. A learner who places a spinal on the strength of the INR has misread the test.
Wait for a spinal. Generally no. Waiting to reach a neuraxial-safe interval delays a time-sensitive operation, and randomized evidence shows no meaningful difference in survival, recovery of walking, or delirium between spinal and general anesthesia for hip fracture. Some hip fracture protocols accept 48 hours for a spinal with adequate renal function; her clearance of about 35 mL/min is at the margin, and ASRA is more conservative. Holding a frail patient on bed rest for the sake of technique is the flag.
PCC. No. Reversal agents are not recommended to enable a neuraxial procedure: PCC is prothrombotic in a patient with AF and a fresh fracture, and it does not reliably reverse apixaban. PCC is reserved for life-threatening bleeding. Andexanet alfa is no longer available in the US; idarucizumab reverses only dabigatran.

2. Block and induction

1100, pre-op bay. Block before the OR? Fascia iliaca? PENG? Femoral? Which? Why? Place it now? Why/why not? Drug? Volume? Midazolam for the block? Why/why not? In the OR. Arterial line before induction? Why/why not? Induction agent? Dose? ETT or LMA? Why? Three minutes after induction, BP 76/40, HR 104, AF. Rx? Phenylephrine? Ephedrine? Which? Dose? Target MAP?

Considerations and pitfalls AI draft

Block choice. A block is expected; it cuts opioid need, eases positioning, and untreated pain is a delirium driver. Fascia iliaca (suprainguinal especially) covers the femoral and lateral femoral cutaneous nerves and variably the obturator. PENG targets the articular branches of the femoral, obturator, and accessory obturator nerves and spares motor function, but misses the lateral thigh skin. A femoral block alone misses the lateral femoral cutaneous and obturator contributions and weakens the quadriceps. Any of the three, defended, is fine.
Place it now. ASRA manages deep plexus and deep peripheral blocks like neuraxial blocks and leaves superficial blocks to clinical judgment, weighing vascularity, compressibility, and the consequence of bleeding. Fascia iliaca is a fascial plane block lateral to the femoral vessels, compressible, and widely placed under ultrasound in anticoagulated hip fracture patients. PENG sits deeper over the pubic ramus beneath the iliopsoas and is less compressible; many still place it but weigh it more. A lumbar plexus block follows neuraxial rules and is off the table.
Drug and volume. Fascial plane blocks need volume: for example ropivacaine 0.2% 40 mL (80 mg) or 0.375% 30 mL (about 112 mg). Her ropivacaine ceiling is roughly 3 mg/kg, about 190 mg; older patients warrant staying well under it. Bupivacaine 0.25% 30 mL (75 mg) is an alternative. Ultrasound, aspiration, incremental injection, monitors on, lipid available.
Midazolam. No. Benzodiazepines are a strong, avoidable delirium trigger in an older patient with cognitive impairment. A well-placed block makes positioning tolerable; if anything is needed, a small dose of fentanyl or ketamine. Reaching for midazolam 2 mg 'to keep her calm' is the flag.
Arterial line. Many would place it before induction: she is 84, dry from a long lie, hypertensive, in AF, and facing cementing, where pressure can fall abruptly. Placing it right after induction, with the cuff cycling every 1-2 minutes until then and a vasoconstrictor running, is defensible.
Induction. Slow, reduced-dose induction with a vasoconstrictor ready: propofol 0.5-1 mg/kg (30-60 mg) titrated, or etomidate about 0.2 mg/kg (about 13 mg), with modest fentanyl. Volume before induction given the long lie. A standard 2 mg/kg propofol bolus in a dry 84-year-old is the error.
ETT or LMA. ETT is the common choice: lateral position, a 1.5-2 hour case, recent opioids slowing gastric emptying, and an older patient. An LMA is defensible in a fasted patient with a good block if the learner engages aspiration risk and access in the lateral position. Donepezil prolongs succinylcholine and can blunt nondepolarizing blockers; rocuronium about 0.6 mg/kg (about 40 mg) is typical.
Hypotension. Phenylephrine 50-100 mcg boluses, then an infusion (or norepinephrine) is the usual answer: it restores SVR without speeding a rate that is already 104 in AF. Ephedrine adds rate and shortens diastolic filling in an older, hypertensive heart. A modest fluid bolus helps a dry patient. Waiting for the pressure to come back on its own is the flag.
Target MAP. Her baseline MAP is about 104. Most aim to stay within about 20% of baseline (MAP roughly 80 or higher) and never below 65; older and chronically hypertensive patients have higher autoregulatory thresholds.

3. Femoral component

Right side down, posterior approach. Incision. Tranexamic acid? Why/why not? Dose? The surgeon is ready to cement the femur. Before he does, what do you do? Cement in, stem seated. One minute later: ETCO2 21 from 34, SpO2 86% from 98%, BP 64/30 from 122/64, HR 122. DDx? Most likely? Why? Immediate Rx? Drug? Dose? Phenylephrine 200 mcg: BP 70/36. Next? Dose? Fluid bolus? Why/why not? How much?

Considerations and pitfalls AI draft

Tranexamic acid. Yes for most: 1 g IV (or about 15 mg/kg) at incision reduces blood loss and transfusion in hip fracture surgery without a clear increase in thrombosis. AF on anticoagulation is not a contraindication; a recent arterial or venous thrombosis is a reason to pause. Reduce or skip repeat doses with her renal function.
Before cementing. Tell the surgeon you are ready and watching; raise FiO2; make sure she is not dry and MAP sits at or above target with a pressor running; have phenylephrine, norepinephrine, and epinephrine drawn up; watch ETCO2, SpO2, and the arterial trace closely. Surgical measures help: lavage and dry the canal, retrograde cement gun with a distal plug, avoid excess pressurization. A learner with nothing to do before cementing in this patient has not thought about the risk.
DDx. Embolic: marrow fat, bone debris and cement (bone cement implantation syndrome), thrombotic PE, air. Also hemorrhage or hypovolemia, anaphylaxis (antibiotic, cement), myocardial ischemia, tension pneumothorax, an arrhythmia.
Most likely. Bone cement implantation syndrome: the timing (within minutes of cementing and stem insertion) and the triad of hypoxemia, hypotension, and a sudden fall in ETCO2. Mechanism: emboli raise pulmonary vascular resistance acutely, the RV fails, LV filling falls, and released mediators add vasodilation. The ETCO2 fall reflects new dead space and falling cardiac output.
Immediate Rx. FiO2 1.0, call for help, tell the surgeon, reduce the volatile, and support the RV's coronary perfusion with a vasoconstrictor: phenylephrine 100-200 mcg or norepinephrine. Be ready for CPR (turning supine) if she loses a pulse. Treating it as anesthetic-induced hypotension with a little ephedrine is the miss.
Next. Escalate: epinephrine 10-50 mcg IV boluses titrated to effect, and a norepinephrine infusion (0.05-0.2 mcg/kg/min), with epinephrine infusion if needed. Full-dose 1 mg epinephrine is for arrest, not for this. Keep systemic pressure up so the RV stays perfused, and avoid hypoxia, hypercarbia, and acidosis, which raise PVR further.
Fluid. Small boluses only (250 mL), watching the response. A failing RV is already pressure-overloaded; large volumes dilate it further, push the septum left, and drop LV output. A reflex liter is the error; withholding volume from a patient who was dry and has bled is also wrong.

4. Closing

Forty minutes later, on norepinephrine 0.04 mcg/kg/min: MAP 74, SpO2 97% on FiO2 0.5. EBL 450 mL; 1.5 L LR. ABG Hgb 8.6. Transfuse? Why/why not? Threshold for her? Assume processed EEG monitoring: sevoflurane end-tidal 1.6%, EEG suppression. Rx? Temp 35.3°C. Of concern? Rx? Assume an ETT and rocuronium; TOF 2 of 4. Sugammadex? Neostigmine? Which? Dose? Extubate in the OR? Why/why not? Where does she go next? Why?

Considerations and pitfalls AI draft

Transfuse at 8.6. Not for most, with modest ongoing loss and stable hemodynamics. A restrictive strategy is the standard; for orthopedic surgery and in patients with cardiovascular disease most use about 8 g/dL or symptoms (tachycardia, ischemia, hypotension not explained otherwise). Some would transfuse sooner after a fresh RV insult; the learner should name a number and the signs that would move it. Transfusing to 10 has no benefit and adds overload risk.
Threshold. About 8 g/dL, or higher with ischemia or instability. A learner applying 7 g/dL to an 84-year-old on a vasopressor after a cementing collapse has not adjusted to the patient.
Suppression. She is too deep: MAC falls with age (sevoflurane MAC at 84 is about 1.4%, so 1.6% is about 1.1-1.2 age-adjusted MAC). Lower the volatile, and check that the suppression is not hypoperfusion (MAP, the norepinephrine). EEG suppression in older patients is associated with postoperative delirium; avoiding unnecessary depth is reasonable even though preventing it has not been shown to reduce delirium.
Temperature. Yes, of concern: hypothermia worsens coagulopathy and bleeding, causes shivering and oxygen demand, raises cardiac event risk, slows drug clearance, and contributes to delirium. Forced-air warming, warmed fluids; aim for 36°C or higher before emergence.
Reversal. Sugammadex 2 mg/kg (about 130 mg) at TOF 2 of 4 is the cleaner choice: donepezil is a cholinesterase inhibitor, so neostigmine's effect is less predictable and adds cholinergic effects (bradycardia) on top of a beta blocker; her creatinine clearance of about 35 mL/min is above the level where sugammadex is not recommended. Neostigmine is not a good choice at TOF 2 of 4; if sugammadex is unavailable, wait for a TOF count of 4 (minimal block) and give neostigmine 30-50 mcg/kg with glycopyrrolate. Confirm a quantitative TOF ratio of 0.9 or more.
Extubate. Yes, if pressure is steady on low-dose norepinephrine, oxygenation keeps improving, she is warm, reversed, and following commands. Leaving an 84-year-old intubated overnight adds sedation, pneumonia, and delirium risk. Extubating on rising pressor or FiO2 1.0 is the error the other way.
Disposition. ICU or a monitored step-down bed: she needed a vasopressor after a cementing reaction. Keep the arterial line, repeat troponin and ECG, and get an echo if she stays on a pressor or hypoxemic. A routine ward bed straight from the OR after a cementing collapse is the flag.

B. POST-OPERATIVE CARE

Teaching focus. Sedation and hypoxemia in recovery; multimodal analgesia limited by age and kidneys; when to restart a DOAC and how to cover VTE until then; hyperactive delirium and its precipitants; bleeding into the thigh and the anticoagulation hold; an honest answer to the family about delirium.

1. PACU arrival

Assume extubated in the OR, norepinephrine off before transfer, and recovering in PACU before a step-down bed. PACU, 15 minutes: rouses to voice, then drifts off; RR 8; SpO2 88% on 4 L nasal cannula. Received fentanyl 100 mcg and hydromorphone 0.6 mg intra-op. DDx? First move? Naloxone? Dose? Twenty minutes later: awake, RR 14, SpO2 95%. Hour 2: pain 7/10 in the buttock and lateral thigh with any movement. Block still working? How do you tell? Acetaminophen? Dose? Ketorolac? Why/why not? Opioid? Which? Dose? Gabapentin? Why/why not?

Considerations and pitfalls AI draft

DDx. Opioid effect (age, reduced clearance), residual volatile, residual neuromuscular blockade, hypercarbia, atelectasis, pulmonary edema (fluid load), aspiration, residual embolic load after cementing, hypoglycemia, and a stroke (AF, anticoagulation held, intraoperative hypotension). Hypoactive delirium belongs on the list too.
First move. Stimulate, jaw thrust, more oxygen, count the rate; quantitative TOF; ABG for CO2; glucose; a quick neuro exam (pupils, face, limb movement) to look for a focal deficit.
Naloxone. Yes, if opioid effect fits: 20-40 mcg IV every 2-3 minutes to a respiratory rate, not to full wakefulness. A 0.4 mg bolus causes pain, hypertension, and tachycardia, poorly tolerated in an older patient hours after a cementing reaction, and can precipitate pulmonary edema. Watch for re-sedation as naloxone wears off.
Block. Test cold or pinprick over the anterior and lateral thigh. A posterior approach incision and buttock pain fall largely outside fascia iliaca and PENG territory, so pain there does not mean the block failed. Repeating a block in this window adds local anesthetic dose; treat systemically.
Acetaminophen. Scheduled, not as needed: 1 g IV or PO every 8 hours (or 650 mg every 6 hours), keeping her under 3 g/day.
Ketorolac. No. Creatinine clearance about 35 mL/min and rising creatinine, age 84, recent hypotension, an anticoagulant about to restart, and GI bleed risk.
Opioid. Small, titrated doses: hydromorphone 0.2 mg IV every 10 minutes as needed, then oxycodone 2.5-5 mg PO. Avoid morphine (active metabolites build up with renal impairment), tramadol (delirium, seizures, serotonergic), and meperidine. Withholding opioids because she was sedated an hour ago leaves her in pain, which also drives delirium.
Gabapentin. No. In an older patient with cognitive impairment and reduced renal clearance it adds sedation, respiratory depression with opioids, dizziness, and delirium for little analgesic gain.

2. POD 1 morning

POD 1, 0800. Wound dry; Hgb 8.1; creatinine 1.3; HR 96, AF; BP 124/70. The surgeon asks when to restart her apixaban. When? Why? Heparin bridge until then? Why/why not? VTE prophylaxis meanwhile? Drug? Dose? First dose when? Metoprolol: restart today? Dose? Lisinopril? Why/why not? Foley out today? Why/why not? Donepezil: continue? Why/why not?

Considerations and pitfalls AI draft

Restart apixaban. Full dose, 5 mg twice daily (she meets only one dose-reduction criterion, age 80 or older), commonly 48-72 hours after a major orthopedic operation once hemostasis is secure and the hemoglobin is stable. Restarting full dose this morning raises bleeding risk; waiting a week leaves her with high VTE and stroke risk.
Bridge. No. Her CHA2DS2-VASc is 4 (age 75 or older 2, female 1, hypertension 1) with no prior stroke; bridging adds bleeding without reducing stroke over a short gap.
VTE prophylaxis. Yes: hip fracture carries a very high VTE risk. Start 12-24 hours after surgery: enoxaparin 40 mg SC daily (creatinine clearance above 30 mL/min; 30 mg daily below 30), or apixaban 2.5 mg twice daily, or heparin 5000 units SC every 8-12 hours, with mechanical compression. With no neuraxial block or catheter, surgical bleeding sets the timing. Leaving her on compression devices alone without a reason is the flag.
Metoprolol. Restart today, perhaps at a lower dose (25 mg) given yesterday's pressor and anemia; stopping a beta blocker invites rebound tachycardia and AF with rapid rate. Hold parameters for bradycardia and hypotension.
Lisinopril. Hold. Creatinine is rising after a long lie, hypotension, and blood loss; an ACE inhibitor adds hypotension and AKI risk. Restart once she is euvolemic, her pressure has recovered, and creatinine is stable.
Foley. Out today: catheters raise infection and delirium risk and tether her from mobilizing. Retention is common after removal in older patients, so pair removal with bladder scans.
Donepezil. Continue. Stopping it abruptly can worsen cognition and delirium; watch heart rate with the beta blocker.

3. POD 1 night

Foley out at 1000. 0200: pulling at her IV, trying to climb out of bed, says she is at home. Oriented to person and place at 2000. DDx? First things you check? Bladder scan: 800 mL. Rx? Catheterized; still agitated. SpO2 94%, glucose 118, Na 132, afebrile. Haloperidol? Why/why not? Dose? Lorazepam? Why/why not? Restraints? Why/why not? Non-drug measures tonight?

Considerations and pitfalls AI draft

DDx. Hyperactive delirium with a search for the precipitant: urinary retention, pain, hypoxemia or hypercarbia, hypoglycemia, sodium, infection (urine, lung, wound), drugs (opioids, anticholinergics such as diphenhydramine given for sleep), anemia, stroke (AF, anticoagulation held), constipation, sleep loss. A learner who jumps to a sedative before looking for a cause is the flag.
First checks. Vital signs and SpO2, glucose, bladder scan, pain, the medication record for anything new overnight, a focused neuro exam for a new deficit, a look at the wound; a delirium screen (CAM or 4AT) to confirm.
800 mL. Catheterize (straight or indwelling); retention is a common, reversible delirium trigger in older women after hip surgery. Plan repeat scans.
Haloperidol. Only if she is a danger to herself (pulling lines, climbing out of bed on a fresh hemiarthroplasty) and non-drug measures have failed: 0.25-0.5 mg IV or PO, repeated cautiously; check QTc. It calms but does not treat or shorten delirium. Avoid with parkinsonism or suspected Lewy body disease.
Lorazepam. No. Benzodiazepines worsen delirium, sedation, and falls in older patients; the exception is alcohol or benzodiazepine withdrawal, which she does not have.
Restraints. Avoid; physical restraints increase agitation, injury, and delirium duration. A sitter or family at the bedside is better; restraint only as a brief last resort for immediate safety, with frequent review.
Non-drug measures. Reorientation, family presence, glasses and hearing aids, day-night lighting, clustered care to protect sleep, early mobilization with physical therapy, hydration, bowel care, steady pain control, and removing tethers (lines, compression devices at night where safe).

4. POD 2 afternoon

POD 2, 1500. HR 112, AF; BP 98/58. Hgb 7.0 from 8.1. DDx? First thing at the bedside? Left thigh swollen and tense compared with yesterday. Transfuse? Why/why not? How many units? Hgb target? After 1 unit: HR 94, BP 118/64. Rate-control drug now? Why/why not? Her prophylactic anticoagulant is due tonight. Give it? Why/why not? Resume when?

Considerations and pitfalls AI draft

DDx. Bleeding (thigh hematoma; hidden blood loss into the thigh is common after hip fracture surgery), hypovolemia, AF with rapid rate from pain or a beta-blocker gap, sepsis, PE, myocardial ischemia. A falling hemoglobin with tachycardia and a soft pressure points to blood loss first.
First at the bedside. Look at the patient: wound, drain, thigh girth and tension, distal perfusion; ECG; a quick volume assessment; type and crossmatch; repeat hemoglobin, platelets, and coagulation tests; and when her last prophylactic anticoagulant dose was given.
Transfuse. Yes: hemoglobin 7 with tachycardia and a soft pressure in an 84-year-old. Tell the surgeon about the thigh.
How many units. One, then reassess clinically and with a repeat hemoglobin, rather than a reflex two units in an older patient at risk of volume overload.
Hgb target. About 8 g/dL, or resolution of the tachycardia and hypotension. Transfusing to 10 adds overload risk without benefit.
Rate control. Not for most. Treat the drivers first (blood, volume, pain); the rate often falls with them, as it did here. Continue (or resume, if it was held) oral metoprolol once pressure allows. Diltiazem boluses vasodilate and depress contractility in a patient who is still volume-down; amiodarone can convert her to sinus after days off full anticoagulation, with embolic risk, so it is not a casual first choice. Reaching for a rate-control drug while she is bleeding is the flag.
Tonight's dose. Most would hold it with a falling hemoglobin and a tense thigh and use mechanical prophylaxis (on the other leg if the operated thigh is tense). Tell the surgeon; a hematoma that keeps expanding may need evacuation. Giving it reflexively is a flag.
Resume when. Once the hemoglobin is stable for about 24 hours and the thigh is not expanding, with the surgeon's agreement. Her VTE risk is high, so the hold is short and has an end point; stopping all prophylaxis open-ended is the flag.

5. POD 3

POD 3. Hgb 8.2 and stable for 24 hours; thigh unchanged; HR 88. Calm and oriented to person and place by day; confused again last evening. The night team ordered haloperidol 0.5 mg every 12 hours, scheduled. Continue? Why/why not? Oxycodone 5 mg twice overnight; pain 6/10 with physical therapy. Change the analgesic plan? How? Restart her apixaban today? Why/why not? Dose? A rehab bed opens tomorrow. Discharge while still confused at night? Why/why not? Her daughter: 'Did the general anesthesia do this to her? Would a spinal have prevented it?' What will you tell her?

Considerations and pitfalls AI draft

Scheduled haloperidol. Stop. Antipsychotics do not shorten delirium; scheduled dosing adds oversedation, aspiration, QT prolongation, and extrapyramidal effects. At most, a low as-needed dose for danger to herself.
Analgesia. Keep acetaminophen scheduled; give oxycodone 2.5-5 mg 30-45 minutes before therapy rather than only at night; add a bowel regimen (constipation is a delirium precipitant). Undertreated pain drives delirium too; cutting opioids to zero is not the fix.
Apixaban. Defensible either way, with the surgeon's agreement. Hemoglobin stable for 24 hours and a thigh that is not expanding on POD 3 support restarting full dose, 5 mg twice daily; it covers VTE prophylaxis as well, so stop the prophylactic agent and give the first dose when the next prophylactic dose would have been due. Others, a day out from a bleed, resume prophylactic dosing first and step up to full dose in 24-48 hours. Restarting full dose while anything is still changing is the flag.
Discharge. Delirium alone is not a reason to keep a medically stable patient in hospital; rehab with mobilization, routine, and family contact often helps. What goes with her: the delirium, medication changes (haloperidol stopped, lisinopril held), and the apixaban restart date.
What to tell her. Honest and specific: delirium after a hip fracture is common, affecting roughly a quarter to a third or more of older patients, and has many causes stacked together here (age, prior memory problems, the fracture and pain, bleeding, urinary retention, sleep loss in hospital). Spinal anesthesia has not been shown to lower delirium compared with general anesthesia, so a spinal would not reliably have prevented it. Most patients improve over days to weeks, but recovery can be slow and some do not fully return to how they were; her doctor should recheck her memory after she recovers. Explain what helps now (family presence, routine, glasses, sleep). Avoid both defensiveness and promising a full return.

Short stem

Elective total hip arthroplasty under spinal in an obese hypertensive man with suspected OSA

A 66 y.o. man, 5'10", 110 kg (BMI 35), is scheduled for elective right total hip arthroplasty for osteoarthritis, posterior approach in the lateral position. He has hypertension treated with lisinopril and amlodipine and took both this morning; he also takes tamsulosin for benign prostatic hyperplasia and aspirin 81 mg daily. His wife reports loud snoring and pauses in his breathing at night; he has never had a sleep study. He tells you he wants to be "completely out" and does not want a needle in his back. BP 156/88, HR 70, SpO2 95% on room air; Hgb 12.1 g/dL, creatinine 1.0 mg/dL. Mallampati III; neck circumference 45 cm.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Choosing and selling a neuraxial technique for elective hip arthroplasty; proceeding with suspected untreated OSA and planning for it; morning ACE inhibitor, alpha-blocker and the BP on arrival; blood conservation with TXA; an analgesic plan built around walking on the day of surgery.

1. Anesthetic technique

Anesthetic technique for his hip. Spinal or GA? Which? Why? Advantages of each in him? Aspirin this morning. Spinal? Why/why not? He repeats that he wants to be completely out. What will you tell him? He still refuses a needle in his back. Proceed with GA? Why/why not? Assume he agrees to a spinal with sedation. Surgeon estimates 2 hours. Single-shot spinal or CSE? Why? Ultrasound before you start? Why/why not?

Considerations and pitfalls AI draft

Spinal or GA. Either is a legitimate choice for an elective hip; a strong learner picks one and defends it on his features rather than on habit.
Advantages of each. Spinal: avoids instrumenting a Mallampati III airway in a man with probable OSA; less systemic opioid and less PONV. GA: a secured airway for a long lateral case and no block failure, at the cost of the airway risks above. Claiming large mortality differences for elective arthroplasty overstates the evidence.
Aspirin. Aspirin alone is not a contraindication to neuraxial anesthesia (ASRA); stopping it or delaying the spinal for it is the error. The concern rises only if other antithrombotics are added.
What to tell him. He can be asleep or deeply sedated for the operation and remember little; the spinal itself is placed with local and light sedation; explain why it is safer for his airway and breathing. Listening for the fear behind the refusal (needle pain, paralysis, hearing the saw) matters more than reciting benefits.
Refusal persists. A competent patient may decline neuraxial; GA is a safe alternative with an airway plan for probable OSA (positioning, preoxygenation, video laryngoscope, full reversal, awake extubation). Coercing a block is wrong; giving up after one sentence without addressing his concern is weak.
Single shot vs CSE. A single-shot spinal with plain bupivacaine covers about 2 to 3 hours, adequate for a 2-hour primary hip; CSE adds a way to extend if the case runs long, at the cost of a more complex procedure. Either defensible.
Ultrasound. Reasonable at BMI 35, especially when landmarks are hard to feel, to find midline and the interspace and estimate depth; Tuffier's line often sits higher than expected in obese patients.

2. Snoring and witnessed apneas

His wife's report and his exam. Significance? What tells you? Cancel for a sleep study? Why/why not? Airway equipment in the room before he is turned lateral and draped? Same-day discharge? Why/why not? Where does he spend tonight? Monitoring? For how long? CPAP in PACU without a home device? Why/why not?

Considerations and pitfalls AI draft

Significance. Snoring, observed apneas, hypertension, age over 50, neck circumference over 40 cm and male sex put him at high risk on STOP-BANG; a strong learner reaches high risk from his features without needing the acronym read back.
Sleep study. Not required before elective surgery; proceed with presumed moderate to severe OSA and precautions. Postponing every suspected patient for a study is not the standard. Postponement is for an uncontrolled systemic problem (unexplained resting hypoxemia, hypoventilation with elevated bicarbonate or PaCO2, signs of pulmonary hypertension or right heart failure); none is present on the data given.
Equipment. Capnography on the nasal cannula from the start, nasal and oral airways, a supraglottic airway sized and at hand, mask and bag, video laryngoscope, suction; a plan for reaching the face under drapes in lateral.
Same-day discharge. No if he receives intrathecal morphine or is likely to need parenteral opioid. Without them it is debated: ambulatory consensus guidance allows same-day discharge with presumed OSA when comorbidities are optimized and pain can be managed largely without opioids, while many keep an untreated suspected-OSA patient overnight after a hip. Either is defensible if the reasoning is his.
Tonight: where, monitoring, how long. Continuous pulse oximetry (and capnography where available) on a floor or step-down bed; at least 24 h after intrathecal morphine. Recurrent PACU respiratory events (desaturation, apneas, bradypnea) push toward a higher level of monitoring.
CPAP. Reasonable to apply in PACU if he obstructs or desaturates; a respiratory therapist can fit a hospital device. Its absence at home is not a reason to withhold it.

3. Morning medications and arrival BP

His lisinopril. Proceed today? Why/why not? What do you expect from it once the spinal is in? What do you have drawn up? Amlodipine: any change to the plan? Why/why not? Tamsulosin taken this morning. Good or bad? Why? BP repeated in holding: 162/90. Proceed? Treat it before the spinal? Why/why not? Foley for the case? Why/why not?

Considerations and pitfalls AI draft

Proceed. Yes; having taken an ACE inhibitor is not a reason to cancel. Current guidance says holding it for 24 hours may be considered in controlled hypertension to limit intraoperative hypotension; today that option has passed, and the plan is to anticipate it.
Expected effect. Sympathectomy from the spinal plus blunted renin-angiotensin response means deeper and more persistent hypotension, less responsive to phenylephrine alone; most relevant under GA, but still real under a spinal.
Drawn up. Phenylephrine and ephedrine ready, a phenylephrine infusion available; vasopressin available for refractory hypotension.
Amlodipine. Continue; adds vasodilation but no change to the anesthetic plan.
Tamsulosin. Continue; it lowers the risk of urinary retention but adds alpha-blockade, so it contributes to hypotension, especially orthostatic hypotension when he first stands.
BP 162/90. Proceed; elective surgery is commonly deferred only at 180/110 or higher. Aggressively lowering it before a spinal sets up a deeper fall; a reflex beta-blocker or hydralazine dose here is the error.
Foley. Not routinely needed for a 2-hour primary hip; avoiding catheters reduces infection and supports early mobilization. A bladder-scan protocol afterward is the usual plan. Placing one for a long case or a planned high fluid load is defensible.

4. Blood conservation and the analgesic plan

Type and screen or crossmatch? Why? EBL you expect? TXA? Why/why not? Route? Dose? Timing? Post-op analgesia: scheduled agents? Which? NSAID? Why/why not? Which one? Dexamethasone? Why/why not? Dose? Block: suprainguinal fascia iliaca, PENG, surgeon infiltration, or none? Which? Why? Surgeon wants him walking this evening. Does that change your block choice? Why?

Considerations and pitfalls AI draft

T&S vs crossmatch. Type and screen is sufficient for a primary hip in most patients; crossmatch if antibodies are present or blood loss is expected to be high.
EBL. Intraoperative losses of roughly 300 to 1000 mL, with additional hidden loss postoperatively; his mild preoperative anemia lowers his margin.
TXA. Yes; IV TXA 1 g (or about 10 to 20 mg/kg) before incision reduces blood loss and transfusion; topical and oral routes also work. Higher doses and repeat doses add little in hips. Weight-based dosing at 110 kg would exceed the usual 1 g with no proven extra benefit. Contraindications to raise: active VTE or recent arterial thrombosis; a history of VTE or coronary stents warrants individual discussion. None is present here, and aspirin is not a reason to withhold it.
Scheduled agents. Acetaminophen and an NSAID or COX-2 inhibitor are the base; opioids as rescue.
NSAID. Reasonable with a normal creatinine for a short course; ACE inhibitor plus NSAID plus volume shifts raise AKI risk, so watch urine output and creatinine. Celecoxib is a common choice; omitting NSAIDs entirely here is overly cautious.
Dexamethasone. A single IV dose of up to 10 mg improves analgesia and PONV; check glucose if diabetic.
Block choice. Suprainguinal fascia iliaca and preoperative PENG both have support; surgeon periarticular infiltration is reasonable when a block is not done. The added benefit of any block over a good multimodal plan plus infiltration is modest and debated, especially for a posterior approach, whose posterior capsule (sciatic branches) neither block covers. Any choice is fine if defended, including no block.
Walking tonight. Quadriceps weakness and falls are the concern; PENG and infiltration spare motor function better than a fascia iliaca or femoral block. A strong learner links the block to fall risk without being asked.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Placing and dosing the spinal in an obese patient; a partial block and early post-spinal hypotension with bradycardia; lateral positioning and sedation with an obstructing airway; hypotension from blood loss and transfusion endpoints; the receding block at closure, then urinary retention and orthostatic intolerance on the way to walking.

1. Spinal placement

Sitting for the spinal. Sedation for placement? Agent? Dose? Landmarks impalpable. Interspace? Why? Second pass: sharp electric pain down his left leg. Rx? Third pass: free-flowing CSF, no paresthesia. Agent? Plain or hyperbaric? Which? Why? Dose? Intrathecal morphine? Why/why not? Dose? Duration you expect from your dose?

Considerations and pitfalls AI draft

Sedation for placement. Minimal: midazolam 0.5 to 1 mg or fentanyl 25 mcg, titrated; he must stay upright and cooperative. Large doses in a sitting patient with probable OSA risk obstruction and a slumping, uncooperative position.
Interspace. L3-4 or L4-5, below the conus (usually ending at L1-2); ultrasound helps confirm the level because palpated landmarks often lead the needle higher than intended in obese patients.
Electric pain, second pass. Stop, withdraw, redirect; do not inject with a persistent paresthesia or pain on injection. Note it in the record and recheck for a deficit afterward.
Agent and baricity. Plain (isobaric) 0.5% bupivacaine is common for hips; it is slightly hypobaric at body temperature, which suits a lateral position with the operative side up. Hyperbaric bupivacaine is also widely used and gives a more predictable spread; if he is turned lateral before it fixes, it favors the dependent (non-operative) side, so some keep the operative side down briefly or turn him promptly. Either defended choice is fine.
Dose. About 12.5 to 15 mg (2.5 to 3 mL of 0.5%); enough for T10 coverage and about 2.5 to 3 hours. Very low doses risk a block that wears off before closure.
Intrathecal morphine. 100 mcg or less is a reasonable choice for an inpatient and improves early analgesia; with probable OSA it commits him to monitored overnight care. Declining it in favor of a block and multimodal plan is equally defensible; higher doses add side effects without much benefit.
Expected duration. About 2.5 to 3 hours from 12.5 to 15 mg of plain bupivacaine, enough for a 2-hour hip with little margin; a learner should already have a plan for supplementation (surgeon local, ketamine) and for GA conversion in the lateral position if it runs long. A CSE would have been the alternative if a long case was expected.

2. Ten minutes after injection

Supine, 10 min after injection: cold lost to T10 on the left; on the right, cold felt normally above the knee. Interpretation? Wait, reposition, repeat the spinal, or GA? Which? Why? Assume you repeat the spinal. Dose? Concern? Assume instead he is turned left lateral, right side up, and 10 min later the level is T8 bilaterally. BP 84/46, HR 54, nauseated. Of concern? Rx? Phenylephrine? Ephedrine? Which? Why? Fluid bolus? Why/why not? How much? Target BP?

Considerations and pitfalls AI draft

Interpretation. A partial, asymmetric block that spares the operative side; still evolving at 10 minutes. Starting surgery on it is the error.
Options. Giving it a few more minutes and repositioning to favor the right side is reasonable first: right side up if he received plain bupivacaine (slightly hypobaric), right side down if hyperbaric. A clearly failed block after 15 to 20 minutes needs a repeat or GA.
Repeat dose. A repeat spinal is acceptable, but the doses add, so a reduced second dose and close watching for a high block; some prefer GA once the first dose was full. Either defended choice is fine.
Of concern. Hypotension plus relative bradycardia and nausea after a T8 sympathectomy, made deeper by his ACE inhibitor and tamsulosin; nausea is often the first sign of cerebral hypoperfusion.
Phenylephrine vs ephedrine. With HR 54, ephedrine 5 to 10 mg (or glycopyrrolate 0.2 mg / atropine 0.4 to 0.5 mg) treats both rate and pressure; phenylephrine alone can worsen the bradycardia. Phenylephrine is reasonable once HR is adequate. Worsening bradycardia toward asystole needs epinephrine.
Fluid. A modest bolus (about 500 mL) is reasonable; large volumes give little BP benefit after a spinal and add to urinary retention risk.
Target. MAP at least 65 and within about 20% of his baseline; his chronic hypertension argues for the higher end.

3. Lateral position and sedation

Left lateral, BP 118/70, HR 72. Checks before draping? Sedation: agent? Target depth? Assume propofol at 50 mcg/kg/min. Twenty minutes later: snoring, then silence; capnogram flat, chest and abdomen still moving, SpO2 88%. Interpretation? Rx? Jaw thrust and a nasal airway; SpO2 95%, capnogram back. Propofol rate now? Switch to dexmedetomidine? Why/why not? Load? Dose? Supraglottic airway in the lateral position: under what circumstances? How?

Considerations and pitfalls AI draft

Positioning checks. Chest roll under the upper chest, not in the axilla, with the dependent arm checked for pulse and compression; neck neutral, dependent ear and eye free; padding over the dependent fibular head; upper arm supported without overabduction; hip supports clear of the femoral vessels and genitals; nasal cannula with capnography in place and the face reachable.
Sedation. Light propofol or dexmedetomidine titrated to rousable and comfortable, with spontaneous unobstructed breathing; deep propofol sedation in the lateral position with a probable OSA airway is where obstruction happens and rescue is hardest. Earplugs or music reduce the dose needed. Ketamine in small doses is an option.
Interpretation. Upper airway obstruction: chest and abdomen moving with no exhaled CO2 is obstructed breathing, not apnea.
Rx. Stop or reduce the propofol, jaw thrust, nasal airway, raise oxygen, assist with mask if needed; the lateral position helps airway patency.
Propofol rate. Lower (often 20 to 30 mcg/kg/min) or off with intermittent small boluses; accept a patient who hears the saw over one who obstructs. At 110 kg, 50 mcg/kg/min by total weight is 5.5 mg/min (330 mg/h); in obesity many dose sedation by adjusted weight (about 88 kg here) and titrate to effect.
Dexmedetomidine. Less respiratory depression and less obstruction at sedative doses; but a loading dose of 0.5 to 1 mcg/kg over 10 minutes brings bradycardia and hypotension on top of his spinal, so a small or no load and 0.2 to 0.7 mcg/kg/h (by ideal or adjusted weight in him) is reasonable.
Supraglottic airway. When obstruction or hypoxemia persists despite basic maneuvers, or when deeper anesthesia is needed; it can be placed in the lateral position with a slight head tilt and an assistant at the face. Waiting for prolonged desaturation before acting is the error.

4. Ninety minutes in

Ninety minutes in, femoral canal being prepared for an uncemented stem. EBL 900 mL. Assume a phenylephrine infusion is running at 80 mcg/min. BP 82/48, HR 98, SpO2 95%. DDx? Rx? Crystalloid? Colloid? Blood? Which? Why? Venous Hgb 9.6. Transfuse? Why/why not? Threshold in him? Arterial line now? Why/why not? TXA now? Why/why not? After 1 L of LR, BP 108/62 on phenylephrine 30 mcg/min. Hgb you expect tomorrow morning? Why?

Considerations and pitfalls AI draft

DDx. Hypovolemia from surgical and hidden blood loss leads; also spinal sympathectomy plus ACE inhibitor, sedation, and less likely an embolic event with femoral canal instrumentation (a stable SpO2 argues against it). A rising pressor need with tachycardia is bleeding until shown otherwise.
Rx. Tell the surgeon, check the field and suction, give volume, keep the pressor while volume goes in.
Fluid choice. Balanced crystalloid or albumin first for a moderate deficit; blood when Hgb or ongoing loss justifies it.
Transfuse at 9.6. No; he is above threshold, and the response to volume will guide the next step. Transfusing to a number without context is the error.
Threshold. Restrictive strategy: about 8 g/dL after orthopedic surgery or with cardiovascular disease, 7 g/dL in most other stable patients; symptoms, ongoing bleeding, or ischemia change it.
Arterial line. Reasonable if pressor needs keep rising or blood loss continues, for beat-to-beat pressure and sampling; not required if he responds to volume. Either is defensible.
TXA now. If a dose was given before incision, a second dose offers little additional benefit in hips; if none was given, giving it now is reasonable.
Hgb tomorrow. Lower than 9.6, often 1 to 2 g/dL more, from hidden postoperative losses into the thigh and hemodilution; plan a morning check.

5. Closure and recovery

Two hours 30 minutes in, skin closure starting. He groans and says his hip hurts. Level now L2. Rx? Ketamine? Fentanyl? Surgeon local? Which? Why? Dose? Convert to GA? Why/why not? PACU, 3 h after arrival: has not voided, no urge, bladder scan 750 mL. Rx? Straight catheter or indwelling? Why? PT stands him at 6 PM: BP 84/50 from 124/72, lightheaded and sweating. DDx? Rx? Walk him again tonight? Why/why not? What has to be true first?

Considerations and pitfalls AI draft

Rx at closure. Surgeon infiltration of the wound plus ketamine 10 to 20 mg IV increments (about 0.1 to 0.2 mg/kg) is a good combination; small fentanyl doses are acceptable with capnography and attention to his airway. Piling on propofol until he is still is the error.
Convert to GA. Not for 10 to 15 minutes of closure that local and ketamine can cover; convert if pain is uncontrolled or he cannot keep still, with a supraglottic airway or ETT in the lateral position and the probable-OSA airway in mind.
750 mL, no urge: Rx. Male sex, age, BPH, spinal anesthesia, intrathecal opioid (if given) and fluid all contribute; 750 mL with no urge needs drainage now to protect the bladder.
Straight vs indwelling. Intermittent straight catheterization is preferred; an indwelling catheter if retention recurs; continue tamsulosin.
Standing at 6 PM: DDx and Rx. Hypovolemia and anemia, residual sympathetic block, tamsulosin and ACE inhibitor, opioids, vasovagal response; check Hgb and the block, lie him down, give fluid, retry later. Standing him again immediately without a cause is the error.
Walk again tonight. Only once he is supine-normotensive after volume, the block has fully regressed (motor and sympathetic), Hgb is known and acceptable, and he can sit and dangle without symptoms; otherwise first mobilization moves to the morning. Pushing a second attempt on the schedule alone is the error, as is cancelling mobilization altogether for one orthostatic episode.

Non-perioperative

PACU agitated emergence, PONV, and hypotension after laparoscopic hysterectomy

A 68 y.o., 70 kg, 160 cm woman arrives in the PACU after an elective total laparoscopic hysterectomy and bilateral salpingo-oophorectomy for atypical endometrial hyperplasia. She is booked for same-day discharge.

PMHHypertension. Severe nausea and vomiting for a full day after an open appendectomy 15 years ago; lifelong motion sickness. Never smoker. Osteoarthritis of both knees. Bilateral hearing aids, removed in preop holding and given to her husband in the waiting room. Lives with her husband, fully independent, no memory complaints. One glass of wine a week.

MEDSLisinopril 20 mg and hydrochlorothiazide 25 mg daily, both taken at 6 AM today. Acetaminophen as needed.

PREOP LABSHgb 13.4 g/dL; Na 138; K 3.6; creatinine 0.9 mg/dL; glucose 104.

INTRA-OPERATIVE COURSEMidazolam 2 mg IV in preop holding for anxiety. Induction with propofol 120 mg, fentanyl 100 mcg, rocuronium 40 mg; easy mask ventilation, grade 1 view. Cefazolin 2 g before incision. Foley catheter placed after induction and removed in the OR at the end of the case. Steep Trendelenburg. Maintenance with sevoflurane in air/oxygen. Dexamethasone 4 mg after induction; ondansetron 4 mg at closure. Total fentanyl 200 mcg; hydromorphone 0.6 mg in the last 20 minutes; acetaminophen 1 g IV. Port sites infiltrated with 20 mL bupivacaine 0.25%. Orogastric tube suctioned and removed. Sugammadex 140 mg at a train-of-four count of 2; extubated awake in the OR. Duration 130 minutes. LR 1.5 L; EBL 100 mL.

PACU ARRIVALThrashing on the stretcher, pulling at the face mask and IV, speech garbled, not following commands. HR 116; BP 172/96; RR 24; SpO2 93% on 6 L face mask; T 36.1 C.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PATIENT ASSESSMENT ON ARRIVAL

Teaching focus. Sorting an agitated emergence by what can hurt her fastest; finding the bedside cause before reaching for a sedative; opioid titration to a safe end point in an older patient; recognizing and managing delirium in the PACU; first-line PONV rescue after failed two-agent prophylaxis.

1. Agitated on arrival

The nurse cannot keep the BP cuff on her arm. First priorities? Two nurses at the bedside, IV taped, rails up. DDx? Which do you exclude first? How? Assume a jaw thrust: SpO2 97%, chest rising, regular end-tidal CO2 waveform on the mask, RR 22. Next? Glucose 132. The nurse asks for midazolam 1 mg to settle her. Give it? Why/why not? Soft wrist restraints? Why/why not? Fentanyl 25 mcg now? Why/why not?

Considerations and pitfalls AI draft

First priorities. Safety and oxygenation together: hands on to protect the IV and keep her on the stretcher, monitors on, airway patency and ventilation checked first. A strong answer starts with the airway and breathing, not with a sedative.
DDx. Hypoxemia and hypercarbia (airway obstruction from residual anesthetic, atelectasis after pneumoperitoneum and steep Trendelenburg), residual neuromuscular blockade (a weak, frightened patient can look agitated), pain, bladder distension (less likely with the catheter just out, but it belongs on the list), hypoglycemia, hypotension or hypoperfusion, emergence delirium (benzodiazepine premedication, volatile, age, hearing aids out), hypothermia, electrolyte disturbance, withdrawal (her alcohol intake makes this unlikely), stroke (look for focal signs).
Exclude first. The fast killers: airway obstruction, hypoxemia, hypercarbia; then glucose and blood pressure. Look, listen, SpO2, capnography, chest movement; ABG only if ventilation stays in doubt.
After jaw thrust. She had partial obstruction from residual anesthetic and opioid; oxygenation and ventilation are now adequate, so look for the remaining bedside causes (pain, bladder, weakness). Sugammadex 2 mg/kg at a count of 2 is the labeled dose for that depth, so residual blockade is unlikely; look at the quality of her movement and grip, and check TOF if anything looks weak.
Midazolam. No. A 68-year-old who already had preop midazolam is at risk for delirium, and a benzodiazepine worsens it, stacks with opioid respiratory depression, and hides whatever is driving the agitation. Sedating before finding the cause is the flag.
Restraints. Avoid if staff can keep her safe; restraints raise agitation and injury risk. Brief hands-on holding for safety is acceptable while the cause is found.
Fentanyl 25 mcg. Defensible once airway and ventilation are confirmed, since pain after laparoscopy is likely. Giving opioid into unrecognized hypoxemia or hypercarbia is the error; treating every agitated emergence as pain misses the bladder and the delirium.

2. Moaning and reaching for her abdomen

Airway open, SpO2 96% on the mask. She moans and pushes your hand away from her lower abdomen; port sites dry, upper abdomen soft. Next? Bladder scan 70 mL. Interpretation? She says her belly and right shoulder hurt, 7/10. Rx? Agent? Dose? Morphine? Why/why not? Ketorolac? Why/why not in her? Assume three doses of hydromorphone 0.2 mg: pain 3/10, RR 10, eyes closing between sentences, SpO2 94% on 2 L nasal cannula. Next? End point for further opioid?

Considerations and pitfalls AI draft

Next. Examine the abdomen and scan the bladder; lower abdominal and pelvic pain is expected after a hysterectomy, but a full bladder, a port-site or pelvic bleed, and peritoneal irritation are the things to exclude at the bedside.
Bladder 70 mL. Retention is excluded for now: the Foley came out minutes ago, so the bladder has not had time to refill. The question comes back hours later, before discharge, after pelvic surgery, opioids, and more fluid. Soft upper abdomen and dry port sites point to incisional and visceral pain.
Pain Rx. Titrated IV opioid: hydromorphone 0.2 mg or fentanyl 25 mcg every 5-10 minutes in a 68-year-old, reassessing pain, sedation, and RR before each dose. Shoulder pain is referred from CO2 under the diaphragm; it responds to time and analgesia, but a hypertensive 68-year-old with new shoulder pain deserves a moment's thought about cardiac pain if the story does not fit.
Morphine. Acceptable with normal renal function, but slower onset makes PACU titration harder, and it carries more histamine release and nausea; hydromorphone or fentanyl titrate more cleanly.
Ketorolac. A reasonable opioid-sparing adjunct after a laparoscopic hysterectomy, at 15 mg IV given her age; concerns are the ACE inhibitor plus thiazide (renal risk if she becomes hypovolemic) and bleeding from the pelvic pedicles or vaginal cuff, so many check with the surgeon. A reflexive 30 mg dose in a 68-year-old on these drugs is the flag.
RR 10, drowsy. Stop further opioid, keep her stimulated, supplemental oxygen, close observation with continuous SpO2 and capnography. Naloxone in small increments (40 mcg) only if she becomes hard to rouse, RR falls further, or SpO2 drops; a full dose brings back pain and agitation.
End point. Tolerable pain with her rousable to voice and breathing adequately, not a pain score of zero. Sedation is the earliest warning; RR and SpO2 fall later.

3. Calmer but still disoriented

Forty minutes in: pain controlled, RR 14, SpO2 96% on 2 L, BP 150/86. She thinks she is in her kitchen, picks at the IV, and cannot say why she is here. Of concern? Possible causes? What do you check? Glucose 142, normothermic, moves all four limbs, face symmetric. Rx? She stands, pulls out the IV, and swings at the nurse. Rx now? A new IV is placed. Haloperidol? Dexmedetomidine? Which? Dose? Why that one? Physostigmine? Why/why not? Assume dexmedetomidine 0.3 mcg/kg given slowly. She settles. How do you decide she is back to baseline?

Considerations and pitfalls AI draft

Of concern. Delirium: acute inattention and disorientation after the reversible causes have been treated or excluded (airway, pain, bladder). In an older patient it is a medical problem in its own right, not a behavioral one, and it predicts a longer stay and later complications.
Possible causes. Age, the preop midazolam, residual volatile and opioid, hearing loss with her hearing aids out, an unfamiliar loud environment, and any recurrence of pain, hypoxemia, or a refilling bladder.
Checks. Repeat SpO2 and capnography, glucose, BP, temperature, a quick neuro exam for focal signs; bladder again if time has passed; electrolytes if the picture does not settle. A focal deficit changes the problem.
Rx. Hearing aids back in, glasses if she uses them, husband at the bedside, calm reorientation, fewer alarms and fewer staff talking at once, treat pain. These are first-line and they work; reaching for a drug at this point, while she is calm enough to reorient, is the flag.
Rx now / which. Hands on and enough staff to keep her and the nurse safe first; drug only for danger to herself or staff, and an IV drug needs a new IV. Dexmedetomidine 0.2-0.5 mcg/kg slowly (watch for bradycardia and hypotension) calms without suppressing respiration. Haloperidol 0.5-1 mg IV is an option for dangerous agitation in an older adult (QT, extrapyramidal effects); it controls behavior but does not shorten delirium. A small propofol dose (10-20 mg) buys minutes of safety, not a solution. Benzodiazepines are out.
Physostigmine. No. It treats central anticholinergic syndrome; she received no scopolamine, atropine, or high-dose antihistamine (sugammadex needs no glycopyrrolate), and physostigmine brings bradycardia, bronchospasm, and seizure risk without an indication.
Back to baseline. Oriented and attentive on a formal bedside screen (a CAM or 4AT, months of the year backward), and her husband says she is herself. Calm alone is not the same as cleared.

4. Retching at one hour

One hour in: oriented, pain 3/10, BP 138/80, HR 92. She retches and vomits 150 mL of bilious fluid. First move? DDx? The prophylaxis she received: enough for her? Why/why not? Ondansetron 4 mg again? Why/why not? Dexamethasone again? Why/why not? Rescue agent? Dose? Promethazine? Why/why not in her? K 3.2. Changes your choice? Why?

Considerations and pitfalls AI draft

First move. Sit her up or turn her to the side, suction, oxygen, check BP and HR; she was drowsy an hour ago and the airway comes first.
DDx. PONV, hypotension, hypoxemia, pain, opioid effect, gastric distension or swallowed blood, vestibular stimulation with movement, anxiety; later, a surgical cause (ileus, unrecognized bowel injury) if it persists.
Prophylaxis. Not enough. Female, non-smoker, prior PONV and motion sickness, and postop opioids give her four risk factors (roughly 80% risk), plus a volatile anesthetic and laparoscopic gynecologic surgery. Consensus guidance calls for three to four interventions with more than two risk factors; she got two. Options were TIVA, a third agent, and more opioid sparing.
Ondansetron again. No. A repeat dose of a 5-HT3 antagonist within about 6 hours of prophylaxis adds little; rescue uses a different class.
Dexamethasone again. No. Its onset takes hours and its role is prophylaxis; a second dose adds glucose and no rescue effect.
Rescue. A dopamine antagonist is the usual next class: amisulpride 10 mg IV, haloperidol 0.5-1 mg IV, or droperidol 0.625 mg IV (boxed QT warning). Metoclopramide 10 mg is weak. An antihistamine is another class but carries the problems below.
Promethazine. A poor choice in her: anticholinergic and sedating in a 68-year-old who was just delirious, and the IV route carries a boxed warning for tissue injury. If used at all, 6.25 mg.
K 3.2. A thiazide plus vomiting. Ondansetron is already on board and the dopamine antagonists prolong QT, so replete potassium, check magnesium, and look at a 12-lead QTc before stacking QT drugs. It does not rule out a dopamine antagonist; it sets the conditions for giving one.

B. COMPLICATION MANAGEMENT AS SCENARIO EVOLVES

Teaching focus. Refractory PONV after three classes and what it says about the anesthetic plan; the DDx and stepwise treatment of PACU hypotension, including how to decide she is not bleeding; applying discharge criteria to a patient who has had a rough recovery; explaining delirium to the patient and planning her next anesthetic.

1. Vomiting again after rescue

Assume amisulpride 10 mg IV after potassium replacement. Twenty minutes later she vomits twice more. Next? Amisulpride again? Why/why not? Next agent? Which class? Dose? Propofol 20 mg? What does it buy? Scopolamine patch now? Why/why not? Gastric tube? Why/why not? Hydromorphone PRN is still on the order set. Keep it? Why/why not? Could you have prevented this? How?

Considerations and pitfalls AI draft

Next. Reassess before the next drug: BP, SpO2, pain, abdominal exam, how much opioid she has had. Vomiting that persists after three classes deserves a look for a cause, not only another antiemetic.
Amisulpride again. No; a repeat of the same class this soon adds little.
Next agent. Few good options remain, which is the lesson. An antihistamine (dimenhydrinate or low-dose promethazine) is a different class but anticholinergic and sedating in a recently delirious 68-year-old; a low-dose propofol bolus or brief infusion in a monitored setting is another. Ondansetron can be repeated once 6 hours have passed.
Propofol. 10-20 mg gives short-lived relief, minutes to perhaps an hour; useful as a bridge, not a plan, and it sedates.
Scopolamine. No in her: onset takes hours, and its anticholinergic central effects (confusion, delirium, urinary retention) are exactly what she has already had today.
Gastric tube. Only if there is distension or the vomiting is from a full stomach; it was suctioned in the OR, and an NG tube is miserable and not a routine PONV treatment.
Hydromorphone PRN. Minimize it: pain is 3/10, and opioid is a driver of both nausea and the delirium. Scheduled acetaminophen, ketorolac if the surgeon agrees and her volume is restored, ice, and reassurance; opioid only for pain that the rest does not cover.
Prevented. TIVA with propofol instead of sevoflurane, a third (or fourth) prophylactic agent from another class (amisulpride, an NK1 antagonist), and a more opioid-sparing plan. Her history predicted this. Skipping the midazolam was the right call for her delirium risk, but it is not a PONV measure; midazolam, if anything, slightly reduces PONV.

2. Lightheaded while sitting up

Ninety minutes in, sitting up to vomit: lightheaded, pale, BP 84/48, HR 108, SpO2 95% on 2 L. Of concern? First move? DDx? Most dangerous in her? Fluid? Crystalloid or colloid? How much? How fast? Phenylephrine or ephedrine while it runs? Why? 500 mL LR in: BP 92/54, HR 104. Enough? Why/why not?

Considerations and pitfalls AI draft

Of concern. A 68-year-old with chronic hypertension and a MAP near 60 is under-perfused relative to her baseline; the tachycardia says this is not just a vasovagal moment.
First move. Lay her flat with legs raised, oxygen, recheck the cuff and the IV (it was replaced after she pulled it), open the fluid, call for help.
DDx. Hypovolemia (NPO, vomiting, a morning thiazide, modest intraop fluid); surgical bleeding (uterine artery or infundibulopelvic pedicles, vaginal cuff, inferior epigastric vessels at a port site); vasodilation (ACE inhibitor taken this morning, dexmedetomidine, opioid, residual volatile); cardiac (ischemia, arrhythmia); anaphylaxis (any antibiotic given, rocuronium, sugammadex); PE; pneumothorax after laparoscopy; vagal response to vomiting.
Most dangerous. Bleeding after a laparoscopic hysterectomy; it can be concealed in the pelvis and abdomen with a soft-looking exam early. Ischemia and anaphylaxis are the other two to exclude quickly.
Fluid. Balanced crystalloid, 250-500 mL rapidly, then reassess; no reason for albumin or blood yet.
Pressor. Phenylephrine 50-100 mcg is the cleaner choice with HR 108; ephedrine adds more tachycardia. A pressor bridges while the volume runs; it is not the treatment for hypovolemia or bleeding.
Enough. No; a small rise with persistent tachycardia means the cause is not yet fixed or not yet known. That moves the question to how you find it.

3. Pressure still low after the first bolus

Abdomen soft, mildly distended, tender at the port sites and low pelvis; dressings dry; scant vaginal spotting on the pad. No rash, no wheeze. 12-lead: sinus tachycardia, no ST changes. Hgb 12.1. Bleeding? What tells you? POCUS: IVC 1.0 cm, collapses more than 50% with sniff; hyperdynamic LV; no free fluid in the pelvis or Morison's pouch. Interpretation? Rx? Assume a second 500 mL LR: BP 114/66, HR 88. Cause in her? Troponin? Why/why not? Lisinopril tomorrow morning? Why/why not? The gynecologic surgeon asks whether she needs to go back to the OR. Your answer? What finding would change it?

Considerations and pitfalls AI draft

Bleeding. Not proven either way by one number. A fall of about 1.3 g/dL after 2 L of crystalloid fits dilution; a repeat Hgb in 1-2 hours, serial abdominal exams, the trend in HR, and POCUS for free fluid decide it. Calling her bleeding on this value alone is as much an error as dismissing it.
POCUS. A small, collapsing IVC with a hyperdynamic LV and no free fluid in the pelvis or hepatorenal space points to a volume-responsive, low-preload state without a large hemoperitoneum. A thin rim of pelvic fluid after laparoscopic irrigation is common and would not by itself mean bleeding; a large or growing collection would. A small bleed can still be missed by one scan; repeat it if the picture changes.
Rx. More crystalloid in 500 mL steps to a response, stop or hold anything adding vasodilation (no more dexmedetomidine), antiemetic control so she stops losing fluid.
Cause. Hypovolemia from NPO, vomiting, and the thiazide, unmasked by the morning ACE inhibitor and residual vasodilators. The response to fluid supports it.
Troponin. Reasonable in a 68-year-old hypertensive who was hypotensive and tachycardic, even with a clean ECG, because perioperative myocardial injury is usually silent; not required if the episode was brief and fully explained, and defensible either way with a reason.
Lisinopril. Hold tomorrow's dose (and the thiazide) until she is eating, drinking, and normotensive; restart once volume is back.
Surgeon. Not now: she responded to fluid, the abdomen is soft, and there is no free fluid. Say what would change it: Hgb falling on repeat, recurrent hypotension or rising HR despite fluid, new free fluid, a tense abdomen, or brisk vaginal bleeding. Confirm a current type and screen so the answer can change quickly.

4. Three and a half hours in the PACU

Three and a half hours in: BP 124/70, HR 82, SpO2 95% on room air, pain 3/10, no nausea for 2 hours, oriented, walking with help. Last hydromorphone 3 hours ago. She has not voided since the Foley came out at the end of surgery. Her husband asks to take her home. Ready to leave phase I? Why/why not? Must she void first? Why/why not in her? Must she drink first? Why/why not? Bladder scan 520 mL; she tries and cannot void. Next? Home today or overnight stay? Why? Assume she stays overnight. Orders for tonight: analgesia? Antiemetic? Fluids?

Considerations and pitfalls AI draft

Phase I. Yes by the usual scored criteria: awake and oriented, stable vital signs near baseline, oxygenating on room air, pain and nausea controlled, no active bleeding concern. No mandatory minimum stay is required once she is no longer at risk of cardiorespiratory depression; 3 hours since the last opioid is ample.
Void first. Not a routine requirement for every ambulatory patient, but yes in her: pelvic surgery with dissection off the bladder, a catheter just removed, opioids, age, and a large fluid load are the setting for retention, and most same-day hysterectomy pathways require a voiding trial before discharge.
Drink first. Not a routine requirement; tolerating fluids helps here only because she has been vomiting and is on a diuretic.
520 mL, cannot void. That is retention after about 3.5 hours of filling on 2.5 L of crystalloid. Straight catheterize and repeat the trial, or place an indwelling catheter; after hysterectomy many gynecology services send the patient home with a Foley and a clinic voiding trial in a few days rather than admitting for retention alone. Leaving her to strain at 520 mL is the flag.
Home vs overnight. Either can be defended if reasoned, but she had delirium, PONV through three drug classes, fluid-responsive hypotension, and a failed voiding trial. An overnight stay is the safer default; sending her home on the original plan because the booking said same-day is the flag. If she does go, she needs a responsible adult with her overnight and clear return criteria.
Orders. Scheduled acetaminophen, ketorolac if the surgeon agrees and volume is restored, low-dose oral opioid only as needed; an antiemetic from a class she has not just had, with ondansetron again after 6 hours; maintenance fluid until she drinks; hold lisinopril and the thiazide; bladder scans with a catheter threshold; delirium precautions (hearing aids in, husband present, lights and sleep, no benzodiazepines).

5. Questions the next morning

Next morning: oriented, eating, voided, BP 132/78. She asks why she 'went crazy' waking up, and whether it means dementia is starting. What will you tell her? She will need a knee replacement next year. Premedication next time? Why/why not? Maintenance agent? Why? PONV prophylaxis: how many agents? Which? Opioid plan? Same-day discharge? Why/why not?

Considerations and pitfalls AI draft

What to tell her. Plainly: she had delirium on waking, which is common in her age group after anesthesia and was likely brought on by the sedative before surgery, the anesthetic and pain medicines, pain on waking, and not having her hearing aids. It cleared. It does not mean she has dementia; it is a sign her brain is more sensitive to these drugs, and some people who have it are at higher risk of memory problems later, which is worth mentioning to her primary care doctor. No false reassurance and no alarm.
Premedication. No benzodiazepine; reassurance, her husband present in preop, and hearing aids kept in until induction if possible.
Maintenance. Propofol TIVA, which lowers PONV risk; she is the patient it is for.
Prophylaxis. Three to four agents from different classes for four risk factors: dexamethasone, a 5-HT3 antagonist, a dopamine antagonist (amisulpride) or an NK1 antagonist, plus TIVA. Avoid scopolamine given her delirium.
Opioid plan. Opioid sparing: regional or periarticular analgesia for the knee, scheduled acetaminophen, NSAID if renal function and volume allow, and minimal intraoperative long-acting opioid.
Same-day. A reasonable question to raise early with the surgeon; her history of delirium, PONV, and retention argues for planning an overnight stay rather than discovering the need in the PACU.

Non-perioperative

Hypoxemia in PACU after laparoscopic sleeve gastrectomy in a patient with severe OSA

A 58 y.o., 128 kg, 175 cm man (BMI 42) arrives in the PACU after elective laparoscopic sleeve gastrectomy under general anesthesia. He is booked for a regular surgical floor bed overnight.

HPIObesity since his twenties; BMI 42 despite a supervised weight-loss program. Completed multidisciplinary bariatric evaluation. Two-week low-calorie liquid diet before surgery.

PMHSevere obstructive sleep apnea (AHI 38 on a sleep study two years ago), on CPAP at 11 cm H2O nightly with good adherence. Hypertension. Type 2 diabetes (HbA1c 7.6%). No prior anesthetic problems.

MEDSLisinopril, metformin, atorvastatin. Metformin and lisinopril held this morning.

PRE-OP EXAMMallampati 3, neck circumference 47 cm, full dentition. Lungs clear. SpO2 97% on room air.

INTRA-OPERATIVE COURSEAprepitant 40 mg PO in pre-op holding. Ramped and preoxygenated. Propofol, fentanyl, rocuronium 50 mg; video laryngoscopy, grade 1 view, first pass. Sevoflurane maintenance. Rocuronium redosed 20 mg at 1 hour. Pneumoperitoneum to 15 mmHg in steep reverse Trendelenburg. Orogastric tube fully removed before stapling; calibration bougie passed by anesthesia, held in place during stapling, then withdrawn; leak test negative. Volume control, Vt 500 mL, PEEP 5. Fentanyl 250 mcg and hydromorphone 1.5 mg in total, the last hydromorphone dose (0.5 mg) during closure. Acetaminophen 1 g IV, dexamethasone 4 mg after induction, ondansetron 4 mg at closure; surgeon infiltrated the port sites with bupivacaine. Surgical time 100 minutes. At closure, TOF count 2 of 4 by visual assessment at the ulnar nerve; neostigmine 4 mg with glycopyrrolate 0.8 mg given. Extubated awake 10 minutes later after a sustained 5-second head lift.

PACU ARRIVALDrowsy but rousable to voice, snoring. Face mask at 6 L/min. HR 92, BP 148/86, RR 10, SpO2 93%, T 36.4 C. Pain 3/10 when roused.

LABSPre-op: Hgb 13.8 g/dL, creatinine 0.9 mg/dL, K 4.1 mEq/L, glucose 168 mg/dL.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PATIENT ASSESSMENT ON ARRIVAL

Teaching focus. The first minutes in PACU for a patient with OSA: relieving upper-airway obstruction and starting positive pressure; sorting the causes of hypoxemia with exam and an ABG; finding and treating residual neuromuscular blockade with a quantitative monitor; opioid-induced ventilatory depression and naloxone titration.

1. Arrival from the OR

OR team gives report at the bedside. What do you check yourself before they leave? Oxygen: face mask? Nasal cannula? Which? Why? Position him how? Why? Five minutes later, asleep: SpO2 85%, chest and abdomen rocking, no airflow at the mask. Rx? Jaw thrust restores airflow; airflow stops each time you let go. Oral airway? Nasal airway? Which? Why? His own CPAP machine came with him. Put it on now? Why/why not? Pressure? SpO2 96% on CPAP, then he wakes coughing and pulls the mask off. Next?

Considerations and pitfalls AI draft

Bedside check. Airway patency and breathing pattern (snoring, paradox), RR and depth, SpO2 with a clean waveform, capnography by nasal or mask sampling if available, arousal, pupils, grip and head lift. From the OR team: OSA severity and home CPAP pressure, ease of mask ventilation and the intubation, opioid doses and timing, the relaxant, the last dose, the reversal and how depth was judged, PONV prophylaxis, and the planned disposition.
Oxygen. Face mask or nasal cannula to a modest SpO2 goal. Supplemental oxygen raises the number but delays the oximeter's warning of hypoventilation; RR, arousal, and CO2 carry the information.
Position. Head of bed up 30 to 45 degrees, or lateral; supine positioning worsens both obstruction and FRC loss in obesity. Leaving him flat and asleep is the setup for what follows.
Obstruction. Chest and abdomen moving in opposition with no airflow is obstruction. Jaw thrust and chin lift, call for help if not relieved, bag-mask with PEEP if he desaturates further. A strong learner names obstruction and acts in seconds.
Oral vs nasal airway. A lubricated nasal airway sized nares to tragus is tolerated by a semi-awake patient; an oral airway in a patient this awake provokes gagging, laryngospasm, or vomiting. Epistaxis is the nasal risk.
CPAP. Yes: a CPAP user who obstructs in PACU should be on CPAP now, not after he 'wakes up more.' Start at his home pressure and titrate up if he still obstructs; his own mask usually fits and is tolerated best; bleed in oxygen to target. A surgeon's worry that CPAP will stress the sleeve staple line is not a reason to withhold it; CPAP has not been shown to increase staple-line or anastomotic leak after bariatric surgery.
Pulls it off. Ask why before reapplying: air hunger from weakness, hypercarbia, hypoxemia, pain, nausea, or a poor fit. Coach, sit him up, reapply. Sedating him to tolerate the mask, or abandoning CPAP for a non-rebreather, are the errors.

2. Desaturation on CPAP

Assume he is back on CPAP, head up. Twenty minutes later: SpO2 88% with FiO2 0.5 through the CPAP, RR 22 and shallow. DDx? Most likely in him? Breath sounds decreased at both bases, no wheeze, no crackles. ABG on FiO2 0.5: pH 7.28, PaCO2 56, PaO2 61. A-a gradient? Interpretation? CXR now? Why/why not? CXR: low lung volumes, bibasilar atelectasis, no pneumothorax, no infiltrate. Explains the ABG? Why/why not? What else do you examine? Why?

Considerations and pitfalls AI draft

DDx. Hypoventilation (opioid, residual neuromuscular blockade, residual volatile, obstruction), V/Q mismatch and shunt (atelectasis from obesity, pneumoperitoneum, low PEEP, and supine positioning; aspiration; pulmonary edema, including negative-pressure edema after obstruction; bronchospasm), and less likely PE, pneumothorax, or an oxygen delivery problem.
Most likely. Atelectasis and hypoventilation together, in an obese man with OSA after laparoscopic upper-abdominal surgery. Settling on one cause and stopping is the trap.
A-a gradient. At sea level, PAO2 = 0.5 x 713 - 56/0.8 = 357 - 70 = about 287; A-a gradient about 225 mmHg (under 20 would be normal on room air at his age, and even on FiO2 0.5 a normal lung stays well under 100). Hypoventilation alone cannot produce this; there is a large shunt or V/Q component on top of the hypercapnia.
Interpretation. Acute respiratory acidosis (a 16 mmHg rise predicts a pH near 7.27, consistent) plus a large oxygenation defect. Two problems, two treatments.
CXR. Yes, portable and fast; it rules out pneumothorax, aspiration, and edema without delaying treatment.
Explains the ABG. No; atelectasis explains the oxygenation, not a PaCO2 of 56 with shallow breathing. A strong learner goes looking for a ventilatory cause: strength, sedation, pupils, airway. Attributing all of it to OSA or atelectasis is the miss.

3. Restless and short of breath

He is restless and says he cannot get a full breath. Eyelids droop, grip is weak, he cannot lift his head off the pillow. Of concern? How do you confirm it? Quantitative monitor at the adductor pollicis: TOF ratio 0.62. Interpretation? The head lift in the OR: how did he pass it? Rx? More neostigmine? Why/why not? Sugammadex? Dose? On which weight? Assume sugammadex. Two minutes later: TOF ratio 0.96, he lifts his head and takes a deep breath, SpO2 94%. Could this have been prevented? How?

Considerations and pitfalls AI draft

Of concern. Residual neuromuscular blockade: ptosis, weak grip, no head lift, and shallow rapid breathing with a sense of air hunger. Pharyngeal weakness at these levels also worsens upper-airway obstruction and aspiration risk. Calling this anxiety, or treating it with a benzodiazepine, is the dangerous answer.
Confirm. Quantitative TOF at the adductor pollicis. Visual or tactile fade cannot be detected once the TOF ratio is above about 0.4, so 'four twitches, no fade' never excludes residual block.
TOF ratio 0.62. Incomplete recovery (target at least 0.9); minimal-depth block by current definitions.
The OR head lift. A 5-second head lift can be sustained at TOF ratios around 0.5; clinical tests are insensitive, and guidelines recommend against clinical assessment alone. Neostigmine given at a TOF count of 2 (moderate block), with only 10 minutes to extubation, was unlikely to restore a ratio of 0.9.
More neostigmine. No; 4 mg is about 0.03 mg/kg and the ceiling is 0.07 mg/kg or 5 mg, whichever is less. Acetylcholinesterase inhibition has a ceiling, so more drug adds little and slowly in a hypercapnic, hypoxemic patient.
Sugammadex. Yes; it works regardless of the earlier neostigmine. With T2 well past reappearance, the label dose is 2 mg/kg on actual body weight: 2 x 128 = 256 mg. Dosing on ideal body weight (about 70 kg, 140 mg) underdoses, and lower-than-recommended doses carry a risk of recurrent block. Watch for bradycardia and, rarely, anaphylaxis.
After reversal. Confirm the TOF ratio of at least 0.9 quantitatively; any hypercapnia that persists now needs another explanation.
Prevention. Quantitative monitoring at the adductor pollicis throughout; at a TOF count of 2, sugammadex 2 mg/kg rather than neostigmine (neostigmine is a reasonable choice only at minimal depth, TOF ratio 0.4 to 0.9); extubation only after a measured TOF ratio of at least 0.9; rocuronium dosed to ideal body weight and no late redose without a plan to reverse it.

4. Asleep mid-sentence

Ten minutes later: strong grip, easy head lift, but he drifts off mid-sentence. RR 7, pupils pinpoint, SpO2 90% on CPAP, repeat PaCO2 63. Most likely cause? Anything you check before you treat? Fingerstick glucose 154. Naloxone? Why/why not? Dose? How do you give it? 40 mcg, then 40 mcg two minutes later: awake, RR 14, SpO2 95%, pain 4/10. Stop there? Why? How long do you keep him in PACU? Why that long? Watching for what?

Considerations and pitfalls AI draft

Most likely. Opioid-induced ventilatory depression: slow RR, miosis, and a rising CO2 with strength now recovered. Patients with OSA are more sensitive to opioids, and the drive to breathe from discomfort and weakness has just been removed. Rising CO2 also sedates, which worsens the obstruction and the hypoventilation.
Check first. Airway patency, a repeat TOF ratio (recurrence after a label dose of sugammadex is unlikely but cheap to exclude), glucose in a diabetic, and a quick neuro exam for anything focal.
Naloxone. Yes; RR 7 with a PaCO2 in the 60s and a sedation level that lets him obstruct is beyond what stimulation and CPAP will fix.
Dose and technique. Dilute 0.4 mg in 10 mL (40 mcg/mL) and give 40 mcg IV every 2 to 3 minutes to RR and arousal. A 0.4 mg bolus is the flag: abrupt pain, hypertension, tachycardia, arrhythmia, vomiting, and pulmonary edema.
Stop there. Yes; the endpoint is adequate ventilation and arousal with analgesia preserved, not a wide-awake patient in pain.
Why that long. Naloxone lasts roughly 30 to 90 minutes; hydromorphone's effect lasts 2 to 4 hours. Re-sedation is expected unless the opioid effect wanes first.
How long in PACU. At least two hours after the last naloxone dose, and through a period of unstimulated sleep, watching RR, apneas, SpO2 off stimulation, sedation score, and CO2. Sending him on at the moment he looks awake is the error.

B. COMPLICATION MANAGEMENT AS SCENARIO EVOLVES

Teaching focus. Treating postoperative atelectasis and choosing a positive-pressure mode and target; opioid-sparing analgesia in a patient with OSA who has needed naloxone; recurrent ventilatory depression and the reintubation decision; disposition after PACU respiratory events; what to tell him about what happened.

1. Oxygen requirement at hour 1.5

Hour 1.5: awake, RR 18, SpO2 91% on CPAP with FiO2 0.5. On 4 L nasal cannula he drops to 86% within five minutes. Keep him on CPAP? Raise the pressure? To what? Raise the FiO2 instead? Why/why not? High-flow nasal cannula? BiPAP? Which? Why? Assume CPAP: at 14 cm H2O, SpO2 95% on FiO2 0.4. Anything else for the atelectasis? What? Target SpO2? Why that number? When do you try him off?

Considerations and pitfalls AI draft

CPAP. Yes; atelectasis responds to positive end-expiratory pressure, and he already tolerates CPAP. Raise in 1 to 2 cm H2O steps toward the mid-teens as tolerated, limited by leak, comfort, and hypotension; gastric insufflation is unlikely below about 20 cm H2O, and CPAP has not been linked to staple-line leak.
FiO2 instead. Raising FiO2 alone treats the number without reopening lung, encourages absorption atelectasis, and hides hypoventilation on the oximeter.
HFNC vs BiPAP. High-flow is a reasonable alternative for mask intolerance but gives only a few cm H2O of distending pressure with the mouth closed and splints his upper airway less reliably when he sleeps. BiPAP adds pressure support for hypercapnia; awake with RR 18, he needs recruitment, not ventilatory support.
Anything else. Sit him upright or in a chair, incentive spirometry and deep breathing, cough, analgesia good enough to breathe deeply, early mobilization, no further fluid unless indicated, minimal opioid.
Target. About 92 to 96%. Nothing suggests chronic CO2 retention (normal pre-op SpO2, an acute pattern on the ABG), so a lower target is not needed; chasing 100% hides the next episode of hypoventilation.
Trial off. When awake with a normal RR on FiO2 0.4 or less; the meaningful trial is on room air or low-flow oxygen while asleep and unstimulated, watching for apneas and desaturation. That trial, not the awake SpO2, predicts how he will do overnight.

2. Pain at hour 2

Hour 2: awake on CPAP, epigastric and port-site pain 7/10, left shoulder pain, splinting. Shoulder pain: cause? More hydromorphone? Why/why not? Dose? Ketorolac? Why/why not? Dose? Acetaminophen: next dose when? Ketamine? Dose? Gabapentin? Why/why not? Surgeon asks for a hydromorphone PCA tonight. Why/why not? Basal rate?

Considerations and pitfalls AI draft

Shoulder pain. Referred pain from diaphragmatic irritation by residual CO2 and peritoneal stretch (phrenic, C3 to C5); it fades over 24 to 48 hours and responds to non-opioids and position. At hour 2 this is the likely cause; new or worsening left shoulder pain later, especially with tachycardia, raises a staple-line leak or bleed.
More hydromorphone. Possible, but in small titrated doses (0.2 mg IV) with continuous monitoring, and only after the non-opioid options are on board. He needed naloxone a little over an hour ago; a reflexive 0.5 to 1 mg dose is the flag, and so is refusing all opioid while he splints.
Ketorolac. Reasonable if the surgeon agrees: normal creatinine, age under 65. Staple-line bleeding is the surgical concern after a sleeve, and many bariatric pathways include a short NSAID course; ask rather than assume either way. 15 mg IV; his ACE inhibitor (last dose yesterday) is a reason to watch renal function, not a contraindication.
Acetaminophen. 1 g was given in the OR, so the next dose is 6 hours later; maximum 4 g/day at his weight. A second dose now is the error.
Ketamine. Useful in OSA because it adds little respiratory depression: a low dose of about 0.1 to 0.3 mg/kg on ideal body weight (roughly 10 to 20 mg) IV, watching for dysphoria.
Gabapentin. Avoid; gabapentinoids add sedation and respiratory depression on top of opioids, a specific concern in OSA, and the analgesic benefit acutely is small.
PCA. Not tonight in a patient who needed naloxone; if one is used later, no basal rate, small demand dose, with continuous pulse oximetry and capnography. A basal infusion in OSA is the clear error.

3. Hard to rouse at hour 2.5

Assume ketorolac and two doses of hydromorphone 0.2 mg. Thirty minutes later: hard to rouse, RR 6, SpO2 87% on CPAP with FiO2 0.4. ABG: pH 7.19, PaCO2 66, PaO2 57. Rx now? Naloxone again? Dose? He wakes after 80 mcg, then drifts off again within 20 minutes, RR 7. Next? Infusion? Rate? Stay on CPAP or switch to BiPAP? Why? Intubate now? Why/why not? What would make you intubate?

Considerations and pitfalls AI draft

Rx now. Stimulate, jaw thrust if obstructing, check the mask seal, repeat TOF and glucose quickly, and give naloxone. The first naloxone, about an hour and a half ago, is wearing off just as the new hydromorphone peaks; re-sedation is the expected pattern.
Naloxone again. Yes, 40 mcg IV every 2 to 3 minutes to RR and arousal.
Infusion. Yes, once he re-sedates after bolus doses: about two-thirds of the effective wake-up dose per hour, so 80 mcg leads to roughly 50 mcg/h, titrated to RR and sedation. This takes him out of an unmonitored bed tonight.
CPAP vs BiPAP. BiPAP; CPAP splints the airway but does not increase ventilation, and this is now a hypercapnic acidosis. Inspiratory pressure several cm above an expiratory pressure near his CPAP level, with a backup rate. It is safe only in a patient who can be roused and protect his airway.
Intubate now. Not if naloxone restores arousal and he protects his airway; this is a reversible drug effect, and a reflexive intubation of an obese OSA patient carries its own risk.
What makes you intubate. No response to naloxone, inability to protect the airway or vomiting under the mask, a pH or CO2 that fails to improve within an hour or so of BiPAP, hemodynamic instability, or exhaustion. Persisting with BiPAP on an obtunded patient who does not respond is the opposite error.

4. Booked for the floor

Assume BiPAP and a naloxone infusion at 50 mcg/h. Hour 4: awake, RR 14, PaCO2 46, pain 3/10. Surgeon: "He's booked for a regular floor bed tonight. Can he still go?" Your answer? Why? Step-down? ICU? Which? Why? Monitoring overnight: what? Continuous capnography? Why/why not? Analgesic orders for the night: what goes in, what stays out? Positive pressure overnight: CPAP? BiPAP? When? Call parameters: which numbers?

Considerations and pitfalls AI draft

Regular floor. No. He has had repeated PACU respiratory events (obstruction, desaturation, two episodes of opioid depression needing naloxone) and is on an infusion; recurrent PACU events predict later events on the ward. ASA OSA guidance is not to discharge from the recovery area to an unmonitored setting until he is no longer at risk of respiratory depression. The floor plan assumed an uncomplicated recovery with minimal opioid need, and that assumption no longer holds.
Bed. A monitored bed: step-down or ICU, matched to where a naloxone infusion and BiPAP can run with the nursing they require. A regular floor bed with intermittent vitals is unsafe tonight, even on a bariatric unit used to OSA.
Monitoring. Continuous pulse oximetry with central alarms, sedation scoring (such as POSS) with vitals at least hourly while on the infusion.
Capnography. Yes; on supplemental oxygen, oximetry detects hypoventilation late, and capnography catches the bradypnea and rising CO2 first.
Analgesia. Scheduled acetaminophen and ketorolac if the surgeon agrees, low-dose ketamine if needed, small PRN opioid doses only after a sedation check; no basal opioid, no gabapentinoids, benzodiazepines, or sedating antiemetics such as promethazine.
Positive pressure overnight. BiPAP or CPAP whenever asleep, naps included; head of bed up or non-supine; his own mask.
Call parameters. RR under 10, SpO2 under 90% on the prescribed support, rising ETCO2, sedation score of frequently drowsy or worse, any observed apnea, or any naloxone requirement.

5. The next morning

Next morning: infusion off since 2 AM, slept on his CPAP, SpO2 94% on room air asleep, RR 16, HR 84, pain 3/10 on oral acetaminophen, tolerating clear liquids. Home today? What has to be true first? Oral opioid for home? Agent? How many tablets? CPAP at home: when? Why? He asks: "Did something go wrong with my anesthesia?" What will you tell him? Next anesthetic: what goes in his record?

Considerations and pitfalls AI draft

Home today. Defensible either way. POD 1 discharge is reasonable if the night was quiet: no naloxone for several hours, no apneas or desaturation on room air while asleep and unstimulated, pain controlled on oral agents, clear liquids tolerated on the bariatric schedule, walking, no unexplained tachycardia (after a sleeve, an early sign of leak or bleeding), an adult at home, and his CPAP with him. A second monitored night is equally defensible when the naloxone infusion stopped only hours ago; what is not defensible is discharge before an unstimulated sleep period on room air has been observed.
Opioid. Minimal or none: scheduled acetaminophen as the base, an NSAID only if the bariatric team allows it, and a small supply of an immediate-release opioid (for example oxycodone 5 mg, a handful of doses, in a form the bariatric diet allows, often liquid) only if needed; no extended-release opioid, no benzodiazepines or gabapentinoids, no alcohol.
CPAP. Every sleep period including naps, especially while taking any opioid; the first several nights after surgery carry the highest risk, partly from REM rebound.
What to tell him. Plain and honest: the muscle relaxant had not fully worn off when he woke, which made breathing harder; it was found and fully reversed. His pain medicine then slowed his breathing more than expected, which is more likely with sleep apnea, and he needed a reversal medicine and a night of monitoring. No lasting harm is expected. Acknowledge it and apologize; no minimizing, no blaming. The event goes through the department's quality reporting.
His record. OSA on CPAP with PACU respiratory events and a naloxone requirement after modest opioid doses; a plan for next time: quantitative monitoring with reversal to a TOF ratio of at least 0.9, sugammadex for rocuronium, an opioid-sparing technique, CPAP in PACU, and an overnight monitored bed if opioid needs are expected. Not an 'allergy' to neostigmine or rocuronium.

Long stem

Inguinal hernia repair in the ex-premature infant with postoperative apnea risk

A 20-week-old, 4.7 kg former premature infant boy is scheduled for elective right inguinal hernia repair.

HPIBorn at 27 weeks' gestation, birth weight 950 g, with a NICU stay of eleven weeks. He was mechanically ventilated for three weeks for respiratory distress and developed bronchopulmonary dysplasia. He was weaned off home oxygen three weeks ago. A right inguinal hernia was noted two weeks ago and has twice reduced spontaneously after brief episodes of incarceration. He has had clear rhinorrhea for four days without fever, is feeding well, and his parents report occasional wheeze with colds.

PMHFormer 27-week premature infant. Bronchopulmonary dysplasia. Grade II intraventricular hemorrhage with normal development so far. Retinopathy of prematurity treated with laser to both eyes. Anemia of prematurity. Gastroesophageal reflux. Prior anesthetic for the ROP laser was uneventful and he was extubated at the end.

MEDSAlbuterol as needed with illness, ferrous sulfate, famotidine. No home oxygen currently.

PHYS EXAMHR 150; RR 42; BP 80/48; SpO2 96% on room air; T 36.9°C; weight 4.7 kg. Clear rhinorrhea, mild intermittent expiratory wheeze, no retractions, no grunting. He is alert and vigorous.

LABSHgb 9.4 g/dL; Hct 29%; platelets 290 K/uL; glucose 74 mg/dL.

PLAN / ARRIVALA peripheral IV is in place. The repair is booked as day surgery. His parents ask whether he really needs to stay overnight.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Apnea-sparing technique choice in a low-postmenstrual-age ex-premie; ventilation and physiologic targets in chronic lung disease of infancy; recognizing intraoperative bronchospasm and infant bradycardia as hypoxia; caudal analgesia and local anesthetic limits in a small infant.

1. Anesthetic technique and induction

Postmenstrual age today? Clear rhinorrhea for four days, wheeze on exam, a hernia that has incarcerated twice. Proceed today or postpone? Why? Spinal alone, caudal with light general, or general with a secured airway? Which? Why? Spinal — agent? Dose in mg? How long will it last? Ketamine 1 mg/kg to keep him still for the block — yes/no? Why? Spinal in; twenty minutes later he is crying and squirming and the surgeon cannot work. Midazolam? Dexmedetomidine? Convert to general? Which? Why? You convert: sevoflurane by mask; wheeze worsens and the chest barely moves with the bag. Rx, in order?

Considerations and pitfalls AI draft

PMA. 27 + 20 = 47 weeks; under 60 weeks PMA is the postoperative apnea window, and under 50 weeks is the highest-risk group. The resident should compute it, not guess.
Proceed or postpone. Clear rhinorrhea without fever, feeding well, and a hernia that keeps incarcerating: proceed with heightened vigilance is the stronger answer; purulent secretions, fever, or lower-airway signs beyond his baseline wheeze would delay. Reflexive cancellation or reflexive proceeding are both flags; weigh reactivity against incarceration risk.
Technique. Spinal without sedation reduces early postoperative apnea and avoids instrumenting BPD lungs; general with a secured airway gives control if the block fails or the case runs long. Commit to a technique tied to his PMA and lungs.
Spinal dose. Hyperbaric bupivacaine 0.5% about 1 mg/kg (4.5-5 mg, roughly 1 mL) or tetracaine 0.5-1 mg/kg; duration 60-90 min, so the surgeon must be fast. Do not lift the legs after the block (for the cautery pad): a high spinal in an infant shows as apnea, bradycardia, and a limp pale baby, not a complaint.
Apnea benefit. Requires no sedation at all: a swaddled calm infant, a pacifier with sucrose, a warm room; the moment midazolam or ketamine is added, the apnea advantage disappears.
Block failing at 20 min. Sedation converts him to a sedated infant with an unprotected airway and no apnea benefit; dexmedetomidine has the least respiratory effect if the surgeon is minutes from done; a general with a secured airway is the cleaner answer when the block will not last the case. Commit and defend.
Bronchospasm on mask induction. 100% O2, deepen the sevoflurane, gentle two-handed hand ventilation with long expiration, oral airway; albuterol into the mask; exclude laryngospasm, obstruction, and breath-stacking; a relaxant before deepening is worth a probe. Secure the airway once ventilation is adequate.

2. Ventilation and physiologic targets

Ventilating and improving. LMA or endotracheal tube? Which? Why? Tube — size? Cuffed? Peak pressure ceiling? Tidal volume — mL? Rate? ETCO2 you will accept? SpO2 target — a number? FiO2? Why not 100%? Maintenance fluid — what is in the bag? Rate in mL/h? Glucose check — when? Glucose 52. Rx? Dose? Temperature 35.8 after prep. Target? How do you get there?

Considerations and pitfalls AI draft

Airway device. An ETT gives control of pressures and PEEP in BPD lungs with reactive bronchospasm just treated; an LMA reduces stimulation but a short, wheezing, ex-premie under positive pressure argues for the tube. Either with reasoning; a size 3.0-3.5 cuffed (microcuff) or 3.5 uncuffed, leak at 20-25 cm H2O.
Ventilation. Pressure-limited ventilation, PIP as low as gives 6-8 mL/kg (30-35 mL), rate 25-30, PEEP 5, long expiratory time; ETCO2 in the 45-55 range is acceptable (BPD infants live with hypercapnia). Ventilating to a normal CO2 at high pressures is the wrong direction; a rising pressure prompts a search, not more pressure.
Oxygen. SpO2 91-95%, FiO2 titrated to it, not 1.0; hyperoxia adds oxidative injury in a lung and retina that have already paid for it. Running 100% to be safe should be challenged.
Fluids. 4 mL/kg/h = about 19 mL/h; a balanced isotonic solution with dextrose 1-2.5% for an ex-premie with limited glycogen; watch the total volume.
Glucose. Check at induction and hourly; 52 in an infant under anesthesia is treated: D10 2 mL/kg (about 10 mL) then a dextrose-containing maintenance; recheck in 30 min. Ignoring glucose is a common miss.
Temperature. Target 36.5-37.5; forced-air warming, room warmed before arrival, warmed fluids, cover the head, measure continuously; his surface-area-to-mass ratio loses heat in minutes.

3. Intraoperative desaturation

Mid-case: SpO2 84, peak pressure 32 from 22, expiratory wheeze at the chest. DDx? First move? Hand-bagging: tight, wheeze bilateral and equal, tube at the same depth. Deepen — with what? Dose? Albuterol — how many puffs into the circuit? Why that many? SpO2 78, HR 90. Now? Drug? Dose? HR 55, SpO2 70. Next? HR 140, SpO2 92, still tight at 30 cm H2O after all that. Now what?

Considerations and pitfalls AI draft

DDx. Bronchospasm, mainstem migration (a 1 cm move does it in this trachea), tube kink or plug, secretions, breath-stacking, pneumothorax, circuit problem, light anesthesia.
First move. Hand-ventilate to feel compliance, 100% O2, check tube depth and bilateral sounds, then treat the cause.
Deepen. Sevoflurane up, or propofol 1 mg/kg (5 mg); ketamine 1 mg/kg bronchodilates and holds pressure.
Albuterol. 8-10 puffs by MDI into the circuit via an adapter, most is lost in the tubing and tube; a single ward-style puff does nothing here.
HR 90 at SpO2 78. Hypoxic bradycardia in an infant: oxygenate and ventilate first; epinephrine 1-10 mcg/kg IV (5-50 mcg) for persistent bradycardia with poor perfusion; atropine does not fix hypoxia.
HR 55. Chest compressions with ventilation when HR stays below 60 with poor perfusion despite oxygenation; epinephrine 10 mcg/kg (50 mcg) IV; the arrest algorithm, not a rhythm chase.
Still tight. Persistence despite deepening and bronchodilator raises tube malposition, plugging, or pneumothorax: pass a suction catheter, reconfirm depth, auscultate and ultrasound the chest, consider tube exchange; epinephrine infusion or IV magnesium 25-50 mg/kg for refractory bronchospasm.

4. Caudal analgesia

Analgesia for the incision — caudal, ilioinguinal block, or IV fentanyl? Which? Why? Caudal — agent? Concentration? mL? Total mg — what is his maximum? Test dose — what, and what tells you the needle is intravascular? Surgeon wants to infiltrate 5 mL of 0.25% bupivacaine as well. Does that fit under the ceiling? Numbers. Incision: HR jumps from 150 to 185. Block failed? Rx? Fentanyl — dose? What does that cost him tonight?

Considerations and pitfalls AI draft

Regional vs opioid. A caudal (or ultrasound ilioinguinal block) gives somatic analgesia and spares opioid in an apnea-prone infant; systemic opioid adds apnea and respiratory-depression risk. The opioid cost drives the reasoning.
Caudal dose. Bupivacaine 0.125-0.2% (or ropivacaine 0.2%) at 1 mL/kg = about 5 mL to reach T12-L1; 5 mL of 0.2% = 10 mg. Maximum bupivacaine about 2-2.5 mg/kg = 9-12 mg; the caudal alone is at the ceiling.
Test dose and intravascular. Epinephrine 0.5 mcg/kg (2.5 mcg) in the first 0.1 mL/kg, incremental injection with aspiration; HR rise of 10 or more, T-wave peaking, or BP rise within 60 s means intravascular; injecting the full dose in one pass is a flag.
Surgeon's infiltration. 5 mL of 0.25% = 12.5 mg on top of 10 mg = 22.5 mg, about 4.8 mg/kg: no. Offer 0.125% or a smaller volume, or reduce the caudal; not counting the surgeon's local is a real miss.
HR 185 at incision. Inadequate block or light anesthesia; deepen first, then supplement with acetaminophen 15 mg/kg IV or PR; fentanyl 0.5-1 mcg/kg (2.5-5 mcg) titrated if needed, accepting that it raises the postoperative apnea risk and mandates monitored observation. A blind 2 mcg/kg is the trap.

B. POST-OPERATIVE CARE

Teaching focus. Emergence and laryngospasm with negative-pressure pulmonary edema; postoperative apnea of the ex-premie and its monitoring; the anemia-apnea link and infant transfusion thresholds; escalation and disposition; honest family counseling against an unsafe day-surgery discharge.

1. Emergence and laryngospasm

Case done. Deep or awake extubation? Why? What has to be true before the tube comes out? Extubated awake. Seconds later: stridor, then silence, chest not moving, SpO2 80. Dx? Maneuvers, in order? No air movement, SpO2 68, HR 80. Drug? Dose? The IV has infiltrated. Route? Dose? Atropine — dose? Spasm breaks. Pink froth from the mouth, SpO2 88 on 100%. Dx? Rx? Reintubate? Why/why not?

Considerations and pitfalls AI draft

Deep vs awake. Awake with returned reflexes protects a reactive, refluxing airway but coughing can trigger spasm; deep reduces stimulation but leaves an ex-premie with GER unprotected. Either is defensible with stated prerequisites; awake is the more common answer here.
Before extubation. Full reversal (sugammadex or TOF confirmed), regular spontaneous breathing with adequate tidal volumes, eyes open or purposeful movement, suctioned pharynx, warm, glucose known.
Dx and maneuvers. Laryngospasm: remove the stimulus, 100% O2, jaw thrust with CPAP (Larson's), suction; propofol 0.5-1 mg/kg if the IV works.
HR 80 at SpO2 68. Break the spasm now: succinylcholine 1-2 mg/kg IV (5-10 mg) with the IV; without it, 4 mg/kg IM (about 19 mg) or intraosseous; atropine 0.02 mg/kg (0.1 mg) IM with it. Delaying paralysis while he slows is the error.
Pink froth. Negative-pressure pulmonary edema from forceful inspiration against a closed glottis; oxygen and CPAP by mask, usually self-limited over hours; diuretics are not the main treatment.
Reintubate. Not if he oxygenates on CPAP with improving work of breathing; reintubate for persistent SpO2 below about 88 on CPAP, rising CO2, or exhaustion. Either with a trigger stated.

2. Postoperative apnea

In recovery: two spells of no breathing, about 20 seconds each, SpO2 to the low 80s, self-resolving. Concerned? Why him in particular? Central or obstructive — how do you tell at the bedside? Workup now? Glucose 70, T 36.6, Hgb pending. Caffeine — give it? Dose in mg/kg? A single load, or maintenance too? The surgeon says a spinal alone would have let him go home today. True? How long apnea-free before you ease the monitoring?

Considerations and pitfalls AI draft

Concern and why him. Yes: PMA 47 weeks, a general anesthetic, fentanyl, anemia, and BPD all raise postoperative apnea risk; apnea with desaturation in the first hour predicts more.
Central vs obstructive. Central: no chest wall effort; obstructive: effort without airflow, paradoxical chest and abdomen; mixed is the common pattern. The distinction guides airway positioning and CPAP vs respiratory drive (caffeine).
Workup. Glucose, temperature, Hgb, SpO2 trend, residual anesthetic and opioid effect, sepsis if anything else fits; treat the correctable before calling it apnea of prematurity.
Caffeine. Caffeine citrate 20 mg/kg IV load (about 94 mg); maintenance 5 mg/kg/day is reasonable while spells continue; a guessed dose is a flag.
Spinal alone. Reduces early apnea but not late apnea; he would still be admitted and monitored. Claiming a spinal makes monitoring unnecessary is wrong.
Duration. Continuous cardiorespiratory and SpO2 monitoring until at least 12 hours free of events (many programs use 12-24 h); day-surgery discharge is unsafe.

3. Anemia and transfusion

Three more spells in the next hour. Hgb 8.6. Related? Transfuse? What Hgb threshold do you use in him? Why not 7? Volume — mL/kg? Over how long? What are you watching for while it runs? He is still on caffeine and warm. You hold off on blood. What else do you do for the spells?

Considerations and pitfalls AI draft

Anemia and apnea. Anemia is an independent risk factor for postoperative apnea in ex-premies; correcting it can reduce spells, one factor among several.
Transfuse. A symptomatic anemic ex-premie with recurrent apnea: transfusing is defensible and many would; optimizing caffeine, temperature, and glucose first is also defensible. Tie the decision to his apnea, not a reflex number.
Threshold. Infant and ex-premie thresholds are higher and symptom-driven: commonly Hgb under 10 with symptoms (apnea, poor feeding, tachycardia) or under 7-8 asymptomatic; the adult 7 does not apply.
Volume and rate. 10-15 mL/kg PRBC (50-70 mL) over 3-4 h; a slow small aliquot, mindful of circulatory overload in BPD.
Watching for. Volume overload (rising RR, crackles, hepatomegaly), hypocalcemia and hyperkalemia with older units, hypoglycemia, temperature drop; reassess spell frequency after.
If holding. Caffeine maintenance, glucose and temperature control, positioning, nasal CPAP for a mixed pattern, continuous monitoring.

4. Overnight deterioration and disposition

Overnight: a spell needing stimulation and three bag-mask breaths, SpO2 62 at the nadir. Now? Floor, step-down, or ICU? Why? Monitoring? High-flow or CPAP — start it? Setting? He is wheezing again. Rx? Gas: pH 7.28, PaCO2 62. Now? What would make you reintubate?

Considerations and pitfalls AI draft

Now. Airway and breathing support, reassess the cause (glucose, temperature, sepsis, aspiration, residual drug), repeat caffeine level or a second dose; a stimulated event with bag-mask marks a high-risk infant.
Disposition. ICU; a regular floor cannot respond to a bag-mask event and step-down depends on the unit; continuous cardiorespiratory, SpO2, and apnea monitoring with staff able to bag.
High-flow or CPAP. Nasal CPAP 5-6 cm H2O or high-flow 2 L/kg/min (about 8-10 L) splints the airway for mixed or obstructive apnea and unloads BPD lungs; a reasonable step short of reintubation.
Wheeze. Albuterol neb, consider ipratropium; the wheeze raises work of breathing and the apnea picture together.
pH 7.28, PaCO2 62. A BPD infant's baseline may be 50-55, so read the trend and the work of breathing: escalate CPAP, treat bronchospasm, repeat the gas in 30-60 min; reintubate for a rising CO2 with fatigue, recurrent apnea unresponsive to caffeine and CPAP, or failure to protect gas exchange. A single number does not intubate him.

5. Family counseling and discharge

Morning: six hours apnea-free on high-flow 6 L, feeding. The parents booked this as day surgery and want him home tonight. Your answer? They ask why a 40-minute operation means nights in the hospital. What will you tell them? What makes him safe to discharge — apnea-free how long? Off high-flow? Off caffeine? Next anesthetic — what changes? Until what age?

Considerations and pitfalls AI draft

Answer. No; admit and monitor; the recommendation is stated plainly and once, not negotiated.
What you tell them. The one counseling beat: premature babies can stop breathing for hours after anesthesia, his has done so and needed help, monitors catch it and staff fix it, and it passes; specific, calm, no alarming language.
Safe to discharge. At least 12 hours (many use 24) apnea-free on room air, off high-flow, feeding normally, caffeine plan settled with pediatrics (it can be continued at home or stopped with a monitored observation period after the last dose).
Next anesthetic. Flag the postoperative apnea and difficult emergence; prefer regional without sedation where possible, plan admission and monitoring for any anesthetic until about 60 weeks PMA (and beyond given this history); treat the BPD and reflux ahead of time.

Short stem

Tonsillectomy and adenoidectomy in an obese 4 y.o. with severe OSA

A 4 y.o., 104 cm, 26 kg boy is scheduled for tonsillectomy and adenoidectomy. His parents describe loud nightly snoring with pauses, restless sleep, and new daytime hyperactivity at preschool; polysomnography shows an obstructive apnea-hypopnea index of 14 events/h with an SpO2 nadir of 78%. Born at term, otherwise healthy, no medications or allergies. At a dental visit last year he had to be held down for a mouth exam and screamed until he vomited. The family lives two hours from the hospital. HR 108; BP 100/62; RR 22; SpO2 96% on room air; tonsils 4+, meeting in the midline; no IV.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Grading pediatric OSA and deciding what further workup it earns; disposition after adenotonsillectomy in a high-risk child; premedication, parental presence, and induction choice in an anxious child whose airway obstructs when sedated; an analgesic plan that respects opioid sensitivity and the codeine contraindication.

1. Sleep study result

Sleep study. Of concern? Why? BMI? Significance? Further testing before surgery? ECG? Echo? Chest radiograph? Which? Why/why not? Mother adds that he wakes with a headache most mornings and is hard to rouse. Of concern? Why? Now which tests? Assume a serum bicarbonate and ECG are sent: bicarbonate 24; ECG normal sinus rhythm, no RV hypertrophy. Proceed today? Why/why not? Mother asks whether he should lose weight first and try surgery later. Delay? Why/why not?

Considerations and pitfalls AI draft

Sleep study. AHI 14 with a nadir of 78% is severe pediatric OSA on either measure (AHI 10 or more, or nadir under 80%). A learner who reads AHI 14 against adult cutoffs and calls it mild is the flag.
BMI. About 24 (26 kg / 1.04 m squared), far above the 95th percentile for a 4 y.o.; ideal weight for 104 cm is roughly 17 kg. Obesity compounds the OSA, raises the risk of residual OSA after surgery, and changes drug dosing. A strong learner has raised his weight before this beat.
Testing before surgery. None are required for every child with OSA. ECG and echo are reserved for signs of RV strain or pulmonary hypertension, very severe nocturnal hypoxemia, or suspected hypoventilation; a chest radiograph adds little. Ordering an echo reflexively for every snorer, or never considering one, are both weak.
Morning headaches, hard to rouse. Suggest nocturnal hypercapnia and hypoventilation, not just obstruction. This raises the stakes for sedatives and opioids and the chance of right-heart effects.
Tests now. Serum bicarbonate (or a blood gas) as a screen for chronic CO2 retention; ECG; echo if the ECG or exam suggests RV strain or the clinical picture is worrying. A normal bicarbonate is reassuring; a normal ECG is reassuring but insensitive for pulmonary hypertension, so ordering an echo here on the symptoms alone is also defensible.
Proceed. Yes; nothing here is optimizable, and the operation is the treatment. The workup changes monitoring, drug dosing, and disposition, not the decision to operate.
Weight loss first. No; adenotonsillectomy is first-line therapy for OSA in obese children with large tonsils, and months of untreated severe OSA carry their own harm. Weight management runs in parallel; CPAP is for residual disease.

2. Day-surgery booking

He is booked as day surgery, home four hours after PACU. Agree? Why/why not? Assume he stays overnight. Ward? PICU? Which? Why? Monitoring there? Routine supplemental O2 overnight? Why/why not? Home the next morning: what has to be true? Bleeding after discharge: when? Where does he go? Why?

Considerations and pitfalls AI draft

Day surgery. No. Severe OSA (AHI 10 or more, or nadir under 80%) warrants overnight admission after adenotonsillectomy on its own, and obesity adds to the risk; respiratory events cluster in the first night. Accepting day surgery here is the flag.
Where. A monitored ward bed with continuous pulse oximetry is usual for a child who is stable in PACU; PICU for oxygen or airway support beyond simple measures, repeated significant desaturation in PACU, or major comorbidity. Either is defensible if the reason is stated; the decision is revisited at PACU discharge.
Monitoring. Continuous pulse oximetry with alarms and nursing able to respond, head of bed up or lateral positioning, opioid orders written conservatively.
Routine O2. No; supplemental O2 masks hypoventilation on the oximeter. Give it for desaturation, and if he needs it, he needs closer watching (capnography or a higher level of care).
Home the next morning. Yes, if he is drinking enough, pain is controlled on oral agents, no significant desaturation on room air during sleep, no bleeding, and the caregivers are taught.
Bleeding after discharge. Secondary bleeding peaks around days 5 to 10. The family lives two hours away: any fresh blood means going to the nearest emergency department, not driving back to the operating hospital. A strong learner raises the distance unprompted. Discharge teaching also covers hydration, the pain regimen, and signs of airway trouble.

3. Separation and premedication

Mother asks to stay until he is asleep. Parental presence at induction? Why/why not? Premedication? Why/why not? Oral midazolam? Dose? On what weight? Intranasal dexmedetomidine instead? Dose? Onset? He gets oral midazolam. Twenty minutes later he is asleep on her lap, snoring with pauses, SpO2 88%. Rx? Where is he monitored from now on? Inhalational induction or IV first? Why? EMLA and an IV in holding? Why/why not?

Considerations and pitfalls AI draft

Parental presence. Reasonable for a cooperative parent who is prepared for what she will see (eyes rolling, noisy breathing, limpness) and escorted out promptly; it does not replace premedication in a child this frightened.
Midazolam. 0.5 mg/kg PO, maximum 20 mg; in an obese child many dose on ideal weight (about 8 to 9 mg here) rather than 13 mg on actual weight. Premedication is not contraindicated by OSA, but it can provoke obstruction and requires continuous monitoring afterward; withholding all premedication from a child who vomited from fear is also a choice to defend.
Dexmedetomidine. 1 to 2 mcg/kg intranasal; onset about 30 to 45 minutes; less respiratory depression and good for anxious children, at the cost of a longer wait. Either drug is defensible.
SpO2 88%. Rouse him, reposition (sitting or lateral, chin up), O2; this is his OSA under sedation, and it previews induction.
Monitoring. Continuous oximetry and an anesthesia provider with him from here; a premedicated child with severe OSA is not left on a parent's lap in holding.
Induction route. Inhalational induction is standard for a child with no IV and acceptable here with a plan for obstruction; IV induction is reasonable if access is easily obtained. A learner who has no plan for the obstruction an inhalational induction will produce is the gap.
EMLA and IV. EMLA needs about 60 minutes and an IV attempt on a terrified 4 y.o. can undo the premedication; usually the IV goes in after induction.

4. Analgesic plan

The surgeon's standard discharge order is acetaminophen with codeine. Agree? Why/why not? Tramadol instead? Why/why not? Home regimen? Doses? Ibuprofen after tonsillectomy? Why/why not? Intra-op opioid: usual dose, reduced, or none? Why? Dose? On what weight? Ketamine? Dexmedetomidine? IV acetaminophen? Which? Dose?

Considerations and pitfalls AI draft

Codeine. Contraindicated (FDA) in children under 12 and after tonsillectomy or adenoidectomy in anyone under 18. Ultrarapid CYP2D6 metabolizers make large amounts of morphine, and children have died after tonsillectomy. Not a 'use with caution' drug here.
Tramadol. Same contraindication, same CYP2D6 mechanism.
Home regimen. Scheduled acetaminophen 15 mg/kg every 6 hours and ibuprofen 10 mg/kg every 6 to 8 hours, both dosed to ideal weight in this obese child (roughly 250 mg and 170 mg), alternating or together; opioids at home only if truly needed, small supply, with clear instructions.
Ibuprofen and bleeding. Recommended after tonsillectomy; it does not meaningfully raise the hemorrhage rate. Refusing it out of bleeding fear pushes the child toward opioids.
Intra-op opioid. Reduced, not reflexively none: children with a nadir under about 85% are more sensitive to opioid respiratory depression and need roughly half the usual dose. Morphine usual 0.05 to 0.1 mg/kg; halved and on ideal weight (about 17 kg) that is roughly 0.5 to 0.8 mg, titrated. The best weight basis for opioids in obese children is not settled; ideal weight is the conservative choice in severe OSA, and titrating to effect matters more than the starting weight. Full dose on 26 kg (2.6 mg) is unsafe.
Adjuncts. IV acetaminophen 15 mg/kg (ideal weight), dexamethasone (single dose, see B3), dexmedetomidine 0.5 mcg/kg, low-dose ketamine 0.25 to 0.5 mg/kg; all reduce opioid need. Each is defensible as an adjunct.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Upper-airway obstruction during inhalational induction and when to place the IV; airway device, tube size, and the shared oropharynx under cautery; antiemetic prophylaxis and the deep-versus-awake extubation decision in severe OSA; laryngospasm after extubation; post-anesthesia desaturation and what to tell the family about residual OSA.

1. Mask induction

Assume an inhalational induction: sevoflurane 8% in 70% N2O. Ninety seconds in: loud snoring, then chest and abdomen moving in opposition, no ETCO2 trace, SpO2 91%. DDx? First maneuvers? Jaw thrust and CPAP 10 cm H2O; partial improvement, SpO2 88%. N2O: keep it on? Why/why not? Oral airway now? Why/why not? Size? Two-handed mask with an oral airway, ETCO2 trace back, SpO2 97%. IV: when? What tells you he is deep enough? IV in. Intubate how? Deep sevoflurane? Propofol? Muscle relaxant? Which? Why?

Considerations and pitfalls AI draft

DDx. Soft-tissue obstruction from the tonsils and adenoids as tone falls (most likely at this stage), laryngospasm, breath-holding. Response to jaw thrust and CPAP helps separate them.
First maneuvers. Chin lift, jaw thrust, CPAP with a tight seal; shoulder roll or lateral tilt. Large tonsils plus obesity make this expected, not a surprise.
N2O. Off, 100% O2 with sevoflurane; N2O lowers the inspired O2 the child needs while he is desaturating.
Oral airway. Helpful once he is deep enough; inserted in a light plane it can trigger laryngospasm or vomiting. Sized from the corner of the mouth to the angle of the jaw. A nasal airway is a poor choice in a child about to have his adenoids removed.
IV. As soon as he is deep enough (regular breathing, central pupils, no movement to stimulation), placed by a second person while the anesthesiologist holds the airway.
Intubation. Deep sevoflurane with propofol 1 to 2 mg/kg, or a small dose of rocuronium if conditions are poor; prolonged blockade for a 30-minute case adds little. Succinylcholine is not routine in children (hyperkalemic arrest with undiagnosed myopathy); keep it for the airway emergency. Any of these is defensible if the learner can defend it.

2. Airway device and surgical setup

Oral RAE tube or flexible LMA? Why? Cuffed or uncuffed? Size? Depth at the lips? Assume a cuffed oral RAE: bilateral breath sounds, cuff pressure 18 cm H2O. Surgeon places the mouth gag and opens it. Peak pressure rises from 16 to 40 cm H2O, ETCO2 waveform flattens, SpO2 96%. DDx? First action? Gag repositioned, pressures back to baseline. Cautery in the oropharynx: FiO2? N2O? Why? Maintenance: sevoflurane or propofol infusion? Why?

Considerations and pitfalls AI draft

ETT vs LMA. An oral RAE tube is the common choice in severe OSA and obesity; a flexible LMA works with an experienced surgeon and team but can be displaced by the gag and protects less from blood. Either defended with the tradeoff is acceptable.
Size. Cuffed 4.5 mm ID for a 4 y.o. (age/4 + 3.5), or uncuffed 5.0; a cuffed tube seals against blood and limits O2 leak into the field. Have a half size up and down ready.
Depth. About 14 cm at the lips (age/2 + 12); a preformed RAE sets its own depth, so confirm bilateral breath sounds after positioning. Neck extension for the surgery pulls the tube outward; flexion pushes it in.
Pressure spike after the gag. Compression or kinking of the tube by the gag blade is most likely; also displacement (out or endobronchial), bronchospasm, secretions. Breath sounds and ETCO2 shape help sort it.
First action. Tell the surgeon to release the gag; if pressures normalize, reposition the blade off the tube. Treating it as bronchospasm with drugs first is the miss.
Cautery: FiO2 and N2O. The tip of the cautery is centimeters from the tube: lowest FiO2 that keeps saturation (30% or less if tolerated), no N2O (it supports combustion), cuffed tube, wet pharyngeal packing.
Maintenance. Either works; propofol reduces PONV and emergence agitation, sevoflurane is simple and reliable. Agent choice matters less than a plan for emergence.

3. Preparing for emergence

Dexamethasone? Dose? Why? Ondansetron? Dose? Surgery ends at 35 minutes, hemostasis complete. Extubate deep or awake? Why? Before extubation, what do you do in the mouth? Stomach? Why? Position for emergence? Why? Assume an awake extubation. End-tidal sevoflurane 0.4%: eyes open, gaze disconjugate, coughing and breath-holding, no response to voice. Extubate now? Why/why not?

Considerations and pitfalls AI draft

Dexamethasone. Single IV dose, 0.15 to 0.5 mg/kg (maximum about 8 to 10 mg); reduces PONV and improves early oral intake; it does not meaningfully raise bleeding risk.
Ondansetron. 0.1 to 0.15 mg/kg IV, maximum 4 mg (about 2 to 2.5 mg here); combined with dexamethasone because swallowed blood and tonsillectomy make PONV common.
Deep vs awake. Awake is usual in severe OSA and obesity: a deep extubation hands over an unprotected, obstructing airway in a child who obstructed on induction. Deep extubation can be defended in a low-risk child; here it needs a strong reason.
Mouth and stomach. Suction the oropharynx under direct vision, remove any throat pack, check the surgical beds for oozing; orogastric suction for swallowed blood, which drives PONV.
Position. Lateral, slightly head down ('tonsil position') so blood drains out rather than onto the cords.
Extubate now. No; disconjugate gaze, coughing, breath-holding, and no response to voice are stage 2. Extubating here is the classic setup for laryngospasm. Wait for purposeful movement, conjugate gaze, regular breathing, and response to voice, or deepen and wait.

4. Noise after extubation

Extubated awake, following commands. Two minutes later: high-pitched inspiratory crowing, then silence; chest and abdomen heaving, no ETCO2 trace, SpO2 90% and falling. Dx? First action? Jaw thrust, CPAP with 100% O2, no air entry, SpO2 72%, HR 92. Next? Drug? Dose? Propofol given; still no air entry, SpO2 60%, HR 64. Now? Agent? Dose? Route? Atropine? Dose? Spasm breaks; masks easily, SpO2 99%. Reintubate? Why/why not? Cause in him?

Considerations and pitfalls AI draft

Dx. Laryngospasm: stridor progressing to complete obstruction with vigorous effort and no gas exchange.
First action. Call for help, remove the stimulus, suction blood from the pharynx, 100% O2 with tight-seal CPAP, jaw thrust with pressure at the laryngospasm notch behind the earlobe.
Drug. Propofol about 1 mg/kg IV (roughly 20 to 30 mg) to deepen and relax the cords; an IV is in place.
SpO2 60%, HR 64. Succinylcholine IV, dosed on actual weight (obesity raises pseudocholinesterase activity and extracellular volume, so ideal-weight dosing underdoses): 0.1 to 0.5 mg/kg (about 3 to 13 mg) to break the spasm, or 1 to 2 mg/kg (about 26 to 52 mg) if intubation is planned; IM 4 mg/kg (about 100 mg) only if there is no IV. Atropine 0.02 mg/kg IV (0.5 mg, the usual pediatric single-dose maximum) given with it, since hypoxia plus succinylcholine drives bradycardia. Re-oxygenation is the definitive fix for the bradycardia. Waiting for the HR to fall further before giving succinylcholine is the error.
Reintubate. Not required if he masks easily, oxygenates, and wakes fully; reintubate if obstruction recurs, oxygenation lags, or there is ongoing bleeding into the airway.
Cause. Blood or secretions on the cords from the tonsil and adenoid beds and an irritable airway; laryngospasm can follow an awake extubation, not only a deep one. Check the surgical field for bleeding before he leaves the room.

5. Desaturation in PACU

Assume morphine 0.8 mg in the OR. PACU, 45 minutes later: asleep, RR 12, obstructive pauses with SpO2 down to 84% on room air, rousable to touch. Cause? Rx now? Naloxone? Why/why not? Dose? Face-mask O2 and repositioning: SpO2 94% between events, but pauses with desaturation to 85% every few minutes. Ward bed with oximetry or PICU? Why? Mother asks, "Now that his tonsils are out, is his sleep apnea cured?" What will you tell her?

Considerations and pitfalls AI draft

Cause. His OSA plus residual anesthetic and opioid, early airway swelling, and sleep in the supine position. Look in the mouth for blood in the airway; a child can swallow a bleed, so a clean look does not fully exclude it.
Rx now. Rouse, reposition lateral or upright with jaw support, O2; CPAP by mask if available. A nasopharyngeal airway through a fresh adenoid bed is a poor choice.
Naloxone. Reasonable if there is an opioid component, in small titrated increments (about 1 mcg/kg, roughly 20 mcg, every 2 to 3 minutes) to restore breathing without full reversal of analgesia; it is short-acting, so he needs monitoring after. A full 0.1 mg/kg arrest dose is wrong for this.
Disposition. Recurrent desaturation needing oxygen and airway maneuvers in PACU moves him toward PICU or a unit with continuous monitoring and staff who can provide airway support; sending him to an unmonitored bed is unsafe. Revisiting the A2 plan on new data is the point.
Mother's question. Plain and honest: most children improve a lot, but it is not guaranteed; it is less likely to resolve fully in a child carrying extra weight. The first nights can be worse because of swelling and pain medicine, which is why he stays tonight. A repeat sleep study after he heals, weight management with his pediatrician, and CPAP if apnea persists. No false promise of a cure.

Short stem

Toddler with a current URI for bilateral myringotomy and tubes

A 2 y.o., 13 kg boy, born at term, is scheduled for bilateral myringotomy and tympanostomy tubes for recurrent otitis media with persistent bilateral effusions and delayed speech. For the past four days he has had clear rhinorrhea and an intermittent wet cough; he attends daycare, and his father smokes at home. He wheezed with two colds last winter and was treated with albuterol by nebulizer; he takes no daily medications. His mother gave him a cup of whole milk at 6:30 AM to settle him in the car, and the case is booked for 9:30 AM. In the pre-op area he is screaming, clinging to his mother, and pulling off the pulse oximeter. HR 128, RR 28, T 37.6 C, SpO2 98% on room air; lungs clear with transmitted upper airway sounds; no IV.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Proceed versus postpone with an active upper respiratory infection, and the risk conversation with the parent; respiratory risk reduction (bronchodilator, airway device, volatile choice) in a child with prior wheezing and smoke exposure; fasting intervals for milk and clear liquids; premedication and parental presence for the distressed toddler.

1. Rhinorrhea and cough on the day of surgery

Proceed today or postpone? Why? ENT: "He's in daycare. If we wait, he will just catch another cold." Change your call? Why/why not? Chest x-ray before you decide? Why/why not? Same child with T 38.6 C and coarse rhonchi. Proceed? Why/why not? Reschedule when? Why that interval? Back to today: afebrile, clear lungs, and you proceed. His mother asks whether the cold makes anesthesia more dangerous for him. What will you tell her?

Considerations and pitfalls AI draft

Proceed or postpone. A mild, uncomplicated URI (clear rhinorrhea, afebrile or low-grade, clear lungs, active child) before a short facemask case is commonly accepted. A strong response names what raises his risk of perioperative respiratory events (laryngospasm, bronchospasm, breath-holding, desaturation, severe cough): an active URI, a history of wheezing with colds, passive smoke exposure, young age, secretions. It also names what lowers it: a 10-minute case with no airway instrumentation. Either call is defensible when those are weighed. "It's just a cold" without engaging the wheeze history and the smoke, or reflex cancellation without weighing the benefit of surgery, are both flags.
ENT's argument. Legitimate in part. A daycare child may never have a clean four-week window, and tubes often break the cycle of ear infections and effusions. It supports proceeding with a mild picture; it does not override a sick child.
Chest x-ray. Not indicated with clear lungs and no fever; it adds delay and radiation and changes nothing. Reserve it for lower respiratory signs.
Fever and rhonchi. Systemic illness and lower respiratory tract involvement: postpone. This is an elective case, and the risk of bronchospasm, desaturation, and postoperative respiratory complications is now clearly higher.
Interval. Commonly 2-4 weeks after symptoms resolve; airway hyperreactivity can persist up to about 6 weeks. In a daycare child the next URI may arrive first, so the interval is judgment, not a fixed rule.
What to tell her. Plain and specific: the cold raises the chance of airway problems during and after anesthesia, such as coughing, breath-holding, a brief spasm of the vocal cords, or a drop in oxygen. These are usually short and treated in the room by a team ready for them; lasting harm is rare. Waiting has costs too (more infections, hearing and speech). Check that she understands and agrees with going ahead today. False reassurance ("no extra risk") or alarm are the flags.

2. Prior wheezing with colds

Bronchodilator before induction? Why/why not? Agent? Dose? Route? How long before induction? Assume nebulized albuterol. He screams through the whole treatment. Effective? Next? Oral steroid this morning? Why/why not? Significance of his father's smoking for today? Airway for the case: facemask? LMA? ETT? Which? Why? Maintenance: sevoflurane or desflurane? Why?

Considerations and pitfalls AI draft

Bronchodilator. Reasonable here. Albuterol pretreatment in children with a current or recent URI reduces perioperative bronchospasm and other respiratory events, and he has wheezed with colds before.
Agent, dose, timing. Albuterol 2-4 puffs (90 mcg/puff) by metered-dose inhaler with spacer and mask, or 2.5 mg nebulized, about 10-30 minutes before induction.
Screaming through it. Crying sharply reduces lung deposition, so calling it done is the flag. Options: repeat with spacer once the premedication has taken effect, or give it after induction through the circuit or facemask.
Oral steroid. No routine role for an uncomplicated URI with clear lungs, and a single dose this morning would not act in time. Active wheezing today would be a reason to postpone, not to give a steroid and go.
Smoke exposure. Passive smoke independently raises airway reactivity and laryngospasm risk, and it adds to the URI. Not a reason to cancel by itself; it raises the stakes of the plan and is worth raising with the family later.
Airway. Facemask with spontaneous ventilation is the usual technique for tubes and avoids instrumenting a reactive airway, the lowest-risk choice with a URI. If a device is needed, an LMA carries fewer respiratory events than an ETT. An ETT for a 10-minute ear case in a child with a URI adds risk without benefit.
Volatile. Sevoflurane. Desflurane is an airway irritant (coughing, breath-holding, laryngospasm), worse in children with reactive airways, and is not used for mask induction.

3. Morning milk before an elective case

Proceed at 9:30? Why/why not? Mother: "It was only a few sips." Change your call? Why/why not? Earliest start? ENT offers to go now with a rapid-sequence induction. Agree? Why/why not? Case moved to 12:30. May he drink anything until then? What? Until when? He drinks a cup of apple juice at 11:45. Start at 12:30? Why/why not? When?

Considerations and pitfalls AI draft

Proceed at 9:30. No. Cow's milk is a nonhuman milk with a 6-hour fasting interval under ASA guidance, the same as infant formula; breast milk is 4 hours. Some European guidance allows milk and other non-clear fluids at 4 hours; three hours fails either standard.
"Only a few sips". The type of ingestion sets the interval; caregiver estimates of volume are unreliable, and milk curdles into a solid load. With an airway already reactive, regurgitation during a mask induction is the risk. Proceeding on a parent's estimate is a flag.
Earliest start. 12:30 PM, 6 hours after the milk under ASA guidance. A center that follows a 4-hour rule for milk could start at 10:30; either way, apply one standard consistently.
RSI now. No. There is no IV, and placing one awake in a screaming 2-year-old is its own hazard; RSI in a small child carries real hypoxemia risk; an elective case does not justify a full-stomach technique when a 3-hour wait solves it.
Clear liquids. Yes, and encourage them (water, pulp-free apple juice, electrolyte drinks) to limit thirst, distress, and dehydration. ASA guidance is clear liquids until 2 hours before (10:30 AM); many pediatric anesthesia societies allow them until 1 hour before (11:30 AM). Either, applied consistently, is defensible.
Juice at 11:45. Inside either window. Delay to 12:45 under a 1-hour rule or 1:45 under a 2-hour rule. A short delay for a clear liquid is a small price; the larger goal is to avoid needlessly long fasts in toddlers.

4. Screaming in pre-op

Premedication? Why/why not? Agent? Route? Assume oral midazolam. Dose? Onset? He spits most of it out within seconds. Redose? Why/why not? Intranasal dexmedetomidine instead? Why/why not? Dose? Onset? His mother asks to come back for induction; she is tearful. Bring her? Why/why not? Will the midazolam delay his discharge? Why/why not?

Considerations and pitfalls AI draft

Premedication. Reasonable. A toddler fighting the oximeter will have a traumatic mask induction; high preoperative anxiety is linked to emergence delirium and to behavior changes at home afterward. Distraction and parental presence without a drug can work for some children; not engaging with his distress is the flag.
Midazolam. Oral 0.5 mg/kg (max 20 mg): 6.5 mg in a sweet vehicle. Onset about 10-15 minutes, peak effect about 20-30 minutes. Intranasal midazolam (0.2-0.3 mg/kg) is faster but burns.
Spat out. If it came out within seconds, little was absorbed and a repeat dose is reasonable. If the amount swallowed is unclear, a partial repeat or a different route. Stacking doses blindly without monitoring risks oversedation and airway obstruction in a child with a URI.
Intranasal dexmedetomidine. 1-2 mcg/kg (13-26 mcg). Onset about 25-45 minutes, so it needs lead time; it gives smoother emergence and less delirium, with mild bradycardia and hypotension. Drawbacks here: it may lengthen PACU stay after a 10-minute case, and copious nasal secretions may reduce absorption.
Parental presence. Can calm some children and improves parental satisfaction; it does not reliably replace a premedication, and a very anxious parent can raise the child's anxiety. Either decision can be defended. If she comes, she needs to know what she will see (eye rolling, noisy breathing, limb movement), when she will be asked to leave, and who will walk her out.
Discharge. Standard-dose oral midazolam adds little or no time to discharge after short procedures. Not a reason to withhold it.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Inhalational induction and the decision to proceed without an IV; judging depth and providing analgesia under a facemask; upper airway obstruction and laryngospasm from partial to complete, treated without IV access; agitation in PACU separated from hypoxia and pain; discharge readiness after an airway event.

1. Mask induction

In the OR he is drowsy and cries as the mask approaches. Sevoflurane alone? With nitrous oxide? Why? Start at 8% or step up? Why? Which monitor first? Why? At 40 seconds: eyes deviated, limbs flailing, holds his breath, HR 160. Interpretation? Rx? Two minutes in: regular breathing, eyes central, HR 125. IV now? Why/why not? Assume you try. Two attempts fail; ENT is ready. Proceed without an IV? Why/why not? What do you have ready? Doses?

Considerations and pitfalls AI draft

Nitrous oxide. Either, if defended. Nitrous oxide 60-70% speeds induction and is odorless, so the mask is better tolerated before sevoflurane is introduced; it lowers the delivered FiO2, so many switch to 100% oxygen once he is asleep.
8% vs step up. In a crying child, starting at 8% exploits large tidal breaths for a fast induction. Stepwise increases suit a calm, cooperative child. Leaving 8% on after loss of consciousness invites bradycardia and hypotension; turn it down once he is asleep.
Monitor first. Pulse oximeter first, the least intrusive; ECG, BP cuff, and capnography through the mask as soon as he tolerates them. Fighting a screaming toddler to place every monitor before induction is the flag; inducing without a pulse oximeter is the larger one.
Excitement phase. Stage 2 (excitement): disinhibited movement, breath-holding, and the highest risk of laryngospasm and vomiting. Keep the mask sealed, support the airway with chin lift and gentle CPAP, keep the room quiet, and let depth increase. Avoid stimulation: no IV attempt, no oral airway, no suctioning.
IV now. Once deep (regular breathing, central eyes, a few minutes after loss of consciousness). Many tubes cases are done without an IV; with a URI and a wheeze history many would try for one. Either is defensible.
Proceed without an IV. Accepted for a short facemask case in a healthy child; repeated attempts lengthen the anesthetic and the airway exposure. The condition is a ready rescue plan, and starting without one is the flag.
Ready. Labeled syringes with IM succinylcholine 4 mg/kg (52 mg) and atropine 0.02 mg/kg (about 0.26 mg) with intramuscular needles; an IO kit; oral airways, an LMA, laryngoscope, and a 4.0 cuffed ETT with a 3.5 cuffed as backup.

2. Maintenance under facemask

Assume no IV. Facemask, sevoflurane 2.5% in oxygen, spontaneous ventilation, head turned for the right ear. RR 26. Depth adequate? What tells you? Analgesia: what? Route? Dose? Ketorolac? Why/why not? Head turned for the left ear. Snoring, rocking chest and abdomen, a flattened ETCO2 trace, SpO2 94%. DDx? Rx? Oral airway now? Why/why not? Jaw thrust restores a clean trace. Tubes and drops in at 9 minutes. Sevoflurane off now, or keep him deep to PACU? Why?

Considerations and pitfalls AI draft

Depth. Regular breathing with no change in rate or pattern, no movement or tachycardia when the speculum goes in and the canal is cleaned, central eyes, and an end-tidal sevoflurane around 1-1.5 MAC (sevoflurane MAC at age 2 is about 2.5%). Too light in a child with a URI means laryngospasm with stimulation or secretions.
Analgesia. Pain after tubes is usually mild and brief. Acetaminophen 15 mg/kg orally with the premedication (about 195 mg) or rectally now (30-40 mg/kg, about 390-520 mg, slow and variable absorption; count it toward the daily maximum); intranasal fentanyl 1-2 mcg/kg (13-26 mcg) is common and reduces emergence agitation, though nasal secretions can blunt absorption; ENT's otic drops.
Ketorolac. 0.5 mg/kg IM (6.5 mg) is an option without an IV; bleeding risk is trivial for tubes. The cost is an intramuscular injection. Acetaminophen with or without an NSAID is often enough.
DDx. Soft-tissue upper airway obstruction as the head turns and the pharynx relaxes (most likely), partial laryngospasm, secretions, a mask leak or poor fit.
Rx. Jaw thrust, chin lift, reposition the head and neck (shoulder roll), CPAP 5-10 cmH2O with 100% oxygen, and check that the mask seal holds while the surgeon works.
Oral airway. Only if he is deep and it is sized correctly; inserted in a light plane it can trigger coughing and laryngospasm. A nasal airway in a child with a URI risks bleeding into the airway.
Off now vs deep to PACU. Both are defensible: wake fully in the OR, or transfer deep in the lateral position with oxygen and an undisturbed recovery. The hazard is stimulating him (suctioning, moving, pulling the mask) while he passes through the light transitional plane. A strong response states a plan for where that happens and who is watching.

3. Noise at the end of the case

Assume sevoflurane is off and he is still in the OR on 100% oxygen by mask. Two minutes later he coughs on secretions, then a high-pitched inspiratory noise, suprasternal retractions, a small ETCO2 trace, SpO2 93%. DDx? Rx? The noise stops. Chest and abdomen heave, no ETCO2 trace, the bag will not move. SpO2 80%. Next? Turn the sevoflurane back up? Why/why not? Drug? Route? Dose? SpO2 62%, HR 80 from 140. Rx? Ninety seconds after the injection the bag moves and SpO2 climbs to 97%; he is apneic. Mask, LMA, or ETT? Which? Why? Abdomen distended. Of concern? Rx?

Considerations and pitfalls AI draft

DDx. Partial laryngospasm is most likely: a cough on secretions in a light plane right after the volatile was turned off, in a child with a URI. Also secretions or soft-tissue obstruction. Bronchospasm is expiratory, with wheeze and a sloped capnogram, not inspiratory stridor.
Rx, partial. Call for help; 100% oxygen with a tight seal and CPAP; jaw thrust with firm pressure at the laryngospasm notch (Larson's point); suction the pharynx; stop all stimulation. Deepening with sevoflurane can work while gas is still moving; propofol 0.5-1 mg/kg is the usual next step when an IV is present.
Complete, next. Silent chest with vigorous effort, no ETCO2, no bag movement. CPAP alone often fails now; gentle positive-pressure attempts continue, but the drug comes next. Watching the saturation fall while repeating maneuvers is the error.
Sevoflurane up. No gas exchange means no uptake; it wastes time.
Drug. Succinylcholine IM 4 mg/kg (52 mg) into the deltoid or vastus lateralis; relaxation begins within about 1-2 minutes (faster in the deltoid), peak effect by 3-4 minutes, and absorption falls if perfusion is poor. IO 1-2 mg/kg if an IO is placed. Give atropine 0.02 mg/kg (about 0.26 mg) IM with it in a hypoxic child. Succinylcholine carries a boxed warning in children for hyperkalemic arrest with undiagnosed myopathy, but hypoxic laryngospasm without IV access is an accepted indication; watch the ECG afterward and keep malignant hyperthermia in mind (rising ETCO2, rigidity, temperature).
HR 80 from 140. Hypoxic bradycardia in a toddler is pre-arrest. Oxygenation is the definitive treatment; give atropine if not already given; if HR falls below 60 with poor perfusion despite oxygenation, start CPR with epinephrine via IO per PALS.
Airway after the break. IM succinylcholine lasts longer than an IV dose. Bag-mask ventilation with 100% oxygen until spontaneous breathing returns is reasonable when the mask is easy; an LMA is reasonable; intubate for suspected aspiration, persistent hypoxemia, or difficult mask ventilation. Place the IV now while he is relaxed. Listen for crackles and look for frothy secretions.
Distended abdomen. Gastric insufflation from positive pressure against closed cords: it splints the diaphragm, lowers FRC, and raises regurgitation risk. Decompress with an orogastric or suction catheter.

4. Agitation in PACU

PACU, 20 minutes later, IV in place. SpO2 97% on blow-by oxygen, RR 30. He arches, kicks, pulls at the IV, and does not settle in his mother's arms. DDx? First thing you check? Why? Glucose 92, chest clear, ETCO2 by nasal sampling 42. He does not look at his mother's face and does not quiet when she holds him and talks to him. Interpretation? Treat now or wait? Why? Drug? Dose? Midazolam? Why/why not? He settles after the drug. Why him? What lowers the risk at his next anesthetic?

Considerations and pitfalls AI draft

DDx. Hypoxia or hypercarbia (after laryngospasm: aspiration, pulmonary edema, residual weakness), pain (ear, injection sites, succinylcholine myalgia), emergence delirium, hypoglycemia after a long fast, full bladder, distress at the IV and restraint. Sedating agitation before excluding hypoxia is the dangerous error.
First check. Oxygenation and ventilation: a reliable SpO2 waveform, work of breathing, breath sounds.
Interpretation. No eye contact, no purposeful actions, unaware of surroundings, and not consoled by a parent fit emergence delirium (the PAED scale formalizes these). Pain is usually consolable, localizes, and responds to the parent.
Treat or wait. Often self-limited within 10-20 minutes. Treat when he risks injury or losing the IV, or when it persists; keep him safe and the parent at the bedside meanwhile.
Drug. Dexmedetomidine 0.3-0.5 mcg/kg IV slowly (about 4-6.5 mcg); propofol 0.5-1 mg/kg (6.5-13 mg) works fast but needs close airway watch after laryngospasm; fentanyl 0.5-1 mcg/kg (6.5-13 mcg) if pain contributes.
Midazolam. Not a first-line rescue; its effect on emergence delirium is inconsistent and it can prolong recovery or cause paradoxical agitation.
Why him. Age 2-5, sevoflurane, ENT surgery, high pre-op anxiety, rapid emergence, pain.
Next anesthetic. Effective premedication; dexmedetomidine (intranasal pre-op or IV during the case); a propofol bolus at the end or a propofol-based technique; adequate analgesia; a calm emergence. Record what worked. The same list overlaps with what lowers laryngospasm risk: suctioning while deep, no stimulation in the light plane, and IV access for propofol.

5. Readiness for home

One hour later: calm, eating a popsicle. SpO2 94% on room air, RR 30, intermittent wet cough, scattered coarse breath sounds that clear with coughing. Home today? Why/why not? How long do you watch him? Why that long? Must he drink before he leaves? Void? Why/why not? Pain at home: drug? Dose? Interval? His mother asks for something stronger, "like codeine." Prescribe? Why/why not? Anything from today for the record before his next anesthetic? What?

Considerations and pitfalls AI draft

Home today. Not yet. He was 98% on room air before the case; 94% an hour after laryngospasm with desaturation to the 60s, positive-pressure ventilation, and IM succinylcholine is below his baseline. DDx: URI secretions, atelectasis, negative-pressure pulmonary edema, aspiration. Extend observation; CXR if hypoxemia persists or crackles appear; admit for monitored observation if he cannot hold his baseline on room air. Discharging on a "good enough" 94% because he looks well is the flag; so is reflex admission once he is back to baseline.
How long. Negative-pressure pulmonary edema usually appears within minutes to an hour or two of the obstruction but can be delayed for several hours. Several hours of observation, with room-air saturation at baseline and normal work of breathing, before he goes.
Drink, void. Neither is required. Mandatory drinking increases vomiting and delays discharge; voiding is not required in a low-risk child without a neuraxial block or urologic surgery.
Pain at home. Acetaminophen 15 mg/kg (about 195 mg) every 6 hours, max 75 mg/kg/day; ibuprofen 10 mg/kg (about 130 mg) every 6-8 hours; ENT's otic drops. Pain after tubes is usually mild and short.
Codeine. No. Codeine (and tramadol) is contraindicated in children under 12 (FDA) because ultrarapid CYP2D6 metabolism has caused fatal respiratory depression. Scheduled acetaminophen and ibuprofen cover pain after tubes.
Record. Laryngospasm with desaturation on emergence during a URI, rescued with IM succinylcholine and atropine; emergence delirium and what treated it. Neither contraindicates a future inhalational induction. Smoke exposure is worth raising with the family.

Short stem

Total shoulder arthroplasty with severe COPD in the beach chair

A 71 y.o., 5'9", 96 kg man is scheduled for right total shoulder arthroplasty in the beach chair position. He has severe COPD on tiotropium and budesonide-formoterol, uses oxygen at night, and was hospitalized six weeks ago for an exacerbation treated with a prednisone course. He has obstructive sleep apnea and does not tolerate his CPAP, hypertension on amlodipine and lisinopril, and type 2 diabetes. He quit smoking two years ago after a 55 pack-year history. The surgeon has requested "a block so we can avoid a general." BP 168/92; P 84; RR 20; SpO2 91% on room air; T 36.9°C. On exam he has a barrel chest with scattered expiratory wheezes, a Mallampati III airway, and a thick neck with full range of motion.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Fitness for elective surgery after a recent COPD exacerbation; block selection when the phrenic nerve is not expendable; cerebral perfusion planning for the beach chair; sedation strategy in OSA with CO2 retention.

1. Pulmonary status and readiness

Preop clinic, six weeks after the exacerbation. Proceed as scheduled? What tells you he is back at his baseline? Room-air ABG: pH 7.38, PaCO2 54, PaO2 62, HCO3 31. Interpretation? Does that cancel the case? Why/why not? PFTs — order them? What result would change your plan? Morning of surgery: scattered wheezes, no change in sputum, SpO2 91%, same as clinic. Proceed? Preop bronchodilator — which? Steroid burst? Why/why not? Surgeon asks whether another month of waiting makes him safer. Your answer?

Considerations and pitfalls AI draft

Proceed / baseline. The question is whether he is at his baseline, not whether he is normal: symptom trajectory since the exacerbation, exercise tolerance, sputum, exam against his usual state. Demanding normality from a severe COPD patient, or waving everyone through, both deserve a probe.
ABG. Compensated chronic respiratory acidosis (PaCO2 54, HCO3 31, near-normal pH) with moderate hypoxemia; a retainer with limited reserve. It does not cancel the case; it sets sedation, oxygen, and the cost of any new diaphragmatic insult.
PFTs. Quantify severity but rarely change an elective shoulder decision; want a reason for the test, not a reflex panel. FEV1 well below his prior value would prompt a look for an unresolved exacerbation.
Wheezes on the day. Chronic wheeze at baseline is his normal; new wheeze, more sputum, or a falling saturation argues for treatment or delay. Same as clinic means proceed.
Preop Rx. Usual inhalers that morning plus a nebulized beta-agonist and ipratropium before the block; a fresh steroid burst for a patient at baseline is overtreatment (glucose, healing).
Another month. Postponement only buys something if something will improve: unresolved exacerbation, new infection, reversible bronchospasm. Six weeks out and at baseline, more waiting buys little; a plan built around his fixed limits is the defensible answer.

2. Block selection and his breathing

Surgeon wants a block, no general. Interscalene as the sole anesthetic in him — yes/no? Why? Incidence of hemidiaphragmatic paresis after a standard-volume interscalene — number? How much vital capacity does that cost him? Supraclavicular instead? Why/why not? Suprascapular plus axillary nerve blocks as the sole anesthetic for an arthroplasty — will they carry the case? Why/why not? Interscalene at 5 mL instead of 20 — does that solve the phrenic problem? Your plan: low-volume interscalene awake, supraclavicular, or GA with a phrenic-sparing analgesic block? Which? Why?

Considerations and pitfalls AI draft

Interscalene yes/no. The standard surgical block for shoulder arthroplasty, and the crux of the case: phrenic (C3-C5) spread at this level produces ipsilateral hemidiaphragmatic paresis in essentially 100% of standard-volume blocks. A flat yes without naming that cost is the flag; a flat no without an alternative is the other.
Numbers. Near 100% paresis at 20 mL; roughly 25-30% loss of vital capacity. In severe COPD with nocturnal oxygen and CO2 retention, that loss may not be tolerable.
Supraclavicular. Phrenic involvement roughly a third to a half at standard volumes, not zero; adds pneumothorax risk in a hyperinflated chest with bullous-prone apices; coverage of the superior shoulder less reliable. Reduces, does not remove, the problem.
Suprascapular + axillary. Phrenic-sparing and good analgesia, but they do not anesthetize the full surgical field (skin over the shoulder cape, deep capsule, glenoid); as the sole anesthetic for an arthroplasty they fail. Claiming they carry the case awake should be challenged.
5 mL. Low-volume ultrasound-guided injection roughly halves paresis (about 45% in the classic 5 mL vs 20 mL comparison) but is analgesic-grade and risks an inadequate surgical block. A risk modifier, not a fix.
Committed plan. All three are defensible if the residual risk and rescue path are named: low-volume interscalene with an explicit conversion plan, supraclavicular with pneumothorax vigilance, or conceding that GA with a phrenic-sparing analgesic block is safer than forcing an awake technique on a retainer. What fails is a plan with no named fallback.

3. Beach chair and cerebral perfusion

Beach chair at 70 degrees. Arm cuff at heart level reads MAP 80. MAP at his brain — roughly? Cuff on the calf instead — better or worse? Why? His clinic pressure is 168/92. Target MAP for him, measured at the arm? Why that number? Arterial line — yes/no? Why? Under GA in this chair, how do you know his brain is perfused? Awake under a block — how? Lisinopril this morning — give or hold? Amlodipine? Why?

Considerations and pitfalls AI draft

MAP at the brain. About 0.77 mmHg per cm of vertical height; the external auditory meatus sits 20-25 cm above the heart in a 70-degree chair, so cerebral MAP runs roughly 15-20 mmHg below the arm: MAP 80 at the arm is about 60-65 at the brain. Want the subtraction done out loud.
Calf cuff. Worse; the calf is below the heart, so the reading overestimates cerebral pressure by an even larger margin.
Target. Chronic hypertension right-shifts autoregulation; a normal MAP may be relative hypotension for him. Common framing: stay within 20-30% of his baseline MAP (~117), corrected for the gradient, so arm MAP roughly 85-90 or higher. A target of 65 lifted from the ICU is the trap.
Arterial line. Reasonable: beat-to-beat pressure, hypertension with a wide swing risk, hydrostatic gradient, and a sedation plan that will itself drop pressure. Transducer zeroed at the meatus if used for the cerebral question.
Cerebral monitoring. Under GA there is no direct signal; cerebral oximetry or a tighter pressure target substitutes. Awake, his conversation is the monitor: a real advantage of block-plus-sedation.
Antihypertensives. Hold the ACE inhibitor the morning of surgery (refractory hypotension under anesthesia, in a position that already threatens perfusion); continue the calcium channel blocker. Controlled but not bottomed-out.

4. Sedation in OSA with CO2 retention

Block plus sedation. Agent? Why that one? Propofol infusion at 50 mcg/kg/min — acceptable? Why/why not? Midazolam 2 mg plus fentanyl 100 mcg up front? Why/why not? Depth you are titrating to — describe it. Oxygen — how much, by what? Monitoring beyond standard? Rescue for obstruction with the head draped and semi-sitting — your sequence? Given that rescue, still start with sedation rather than GA? Why/why not?

Considerations and pitfalls AI draft

Agent. Dexmedetomidine preserves respiratory drive and arousability and is the reasoned pick, with the caveat that its bradycardia and hypotension compound sitting-position physiology; small ketamine adjunct acceptable. No agent is safe at excessive depth.
Propofol 50. That rate in an OSA retainer is deep sedation with an unprotected, draped airway; a titrated low-dose infusion is defensible only with the endpoint below kept honest.
Midazolam + fentanyl. The classic offender combination in OSA; opioids depress the hypercapnic drive he leans on. Opioid-sparing sedation is the point of the block.
Endpoint. Responsive and conversant through the case; that conversation is also the cerebral and airway monitor. Sedation deep enough to obstruct has overshot.
Oxygen. Titrated to SpO2 ~88-92% by nasal cannula; liberal oxygen masks hypoventilation on the oximeter in a retainer.
Monitoring. Capnography under the drapes at minimum; arterial line per A3.
Obstruction rescue. Stop the infusion, verbal and physical stimulation, jaw thrust or nasal airway as access allows, call for drapes down, surgeon pauses, convert to GA if not quickly recoverable. No rehearsed sequence is the flag.
Still sedation?. Rescue difficulty is a genuine argument for GA from the start; light sedation with a rehearsed conversion is the counterargument. Either, if the risk is acknowledged before the drapes go up.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Executing a phrenic-conscious interscalene plan; early LAST recognition and the proceed-or-cancel decision; sitting-position hemodynamics and vasovagal bradycardia; mid-case respiratory deterioration and conversion to general anesthesia; PACU disposition and disclosure.

1. Performing the block

Interscalene with light sedation, ultrasound. Agent? Concentration? Volume? Why that volume in him? Total dose in mg — your ceiling for him? Computed on what weight? Dexamethasone — perineural or IV? Dose? Epinephrine in the syringe — yes/no? Why? Injection — describe exactly how you give it. Twenty minutes later: numb hand, weak grip, still shrugs and abducts the shoulder. Surgical block? What do you test?

Considerations and pitfalls AI draft

Agent / volume. Ropivacaine 0.5% is standard; the tension is explicit: 15-20 mL is surgical-grade and near-certain phrenic palsy, 5-8 mL roughly halves paresis but may be non-surgical. Want the resident to own the trade-off chosen in A2 and name the fallback if the block proves inadequate. An unreflective 20-30 mL ignores the preop discussion; an unreflective 5 mL 'surgical' block ignores pharmacology.
Ceiling. A number in milligrams, on lean or ideal body weight: ropivacaine about 3 mg/kg lean, roughly 200 mg for him, not 3 x 96 = 288. Bupivacaine lower (~2 mg/kg).
Dexamethasone. Perineural 4 mg and IV 8-10 mg both prolong analgesia with a modest perineural edge in meta-analyses; IV avoids off-label perineural use; either if reasoned. Dexmedetomidine also prolongs but adds bradycardia and hypotension, unwelcome in the chair.
Epinephrine. 2.5-5 mcg/mL as an intravascular marker and to slow uptake; reasonable. Note it can contribute to the vasovagal reflex in the sitting position.
Injection. The LAST-prevention bundle: needle tip in view, 3-5 mL aliquots, aspirate between each, low injection pressure, stop for any symptom.
Surgical adequacy. A numb hand is not a numb shoulder. Test sensory loss over the deltoid (axillary), the cape of the shoulder where the incision runs (supraclavicular nerves C3-C4, often needing a superficial cervical plexus supplement), and motor loss of abduction and external rotation. Preserved shrug and abduction at 20 minutes means the block is not surgical; supplement or convert.

2. Symptoms after injection

Ninety seconds after the last aliquot he is restless, reports ringing in his ears and a metallic taste. Dx? Rx now? Lipid now — yes/no? Why? Lipid kit is at the bedside. Bolus you will give — mL? On what weight? Then what rate? Midazolam drawn up — dose? He seizes despite it — next drug? Propofol? Why/why not? He arrests. Epinephrine — dose per push? Why? Amiodarone or lidocaine for VT? Vasopressin? Ten minutes later he is back at baseline, no arrhythmia, block setting up. Proceed with surgery today? Why/why not?

Considerations and pitfalls AI draft

Dx. Prodromal local anesthetic systemic toxicity: tinnitus, metallic taste, agitation are the classic early neurologic signs. Calling it anxiety is the dangerous miss.
Rx now. Stop injecting, call for help and the lipid kit, 100% oxygen, confirm IV, continuous monitoring, benzodiazepine drawn up, ACLS at hand.
Lipid now. For isolated prodromal symptoms most prepare and watch; any seizure, arrhythmia, or hemodynamic sign triggers it immediately. Aggressive-early or prepared-watchful both fine if the trigger is explicit.
Lipid dose. 20% lipid: 1.5 mL/kg on lean weight, about 100 mL bolus over 2-3 minutes (ASRA's simplified 100 mL for >70 kg), then 200-250 mL over 15-20 minutes (~0.25 mL/kg/min); repeat bolus for persistent instability; upper limit around 12 mL/kg.
Seizure. Midazolam 2-4 mg (or lorazepam) first; airway and oxygenation; start lipid. Propofol only in small doses with stable hemodynamics; it is not the lipid therapy and depresses the myocardium.
Arrest drugs. Epinephrine in small aliquots (≤1 mcg/kg, ~50-100 mcg) because large doses worsen LAST arrhythmias and blunt lipid efficacy; amiodarone for VT; no lidocaine or other class I agents; no vasopressin; expect prolonged CPR and mobilize ECMO/bypass early.
Proceed or cancel. Genuinely debatable: symptoms resolved, block in, elective case. Proceeding with heightened monitoring is done; cancelling after a systemic toxic event is equally defensible. Want an owned decision with reasons and what the surgeon is told.

3. Sitting him up

You proceed. Chair up to 70 degrees. Arm cuff 102/58, HR 76, talking to you. MAP at his brain? Acceptable for him? Why/why not? Rx? Phenylephrine or ephedrine? Dose? Forty minutes in: pale, nauseated, HR 38, BP 74/40. DDx? Most likely? Mechanism? Rx — atropine, ephedrine, or epinephrine first? Dose? Why that one? He recovers over five minutes. What do you change for the rest of the case?

Considerations and pitfalls AI draft

MAP at the brain. Arm MAP ~73 minus 15-20 = mid-50s. Against a baseline MAP near 117, that is a large fractional drop for a chronic hypertensive; marginal at best.
Rx. Vasopressor, modest fluid, lower the chair angle if surgeon allows, lighten sedation; while he is conversant his mentation corroborates. Phenylephrine 50-100 mcg boluses or an infusion; ephedrine 5-10 mg if rate is also soft.
DDx. Vasovagal (Bezold-Jarisch-type) reflex of the sitting position, spreading or high block, oversedation, ischemia, embolic event, anaphylaxis. Abrupt bradycardia with pallor and nausea in a sitting shoulder patient under block points strongly vasovagal.
Mechanism. Venous pooling reduces ventricular filling; sympathetic tone (plus any absorbed epinephrine) drives vigorous contraction of an underfilled ventricle; ventricular mechanoreceptors fire a paradoxical vagal reflex: bradycardia, vasodilation, hypotension. Up to a fifth of sitting shoulder cases under interscalene with sedation.
Which first. Combined bradycardia and hypotension: ephedrine 10 mg addresses both; atropine 0.5 mg for the rate; epinephrine 10-20 mcg for profound or refractory collapse. Any sequenced escalation is fine; fluid alone or waiting is the failure.
Change for the remainder. Vasopressor infusing or at hand, volume topped up, leaner sedation, lower threshold to treat; recurrence is common once the reflex has fired.

4. Dyspnea mid-case

Two hours in: dyspneic and anxious, SpO2 87% on 4 L. DDx? First thing you check at the bedside? Breath sounds equal, no wheeze, lung sliding both sides, breathing shallow and fast, EtCO2 52. Now which? Rx? Midazolam 2 mg to settle him? Why/why not? He tires: RR 34, SpO2 84%, surgeon has 45 minutes left. Convert to GA? Level him or stay sitting? Why? Induction drugs and doses? Tube or LMA? Why?

Considerations and pitfalls AI draft

DDx. Hemidiaphragmatic paresis declaring itself, pneumothorax, bronchospasm, oversedation with hypoventilation, aspiration, ischemia or failure. In severe COPD under interscalene, phrenic palsy leads.
Bedside. Auscultation for wheeze and symmetry, sedation depth, capnogram, ultrasound for lung sliding and diaphragm motion: targeted discrimination, not a shotgun.
Now which. Equal breath sounds, no wheeze, sliding present, rising CO2 with shallow fast effort = diaphragmatic paresis with an exhausting accessory-muscle pattern; the anticipated complication.
Rx. Sit more upright if possible, oxygen up with attention to retention, stop sedation contributors, prepare the escalation path. The block will not recede on a useful timescale; NIV is a bridge at best under a head-and-neck field.
Midazolam. No; sedating an exhausted hypercapnic patient removes the drive keeping him alive and converts compensation into failure.
Conversion. Call for help, surgeon pauses, drapes down for airway access, level or partially recline (laryngoscopy fully sitting without a compelling reason is the flag), preoxygenate as tolerated, induction with hemodynamic care in a preload-reduced patient: etomidate 0.2-0.3 mg/kg or reduced propofol with pressor running, rocuronium 1.2 mg/kg, a cuffed tube rather than a supraglottic in a shoulder case with limited later access and a retainer who will need controlled ventilation.

5. PACU and the conversation

Case done, extubated, PACU, dense block, comfortable. Orders for tonight? 0200: block gone, pain 9/10. Rx? Opioid — which, what dose, what monitoring? Disposition — floor, telemetry, or monitored bed? Why? Surgical pathway sends shoulders home POD 1. Right for him? Why/why not? His wife asks what happened during the block this morning. What will you tell her?

Considerations and pitfalls AI draft

Orders. Get ahead of block regression: scheduled acetaminophen, NSAID if renal function and surgeon allow, ice, and a rescue plan timed to the expected overnight recession rather than started after rebound pain.
Opioid. Low-dose short-acting (oxycodone 5 mg or small IV hydromorphone titrated), sedation scoring, continuous oximetry and capnography where available; he combines OSA without CPAP, CO2 retention, and a fresh phrenic hit.
Disposition. Monitored bed: the triad above plus the day's events (LAST prodrome, vasovagal collapse, respiratory failure with conversion). His overnight respiratory risk decides it, not the surgical routine.
POD 1 discharge. The pathway is for the average patient; anticipate a longer monitored course and tell the surgical team now rather than at dawn.
His wife. A plain account: early warning signs of local anesthetic toxicity appeared, the injection was stopped, he was treated and monitored, it resolved; what it means for future anesthetics (a documented event, not an allergy). Honest and unhedged without catastrophizing.

Short stem

Ankle ORIF with popliteal sciatic and saphenous blocks in a diabetic with neuropathy and OSA

A 61 y.o., 5'5", 102 kg woman is scheduled for open reduction and internal fixation of a right trimalleolar ankle fracture-dislocation, reduced and splinted in the ED 6 days ago after a fall on ice; the swelling has now settled. Type 2 diabetes, HbA1c 8.6%, on metformin, with numbness in both feet. Obstructive sleep apnea on nightly CPAP. She lives alone in a second-floor walk-up and plans to go home this afternoon. BP 146/84; HR 78; SpO2 95% on room air; creatinine 0.9 mg/dL. Mallampati III.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Matching blocks to the ankle's innervation and the tourniquet; regional anesthesia in a patient with diabetic neuropathy; airway risk with OSA and obesity when choosing GA or sedation; answering a surgeon's compartment syndrome objection and choosing single shot or catheter.

1. Block plan for the ankle

Regional plan for this ORIF. Which block(s)? Why? Surgeon plans a medial malleolus screw and a lateral fibular plate. Both incisions covered by your plan? Why/why not? Surgeon will use a thigh tourniquet. Do your blocks cover it? Why/why not? Calf tourniquet instead. Any different? Why? Spinal instead? Advantages in her? Disadvantages? Which do you choose? Why?

Considerations and pitfalls AI draft

Which blocks. Popliteal sciatic plus a saphenous block (adductor canal or a more distal saphenous approach). The sciatic, through the tibial and common peroneal nerves and the sural, supplies the bones, joint, and most of the skin of the ankle and foot; the saphenous supplies the skin of the medial leg and medial malleolus. Popliteal alone leaves the medial skin incision uncovered; a weak answer names the sciatic and stops. Some learners will say the saphenous adds little to deep pain; it still matters for a medial incision.
Incisions covered. Medial incision is saphenous skin; lateral fibular incision is superficial peroneal and sural (sciatic). Bone and periosteum are mostly sciatic.
Thigh tourniquet. Not covered. A thigh cuff compresses femoral, obturator, lateral femoral cutaneous, and posterior femoral cutaneous territory and the sciatic above the popliteal block. Expect tourniquet pain after 30 to 60 minutes; the blocks need GA, sedation, or neuraxial on top.
Calf tourniquet. Sits over territory the popliteal and saphenous blocks largely cover, so it is better tolerated, though many patients still need sedation. It also sits near the common peroneal nerve at the fibular neck, one reason some surgeons avoid it. A surgical choice, worth asking about.
Spinal instead. Advantages: avoids airway instrumentation with OSA and covers the tourniquet. Disadvantages: urinary retention, delayed ambulation and discharge, hypotension, no analgesia beyond a few hours unless blocks are added anyway. A short-acting spinal (mepivacaine, or chloroprocaine only if the case will be short, since it lasts about an hour) plus blocks for analgesia is a defensible alternative.

2. Pre-existing numbness and the block

Monofilament sensation absent to mid-shin in both legs, ankle reflexes absent, strength 5/5 throughout. Peripheral nerve block in her? Why/why not? What do you document before the block? Nerve stimulator, useful in her? Why/why not? Ropivacaine concentration? Volume? Why? Epinephrine in the injectate? Why/why not? Fingerstick glucose 212 mg/dL. Dexamethasone to prolong the block? Perineural, IV, or none? Dose? Why?

Considerations and pitfalls AI draft

Block in her. Not contraindicated. Diabetic neuropathy is a relative risk factor for block-related nerve injury (the injured nerve may be more vulnerable to a second insult), weighed against real benefits: opioid sparing with OSA, avoiding a deeper anesthetic. A reflexive refusal and a reflexive yes without discussing the risk are both weak.
Documentation. A written baseline sensory and motor exam of both legs, including the distribution and level of the numbness, and the risk discussion with her. Without a baseline, any postoperative deficit cannot be attributed.
Nerve stimulator. Less reliable: neuropathic nerves may need higher currents to produce a motor response, so a missing twitch does not mean the needle is far away. Ultrasound is the primary guide; stimulation is an adjunct at most.
Concentration and volume. Many reduce concentration and volume in a neuropathic nerve, which may be more sensitive to local anesthetic and may block longer. A reasonable answer is ropivacaine 0.375% to 0.5% at a modest volume, with a stated reason.
Epinephrine. Many avoid it here: vasoconstriction on an already poorly perfused nerve is a theoretical added risk. Not an absolute rule; a learner who wants it as an intravascular marker should say why and how much.
Dexamethasone. IV dexamethasone 4 to 8 mg prolongs a single-shot block nearly as well as perineural and avoids an off-label perineural injection on a neuropathic nerve. It also reduces PONV. Expect a modest glucose rise peaking hours later; glucose 212 is not a reason to withhold 4 mg, but it is a reason to recheck glucose before discharge and tell her to monitor tonight. Omitting it is defensible if stated with a plan for the shorter block.

3. Anesthetic plan with the blocks

Assume blocks, no spinal. Anesthetic for the case: GA or sedation? Which? Why? Assume GA. LMA or ETT? Why? Fentanyl at induction? Dose? Why? Propofol sedation with a natural airway and nasal cannula instead? Why/why not? Her CPAP in PACU? Why/why not? She left her CPAP machine at home. Next?

Considerations and pitfalls AI draft

GA vs sedation. The thigh tourniquet makes sedation alone hard; deep sedation in a patient with OSA, Mallampati III, and BMI about 37 means an unprotected airway at its most obstructed. GA with a controlled airway is the more defensible plan; light sedation with the blocks is defensible only if the surgeon uses a calf tourniquet and the learner sets a low ceiling.
LMA vs ETT. LMA is reasonable for a fasted patient in a case of this length if she has no reflux or symptoms of gastroparesis; ETT is defensible given BMI about 37 and the possibility of diabetic autonomic neuropathy with delayed gastric emptying. A strong learner asks about reflux and early satiety. The weak answer is an LMA with no thought about aspiration or about seal and ventilation in obesity.
Fentanyl. Little is needed: the blocks cover the surgical field. A small dose (25 to 50 mcg) for LMA insertion and early tourniquet stimulation is reasonable; ketamine is an opioid-sparing option for tourniquet pain later. Long-acting opioid in a patient with OSA is the error.
Natural airway sedation. Obstructs, desaturates, and invites escalating propofol until she is under a GA without an airway; nasal cannula oxygen hides hypoventilation from the pulse oximeter, so capnography is the monitor that would show it.
CPAP. Yes, in PACU and whenever she sleeps tonight, especially with any opioid.
Machine at home. Hospital CPAP in PACU (auto-titrating, or her settings if known). Her own machine is at home, so it is available tonight; a patient who will not use it at home is a reason to limit opioid or reconsider same-day discharge.

4. Surgeon's objection to a block

Surgeon: "No nerve block. If she gets compartment syndrome, I won't know." Her risk with this injury? Why? Block anyway? Why/why not? What would make you agree to skip it? Assume the blocks go ahead. Single shot or a popliteal catheter? Why? What finding tonight would make you worry about compartment syndrome? Why? Neurovascular checks, how often? For how long?

Considerations and pitfalls AI draft

Risk. Low, not zero. Acute compartment syndrome is mainly a tibial shaft, high-energy, or crush-injury problem; an ankle fracture six days out with swelling settled is a low-risk setting, though the fixation itself is a second insult. A learner who treats every lower-leg fracture the same has missed the risk stratification.
Block anyway. Reasonable in a low-risk injury, with a plan the surgeon can live with: dilute local anesthetic for any infusion, documented neurovascular checks, and a clear escalation path. The surgeon's concern is legitimate and deserves a clinical answer, not a dismissal. Dense, long blocks are the surgeon's real worry; a lower concentration preserves some sensation so ischemic pain can break through, and her neuropathy strengthens the case for a more dilute block.
Agree to skip. A high-risk mechanism (tibial shaft or plateau, crush, prolonged ischemia), a patient who cannot be examined reliably, or no capacity for frequent checks after discharge.
Single shot vs catheter. Single shot with IV dexamethasone and multimodal analgesia is the usual choice for her: she lives alone, has neuropathy and fall risk, and an ambulatory catheter needs a caregiver, pump teaching, and daily phone follow-up. A catheter is defensible if she will have help at home and a dilute infusion is used.
Worrying finding. New or escalating pain in a limb that was comfortable under a working block, pain on passive toe stretch, a tense splint or compartments. Breakthrough pain through a block is a warning sign, not a reason for more opioid.
Checks. Frequent (for example, hourly early on) while admitted, then at defined intervals; she or a caregiver must know to call for escalating pain. Measure compartment pressure if suspected; a splint that is too tight is loosened first.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Block sequence and ultrasound technique for popliteal sciatic and saphenous blocks; local anesthetic dose by lean weight and an early toxicity prodrome; tourniquet physiology; PACU assessment of the blocked limb and rescue options; fall risk, discharge, and the rebound pain plan.

1. Placing the blocks

Pre-op holding, 07:30. Blocks before induction or after? Why? Sedation for the block, agent? Dose? Popliteal or saphenous first? Why? She cannot lie prone in the splint. Approach? Ultrasound: needle tip beside the sciatic in the popliteal fossa. Inject where? Why? Injection pressure is high on the first 1 mL. Next? Saphenous, at what level of the leg? Femoral block instead? Why/why not? Twenty minutes later. How will you tell the popliteal block has worked?

Considerations and pitfalls AI draft

Before or after. Before induction, awake or lightly sedated, so she can report pain or paresthesia on injection. In a neuropathic patient that feedback is less reliable, which raises the weight on ultrasound and injection pressure. Placing them under GA is defensible in some adults but is a deliberate choice, not a default.
Sedation. Small doses (midazolam 1 to 2 mg, or fentanyl 25 to 50 mcg) with monitoring and oxygen; she has OSA, so a light touch and a responsive patient.
Order. Order matters little. Popliteal first gives the slower-onset block more time; saphenous is quick.
Approach. Lateral decubitus or supine with the leg raised on a bolster and the probe posterior in the popliteal fossa (lateral approach); no need to turn her prone.
Where to inject. Inside the common paraneural sheath at or just above the bifurcation, not into the nerve: faster onset and spread around both tibial and common peroneal components.
High pressure. Stop. Withdraw slightly and reassess; high opening pressure suggests intraneural or intrafascicular tip position. Never push through resistance.
Saphenous level. Adductor canal at mid-to-distal thigh, deep to sartorius next to the femoral artery, or a more distal subsartorial approach near the knee, which spares the nerve to vastus medialis.
Femoral. No: quadriceps weakness adds fall risk with nothing gained for an ankle. A learner who chooses it should be pushed on how she gets home on crutches.
Testing. Her baseline numbness makes foot sensation useless as a test. Test motor (plantar flexion, dorsiflexion) and sensation above her numb level (posterior calf, lateral leg, medial leg for saphenous).

2. Dosing and a new symptom after injection

Assume ropivacaine 0.5%: 20 mL popliteal, 10 mL saphenous. Total dose? Her maximum? Dosed on which weight? Why? Two minutes after the saphenous injection: perioral tingling, metallic taste, HR 96 from 74, BP unchanged. DDx? Rx now? Lipid emulsion now, or hold? Why? Symptoms resolve over three minutes; ECG and vitals normal. Proceed with surgery today? Why/why not? At closure the surgeon asks for 20 mL of 0.25% bupivacaine in the incision. Agree? Why/why not?

Considerations and pitfalls AI draft

Total dose. 150 mg ropivacaine (100 mg popliteal, 50 mg saphenous).
Maximum and weight. About 3 mg/kg for ropivacaine, dosed on ideal or lean body weight in obesity, not her 102 kg. Ideal body weight at 5'5" is about 57 kg, so roughly 170 mg. A learner who uses actual weight arrives at about 300 mg and has no margin; that is the error to catch.
DDx. Early local anesthetic systemic toxicity from intravascular injection or rapid uptake (the saphenous needle sits beside the femoral artery and vein), anxiety, hyperventilation, a sedation effect.
Rx now. Stop injecting, call for help, oxygen, airway readiness, monitor ECG and BP closely, a benzodiazepine for seizure, lipid emulsion and the LAST checklist at the bedside.
Lipid. Either is defensible for prodromal symptoms that are already resolving; give it at once for seizure, arrhythmia, or any progression. At over 70 kg the ASRA checklist dose is 100 mL of 20% lipid over 2 to 3 minutes, then 200 to 250 mL over 15 to 20 minutes. Withholding lipid while symptoms worsen is the error.
Proceed. Reasonable after resolved minor CNS symptoms with stable vitals; she will be continuously monitored, though GA masks CNS signs, so the ECG and BP become the early warning. Canceling is also defensible. The learner should state the observation period they would want afterward.
Surgeon's bupivacaine. Decline, or cut it sharply. 50 mg bupivacaine on top of 150 mg ropivacaine is additive toxicity and puts her over a combined limit after a prodrome; the incisions are already covered by the blocks.

3. Hypertension late in the case

Assume LMA, sevoflurane, spontaneous ventilation. Tourniquet up 75 minutes: BP 178/98 from 130/75, HR 104. Surgeon needs 40 more minutes. DDx? Rx? Deeper sevoflurane? Fentanyl? Ketamine? Labetalol? Which? Why? Tourniquet down at 110 minutes: EtCO2 39 to 52 mmHg, BP 105/60, HR 98. Interpretation? Rx? Surgeon wants the tourniquet reinflated to finish closing. Agree? Why/why not? How long can it stay up?

Considerations and pitfalls AI draft

DDx. Tourniquet pain and tourniquet-induced hypertension (thigh cuff outside the blocked territory), light anesthesia, hypercarbia under spontaneous ventilation, bladder distension, untreated essential hypertension.
Rx. Deepen anesthesia and treat the stimulus; small-dose ketamine (for example 0.25 to 0.5 mg/kg on ideal weight, about 15 to 25 mg) or fentanyl in small increments given her OSA. Labetalol treats the number, not the cause, and is a second step. Large opioid doses in her are the pitfall.
Interpretation after deflation. Expected: washout of CO2, lactate, and potassium from the ischemic limb, plus vasodilation from reperfusion and loss of the tourniquet stimulus. Assist ventilation briefly, small vasopressor if needed; it usually settles in minutes.
Reinflation. Total ischemia time is the concern. A common convention limits a thigh tourniquet to about 2 hours, then deflates for a reperfusion interval (commonly 15 to 30 minutes) before reinflating; these are conventions, not hard thresholds. Reinflating now, at 110 minutes with no reperfusion interval, adds to the same ischemic period. Closure rarely needs it.

4. PACU: an insensate leg and medial pain

PACU, 30 minutes. SpO2 89% on 2 L, snoring with pauses, arousable. Rx? Surgeon examines her: no plantar flexion or dorsiflexion, no sensation below the knee posteriorly or medially. He asks if this is the block or a nerve injury. What tells you? One hour later: pain 7/10 over the medial incision, rest of the leg still numb. DDx? Rx? Rescue saphenous block? Why/why not? Agent? Concentration? Volume?

Considerations and pitfalls AI draft

Desaturation. Positional and opioid-free measures first: head up, jaw support, CPAP on her own settings or PACU CPAP. Naloxone only if she received meaningful opioid and is hypoventilating. Supplemental oxygen alone without addressing obstruction is a weak answer.
Block or injury. A deficit that matches the expected block territories, timing, and her documented baseline is the block; reassess as it recedes. Comparing with the pre-block exam is the key move, and why the documentation mattered.
DDx. Incomplete or regressing saphenous block, an incision extending outside saphenous territory, a tight splint, early compartment pressure (unlikely in an ankle, still checked), tourniquet-related pain.
Rx. Look at the leg and splint first; then scheduled acetaminophen, an NSAID if the surgeon agrees, and small opioid doses with monitoring given OSA.
Rescue block. Reasonable as a low-volume distal saphenous block, but it must fit her dose budget after a prodrome. She has had 150 mg (plus any bupivacaine the surgeon infiltrated) against roughly 170 mg. Maximum doses are single-injection figures and some ropivacaine has cleared about four hours later, so the budget is not strictly cumulative, but after a prodrome staying low is prudent: 10 mL of 0.2% (20 mg) is reasonable; 10 mL of 0.5% (50 mg) is hard to defend. Skipping it in favor of systemic analgesia is defensible.

5. Discharge and the night ahead

15:00. Pain 2/10, glucose 248, she wants to go home. Discharge today? Why/why not? Home alone tonight? Why/why not? Crutches, no weight on the right leg. Safe? Why/why not? Alternative? Block placed at 07:45. When will it wear off? Oral analgesics? Which? When to start? Oxycodone? Why/why not? How many tablets? She asks what will happen when the numbness wears off. What will you tell her?

Considerations and pitfalls AI draft

Discharge. Possible if PACU criteria are met and OSA is controlled with CPAP and minimal opioid; glucose 248 after dexamethasone needs a plan (resume home regimen, check tonight), not admission by itself.
Home alone. No. After anesthesia she needs a responsible adult for the first night, and here the reasons stack: OSA with any opioid, an insensate leg, contralateral foot numbness, a walk-up. If no one can stay, admit overnight.
Crutches. High fall risk: numb blocked leg, neuropathic opposite foot, obesity, stairs. A walker or wheelchair (a knee scooter needs balance she may not have), physical therapy assessment before discharge, and no stairs alone. The blocked limb also needs protection from pressure and heat.
Duration. Single-shot popliteal ropivacaine 0.5% with IV dexamethasone often lasts about 18 to 24 hours, longer in neuropathic nerves; plan for it to wear off overnight or early tomorrow.
Oral plan. Scheduled acetaminophen and an NSAID (if the surgeon agrees and renal function allows), started before the block wears off, with a dose at bedtime rather than waiting for pain.
Oxycodone. Yes, a small supply (for example 5 mg tablets, about 10 to 15) for the first days, with CPAP whenever she sleeps and no other sedatives; a large supply in a patient with OSA is the error.
What to tell her. The block will wear off over a few hours, possibly at night; pain may be sharp when it does, so take the scheduled doses on time and have oxycodone at the bedside before it wears off; call for pain that escalates despite medication, new numbness that does not recede by the next day, or a splint that feels too tight.

Short stem

Supraclavicular block for distal radius ORIF in an anxious outpatient with mild asthma

A 38 y.o., 5'4", 55 kg woman is scheduled for outpatient open reduction and internal fixation of a displaced right distal radius fracture, two days after falling from her bicycle. She has mild intermittent asthma and uses albuterol about once a month; she takes no other medications. Since the fall she has had tingling in her right thumb and index finger. She is very anxious and says she does not want to see or hear anything during surgery. She lives alone; her sister will drive her home. BP 128/76, HR 88, SpO2 99% on room air; lungs clear; Mallampati II.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Block choice for a distal radius fixation and its tourniquet; matching the anesthetic to her request; consent for a supraclavicular block in a patient with mild asthma; a preexisting median nerve deficit and how it shapes drug choice and documentation; safe setup and sedation for block placement.

1. Anesthetic plan for the wrist

Surgeon plans a volar plate with an upper-arm tourniquet, about 90 minutes. Block with sedation, block with GA, or GA alone? Which? Why? Assume a block. Supraclavicular? Infraclavicular? Axillary? Which? Why? Interscalene? Why/why not? Upper-arm tourniquet: covered by your block? Why/why not? Add anything for it? What? Block with GA: place it awake, or after induction? Why?

Considerations and pitfalls AI draft

Technique. All three are defensible. Her wish not to see or hear anything is met by deep sedation or by a block plus an LMA. GA alone gives up the block's analgesia and opioid sparing. Mild, controlled asthma is not a reason to avoid GA, though an LMA irritates the airway less than a tube. The learner should name her request and how the plan honors it.
Block choice. Supraclavicular, infraclavicular, and axillary all cover a distal radius fixation; any is defensible if defended. Supraclavicular is fast and dense because the plexus is compact at the trunks and divisions. Infraclavicular affects the diaphragm far less, a reasonable pick with her asthma. Axillary spares the diaphragm and the pleura but needs a separate musculocutaneous injection for the lateral forearm skin over a volar-radial incision. A learner who picks one without saying why over the others is the flag.
Interscalene. No. It targets the roots and upper trunks and often spares C8-T1 (the inferior trunk, ulnar territory), and it blocks the phrenic nerve almost every time. Wrong block for the hand.
Tourniquet. The skin of the medial upper arm is supplied by the intercostobrachial nerve (T2), outside the brachial plexus, so no plexus block covers it reliably; a subcutaneous injection across the medial upper arm adds it. Much of the pain from a tourniquet after 45-60 minutes is deep ischemic pain that comes through even a good block, so a sedation plan for it matters more than the extra injection.
Awake or asleep. Awake or lightly sedated is the usual practice in adults: she can report pain or paresthesia on injection, a warning of intraneural needle placement, and the first symptoms of toxicity. Some centers place upper extremity blocks under GA, but both warnings are lost; choosing it without naming that tradeoff is the flag.

2. Consent for the supraclavicular block

Supraclavicular block planned. Risks you consent her for? Pneumothorax: how likely with ultrasound? When would it show up? What does she watch for at home? Diaphragm on that side: how likely to be affected? Still supraclavicular for her? Why/why not? Infraclavicular instead: which risk changes? Nerve injury: how often? Lasting? Block fails: backup plan? Agreed when?

Considerations and pitfalls AI draft

Risks. Block failure or an incomplete block, pneumothorax, diaphragm weakness on the blocked side, vascular puncture, local anesthetic toxicity, nerve injury, and transient Horner syndrome or hoarseness from spread to the stellate ganglion or recurrent laryngeal nerve. Infection is rare with a single injection.
Pneumothorax. Rare with ultrasound and the needle tip kept in view, on the order of 1 in 1,000 or fewer in large series; more common with landmark technique. It can present hours later, up to about a day. She is planned to go home the same day, so she needs to know: new chest pain or shortness of breath, worse with a deep breath, means the emergency department.
Diaphragm. Reported rates vary widely, from near zero to more than half on ultrasound imaging, depending on volume and where the local anesthetic goes. Most healthy patients do not notice it; some feel short of breath, especially lying flat. It lasts as long as the block.
Still supraclavicular. Mild intermittent asthma with clear lungs and a normal SpO2 does not rule out a supraclavicular block; a healthy patient tolerates a weak hemidiaphragm. The concern is limited reserve (severe COPD or asthma, obesity, an existing palsy on the other side). Choosing infraclavicular to avoid the diaphragm question is also defensible.
Infraclavicular. Much less diaphragm involvement. Pneumothorax risk is lower but not zero, since the pleura lies deep to the cords; the target is deeper and harder to image in some patients. Axillary removes both risks.
Nerve injury. New tingling or numb patches in the first days are fairly common (several percent) and mostly resolve over weeks; lasting injury is rare, a few per 10,000. Her symptoms before the block are part of this conversation (A3).
Backup plan. Stated up front: supplement the block, surgeon's local, deeper sedation, or GA. She agrees to GA as the backup before the block, not in the middle of the case.

3. Tingling since the fall

Neuro exam of the right hand before the block: what? Light touch reduced on the thumb and index pad, two-point discrimination 8 mm, thenar strength normal, forearm soft, fingers warm. Of concern? Block her today? Why/why not? Surgeon: 'Let's just get going.' What do you need from him first? Long-acting local, or shorter? Why? Dexamethasone to prolong it? Why/why not? Document what?

Considerations and pitfalls AI draft

Exam. Sensation by nerve territory (median, ulnar, radial, lateral forearm), motor (thumb abduction and opposition, the OK sign for the anterior interosseous nerve, finger abduction, wrist and finger extension), two-point discrimination, perfusion, forearm compartments, and pain with passive finger stretch. A documented baseline is the point.
Of concern. Median nerve symptoms after a distal radius fracture are common (contusion, traction, swelling), and a stable deficit is not a contraindication to a block. Numbness that progresses with rising pain points to acute carpal tunnel syndrome, which needs urgent release; that is what a dense, long block can hide after surgery.
Block today. Yes is defensible once the baseline is documented and the surgeon agrees. Refusing a block only because of a preexisting deficit is overly cautious; blocking without examining and documenting is the flag.
Surgeon. Is the deficit stable or getting worse? Has he examined and documented it? Will he release the carpal tunnel at the same time? Does he need a neuro exam early after surgery? The answers set the agent and duration.
Duration. A long-acting agent (ropivacaine or bupivacaine) gives analgesia overnight but hides the hand exam for 12-18 hours or more; a shorter agent (mepivacaine) returns the exam in a few hours. If symptoms are stable and the surgeon will decompress as needed, long-acting is defensible; if he wants an early exam, shorter. Either if defended.
Dexamethasone. Adds several hours of analgesia, IV (about 0.1 mg/kg, 4-8 mg) or perineural (4 mg, preservative-free, off-label), with similar effect. Here it also lengthens the window in which a worsening median nerve would go unnoticed; skipping it, or using it after naming that tradeoff, are both reasonable.
Documentation. The exam by nerve territory, the discussion with the surgeon, and consent that names the preexisting deficit, all in the chart before the needle.

4. Preparing for the block

Block area. Monitors? IV in which arm? Why? Sedation for placement: drug? Dose? End point? Rescue drugs in the block area: which? Where kept? Before the needle goes in, what has to happen? Midazolam 1 mg and fentanyl 25 mcg given: eyes closed, opens them to her name, RR 12, SpO2 99% on 2 L. Proceed with the block? Why/why not? She asks for more so she won't feel the needle. More? Why/why not?

Considerations and pitfalls AI draft

Monitors. Standard monitors (ECG, cycling BP, pulse oximetry), supplemental oxygen, capnography if sedated, airway equipment, and suction.
IV. The left arm, away from the surgical field and the tourniquet; a reliable line for sedation and for rescue.
Sedation. Light anxiolysis, titrated in small steps (midazolam 0.5-1 mg, fentanyl 25 mcg at a time); the two together are synergistic. End point: calm but still answering, so she can report pain on injection and early symptoms of toxicity.
Rescue drugs. 20% lipid emulsion and a toxicity checklist in the block area itself, not somewhere that takes minutes to reach; also a benzodiazepine for seizure, airway drugs, and resuscitation drugs. A learner who does not name lipid is the flag.
Before the needle. A time-out at the bedside immediately before needle insertion: right side confirmed against the consent and the site mark, allergies, agent and dose. Wrong-side blocks happen when the block area skips this step.
Proceed. Yes. She is at the end point: calm, rousable to voice, breathing well, so she can still report pain on injection and early toxicity. Capnography confirms the RR on a sedated patient.
More. Skin local at the needle site and reassurance first; a further small step (midazolam 0.5 mg or fentanyl 25 mcg) is defensible if she stays rousable to voice. Sedating her until she cannot answer before the needle goes in loses the paresthesia and toxicity warnings and adds airway risk; that is the flag.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Ultrasound technique and safe injection; dosing to her weight; diaphragm weakness versus pneumothorax; ulnar sparing and a rescue limited by dose; sedation and tourniquet pain; toxicity from cumulative local anesthetic; discharge with a resolving block and a disclosure conversation.

1. Supraclavicular block placement

Supine, head turned to the left. Probe: where? What must you see before the needle moves? Needle: in-plane or out-of-plane? Which direction? First injection: where? Why there? Agent? Volume? Max dose for her, in mL? 3 mL in, she cries out with an electric pain into her hand, and the syringe pushes hard. Next? Needle withdrawn slightly; injection now easy and painless. Continue? Why/why not?

Considerations and pitfalls AI draft

Probe. High-frequency linear probe in the supraclavicular fossa, parallel to and just above the clavicle, tilted toward the chest. Before the needle moves: the subclavian artery on the first rib, the plexus as a cluster lateral and superficial to the artery, the first rib (bright line with a shadow) and the pleura (bright line that slides), and color Doppler for vessels crossing the path (transverse cervical or dorsal scapular artery).
Needle. In-plane, lateral to medial, with the shaft and tip seen at every advance; if the tip is lost, stop and find it. Out-of-plane over the pleura is the flag.
First injection. The corner pocket, between the artery and the first rib, deep to the plexus, to reach the inferior trunk (ulnar fibers); then one or two injections around the superficial clusters. With the rib directly under the target, the rib sits between the needle and the pleura.
Agent and volume. A long-acting agent for a painful fixation: ropivacaine 0.5% or bupivacaine 0.5%, 20-30 mL; mepivacaine 1.5% if a shorter block was chosen in A3. Lower volumes may spare the diaphragm more.
Max dose. Ropivacaine 3 mg/kg = 165 mg = 33 mL of 0.5%. Bupivacaine 2.5 mg/kg = about 137 mg = about 27 mL of 0.5%. A planned 25 mL of 0.5% ropivacaine is 125 mg (2.3 mg/kg), under the limit. The learner should do the math at her weight, not quote a volume used for a larger patient.
Pain and pressure. Stop at once. Sharp pain with high injection pressure suggests the tip is in the nerve; never push against resistance. Withdraw slightly, re-image, and confirm spread outside the nerve before injecting again.
Continue. Yes, in 3-5 mL aliquots with gentle aspiration, watching spread around (not within) the clusters, keeping pressure low and asking about symptoms. Document the event; it matters if she has new symptoms later.

2. Twenty minutes after the block

Twenty minutes after 25 mL of 0.5% ropivacaine, she says it is harder to take a deep breath. SpO2 96% on room air, RR 18, full sentences. DDx? Bedside test? Lung sliding both sides; right hemidiaphragm moves up with a sniff. Rx? Proceed with surgery? Why/why not? Pinprick absent over the thumb, index finger, and lateral forearm; intact over the little finger and ulnar hand. Interpretation? Incision is volar, radial side. Will she feel the surgery? Why/why not? Wait, repeat injection, distal ulnar block, or GA? Which? Why? More local anesthetic: how much can she still have?

Considerations and pitfalls AI draft

DDx. Diaphragm weakness from phrenic spread (most likely, common, benign in healthy lungs), pneumothorax (rare, must be excluded), bronchospasm, anxiety, sedation.
Bedside test. Ultrasound: lung sliding and a lung point for pneumothorax, and diaphragm movement on a sniff. Listen for wheeze. Chest X-ray if ultrasound is not available.
Rx. Sit her up, reassure, oxygen if needed; it resolves as the block wears off. Treat wheeze if present. A learner who does not look for a pneumothorax before calling it phrenic spread is the flag.
Proceed. Yes. SpO2 and work of breathing are fine and her asthma is mild. Deep sedation adds hypoventilation, so watch closely; she will go home with this, and she needs to know it lasts as long as the block.
Interpretation. Ulnar sparing: the inferior trunk (C8-T1) was missed or is slow to set up. This is the classic gap with a supraclavicular block.
Incision. Partly. The skin over a volar-radial approach comes from the lateral antebrachial cutaneous and median nerves, both blocked. Deep work on the radius, retraction toward the ulnar side, any fixation of the ulnar styloid, and the medial arm under the tourniquet may still be felt. Not a reason to abandon the block.
Rescue. Wait another 10 minutes (the lower trunk often sets up last), an ultrasound-guided ulnar block at the forearm or elbow, a repeat corner-pocket injection, surgeon's local, or GA; any is defensible if it stays inside the dose. A repeat injection into a partly blocked plexus loses the paresthesia warning.
Dose left. 125 of 165 mg used (about 76%); 40 mg left, which is 8 mL of 0.5% or 20 mL of 0.2% ropivacaine. A different agent draws on the same budget because toxicity adds: about a quarter of lidocaine's 4.5 mg/kg, roughly 60 mg or 6 mL of 1%. Adding a usual ulnar block dose without counting is the flag.

3. Deep sedation and restlessness at 60 minutes

Assume block plus propofol sedation, no airway device. Propofol rate? Monitoring for deep sedation: what? Tourniquet about to go up. Pressure? Why? Sixty minutes of tourniquet time: HR 112, BP 168/94, restless, says her arm aches. DDx? Rx? Fentanyl 50 mcg; still restless. Ketamine? Why/why not? Dose? Convert to an LMA? Why/why not? Surgeon needs 40 more minutes. Deflate the tourniquet? Why/why not?

Considerations and pitfalls AI draft

Propofol. A titrated infusion, about 25-75 mcg/kg/min, with small boluses as needed, to the depth she asked for; dexmedetomidine is an alternative.
Monitoring. Continuous capnography through a sampling nasal cannula or mask, supplemental oxygen, and airway equipment ready (chin lift, nasal airway, LMA). Hypoxia and hypoventilation are the main risks of deep sedation without an airway device; planning deep propofol without capnography is the flag.
Pressure. Lowest pressure that keeps the field dry. Limb occlusion pressure (the cuff pressure at which the distal pulse disappears) plus a margin, about 40 mmHg when it is under 130 and 60 mmHg when it is 131-190, is the most precise method. Without it, many arm cases run at roughly systolic plus 50-100 mmHg, about 200-250 mmHg in a normotensive adult. Higher pressure adds nerve and skin injury risk without benefit.
DDx. Tourniquet pain (typical at 45-60 minutes: dull ache with hypertension and tachycardia despite a working block), the ulnar-side and medial arm gap from B2, light sedation, hypoxia or hypercarbia, a full bladder, surgical stimulus outside the block.
Rx. Check airway and capnography first, then treat pain: a small opioid dose, ketamine, deeper sedation, or dexmedetomidine. Turning up propofol alone, without checking the airway and capnography first, is the flag.
Ketamine. 0.1-0.3 mg/kg, about 5-15 mg. Tourniquet pain and the hypertension that comes with it often respond poorly to more opioid; low-dose ketamine is a reasonable adjunct, and more opioid on top of propofol without an airway device adds hypoventilation.
LMA. Reasonable if she stays uncomfortable or the airway is unstable at the depth she needs; converting to GA with an LMA is a clean fallback, not a failure.
Deflate. No. About 100 minutes total is within the usual 2-hour limit for an arm; deflating in the middle of fixation floods the field and the pain returns on reinflation. If the case runs past 2 hours, the surgeon deflates for 10-15 minutes of reperfusion before reinflating.

4. Closing the wound

Assume she stays on sedation; propofol off for closure, she is awake and calm. At 100 minutes, the surgeon says he has infiltrated the wound with 20 mL of 0.5% bupivacaine, and deflates the tourniquet. Three minutes later, she says her mouth tastes of metal and her ears are ringing. Of concern? Why now? First steps? She has a generalized seizure. Drug? Dose? Lipid emulsion now, or wait? Why? Dose? Seizure stops. HR 42, BP 76/40, QRS widening. Rx? Epinephrine: dose? Vasopressin? Why/why not? After a second lipid bolus: HR 74, BP 108/64, breathing, drowsy. Monitor how long? Where?

Considerations and pitfalls AI draft

Of concern. Early central nervous system signs of local anesthetic systemic toxicity (metallic taste, tinnitus, perioral numbness, agitation or confusion); a seizure or arrhythmia may follow within minutes. Sedation can hide these early signs.
Why now. Cumulative dose: ropivacaine 125 mg (2.3 mg/kg, about three quarters of its maximum) plus bupivacaine 100 mg (1.8 mg/kg, about three quarters of its maximum) is roughly one and a half maximum doses, more if a rescue injection was given in B2, and the toxicity adds. Infiltration into a raw wound under a tourniquet, then deflation, sends it into the circulation at once. The surgeon's local draws on the same budget and is agreed on beforehand.
First steps. Stop any local anesthetic, call for help and the lipid kit and checklist, 100% oxygen, support the airway (hypoxia, hypercarbia, and acidosis all worsen toxicity), confirm the IV, tell the surgeon, prepare for a seizure.
Seizure. A benzodiazepine: midazolam 1-2 mg IV, repeated as needed. A small propofol dose is acceptable only if hemodynamics are stable; it depresses the heart and is not a substitute for lipid. Ventilate by mask; a small dose of succinylcholine if the convulsion prevents ventilation.
Lipid. Starting now fits current toxicity guidance, which counts a seizure as a serious event and gives lipid at the first serious sign rather than waiting for cardiovascular collapse. Some clinicians treat an isolated seizure that stops with a benzodiazepine first and start lipid at the first cardiovascular sign; that is defensible if stated. Waiting for an arrest is the flag. 20% lipid; under 70 kg, a bolus of 1.5 mL/kg over 2-3 minutes (about 80 mL for her), then 0.25 mL/kg/min (about 14 mL/min). Repeat the bolus once or twice and double the infusion for persistent instability; upper limit about 12 mL/kg.
Bradycardia, hypotension, wide QRS. Cardiotoxicity. Repeat lipid bolus and double the infusion, oxygenate and ventilate, small epinephrine doses; atropine is a reasonable adjunct for the bradycardia; amiodarone for ventricular arrhythmias. Call early for cardiopulmonary bypass or ECMO support where available if she worsens; CPR, if needed, is prolonged.
Epinephrine. Small boluses, 1 mcg/kg or less (55 mcg or less for her), not 1 mg; large doses worsen arrhythmias and blunt the lipid effect.
Vasopressin. Avoid. Also avoid calcium channel blockers, beta-blockers, and more local anesthetic (lidocaine, procainamide) for the arrhythmia.
Monitoring. At least 4-6 hours after cardiovascular signs (at least 2 hours after a seizure without cardiovascular signs), in a monitored setting. Cardiovascular toxicity that needed two lipid boluses, in a patient who lives alone, justifies overnight admission rather than same-day discharge; sending her home from PACU is the flag.

5. The next morning

Admitted overnight on a monitored bed after the toxicity event; vitals and ECG normal, no further events. 07:00: sensation back in the forearm and little finger; thumb and index finger still numb and tingling; pain 4/10. DDx? Exam: what? Fingers warm, forearm soft, passive finger extension painless, two-point discrimination 8 mm on the index pad. Of concern? Discharge today? Why/why not? Analgesic plan for home: what? Start when? The numb part of her hand: instructions? She asks why she had a seizure. What will you tell her?

Considerations and pitfalls AI draft

DDx. Uneven regression of a long-acting block, the preexisting median nerve injury from the fracture, surgical traction, acute carpal tunnel syndrome (worsening numbness with rising pain and swelling, urgent), injury from the painful injection in B1, a tight splint or dressing.
Exam. Compare with the preoperative baseline from A3: sensory map, two-point discrimination, thenar strength, perfusion, compartments, splint tightness. Tell the surgeon what you find.
Of concern. Unchanged from her documented baseline with soft compartments and controlled pain is reassuring: the old deficit plus a resolving block. Follow it. Worse than baseline, or pain climbing, means the surgeon now. Without the A3 baseline this question cannot be answered.
Discharge. Reasonable: more than 12 hours since the toxicity event with normal vitals and ECG, pain controlled on oral drugs, the block resolving, a clear follow-up plan. With one arm in a splint and opioids, someone should stay with her tonight, not just drive her home.
Analgesia. Scheduled acetaminophen and an NSAID (ask about NSAID-sensitive asthma first), started before the block fully wears off because rebound pain often peaks then, a small opioid supply for breakthrough, ice and elevation.
Numb hand. Sling; protect numb skin from heat, cold, and pressure; no driving. Call for numbness that worsens or does not improve over a few days, or pain that escalates; new chest pain or shortness of breath means the emergency department. A follow-up call in the next day or two; a deficit that persists for weeks needs neurology and nerve testing, arranged with the surgeon.
What to tell her. Plain and honest: the numbing medicine from the block and from the wound injection together reached a level in her blood that caused the seizure and the slow heart rate; it was recognized and treated with a specific antidote, and no lasting effect is expected. It is not an allergy, but future anesthesia teams should know, and it is documented. Give her room for questions. Minimizing the event, or putting the blame on the surgeon, is the flag.

Short stem

Total knee arthroplasty with anticoagulation and aortic stenosis

A 68 y.o., 95 kg woman is scheduled for elective right total knee arthroplasty. She has atrial fibrillation on apixaban, last taken three days ago per preoperative instruction, with normal renal function. A recent echo showed moderate aortic stenosis (valve area 1.1 cm2, mean gradient 30 mmHg). She has obstructive sleep apnea on home CPAP with a body mass index of 35, hypertension, and type 2 diabetes. She takes tramadol daily for osteoarthritis pain and had severe nausea and prolonged sedation after a previous joint replacement under general anesthesia. On exam she is Mallampati III with full neck motion. BP 150/85; HR 76 and irregular; SpO2 95% on room air; Hgb 12 g/dL; platelets 240 K/uL; creatinine 0.9 mg/dL.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Neuraxial timing on a direct oral anticoagulant and which blocks residual anticoagulation permits; hemodynamic goals and neuraxial risk in moderate aortic stenosis; opioid-sparing regional strategy for the OSA patient; the chronic-tramadol, high-PONV patient.

1. Anticoagulation and neuraxial timing

Apixaban last taken 72 hours ago, creatinine 0.9. Spinal today — yes/no? Why? The interval you require off apixaban — hours? Creatinine clearance under 30 — how does the interval change? Anti-Xa level — order one? What would you do with the result? Blocks you would still place with a residual apixaban effect: adductor canal? Femoral? Lumbar plexus? Which yes, which no? Why? She asks when she can restart apixaban after the spinal. Your answer?

Considerations and pitfalls AI draft

Spinal yes/no. Yes: a documented adequate hold with normal renal function makes neuraxial reasonable. The learner must know the interval rather than react to the word 'apixaban'.
Interval. 72 hours (ASRA 2018); some guidelines accept 48 hours at standard dosing with normal renal function. Far longer or far shorter needs a justification.
Reduced clearance. Apixaban is ~25% renal; the effect is prolonged with CrCl <30, and the interval lengthens (many extend to 4-5 days) with an anti-Xa level if available.
Anti-Xa. A calibrated apixaban anti-Xa level can confirm negligible drug; a rising/undetectable result reassures, a measurable level postpones. Not required with a clean 72-hour hold.
Blocks with residual DOAC. Superficial, compressible blocks (adductor canal, IPACK) are acceptable at lower risk; deep, non-compressible blocks (lumbar plexus, paravertebral) carry neuraxial-equivalent bleeding rules; femoral is intermediate and often done with ultrasound. 'Blocks are always fine' deserves a probe.
Restart. Wait until surgical hemostasis is secure and typically 24 hours after a single-shot spinal; with a catheter in place, hold the drug until at least 6 hours after catheter removal (ASRA), or if a dose was given with the catheter in, wait about 5 half-lives (roughly 26-30 hours) before pulling it; her AF stroke risk means it should not be forgotten either.

2. Aortic stenosis and spinal hemodynamics

Moderate AS, area 1.1, mean gradient 30. Single-shot spinal — yes/no? Why? Target heart rate? She is in AF at 76 — what does losing atrial kick cost her? Preload — where do you want it? Spinal dose you would give — mg? Why that dose? Vasopressor drawn up before the spinal: phenylephrine or ephedrine? Why? Valve area or gradient at which you would abandon the single-shot spinal — number? What would you do instead?

Considerations and pitfalls AI draft

Spinal in moderate AS. Acceptable with a controlled dose and vasopressor in hand; the concern is abrupt sympathectomy dropping preload, afterload, and coronary perfusion of a hypertrophied ventricle. Refusing all neuraxial in moderate AS and ignoring the risk are both wrong.
Rate / rhythm. 60-80, sinus if possible; a stiff hypertrophied LV depends on atrial contribution (up to 30-40% of filling), so AF already costs her preload and any tachycardia shortens diastolic filling and coronary perfusion. Rate control matters.
Preload. Full; hypovolemia in a fixed-output valve is poorly tolerated.
Dose. A reduced single-shot dose (e.g., hyperbaric bupivacaine 7.5-10 mg rather than 12-15) or a titrated CSE/continuous spinal; a large bolus producing a fast high block is the error.
Phenylephrine vs ephedrine. Phenylephrine: restores afterload and coronary perfusion without tachycardia; ephedrine's chronotropy is unwelcome. Infusion started with the spinal is reasonable.
Threshold. Severe (area <1.0 cm2, mean gradient ≥40, or symptomatic) shifts most toward a carefully controlled GA with invasive monitoring or a slow titrated neuraxial (CSE, continuous spinal); the distinction should change the plan.

3. OSA and analgesic strategy

OSA on CPAP, BMI 35. Sedation for the spinal and the case — agent? Dose? Why that dose? Regional plan to keep her opioid-free — which blocks? Airway plan if the spinal fails — positioning? Device? Video or direct laryngoscopy? Why? Postop CPAP — when does it go on? Where does she recover tonight? Why?

Considerations and pitfalls AI draft

Sedation. Minimal: low-dose dexmedetomidine or small propofol boluses, capnography, no benzodiazepine-opioid stacking; sedatives compound obstruction and blunt arousal. Unmonitored sedation is a flag.
Opioid-free plan. Spinal plus adductor canal and IPACK, periarticular infiltration by the surgeon, scheduled acetaminophen and NSAID/celecoxib; a knee can be nearly opioid-free intraoperatively and well into recovery.
Airway backup. Obesity plus Mallampati III predicts a difficult mask and view: ramped position, preoxygenation with CPAP, video laryngoscope first pass, supraglottic and second-generation rescue ready; a plan made before the spinal, not after it fails.
CPAP. On in PACU as soon as she is awake enough; continue overnight; residual block and any opioid change her risk, so monitoring continues.
Disposition. Continuous oximetry with capnography at minimum; monitored bed if opioid was needed. OSA plus opioid on an unmonitored floor is the error.

4. Chronic tramadol and prior PONV

Tramadol 100 mg three times daily at home, severe PONV last time. Continue tramadol today? Why/why not? Ondansetron alongside her tramadol — any problem? Meperidine for shivering after the spinal — why/why not? PONV prophylaxis — agents? How many? Why that many? Dexamethasone in her diabetes — give it? Dose? Why/why not? Scopolamine patch at 68 — why/why not?

Considerations and pitfalls AI draft

Continue tramadol. Reasonable: avoids withdrawal and rebound pain; note it implies some opioid tolerance and a serotonergic, seizure-threshold-lowering drug.
Ondansetron. Two issues: both are serotonergic (serotonin syndrome is rare but reported), and 5-HT3 antagonism blunts tramadol's analgesia. Acceptable with awareness; not a reason to skip antiemesis.
Meperidine. No: serotonergic on top of tramadol (serotonin toxicity), and it adds opioid load in OSA. Warm her, small dexmedetomidine if needed.
Risk factors. Female, non-smoker (assume), prior PONV, likely postoperative opioid: 3-4 Apfel factors, ~60-80% risk. Multimodal prophylaxis with 2-3 agents from different classes, plus regional to cut opioid and avoiding volatile.
Dexamethasone. 4 mg is effective with a modest, transient glucose rise; acceptable in a controlled diabetic with glucose monitoring; 8 mg and above raise glucose more.
Scopolamine. Avoid in an older patient: anticholinergic delirium, blurred vision, dry mouth.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Executing a spinal-plus-peripheral-block plan with attention to dose and local anesthetic totals; spinal hypotension in a stenotic valve; tourniquet physiology and tourniquet pain; bone cement implantation syndrome; postoperative multimodal handoff and early LAST recognition.

1. Block technique and local anesthetic totals

Spinal plus a peripheral block, ninety-minute case. Spinal — agent, baricity, dose in mg? Why that dose? Adductor canal or femoral? Why? What do you lose with adductor canal? IPACK — add it? What does it cover? Ropivacaine 0.5% — how many mL for the adductor canal? IPACK — concentration and mL? Total mg? Your ceiling for her? On what weight? Injection — how do you give it?

Considerations and pitfalls AI draft

Spinal. Hyperbaric bupivacaine 7.5-10 mg, controlled dose for the valve, enough for ninety minutes; isobaric acceptable. An oversized dose producing a fast high sympathectomy is the error.
Adductor canal vs femoral. Adductor canal preserves quadriceps strength for early mobilization and fall prevention while covering the anteromedial knee; femoral is denser but blocks the quadriceps. Adductor canal is the standard TKA answer; commit and defend.
What you lose. The anterior femoral cutaneous coverage above the knee and some density; supplement with surgeon infiltration.
IPACK. Covers the posterior capsule (genicular branches of the tibial and obturator nerves) that adductor canal misses, without foot drop; reasonable add.
Volumes / total. Adductor canal 15-20 mL of 0.5% (75-100 mg); IPACK 20 mL of 0.25% (50 mg); plus the spinal (~10 mg). Total ~150-160 mg against a ceiling of about 3 mg/kg on ideal weight (~60 kg for an average-height woman), roughly 180-200 mg. Not tallying is a real error.
Injection. Ultrasound with needle tip in view, aspirate, 3-5 mL increments, low pressure, stop for symptoms.

2. Spinal hypotension in aortic stenosis

Ten minutes after the spinal: BP 78/40, HR 52. Level? T6. Rx now? Phenylephrine — dose? Fluid — how much? Ephedrine instead? Why/why not? After 200 mcg phenylephrine and 500 mL: BP 70/38, HR 48. Next? Epinephrine — dose? She reports chest tightness. Now? Target MAP you are chasing? Why does this matter more in her than in the last knee you did?

Considerations and pitfalls AI draft

Rx. Phenylephrine 100-200 mcg boluses then an infusion, legs up, 250-500 mL co-load; treat bradycardia if it persists. Restore afterload first: coronary perfusion of a hypertrophied ventricle depends on diastolic pressure.
Ephedrine. Acceptable for combined bradycardia and hypotension, but its chronotropy shortens diastole; phenylephrine preferred, glycopyrrolate or small ephedrine for rate.
Refractory. Epinephrine 5-10 mcg boluses, escalate to infusion, ECG, consider that the spinal has climbed; TTE if available. Over-aggressive fluid in a stiff ventricle backfires.
Chest tightness. Demand ischemia from hypoperfusion of a hypertrophied LV; fix pressure now, 12-lead, oxygen; this is the failure mode the valve threatened.
Target. MAP ≥70-75 (near her baseline ~105); she has no reserve, so push early and decisively while avoiding tachycardia and volume overload.

3. Tourniquet physiology

Tourniquet up at 300 mmHg. BP change you expect? Why does that matter in her? Sixty minutes in: BP 170/95, HR 98, restless; the block was solid. DDx? How do you tell tourniquet pain from a receding spinal at the bedside? Rx? Sedation — agent, dose, monitoring? Antihypertensive — which? Why/why not? Surgeon: ten more minutes. Deflation — what do you expect in the first two minutes? What do you do before they let it down?

Considerations and pitfalls AI draft

Inflation. Afterload and BP rise; exsanguination adds a few hundred mL of central volume. Both the afterload and any tachycardia are unwelcome in AS and hypertension; watch for ischemia.
DDx. Tourniquet pain (dull, building after 45-60 minutes, sympathetic rise, through a working block), receding spinal, full bladder, positioning pain.
Distinguish. Check the level: intact sensory block at the knee and a dermatomal level still adequate means tourniquet pain; a falling level means the spinal is receding. Timing and character corroborate.
Rx. Definitive relief is deflation; meanwhile small doses of ketamine (10-20 mg) or dexmedetomidine, cautious given OSA, with capnography; ask the surgeon about tourniquet time; treat pressure with labetalol in small doses if needed (rate-friendly), avoiding a big drop before deflation.
Deflation. Expect a fall in BP from reperfusion, a transient EtCO2 rise, potassium and lactate washout, and a rate rise; have phenylephrine running or in hand, volume topped up, ventilation ready to increase, and the ECG watched. Anticipate rather than react.

4. Bone cement implantation

Cementing and reduction. SpO2 82%, BP 74/40, EtCO2 34 to 18. DDx? Most likely? Rx now? FiO2? Pressor — which? Dose? How is this different from the spinal hypotension an hour ago? What does the falling EtCO2 tell you? She loses her pulse, PEA. What is specific to this cause in your resuscitation?

Considerations and pitfalls AI draft

DDx / most likely. Bone cement implantation syndrome (fat/marrow/cement embolism) with cementing and impaction; pulmonary thromboembolism, anaphylaxis, hemorrhage. Timing points to BCIS.
Rx. 100% oxygen (hypoxemia drives PVR up further and the RV down), vasopressor, fluids as tolerated, tell the surgeon; epinephrine 10-20 mcg boluses or norepinephrine for a failing RV, not phenylephrine alone.
Difference. The spinal drop was vasodilatory with a normal EtCO2; here EtCO2 falls because pulmonary blood flow has fallen (dead space) and hypoxemia coexists: an obstructive RV problem. Treatment leans on oxygenation and RV support.
PEA. ACLS with the obstructive cause in mind: epinephrine, high-quality CPR, TEE to see the RV, avoid excessive fluid on a failing RV, consider inhaled pulmonary vasodilator and mechanical support if refractory. Treat the cause, not just the rhythm.

5. Postoperative analgesia and LAST watch

Case done, comfortable in PACU. Floor orders — what is scheduled? Adductor canal catheter — yes/no? Why? Ropivacaine 0.2% at 8 mL/h — total mg per day? Acceptable? Forty minutes later: circumoral tingling and 'feeling off.' Dx? Rx now? Stop the catheter? Lipid — ready or running? Dose? She asks what is wrong. What will you tell her?

Considerations and pitfalls AI draft

Orders. Scheduled acetaminophen and an NSAID or celecoxib, the block, limited rescue oxycodone, antiemetics, CPAP, continuous oximetry; tramadol resumed.
Catheter. Extends motor-sparing analgesia and cuts opioid, which helps OSA; against are catheter care, cumulative-dose LAST risk on top of today's ~150 mg, and a restart of apixaban complicated by a catheter. A reasoned weigh-up, not a reflex.
Infusion math. 8 mL/h of 0.2% = 16 mg/h = ~384 mg/day; within the usual ~28 mg/h ceiling for ropivacaine infusions, but stacked on a large bolus day; know the number.
Tingling. Early LAST until proven otherwise; stop the infusion, oxygen, monitor, lipid at the bedside, benzodiazepine drawn up; dismissing early neurologic symptoms is the danger.
Lipid. Prepared; infuse for any progression (seizure, arrhythmia, hypotension): 100 mL bolus (1.5 mL/kg lean) then 200-250 mL over 15-20 minutes.
What you tell her. Plainly: the numbing medicine may be reaching her bloodstream, the infusion is stopped, she is monitored, treatment is ready, and what symptoms to report; the floor gets the same message.

Non-perioperative

SICU postop perforated diverticulitis (Hartmann's), septic shock

A 64 y.o., 92 kg, 5'10" man is admitted directly to the SICU from the OR following emergent exploratory laparotomy with sigmoid resection and end colostomy (Hartmann's procedure) for perforated diverticulitis with feculent peritonitis.

PMHHypertension, type 2 diabetes (HbA1c 8.4%), CKD stage 3 (baseline Cr 1.4), current smoker (30 pack-years), BMI 29. Home meds: lisinopril, metformin, atorvastatin.

INTRA-OPERATIVE COURSE6 hours. EBL 400 mL. 4 L crystalloid, 1 unit PRBC. Right IJ triple-lumen and left radial arterial line placed. Norepinephrine started at 0.1 mcg/kg/min during peritoneal washout. Intra-op lactate trended from 2.8 to 4.2. Total UOP 250 mL. Remains intubated and sedated on transfer.

ARRIVAL TO SICUHR 112; BP 95/55 on norepinephrine 0.1 mcg/kg/min; T 38.7°C; SpO2 96% on FiO2 50% / PEEP 8 / Vt 500 / RR 16. Sedated on propofol 30 mcg/kg/min + fentanyl 50 mcg/hr. Piperacillin-tazobactam given intra-op.

LABSWBC 22; Hgb 9.4; platelets 110; Na 138; K 3.1; Cr 2.0; glucose 248; lactate 4.2; ABG pH 7.28 / pCO2 38 / HCO3 18.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INITIAL ASSESSMENT ON ADMISSION

Teaching focus. Organized handoff and first-hour priorities in septic shock; recognizing and treating abdominal compartment syndrome; ARDSnet ventilation and escalation paths; oliguria DDx and the RRT decision under refractory hyperkalemia.

1. Handoff and initial priorities

OR team is at the bedside, ready to leave. Before they go, what do you check yourself at the bedside? Norepi 0.1, MAP 68, lactate 4.2, 4 L in. More fluid now? How much? What tells you? K 3.1 — replace how? Through which line, at what rate? Glucose 248 — Rx? Target? Blood cultures — send now? Why/why not? Mid-handoff, BP 85/48. First move? Surgeon: "I need him awake by 6 AM for an abdominal exam." Wean sedation overnight to make that happen? Why/why not?

Considerations and pitfalls AI draft

Handoff. A personal bedside check before the OR team leaves: ETT position and breath sounds, perfusion, abdomen and drains, Foley output, line sites, pressor line and rate. While they are there, get the operative findings (stump, contamination, drains), hemodynamic and pressor trajectory, fluids/blood/UOP, airway grade, antibiotic timing.
Fluid. He has had 4 L and is on a pressor with lactate 4.2; a further bolus only if volume-responsive (POCUS IVC, pulse-pressure variation on the art line, passive leg raise). Reflex liters in a patient headed toward an open abdomen and AKI are the error; so is refusing volume with a collapsing IVC.
Potassium. Central line, 10-20 mEq/h with monitoring; target ≥4.0 given arrhythmia risk on pressors; check Mg.
Glucose. Insulin infusion, target 140-180; hold metformin (AKI, lactate).
Cultures. Two sets before any antibiotic change; confirm intra-op cultures were sent.
BP 85/48. Pause the handoff, look at the patient (bleeding? drains? abdomen?), titrate norepinephrine to MAP ≥65, quick POCUS, repeat Hgb/lactate; do not simply bolus.
Surgeon's request. Agree the exam matters; the timeline is set by perfusion, oxygenation, and analgesia, not the clock. Sedation weaned when he is stable, with a daily SAT; propofol allows a quick exam window if needed.

2. Hypotension overnight

Hour 4: BP 78/42, HR 124, norepi 0.15, UOP 20 mL/h. DDx? First test at the bedside? POCUS: IVC 1.2 cm and collapsing, hyperdynamic LV, no pericardial fluid, lung sliding both sides. Rx? One liter in, BP 80/45. Next? Vasopressin — dose? Hydrocortisone — yes/no? Dose? Hgb 8.9 from 9.4 — bleeding? What tells you? Abdomen tense; bladder pressure 28 mmHg. Dx? Medical measures — which, in what order? One hour later bladder pressure 30, UOP 5 mL/h, peak pressure 38. Decompressive laparotomy now? Why now and not an hour ago?

Considerations and pitfalls AI draft

DDx. Distributive (uncontrolled sepsis, adrenal insufficiency), hypovolemic (under-resuscitated, occult bleeding, third-spacing), cardiogenic (postoperative MI, septic cardiomyopathy, AF), obstructive (PE, tension pneumothorax, abdominal compartment), sedation.
First test. POCUS: IVC, LV/RV function, pericardium, lungs; with ECG, Hgb, lactate, ABG, and a look at the drains and abdomen.
Rx. Collapsing IVC with a hyperdynamic LV = volume-responsive distributive shock: 500 mL-1 L crystalloid while titrating norepinephrine to MAP ≥65.
No response. Vasopressin 0.03 U/min once norepinephrine is ~0.25 or rising; hydrocortisone 200 mg/day (50 mg q6h) for ongoing pressor requirement; repeat echo; surgical re-evaluation; second large-bore access.
Hgb. A 0.5 drop after 5 L of fluid is dilution until proven otherwise; drains, abdomen, and a repeat in two hours decide it. Not a transfusion trigger.
ACS. Bladder pressure >20 with new organ dysfunction (oliguria, rising airway pressures) = abdominal compartment syndrome. Medical first: deepen sedation, neuromuscular blockade, NG decompression, stop further fluid, drain ascites if present, head of bed <20 degrees.
Decompression. Sustained >20 with organ failure worsening despite medical measures, or any pressure >25 with organ failure, is a surgical emergency. The numbers trend the wrong way with a failing kidney and lung; waiting for arrest is the failure. Call now, document, escalate attending-to-attending if refused.

3. Worsening oxygenation at hour 12

Back from decompressive laparotomy, open abdomen with a vacuum dressing. Hour 12: FiO2 70%, PEEP 8, PaO2 105, pH 7.30, pCO2 42. P/F? DDx? CXR: new bilateral lower-zone opacities. Dx? What must you exclude before you call it that? How? Vent settings now — Vt in mL? On what weight? Plateau goal? Driving pressure goal? PEEP — how do you choose it? Vt 420, RR 28: pH 7.22, pCO2 58. Accept? Why/why not? Hour 18: P/F 90 on PEEP 16, paralyzed, 16 hours prone. Next? Inhaled NO — what does it buy? ECMO — refer? Does he meet criteria? What argues against?

Considerations and pitfalls AI draft

P/F. 150: moderate ARDS.
DDx. ARDS from sepsis, atelectasis, mucus plug or ETT migration, hydrostatic edema after 5+ L, aspiration, TRALI (1 unit within 6 hours), PE, pneumothorax; VAP unlikely under 48 hours.
Bilateral opacities. ARDS in a septic patient; exclude cardiogenic edema (echo, clinical) and TRALI (timing, transfusion service notified). Recheck ETT depth and suction.
Vent. PBW for 5'10" male ~73 kg: Vt 6 mL/kg = ~440 mL (4-8 range); plateau ≤30, driving pressure ≤15; PEEP by the ARDSnet table or a decremental trial to best compliance; conservative fluids; 500 mL was ~6.9 mL/kg, and it climbs if compliance falls.
Permissive hypercapnia. Accept pH ≥7.20; 7.22 is fine at 28 breaths rather than raising Vt; bicarbonate or a small rate increase if it drifts lower.
Refractory P/F 90. Prone in 16-hour cycles, adequate paralysis and sedation, recruitment only if a responder, inhaled NO or epoprostenol as a bridge (improves oxygenation, no mortality benefit), fluid removal if tolerated.
ECMO. EOLIA: P/F <80 for >6 h despite optimized ventilation and prone, P/F <50 for >3 h, or pH <7.25 with pCO2 >=60 for >6 h. At P/F 90 he does not yet meet the P/F threshold; he is close, trending toward it, and early referral/discussion is still right because outcomes worsen with delay. Against: active abdominal sepsis with an open abdomen and anticoagulation, multi-organ failure, age 64; for: reversible cause with source controlled.

4. Oliguria and rising creatinine

Hour 20: UOP 12 mL/h for three hours, Cr 2.8 from baseline 1.4. DDx? First thing you check? Foley flushes clear, bladder pressure 12, IVC 2.2 cm without collapse. Now which? Urine sodium, urine sediment — what do you expect? Nephrotoxins on his list — which do you stop? Plan? Hour 24: K 6.1, peaked T waves. Rx — sequence and doses? What do you recheck at one hour? Hour 25: K 6.4, anuric for four hours, Cr 3.5, pH 7.18. RRT now or wait? Why? Which modality? Why that one?

Considerations and pitfalls AI draft

DDx. Pseudo-oliguria (Foley) first; pre-renal (volume, MAP, intra-abdominal pressure); intrinsic (ischemic/septic ATN, AIN from beta-lactams, pigment); post-renal (ureteral injury with sigmoid resection).
Check first. Flush the Foley; then bladder pressure and IVC. Full IVC with a normal bladder pressure excludes the easy reversible causes.
Now which. Intrinsic AKI, septic and ischemic ATN after 20 hours of shock; urine sodium >40, FENa >2%, muddy brown casts.
Nephrotoxins. Hold lisinopril and metformin (already), avoid NSAIDs, no contrast unless needed, dose antibiotics to clearance (pip-tazo dose adjust), avoid vancomycin-pip-tazo combination if MRSA coverage is added.
Plan. MAP ≥65 (higher, ~70-75, is reasonable in a chronic hypertensive), no further fluid unless responsive, renal dosing, nephrology, daily lytes, watch potassium.
Hyperkalemia. Calcium gluconate 2 g (or chloride 1 g) over 5 minutes for the ECG; insulin 5-10 U with D50 (5 U reasonable in AKI); albuterol 10-20 mg nebulized; bicarbonate 50 mEq given his acidosis; loop diuretic if any UOP; recheck K and glucose at one hour.
RRT. Start now: refractory hyperkalemia after a full shift regimen, anuria, worsening acidosis, and rising creatinine (A, E, and impending O of AEIOU). Another round of shifting buys minutes, not a solution. CRRT because he is on pressors; intermittent HD will drop his pressure. Nephrology and a dialysis catheter now.

B. ONGOING MANAGEMENT AND COMPLICATIONS

Teaching focus. Source control as the dominant lever in persistent septic shock; ICU agitation and the alcohol-withdrawal carve-out; extubation readiness when cuff leak is the limiting factor; the delirium workup as a syndrome with a driver; goals-of-care and family communication when the course turns long.

1. New fever on POD 2

POD 2, abdomen closed yesterday: T 39.4, WBC 24, lactate 2.8, norepi 0.08 plus vasopressin 0.03. DDx? Most likely in him? Cultures — from where? CT — tonight or wait for cultures? Antibiotics — change? To what? Why? Add MRSA coverage? Antifungal? CT: 4 cm rim-enhancing pelvic collection at the rectal stump. Rx? IR can drain at 2 AM; surgeon says decide on morning rounds. Drain tonight or wait? Why?

Considerations and pitfalls AI draft

DDx. The 5 Ws: wind (atelectasis, HAP, aspiration), water (UTI), walking (DVT/PE), wound (surgical site, undrained collection, stump leak, line), wonder drugs (drug fever, transfusion); plus translocation and primary bloodstream infection.
Most likely. POD 1-2 atelectasis is common, but a new spike with persistent pressors and leukocytosis after feculent peritonitis is an undrained source until proven otherwise.
Cultures. Blood x2 (one from the line), urine, tracheal aspirate, drain fluid; line site inspection; CXR.
CT. Tonight; CT abdomen/pelvis with contrast (renal risk accepted given the stakes, or non-contrast plus ultrasound if creatinine forbids) because the finding changes management now.
Antibiotics. Confirm gut coverage (GNR + anaerobes); escalate pip-tazo to a carbapenem for persistent shock and possible resistant flora after hospital exposure; MRSA coverage (linezolid or vancomycin with renal dosing) if prior colonization or line concern; echinocandin for persistent shock with perforation and TPN/CKD risk factors is reasonable; de-escalate to cultures.
Collection. Source control; antibiotics without it fail. Percutaneous drainage is the answer if reachable; OR if not.
Tonight vs morning. Not a wait-until-morning problem: persistent septic shock plus an identified undrained source is an emergency. Push for IR now, frame it as patient safety, escalate attending-to-attending if refused, and document. 'What did we miss?' not 'what do we add?'

2. Agitation after lightening sedation

POD 3, drain in, off vasopressin. SAT: HR 130, BP 165/95, RASS +3, biting the tube. DDx? First three things you check? ABG fine, vent synchronous, no bladder distension, grimacing. Rx first — analgesic or sedative? Drug? Dose? Fentanyl 100 mcg, still fighting. Next? Propofol back on, or dexmedetomidine? Why? Wife arrives: twelve beers a day at home. What changes? CIWA-Ar 18, tremulous, diaphoretic. Rx? Drug, dose, route? Why a benzodiazepine here when you avoid them in delirium? Thiamine — dose? Before or after the D50? Haloperidol for the agitation instead? Why/why not?

Considerations and pitfalls AI draft

DDx. Pain, delirium, hypoxia/hypercarbia, ETT discomfort, full bladder, withdrawal (alcohol, nicotine, opioid), hypoglycemia, hypovolemia, evolving sepsis, ischemia.
Check first. ABG and vent, pain score/grimace, glucose; then tube position, Foley, ECG, abdomen; CAM-ICU after the basics.
Order. Pain first: fentanyl 50-100 mcg bolus and an adequate background; scheduled IV acetaminophen; no NSAIDs in AKI. Agitation in a ventilated postoperative patient is pain or hypoxia until proven otherwise.
Sedative. Dexmedetomidine over propofol for a patient you want to wake and extubate; avoid benzodiazepines for undifferentiated agitation.
Withdrawal. Twelve beers a day with a CIWA of 18 at ~72 hours (propofol masked it) is alcohol withdrawal; seizures and DTs are the risk. Symptom-triggered diazepam 10-20 mg IV or lorazepam 2-4 mg IV by CIWA; phenobarbital if refractory; continue dexmedetomidine as an adjunct, not a substitute.
Benzos here vs delirium. Chronic ethanol upregulates NMDA and downregulates GABA; withdrawal is CNS hyperexcitability, and GABA agonism treats the mechanism. In delirium, benzodiazepines worsen it. Same drug, opposite role; match the pathophysiology.
Thiamine. 500 mg IV before glucose (Wernicke precipitated by glucose in a deficient patient); magnesium, folate. Haloperidol alone lowers the seizure threshold and treats nothing here.

3. Extubation readiness

POD 5: off pressors 24 hours, FiO2 30% / PEEP 5, awake on dexmedetomidine 0.4, following commands, CIWA 6. Extubate? What must be true first? SBT settings? Pass criteria? He passes. Cuff leak 40 mL. Extubate anyway? Why/why not? Steroids — which, dose, timing? After steroids: leak 60 mL. Extubate? With what at the bedside? Five minutes after extubation: stridor, SpO2 88%. Rx? Racemic epinephrine — dose? Not improving. Reintubate — device? Tube size? POD 7: same picture, leak 50 mL. Extubate again? What has to be different? Trach — when?

Considerations and pitfalls AI draft

Checklist. Cause resolved, P/F >200 on FiO2 ≤40% and PEEP ≤5-8, hemodynamically stable off pressors, mental status adequate, cough and secretions manageable, cuff leak, volume status, a post-extubation plan.
SBT. PS 5/PEEP 5 or T-piece for 30-120 minutes; pass = RSBI <105, RR <35, SpO2 >90%, no distress or hemodynamic change.
Cuff leak 40 mL. Under 110 mL or 10-12% of Vt predicts post-extubation stridor; with a week of a tube, an open-abdomen fluid course, and a septic patient, laryngeal edema is likely. Extubating on a 40 mL leak without preparation is the flag.
Steroids. Methylprednisolone 20 mg IV q4h x4 starting 12 hours before extubation (or 40 mg once ≥4 hours before); reassess the leak.
Extubate at 60 mL. Borderline; acceptable with the full airway team (video laryngoscope, bougie, smaller ETT, flexible scope, surgical airway plan stated, attending present), or defer another day.
Stridor. 100% oxygen, sit up, racemic epinephrine 0.5 mL of 2.25% in 3 mL nebulized, dexamethasone 8-10 mg IV, heliox as a bridge; reintubate early rather than late: video laryngoscope first pass, tube a half to full size smaller (7.0), surgical airway ready.
POD 7. Failed once for the same reason; re-attempt only with demonstrated resolution: quantitative leak >110 mL or >12%, a completed steroid course, direct or flexible look at the larynx if equivocal, team present. Same leak, same result.
Trach. Anticipated ventilation >10-14 days or a second failed extubation for the same cause in an otherwise improving patient; earlier trach (7-10 days) reduces sedation and ICU days without a mortality benefit. After a second laryngeal failure, have the conversation, not 'wait and see'.

4. Acute confusion on POD 8

POD 8, extubated since POD 7, step-down. Overnight: pulling at the Foley and the central line, climbing out of bed, talking to people not in the room. CAM-ICU positive. DDx? First things you check at the bedside? Glucose 96, SpO2 94% room air, Na 134, afebrile, no lateralizing signs, bladder scan 80 mL. Next? Non-pharmacologic measures — what? Restrain — yes/no? He punches a nurse. Drug? Dose? Route? What do you monitor? Haloperidol 1 mg IV, still swinging twenty minutes later. Next? Dose? QTc 510 on the ECG. Now what?

Considerations and pitfalls AI draft

DDx. Drivers, not the label: pain, infection (abdomen, UTI, pneumonia, line, CNS), hypoxia/hypercarbia, electrolytes (Na, glucose, Mg, Ca, phos), medications (opioids, benzodiazepines from withdrawal treatment, anticholinergics, steroids), withdrawal (alcohol, nicotine), sleep deprivation, retention, stroke, sepsis-associated encephalopathy, non-convulsive status.
Check first. Vitals, glucose, oxygen, neuro exam for lateralizing signs, bladder scan, pain, medication list; then electrolytes with Mg/phos, infection workup, family for baseline; EEG if no improvement.
Next. Medication reconciliation (opioid dose, any benzodiazepine, anticholinergics), infection screen (cultures, CXR, abdominal exam, line), Mg/phos/Ca, thiamine; nicotine patch.
Non-pharm. Reorient, glasses and hearing aids, day-night cues, family at the bedside, mobilize, sleep, treat pain, remove the central line and Foley if not needed.
Restraints. Last resort, time-limited, documented; soft restraints to protect lines during the workup.
Pharm. Only for danger to self or staff while the driver is addressed: haloperidol 2-5 mg IV for this degree of violence (0.5-1 mg for mild), repeat q15-30 min x2 with QTc and BP checks; olanzapine 5-10 mg IM if no IV; avoid benzodiazepines unless withdrawal has recurred (check CIWA).
Escalation. Haloperidol 2-5 mg; if unsafe after two rounds, dexmedetomidine infusion in a monitored setting (transfer back to ICU); goal calm, not unconscious. Security if active threat.
QTc 510. Stop haloperidol and other QT-prolonging drugs (ondansetron, quinolones), replace K and Mg, switch to dexmedetomidine; QTc >500 is the line. Sedating through delirium without a cause found prolongs it.

5. Goals of care and family communication

POD 12: step-down, nasal cannula, intermittent hemodialysis, delirium waxing and waning, two more fevers, a wound infection drained. Daughter asks: "Is he going to get out of this?" What will you tell her? Surgery told her "a few more days"; nephrology said "weeks, maybe months of dialysis." Which is right? Why? Palliative care consult — yes/no? Why? Does it change anything you order tomorrow?

Considerations and pitfalls AI draft

Daughter. Honest and plain: what is better (off pressors, breathing on his own, source drained), what is not (kidneys, brain, repeated infections), that the course is long and the outcome uncertain; no false reassurance, no premature certainty either way. Room for her questions.
Which is true. Nephrology's: dialysis-dependent AKI after septic shock may or may not recover over weeks; a single medical voice is needed before the next meeting, and the ICU team convenes it.
Palliative care. Yes, early, for symptom management and family support; not a signal that treatment stops.
Tomorrow. Nothing withheld; the framing changes the pace of decisions (trach, feeding access, dialysis catheter), not today's care.

Non-perioperative

Postoperative hypoxemic respiratory failure from hospital-onset aspiration pneumonia after hip hemiarthroplasty

A 79 y.o., 58 kg, 5'2" (157 cm) woman is on the orthopedic floor, POD 3 after left hip hemiarthroplasty for a femoral neck fracture. The SICU team is called to a rapid response for low oxygen saturation.

HPIFell at home and fractured her left femoral neck; hemiarthroplasty on hospital day 2 was uneventful. Diet advanced to regular on POD 1. Oxycodone at night for hip pain, drowsy after doses. On POD 2 her nurse noted coughing during lunch. Fever overnight, with her oxygen requirement climbing from 2 L to 6 L nasal cannula over six hours.

PMHHypertension. Heart failure with preserved ejection fraction (echo 6 months ago: LVEF 60%, grade II diastolic dysfunction). Paroxysmal atrial fibrillation. Left MCA ischemic stroke 2 years ago with mild residual right-sided weakness and dysphagia; on a modified diet at home. Former smoker, 20 pack-years, quit two decades ago. Lives with her daughter. Full code.

MEDSApixaban 5 mg BID (held on admission, restarted POD 1), metoprolol succinate 50 mg daily, amlodipine 5 mg daily, furosemide 20 mg daily (held since admission), atorvastatin. In hospital: acetaminophen 1 g q8h; oxycodone 5 mg PRN, four doses in the last 24 hours.

PHYS EXAMDrowsy but rousable, oriented to person only (fully oriented at baseline per her daughter). HR 118, irregularly irregular; BP 148/80; RR 32; T 38.6 °C; SpO2 86% on 6 L nasal cannula. Accessory muscle use, speaking in short phrases, weak cough. Bronchial breath sounds and coarse crackles at the right base; left base clear. JVP difficult to assess. Trace bilateral ankle edema. Left hip incision clean and dry.

LABSWBC 15.2 (9.8 on POD 1); Hgb 9.6; platelets 248; Na 137; K 4.1; Cr 0.9 (baseline 0.8); glucose 162; lactate 1.6. ABG on 6 L nasal cannula: pH 7.47; PaCO2 31; PaO2 52; HCO3 22.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INITIAL ASSESSMENT ON ADMISSION

Teaching focus. Bedside evaluation of new postoperative hypoxemia; prompt cultures and empiric antibiotics for a hospital-onset pneumonia; matching the oxygen device to the patient and recognizing high-flow failure; intubating the hypoxemic patient safely.

1. Rapid response on the orthopedic floor

You arrive at the bedside. Immediate priorities? Oxygen: which device? SpO2 target? Why that number? Non-rebreather on: SpO2 90%, RR 30. DDx? Most likely in her? Why? Oxycodone: hold? Why/why not? Portable CXR: dense right lower lobe opacity with air bronchograms, small right effusion, clear left lung, no vascular congestion. POCUS: right basal consolidation, B-lines over the right base only, normal LV function, RV not dilated. Interpretation? CT pulmonary angiogram tonight? Why/why not? Furosemide? Why/why not?

Considerations and pitfalls AI draft

Immediate priorities. Sit her upright, escalate oxygen, clear and suction the mouth, judge airway protection and work of breathing, call for an ICU bed now; glucose and telemetry. Ordering tests while she sits at 86% on nasal cannula is the flag.
Device and target. Non-rebreather or high-flow nasal cannula if the floor can run it; target SpO2 92-96%. PaCO2 31 and no history of CO2 retention, so the 88-92% target used in chronic hypercapnia does not apply; pushing above 96% adds nothing.
DDx. Aspiration pneumonitis or pneumonia, hospital-acquired pneumonia, atelectasis, cardiogenic pulmonary edema (HFpEF, furosemide held, AF, perioperative fluid), PE after hip fracture surgery (though anticoagulated since POD 1), fat embolism (24-72 h window, usually with petechiae and neurologic change), MI presenting as edema, opioid hypoventilation (PaCO2 31 argues against).
Most likely. Aspiration-related pneumonia: post-stroke dysphagia on a regular diet, opioid drowsiness, coughing with a meal, fever and a rising WBC, focal right basal findings. Settling on edema because of the HFpEF label without accounting for the fever and the focal exam is the trap.
Oxycodone. Hold it for now: sedation blunts cough and airway protection. Scheduled acetaminophen continues; a small opioid dose returns once she is safer, because untreated hip pain also limits cough and mobility.
Interpretation. Lobar consolidation with air bronchograms and unilateral B-lines: pneumonia. No bilateral B-lines or congestion argues against edema; a normal RV makes a large PE unlikely.
CTPA. Not tonight: an alternative diagnosis explains the picture, she has been anticoagulated since POD 1, and the RV is normal; transport on a non-rebreather and a contrast load carry real risk. Revisit if the course stops fitting pneumonia or the RV changes.
Furosemide. No: no congestion on film or ultrasound, and she is febrile and tachypneic with insensible losses; diuresis risks hypotension. Liberal fluid is also wrong with her diastolic dysfunction; the home diuretic resumes once she is euvolemic.

2. Waiting for the SICU bed

SICU bed in 30 minutes. Antibiotics now, or after cultures in the unit? Why? Cultures: which? Sputum: how do you get one from her? Empiric regimen? Drug? Dose? Anaerobic coverage: add? Why/why not? MRSA coverage? Why/why not? Procalcitonin returns 1.9. Changes anything? HR 128 in AF, BP 134/72. IV metoprolol? Why/why not? What brings her rate down?

Considerations and pitfalls AI draft

Timing. Infection with new respiratory organ dysfunction is a high likelihood of sepsis: first dose within the hour, on the floor. Blood cultures first only if they do not delay the dose. Waiting for the unit is the error.
Cultures. Blood x2, a lower respiratory sample, MRSA nasal PCR; respiratory viral PCR in season.
Sputum. Drowsy with a weak cough, so an expectorated sample is unlikely: nasotracheal suction or induced sputum by respiratory therapy, or a tracheal aspirate right after intubation if it comes to that. Never hold antibiotics for it.
Regimen. Onset more than 48 hours into the admission makes this hospital-acquired pneumonia. Not ventilated and not in shock: a single antipseudomonal agent that also covers MSSA, e.g. piperacillin-tazobactam 4.5 g IV q6h (full dose at her estimated CrCl of ~45 mL/min) or cefepime 2 g IV with the interval adjusted for CrCl, guided by the local antibiogram. Ceftriaxone alone is a community regimen and misses hospital flora.
Anaerobes. Not added routinely for aspiration pneumonia; reserved for lung abscess or empyema. Piperacillin-tazobactam covers them anyway; metronidazole on top of cefepime is not needed.
MRSA. Add vancomycin or linezolid for IV antibiotics within 90 days, a unit where MRSA is common or its prevalence unknown among S. aureus isolates, or high mortality risk (ventilatory support for the pneumonia, septic shock). She is not ventilated or in shock yet. Her perioperative cefazolin is technically IV antibiotic exposure within 90 days; read strictly, that adds MRSA coverage and a second antipseudomonal agent, but many do not count a day of prophylaxis. Either reading is defensible; the nasal PCR lets you stop vancomycin quickly.
Procalcitonin. Does not decide whether to start; it helps later in deciding when to stop. Holding antibiotics for a low value is the error.
Rate. AF at 128 driven by fever, hypoxemia, and pain: oxygen, antipyretic, analgesia first. A small IV dose (metoprolol 2.5-5 mg) is reasonable if the rate stays high with a stable BP once those are treated; aggressive rate control of a compensatory tachycardia risks hypotension.

3. Arrival in the SICU on a non-rebreather

SICU: non-rebreather, SpO2 88%, RR 34, speaking in single words. HFNC, NIV, or intubate now? Which? Why? Assume HFNC. Flow? FiO2? At 30 minutes on 60 L/min, FiO2 0.8: SpO2 94%, RR 28. Reassess when? What would make you intubate? Respiratory therapy suggests BiPAP instead. Agree? Why/why not? Three hours later: RR 36, SpO2 89% on FiO2 1.0, drowsier, pooled oral secretions, weak cough. ABG: pH 7.34, PaCO2 44, PaO2 55. Interpretation? Intubate now? Why/why not?

Considerations and pitfalls AI draft

Device. HFNC: hypoxemic rather than hypercapnic, still rousable; it delivers high FiO2, some end-expiratory pressure, dead-space washout, and lets her cough and be suctioned. Intubating now is defensible if mental status is falling; intubating reflexively without a short HFNC trial, or starting HFNC with no stated failure criteria, are the softer flags.
Settings. Start high: 50-60 L/min, FiO2 titrated to SpO2 92-96%.
Reassess. At 1-2 hours, then every few hours: RR, SpO2/FiO2, work of breathing, mental status, secretion clearance, gas. ROX index (SpO2/FiO2 ÷ RR) ≥4.88 is reassuring; <2.85 at 2 h, <3.47 at 6 h, or <3.85 at 12 h predicts failure. At 30 minutes she is 94/0.8 ÷ 28 ≈ 4.2: intermediate, keep watching.
What would make you intubate. Rising RR, rising FiO2 need, falling ROX, worsening mentation, rising PaCO2, secretions she cannot clear. Delayed intubation after prolonged HFNC failure is linked to worse outcomes; the decision is made within hours at the bedside, not deferred to morning.
BiPAP. No: drowsy, aspiration-prone, pooled secretions, no hypercapnia or edema to treat. NIV for de novo hypoxemic failure has not shown benefit, drives large tidal volumes, and hides deterioration. Its roles are COPD exacerbation and cardiogenic edema, not this.
Interpretation. Severe hypoxemia on maximal HFNC with PaCO2 climbing from 31 to 44 while RR rises: she is tiring. A normal-looking PaCO2 in this setting is the warning, not reassurance.
Intubate now. Yes: HFNC failure, falling mental status, unable to clear secretions, full code. Waiting for a lower saturation or a trial of NIV as a bridge is the error.

4. Intubation in the SICU

Decision made to intubate. BP 146/78, HR 120 in AF. Preoxygenation: device? Position? Induction agent? Dose? Why? Rocuronium or succinylcholine? Which? Dose? Why? Mask ventilation between induction and laryngoscopy? Why/why not? Video or direct laryngoscope? Why? Tube placed, waveform capnography confirmed. Two minutes later: BP 72/40, HR 132. DDx? Rx now? Drug? Dose? Assume phenylephrine 100 mcg twice and 500 mL crystalloid: BP 104/58. Vasopressor infusion? Why/why not? Arterial line? Why/why not?

Considerations and pitfalls AI draft

Preoxygenation. Head up 20-30 degrees; NIV by face mask at FiO2 1.0 with PEEP 5-10 for about 3 minutes (HFNC at 60 L/min if she cannot tolerate the mask), with HFNC left on under the mask and through laryngoscopy for apneic oxygenation. A standard face mask alone is weak in a shunting patient who will desaturate within seconds of apnea.
Induction. Older, septic, hypoxemic: ketamine 0.5-1 mg/kg (30-60 mg) or etomidate 0.2-0.3 mg/kg (12-18 mg), or reduced-dose propofol with a pressor in hand. A full propofol dose (~2 mg/kg, about 115 mg) here is the flag.
Rocuronium or succinylcholine. Rocuronium 1.2 mg/kg (~70 mg) for rapid-sequence conditions. Succinylcholine 1-1.5 mg/kg: K is normal, but her residual hemiparesis is an upper motor neuron lesion with upregulated acetylcholine receptors on the paretic side (hyperkalemia risk), and days of immobility add to it. Avoid it; rocuronium at this dose is equally fast.
Mask ventilation. Yes: gentle bag-mask ventilation with a PEEP valve between induction and laryngoscopy reduces desaturation in a hypoxemic patient. Aspiration risk is real, but desaturation is the larger threat; keep pressures low.
Laryngoscope. Video laryngoscope with a bougie or stylet for first-pass success, most experienced operator, backup supraglottic and front-of-neck plan stated; 7.0 tube.
DDx for 72/40. Induction agent and loss of sympathetic drive, positive pressure cutting preload in a febrile, under-filled patient, PEEP, rapid AF, breath stacking from aggressive bagging, tension pneumothorax, ischemia. Look at the ventilator, capnography, and breath sounds while treating.
Rx. Phenylephrine 100-200 mcg or norepinephrine 4-8 mcg IV boluses, 250-500 mL crystalloid, slow the bagging rate; epinephrine 10-20 mcg if refractory.
Infusion. One dip that responds does not commit her to an infusion; recurrent hypotension does: norepinephrine 0.02-0.1 mcg/kg/min, peripherally for a short time if needed. Arterial line: yes, for beat-to-beat pressure during sedation and frequent gases.

B. ONGOING MANAGEMENT AND COMPLICATIONS

Teaching focus. Lung-protective initial ventilator settings and reading the first gas and airway pressures; light sedation with a daily awakening trial; narrowing antibiotics to culture data; extubation readiness beyond the breathing trial; preventing a second aspiration and disclosing to family.

1. First hour on the ventilator

BP 112/66, no vasopressor running. Mode? Tidal volume in mL? Why that number? Rate? PEEP? FiO2? Assume volume control, Vt 300, rate 22, PEEP 8, FiO2 1.0. ABG at 30 minutes: pH 7.30, PaCO2 51, PaO2 142. Interpretation? Changes? FiO2 1.0: keep it? Why/why not? Peak pressure 36, plateau 21. Interpretation? Rx? Antibiotics unchanged since the floor. Change them now? Why/why not?

Considerations and pitfalls AI draft

Mode. Volume or pressure assist-control, full support while sedated and recently paralyzed.
Tidal volume. Set on predicted body weight, not actual: female, 157 cm, PBW ≈ 45.5 + 0.91 × (157 − 152.4) ≈ 50 kg; start at 6 mL/kg ≈ 300 mL, adjusting within roughly 4-8 mL/kg (200-400 mL) by plateau and driving pressure. Setting it on her 58 kg actual weight (350 mL at 6 mL/kg, 460 mL at 8) is the common error. Lung-protective volumes apply without ARDS.
Rate, PEEP, FiO2. Rate 20-24 to approach the minute ventilation she was generating; a rate of 10-12 after breathing at 36 with a PaCO2 of 44 produces acute acidosis. PEEP 5-8, FiO2 1.0 to start, then wean.
ABG. Acute respiratory acidosis (calculated HCO3 ~24) with PaCO2 still climbing; P/F 142 on PEEP 8: shunt through the consolidated lobe.
Changes. PH 7.30 is tolerable, but PaCO2 is still climbing: rate up modestly to 24-26 (minute ventilation 6.6 L to about 7.2-7.8 L), watch expiratory flow for auto-PEEP at her high rate, and recheck. Vt up toward 7 mL/kg (~350 mL) only if plateau stays ≤30 and driving pressure ≤15. Chasing a normal PaCO2 with large volumes is the error.
FiO2. Wean to SpO2 92-96% (PaO2 ~65-100); staying at 1.0 adds absorption atelectasis and oxygen toxicity. High PEEP does little for a lobar consolidation and overdistends the good lung.
Peak 36 / plateau 21. A 15 cmH2O peak-to-plateau gap is airway resistance: secretions or a plug, biting, a kinked or small tube, bronchospasm. Driving pressure 13 (21 − 8) is acceptable. Rx: suction, bite block, check the tube, bronchodilator if wheezing, bronchoscopy for a persistent plug. Raising the pressure alarm limit is the flag.
Antibiotics. Needing ventilatory support for the pneumonia puts her in the guideline's high-mortality-risk group: the empiric regimen adds MRSA coverage (vancomycin load ~20-25 mg/kg, about 1200-1500 mg, then level- or AUC-guided; or linezolid 600 mg q12h) and a second antipseudomonal agent from a different class (aminoglycoside or fluoroquinolone; not a second beta-lactam), tailored to the local antibiogram (a weak guideline recommendation built on low-quality evidence, but the standard empiric step), pending the tracheal aspirate sent now. Plan to narrow at 48-72 hours. Leaving the floor regimen unchanged without a reason is the flag.

2. Ventilator day 1, overnight into morning

Overnight: propofol 45 mcg/kg/min, fentanyl 100 mcg/h, RASS −4. Target RASS? Why? Propofol, dexmedetomidine, or midazolam? Which? Why? BP 88/48. DDx? Rx? Her hip: analgesia plan? Morning: FiO2 0.5, PEEP 8. Sedation interruption this morning? Why/why not? Off propofol 40 minutes: RASS +2, pulling at the tube, RR 37, SpO2 87%. Pass or fail? Next? Restart at what dose?

Considerations and pitfalls AI draft

Target. RASS 0 to −2: calm and rousable. Deep sedation is for specific indications (paralysis, refractory hypoxemia, dyssynchrony that cannot be fixed otherwise). Light sedation shortens ventilation and ICU stay; −4 is deeper than she needs.
Agent. Analgesia first, then propofol or dexmedetomidine; both defensible, propofol easier to titrate early. Midazolam is the agent to avoid: benzodiazepines prolong ventilation, accumulate in older patients, and raise delirium risk.
BP 88/48. At RASS −4 the sedation is the most likely cause; worsening sepsis, auto-PEEP, and bleeding are the alternatives to check. Turn the propofol down toward the target RASS (dose-dependent vasodilation and myocardial depression) rather than adding a pressor to support oversedation. Fentanyl 100 mcg/h may be more than a 58 kg 79-year-old needs at RASS −4; titrate to a behavioral pain scale.
Hip. Scheduled acetaminophen (1 g IV q8h), opioid titrated to a behavioral pain scale, positioning; no NSAIDs at her age while anticoagulated. Unrecognized hip and tube pain often drives what looks like agitation. Her anticoagulation (no beat; for the educator): apixaban was held when she went NPO for intubation and lines. With a CHA2DS2-VASc of 7 (prior stroke, age, HF, hypertension, female) and a recent hip fracture repair, it should not stay off: resume apixaban crushed by orogastric tube once lines are in and no procedure is imminent, or cover the gap with an unfractionated heparin infusion (no bolus) that can be stopped a few hours before a line or a tap. Both defensible; no anticoagulation plan at all is the flag.
SAT. Yes: no paralytic, no escalating sedation for agitation, no seizures or withdrawal, no active ischemia, no raised ICP. FiO2 0.5 is not a reason to skip the awakening trial.
Result. Sustained agitation, RR >35, SpO2 <88%: failed. Next: bolus analgesia, look for the cause (tube position, secretions, hypoxemia, pain), restart propofol at half the prior dose and titrate to target; repeat tomorrow. Restarting the full overnight dose, or dropping the daily trial, is the flag.

3. Ventilator day 2 culture data

Assume she is on piperacillin-tazobactam, vancomycin, and tobramycin. Day 2: T 38.1, FiO2 0.4, PEEP 8. Tracheal aspirate Gram stain: many neutrophils, gram-positive cocci in clusters. MRSA nasal PCR negative. Interpretation? Vancomycin: continue? Why/why not? Tobramycin: continue? Why/why not? Day 3: Staphylococcus aureus, methicillin-susceptible; blood cultures no growth. Regimen now? Drug? Dose? Duration? How will you judge her response? Ultrasound of the right base: small, free-flowing, anechoic effusion, under 1 cm deep. Tap it? Why/why not? What would make you tap it later?

Considerations and pitfalls AI draft

Interpretation. Gram-positive cocci in clusters with neutrophils in a good sample: S. aureus most likely. A negative MRSA nasal PCR has a high negative predictive value for MRSA pneumonia.
Vancomycin. Stop it: the negative PCR supports it, and continuing 'until final cultures' adds kidney injury risk, especially alongside piperacillin-tazobactam and an aminoglycoside, for little gain.
Tobramycin. No gram-negative rods on a good-quality Gram stain argues against a gram-negative cause; stopping it now or when the culture finalizes at 48-72 hours are both defensible. Continuing an aminoglycoside past a culture with no gram-negative growth adds kidney and ear toxicity for nothing.
MSSA regimen. Narrow to cefazolin 2 g IV q8h (or nafcillin/oxacillin) and stop piperacillin-tazobactam and any remaining tobramycin; vancomycin is inferior for MSSA. Seven days total if she improves; longer only for bacteremia, abscess, or empyema.
Response. Fever curve, FiO2 and PEEP needs, secretion volume, WBC, procalcitonin trend. The chest film lags for weeks; chasing it with longer antibiotics is the error.
Effusion. Small, free-flowing parapneumonic effusion: observe, no tap.
Later tap. Growth, loculation or septations, or persistent fever and sepsis despite appropriate antibiotics: diagnostic thoracentesis, with the anticoagulant dose held or the heparin paused beforehand (pH, glucose, LDH, Gram stain and culture); pus or a pH <7.2 means drainage.

4. Day 4 weaning screen

Day 4: afebrile 36 hours, FiO2 0.35, PEEP 6, no vasopressor. Sedation off since 7 AM: RASS 0, CAM-ICU negative, follows commands. SBT now? Why/why not? Settings? How long? At 30 minutes: RR 26, Vt 280 mL, SpO2 95%, HR 96, BP 138/72. RSBI? Pass? Why? Suctioned hourly overnight for thick secretions; cough weak on suctioning. Extubate today? Why/why not? Day 5: passes the SBT again, strong cough, suctioned twice overnight. Extubate to what: nasal cannula, HFNC, or NIV? Why?

Considerations and pitfalls AI draft

SBT now. Yes: cause improving, FiO2 ≤0.4-0.5, PEEP ≤8, off pressors, awake, breathing spontaneously. The awakening trial and the breathing trial run together.
Settings. Pressure support 5-8 with PEEP 5, or T-piece/CPAP; 30-120 minutes, with 30 minutes enough for most.
RSBI. 26 ÷ 0.28 L = 93 (<105). Passing also requires no distress, stable HR and BP, SpO2 ≥90%, RR <35.
Extubate today. Not yet: hourly suctioning with a weak cough, after an aspiration and with known dysphagia, predicts reintubation from retained secretions. A passed SBT is not enough; she also has to protect and clear her airway (cough strength, secretion volume and suction frequency, mental status). Deferring 24 hours with pulmonary toilet is defensible; extubating on a passed SBT alone is the common error.
Extubate to what. High risk of extubation failure (over 65, heart disease, pneumonia as the cause, a recently weak cough): extubate directly to HFNC or prophylactic NIV, not plain cannula. HFNC suits a dysphagic, aspiration-prone patient better than a tight mask; NIV is a reasonable alternative. Upright, nothing by mouth until a swallow evaluation. Using NIV to rescue established post-extubation failure delays reintubation and is the flag.

5. Day 7 diet order

Day 7: extubated 48 hours, on 2 L nasal cannula, alert and oriented. Orthopedics writes for a regular diet. Agree? Why/why not? What first? Swallow evaluation: coughs with thin liquids, clears with mildly thick liquids and soft solids. Diet? What else goes in the order? Hip pain 7/10 with physical therapy. Oxycodone: restart? Dose? Why? Her daughter: "She told the nurses she needed thick liquids. Did the regular diet cause this?" What will you tell her?

Considerations and pitfalls AI draft

Regular diet. No: post-stroke dysphagia, an aspiration, and five days of intubation (post-extubation dysphagia is common); nothing by mouth until a formal swallow evaluation by speech-language pathology.
Diet and order. Mildly thick liquids and soft solids per the evaluation; upright for meals and 30 minutes after, head of bed 30-45 degrees, supervised meals, small bites, pills crushed in puree or given whole per SLP, oral care; re-evaluate before advancing. Carry the modified diet onto the discharge orders.
Oxycodone. Yes, low dose (2.5 mg PRN, timed before therapy) with scheduled acetaminophen, checking sedation before each dose. Undertreated hip pain limits mobilization and cough and feeds delirium; oversedation recreates the setup for aspiration.
The daughter. Honest and plain: her dysphagia and the regular diet likely contributed, along with drowsiness from pain medicine; say you are sorry this happened, that it is being reviewed, and what has changed now (diet, swallow evaluation, sedation checks). No speculation about who is at fault, no defensive 'pneumonia just happens after surgery'. Leave room for her questions.

Long stem

Cervical mediastinoscopy and biopsy of a large anterior mediastinal mass

A 34 y.o., 60 kg, 5'5" woman is scheduled for cervical mediastinoscopy and biopsy of a bulky mediastinal mass with anterior and right paratracheal extension for tissue diagnosis.

HPISix weeks of cough and progressive dyspnea, now breathless at rest and unable to lie flat; she sleeps upright in a recliner. Two episodes of near-syncope when supine. Facial fullness and a sense of head pressure when she bends forward. No treatment to date; oncology wants tissue before starting therapy.

PMHPreviously healthy. Over the last two weeks she has noticed morning facial puffiness and prominent veins across the upper chest.

MEDSNone. No corticosteroids given to date.

PHYS EXAMHR 104; BP 118/72; RR 22 sitting; SpO2 94% on room air; T 37.1°C. Facial plethora and periorbital edema, distended neck and upper-chest veins, soft stridor audible when she leans back.

IMAGINGCT chest: bulky mediastinal mass with anterior and right paratracheal components, roughly 10 cm, narrowing the tracheal cross-section by about 60% down to the carina, compressing and displacing the SVC, and abutting the main pulmonary artery.

ECHOSmall-to-moderate pericardial effusion with intermittent right atrial and RV inflow compression; preserved LV function.

LABSHgb 12.8 g/dL; platelets 240 K/uL; INR 1.1; K+ 4.0 mEq/L; creatinine 0.8 mg/dL; uric acid mildly elevated; LDH elevated.

OR ARRIVALAwake, sitting at 45°. Two large-bore lower-extremity IVs and femoral arterial and venous introducer sheaths placed under local; perfusion in the room with a primed circuit; radial arterial line. Surgeon and perfusion are aware; a rigid bronchoscope is open in the room.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Choosing an anesthetic that preserves the airway and venous return in front of a mass that compresses both; rescuing the predicted induction collapse; reading a damped right-sided arterial trace during mediastinoscopy; managing major mediastinal hemorrhage to a clear end point.

1. Anesthetic plan and ventilation strategy

60% tracheal narrowing, SVC compression, a pericardial effusion, can't lie flat. General anesthesia — is it needed at all for this biopsy? What is the alternative? She cannot tolerate lying flat for a core needle. Now GA. Spontaneous or controlled ventilation? Why? Paralyze her — yes/no? Why? Induction agents to keep her breathing — which? Position for induction? Why that one? The femoral sheaths and lower-extremity IVs — why placed there rather than an arm? You begin induction; SpO2 falls to 86% and the bag is hard to squeeze. What is happening? First move?

Considerations and pitfalls AI draft

GA vs alternative. Many mediastinal biopsies (anterior Chamberlain, core, or EBUS) go under local with sedation and avoid the collapse risk of GA; reaching for GA without weighing a less-invasive route is worth probing. Here she cannot lie flat, which constrains the awake option and pushes toward the OR plan already staged.
Spontaneous vs controlled. Spontaneous ventilation preserves the transpleural gradient and airway patency and is the conservative default; positive pressure and paralysis can precipitate dynamic collapse. The evidence is softening: with a rigid scope, surgeon, and femoral access standing by, a staged controlled-ventilation technique titrated only after confirming the airway can be maintained is defensible in experienced hands. Early paralysis with no rescue is the red flag.
Paralyze. Not before the airway is secured distal to the lesion and ventilation is proven; loss of tone can close a dynamically compressed airway.
Agents. Inhalational (sevoflurane) or titrated IV (ketamine, low-dose propofol/dexmedetomidine) that keeps her breathing; avoid abolishing drive and tone up front.
Position. Induce semi-sitting; map the symptom-relieving position ahead of time (often lateral or prone) as the rescue.
Access. SVC compression makes upper-body access unreliable and slow to reach the heart; lower-extremity large-bore and femoral sheaths pre-stage rescue cannulation and resuscitate below the obstruction.
Desaturation on induction. Dynamic airway and vascular compression as spontaneous effort fades: the predicted mechanical event, not simply light anesthesia.

2. Cardiopulmonary collapse on induction

SpO2 78%, BP 60/40, cannot ventilate despite an ETT confirmed at the cords with end-tidal CO2. DDx? First maneuver — before any drug? You turn her lateral; still no chest rise. Rigid bronchoscopy now — what does it achieve? The surgeon stents past the lesion and you can ventilate, but there is still no arterial output. Cause? Go on femoral bypass? What is your resuscitation end point? When do you abandon and wake her?

Considerations and pitfalls AI draft

DDx. Airway compression distal to the ETT tip, SVC/PA/cardiac compression obstructing venous return and output, tension physiology, tamponade from the effusion.
First maneuver. Reposition — lateral, prone, or sitting — to relieve mechanical compression; the immediate move that addresses the mechanism. Chasing pressors alone misses it.
Rigid bronchoscopy. The surgeon passes the rigid scope past the obstruction to stent the airway distal to the lesion; the planned rescue, which is why it is open in the room.
No output despite ventilation. The mass is obstructing venous return or the pulmonary artery / heart; ventilation restored but circulation still mechanically obstructed points to CPB.
Femoral CPB. The reason both femoral sheaths are in; go on bypass for circulatory rescue when repositioning and airway stenting do not restore output.
End point / waking. Resuscitation targets a perfusing rhythm and MAP; if the airway can be maintained by any means, aborting and waking her to breathe spontaneously is a legitimate and sometimes correct choice.

3. Damped arterial trace during mediastinoscopy

The scope is in the mediastinum. The right radial trace flattens and the right-hand pulse oximeter loses its signal; the left radial reads MAP 70. Dx? Rx? Moments later blood fills the field and the left radial reads 70/40. Priorities? Transfuse — at what trigger? Blood goes in through the arm IV or the femoral sheath? Why? Resuscitation end point? Surgeon packs and calls for a sternotomy tray. She is still breathing spontaneously. Take over ventilation now? Why/why not?

Considerations and pitfalls AI draft

Artifact vs real. The scope is compressing the innominate (brachiocephalic) artery; the right radial and right pulse oximeter go flat while the left reads true pressure. Treating this as true hypotension and escalating pressors is the classic trap.
Tell the surgeon. Ask them to release the compression; the right-sided trace is the early-warning monitor for innominate and right cerebral flow.
Bleeding / priorities. Major vascular injury (innominate, SVC, azygos): call for help and blood, activate massive transfusion, confirm large-bore lower-body access, prepare for sternotomy.
Access for SVC injury. Fluid and blood given above an SVC injury pool above the tear; the lower-extremity IVs and femoral sheath let you resuscitate from below, which is why they were placed there.
Trigger / end point. Transfuse to ongoing loss and hemodynamics, not a single number; target a MAP that perfuses while surgical control is achieved; anticipate sternotomy or bypass and resource accordingly.
Take over ventilation. With the airway still dynamically compressible, keep spontaneous effort if she is oxygenating; take over only if she cannot sustain gas exchange, with the rigid scope ready. Meanwhile products through lower-body access, sternotomy tray and perfusion ready, modest pressure targets until the source is controlled.

4. Hemodynamics after control

Bleeding controlled. BP 88/52 on norepinephrine 0.05, CVP rising, repeat echo shows the pericardial effusion slightly larger with RA collapse. Still hypotensive — why now? DDx? How do you tell tamponade from RV strain from ongoing bleeding? Drain the pericardium — indication met? Volume, pressor, or drainage first? Target MAP and filling pressure? Transport her to the ICU extubated or intubated? Why?

Considerations and pitfalls AI draft

Why now. Persistent hypotension after surgical control: tamponade from the enlarging effusion with RA collapse, RV strain from PA compression, vasoplegia, or ongoing occult bleeding.
Distinguish. Echo for tamponade (RA/RV collapse, respiratory variation) and RV function, response to a fluid challenge, and the surgical field; do not anchor on one cause.
Drainage. RA collapse with hypotension is tamponade physiology; drain, coordinated with surgery given the open field.
First. Support preload and perfusion (fluid, norepinephrine) while identifying the mechanism, then relieve the tamponade; drainage is definitive if that is the driver.
Targets. A named MAP (~65-70) and filling target rather than treating the CVP number blindly.
Transport. Marginal airway (the mass and edema) and hemodynamics argue for controlled, intubated transport with continued ventilation.

B. POST-OPERATIVE CARE

Teaching focus. Extubation judgment in an airway that already obstructed once; recognizing a post-mediastinoscopy tension pneumothorax; reading new hoarseness and a weak cough; the timing of treatment and tumor lysis; and an honest disclosure when the course goes badly.

1. Extubation decision

Biopsy done, hemodynamically stable, effusion drained. Extubate now? Why/why not? What must be true first? There is a cuff leak. Does that clear her for extubation? Why/why not? Extubate over an airway exchange catheter or pull the tube? Why? You extubate over the catheter; within minutes stridor and retractions. Rx? It settles on racemic epinephrine and steroid. Keep the exchange catheter — how long? If she needs the tube back, what makes that intubation hard? Plan if a tube will not pass?

Considerations and pitfalls AI draft

Extubate or not. The airway that obstructed on induction can obstruct on emergence; keeping her intubated, or extubating only over an exchange catheter with the surgeon and rigid scope present, is defensible. Reflexive extubation is the flag.
Before extubation. Fully reversed, awake, sitting, hemodynamically stable, effusion managed, equipment and surgeon at the bedside.
Cuff leak. A leak suggests some patency but does not prove the dynamic compression has resolved; its absence is more worrying than its presence is reassuring. Not a green light by itself.
Exchange catheter. Extubate over a catheter so reintubation is guided if she obstructs; the mass has not gone away.
Post-extubation stridor. Residual compression plus laryngeal edema: sit up, 100% oxygen, racemic epinephrine and steroid; keep the exchange catheter until she has been stable for hours and the laryngeal edema is treated (many keep it 1-2 hours minimum, longer with a mass this size); reintubation is hard because the tube must pass the edematous larynx and then the 60% narrowing; rigid bronchoscopy and the surgeon are the staged rescue if the tube will not pass.

2. PACU respiratory distress

One hour later: oxygen requirement climbing, RR 30, breath sounds diminished on the right, BP falling and trachea deviating left. DDx? Most likely? Confirm — how, and how fast? SpO2 82% and dropping — act before the chest film? Needle or tube, and where exactly? Given a mediastinoscopy, what injury caused this? To what end point do you resuscitate?

Considerations and pitfalls AI draft

DDx. Tension pneumothorax from a pleural breach during mediastinoscopy, hemothorax, recurrent airway or cardiac compression, atelectasis.
Most likely / confirm. Tension pneumothorax: diminished sounds, tracheal deviation, hypotension; ultrasound (absent lung sliding) at the bedside; do not wait for a portable film in an unstable patient.
Act before imaging. Yes: immediate needle decompression (2nd intercostal space midclavicular or 4th-5th anterior axillary) then a chest tube on the right.
Injury. Pleural entry during the mediastinoscopy; keep tracheobronchial and vascular injury in mind if it does not resolve.
End point. Restored oxygenation, re-expanded lung on the tube, stable hemodynamics; ongoing air leak or bleeding escalates to the surgeon.

3. New hoarseness and weak cough

Awake, hoarse, with a weak ineffective cough and soft stridor on exertion. DDx? Which of these threatens the airway most? Why? How do you evaluate the cords? She is comfortable at rest but desaturates with effort and after sips of water. Floor, monitored bed, or ICU? Why? What finding makes you secure the airway now rather than watch?

Considerations and pitfalls AI draft

DDx. Recurrent laryngeal nerve injury (the left nerve is at risk during mediastinoscopy), laryngeal edema, residual mass compression, aspiration.
Most threatening. Bilateral cord dysfunction can close the airway; unilateral RLN injury is usually tolerated at rest but brings a weak cough and aspiration risk. Edema on top of either can tip her.
Evaluate. Direct or flexible fiberoptic laryngoscopy and ENT.
Disposition. Monitored bed or ICU: she desaturates with effort and aspirates with sips; watch for fatigue.
Secure now. Rising stridor at rest, progressive desaturation, aspiration, or fatigue — secure the airway before it closes rather than after.

4. Treatment timing and tumor lysis

Tissue obtained; oncology wants high-dose steroids and chemotherapy tonight. Start tonight or in the morning? Why? Uric acid and LDH are already up. Labs you follow — which, how often? IV fluids — rate? Rasburicase or allopurinol? Which? Why? ICU or floor tonight? Why? 0400: K 6.0, phosphate 8.1, Ca 7.0, creatinine 1.4. Rx? Calcium — give it? Why/why not? Dialysis — what triggers it?

Considerations and pitfalls AI draft

Tonight. Starting is reasonable given her symptomatic compression: steroids shrink lymphoma fast and relieve airway and SVC compression; the price is tumor lysis, so start with monitoring in place. Tissue came first because steroids before biopsy can obscure the diagnosis.
Tumor lysis labs. Potassium, uric acid, phosphate, calcium, creatinine, LDH every 4-6 hours for the first 24-48 hours; the elevated uric acid and LDH plus a bulky mass flag high risk.
Fluids. Aggressive IV hydration, 2-3 L/m2/day (about 150-200 mL/h in her) targeting UOP >100 mL/h, watching the effusion and RV; no potassium in the fluids.
Rasburicase vs allopurinol. Rasburicase (0.15-0.2 mg/kg, or a single 3-6 mg dose) for high-risk or established TLS with uric acid already up; allopurinol only prevents new urate formation and is for lower risk. Check G6PD if time allows.
Disposition. ICU for airway and metabolic risk; arterial line and large-bore access stay.
0400 labs. Hyperkalemia: calcium only if ECG changes or symptomatic, because the calcium-phosphate product is already high and calcium precipitates; insulin/dextrose, albuterol, binders; phosphate binder (sevelamer) and hydration for the phosphate; asymptomatic hypocalcemia is not treated.
Dialysis. K refractory to medical therapy, rising creatinine or oliguria, phosphate that will not fall, symptomatic hypocalcemia, volume overload; nephrology called early, CRRT if hemodynamics are marginal.

5. Disclosure after a hard course

Overnight: stridor at rest, reintubated by the ICU team. On the ventilator she is coughing and fighting, peak pressure 35. Paralyze her now? Why/why not? Tube tip — where do you want it? How do you check? Her mother asks whether the biopsy should have waited. What will you tell her?

Considerations and pitfalls AI draft

Paralyze. Only if the tube tip sits distal to the compressed segment and ventilation is proven through it; with a 60% narrowing to the carina a standard tube may sit above the lesion, in which case loss of tone can close the airway distal to the tube. Deepen sedation and keep spontaneous effort if the tip is proximal; rigid bronchoscope at the bedside.
Tube tip. As far as it will safely go, ideally beyond the narrowest segment, near the carina; confirm by flexible bronchoscopy through the tube, not by depth marking or CXR alone.
Her mother. The one counseling beat: plain and honest, no blame; tissue was needed before treatment could start, the collapse was a known risk that was planned for with the rigid scope and bypass ready, she was supported through it, and treatment is now under way; room for her questions.

Long stem

Right upper lobectomy with one-lung ventilation in severe COPD

A 68 y.o., 70 kg, 5'9" man is scheduled for a right upper lobectomy for a 4 cm non-small-cell lung cancer.

HPIA 50 pack-year smoker who quit two weeks ago. Progressive dyspnea on exertion, now limited to one flight of stairs, with chronic productive cough. An upper respiratory infection three weeks ago has resolved.

PMHSevere COPD. Myocardial infarction four years ago, treated with a drug-eluting stent to the right coronary artery; no angina since. Hypertension, type 2 diabetes, GERD. Echocardiogram shows moderate right ventricular dilation and dysfunction with an estimated PA systolic pressure of 50 mmHg.

MEDSTiotropium, inhaled fluticasone, albuterol prn, aspirin 81 mg, metoprolol, lisinopril, atorvastatin, metformin (held).

PHYS EXAMHR 88; BP 150/85; RR 18; SpO2 92% on room air; T 36.8°C. Barrel chest, prolonged expiratory phase, diminished breath sounds bilaterally with scattered expiratory wheezes.

PFTsFEV1 1.4 L (45% predicted); FEV1/FVC 0.55; DLCO 48% predicted.

ABG (room air)pH 7.36; PaCO2 48 mmHg; PaO2 64 mmHg; HCO3 27 mEq/L.

ECGSinus rhythm with occasional PVCs, right ventricular strain pattern, old inferior Q waves.

IMAGINGCT chest: 4 cm right upper lobe mass without carinal or proximal airway involvement; diffuse hyperinflation; thin-walled bullae in the left upper lobe.

LABSHgb 16.5 g/dL; platelets 210 K/uL; INR 1.0; K+ 3.4 mEq/L; creatinine 1.3 mg/dL; glucose 180 mg/dL.

OR ARRIVALThoracic epidural placed at T6-7 preop; test dose negative, not yet dosed. Left-sided 39 Fr double-lumen tube planned. Radial arterial line and two 18 g peripheral IVs.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Lung isolation choice and confirmation in severe COPD; a ventilator strategy that respects air-trapping; protecting a pressure-loaded RV on one-lung ventilation; recognizing a dependent-lung tension pneumothorax.

1. Lung isolation and induction

Left DLT as planned, right DLT, or bronchial blocker? Why? Induction agent and dose? Target HR and BP through induction? Why those numbers? Tube in. Confirm position — how? You go to OLV. Peak pressure 38, BP 88/50. DDx? First move? You disconnect the circuit for 20 seconds; BP climbs to 118/70. What happened? Ventilator settings now — tidal volume, rate, I:E, PEEP? Why?

Considerations and pitfalls AI draft

DLT vs blocker. Left DLT is the expected commit: the bronchial cuff stays clear of the RUL takeoff and the operative bronchus, and the operative lung can be suctioned and given CPAP. A blocker is defensible only with a reason (difficult airway). A right DLT for a right upper lobectomy is a flag.
Induction. Etomidate 0.2-0.3 mg/kg or propofol titrated in 30-50 mg increments with fentanyl 1-2 mcg/kg; rocuronium 0.6-1 mg/kg. Phenylephrine or norepinephrine drawn up before the drug goes in.
Targets. HR 60-80, MAP within ~20% of baseline (roughly 80-95). Tachycardia and hypotension both threaten the RCA stent territory and RV coronary perfusion. Not naming the RV is a flag.
Confirm. Fiberoptic through the tracheal lumen: bronchial cuff just below the carina in the left main; then through the bronchial lumen to see the LUL/LLL split. Auscultation alone is worth challenging.
Peak 38, BP 88/50. DDx: breath-stacking/auto-PEEP, tube malposition (bronchial lumen too deep or herniated cuff), tension pneumothorax, RV strain. First move is a disconnect to let him exhale — reaching for pressor or fluid first is the trap.
BP recovers on disconnect. Dynamic hyperinflation was impeding venous return; that is the diagnosis.
Settings. TV 4-6 mL/kg PBW (~300-400 mL), rate 10-12, I:E 1:3-1:4, PEEP 0-5 (measure intrinsic PEEP before adding extrinsic), accept PaCO2 in the 50s-60s. PEEP 10 in severe COPD without a word about auto-PEEP is a flag.

2. Hypoxemia on one-lung ventilation

20 min into OLV, SpO2 84% on FiO2 1.0. DDx? Most likely? First move? Fiberoptic: tube in good position, no secretions. SpO2 81%. CPAP to the right lung, PEEP to the left lung, or a recruitment maneuver of the left lung? Which first? Why? Numbers? SpO2 88% after your move, not better. Next? Surgeon says the CPAP is inflating the field. Now what?

Considerations and pitfalls AI draft

DDx. Tube migration/malposition, secretions or plug, shunt through the nonventilated right lung, dependent-lung atelectasis or derecruitment, bronchospasm, low cardiac output.
Most likely / first move. Malposition on a fresh OLV desaturation; FiO2 is already 1.0, so scope first. Escalating to CPAP/PEEP before looking is worth probing.
Tube confirmed fine. Now it is shunt through the up lung plus dependent-lung derecruitment. CPAP 5 cm H2O to the nondependent lung attacks the shunt directly; a dependent-lung recruitment (30 cm H2O for 20-30 s) then PEEP 5 attacks atelectasis. Either is defensible with a number. In severe COPD, PEEP without checking intrinsic PEEP is the flag.
Still 88%. Add the other maneuver; check cardiac output and hemoglobin; consider a brief two-lung reinflation.
Surgeon conflict. Intermittent two-lung ventilation or a brief reinflation coordinated with the surgeon; ask for early ligation of the RUL pulmonary artery branches if the surgeon can; oxygenation wins over the field.

3. Hemodynamic deterioration on OLV

One hour into OLV, chest open: BP 80/45, HR 120, CVP 18 from 10, SpO2 90%. DDx? Most likely in him? Pressor — norepinephrine, vasopressin, or phenylephrine? Which? Why? Starting rate? BP 92/55 on your pressor, CVP still 18. Add what? Inhaled pulmonary vasodilator — which? Dose? BP drops again to 76/40 as the surgeon retracts the hilum. What do you ask for? Why?

Considerations and pitfalls AI draft

DDx. Acute RV failure from rising PVR (hypoxemia, hypercapnia, OLV), surgical compression of heart or great vessels, dynamic hyperinflation, ischemia or arrhythmia, hemorrhage.
Most likely. Decompensation of a chronically pressure-loaded RV (echo: RV dysfunction, PASP 50). Rising CVP with falling BP is the RV signature; the learner should tie it to the stem.
Pressor. Norepinephrine 0.05-0.1 mcg/kg/min or vasopressin 0.03-0.04 U/min to restore RV coronary perfusion pressure; vasopressin has the advantage of little pulmonary vasoconstriction. Phenylephrine raises PVR — leaning on it without saying so is worth challenging.
CVP still 18. The RV needs contractility, not volume: epinephrine 0.03-0.05 mcg/kg/min or dobutamine 2-5 mcg/kg/min; fix PaCO2 and oxygenation.
Inhaled vasodilator. INO 20 ppm or inhaled epoprostenol 50 ng/kg/min through the ventilated lumen; selectively drops PVR without systemic hypotension. Not a substitute for fixing ventilation.
Retraction. A mechanical cause: ask the surgeon to release retraction and pause; reaching for another drug while the heart is compressed is the flag.

4. Acute dependent-lung deterioration

Sudden: left-lung peak pressure 45, SpO2 80%, BP 70/40, hard to hand-ventilate. DDx? Most likely in him? Why him? You disconnect for 20 seconds — no improvement. Now what? Fiberoptic: tube in position, no plug. Next? Where do you decompress, with him in left lateral decubitus and the right chest open? Needle in; a rush of air, BP 95/60. Next?

Considerations and pitfalls AI draft

DDx. Tension pneumothorax of the dependent left lung, DLT migration or obstruction, mucus plug, severe bronchospasm, auto-PEEP.
Most likely / why him. Left tension pneumothorax from the thin-walled LUL bullae in the stem, under positive pressure at high peak pressures. Not connecting it to the CT is a miss.
Disconnect fails. Excludes breath-stacking; move to the scope and to decompression in parallel; call for help; 100% O2, hand-ventilate at low pressure.
Decompress. The down chest is under the drapes: needle or finger thoracostomy at the left 4th-5th intercostal space anterior axillary line reached from the front, or ask the surgeon to open the mediastinal pleura from the right to vent the left hemithorax. Either is defensible; waiting for a film is the flag.
Open chest. The operative side cannot tension; the danger is the ventilated lung, so recognition rests on airway pressure and hemodynamics, not the classic exam.
After needle. A left chest tube now, placed by the surgeon; then reassess whether to finish the lobectomy or close.

B. POST-OPERATIVE CARE

Teaching focus. Extubation judgment with marginal reserve; postoperative hypoxemia after resection; an air leak and the limits of positive pressure; post-thoracotomy atrial fibrillation; analgesia-dependent pulmonary toilet and honest disclosure.

1. Extubation decision

Lobectomy done, left chest tube in, on norepinephrine 0.04 mcg/kg/min. Extubate in the OR? Why/why not? What has to be true first? Epidural — dose it now? Agent? Volume? You extubate. 30 min later: RR 30, PaCO2 62, pH 7.26, awake. Rx? NIV in him — yes/no? Why? Settings? On NIV for 1 hour: PaCO2 55, RR 22. Continue? What would make you reintubate?

Considerations and pitfalls AI draft

Extubate or not. Early extubation spares a fresh stump and a fresh air leak from positive pressure; marginal reserve, RV disease, and pressor need argue caution. Either is defensible if committed and the preconditions are named.
Preconditions. Reversal confirmed by quantitative TOF, normothermia, PaCO2 near his baseline of 48, stable on minimal pressor, and a working epidural before the tube comes out.
Epidural. Yes, dose before emergence: bupivacaine 0.125% or ropivacaine 0.2% with fentanyl 2 mcg/mL, 5-8 mL then 5-6 mL/h; a dense bolus of 0.5% bupivacaine on a pressor is a flag.
PaCO2 62 awake. Splinting, retained secretions, COPD: bronchodilator, toilet, fix the analgesia, then support. NIV is reasonable here despite the fresh stump and a chest tube in place — low pressures (IPAP 10-12, EPAP 4-5); the stump concern is real but not absolute.
Reintubation threshold. Worsening pH below ~7.25, somnolence, inability to clear secretions, hemodynamic instability. Delaying a clearly failing patient is the flag.

2. Postoperative hypoxemia

6 hr postop in the ICU, off NIV: PaO2 80 on FiO2 0.5, RR 28, diminished left base. DDx? Most likely in him? Studies? CXR: left lower lobe collapse, right chest tube on suction, no pneumothorax. Rx? Bronchoscopy — now or after chest physio? Why? Epidural level checked: T8 on the right only. What do you do with it?

Considerations and pitfalls AI draft

DDx. Atelectasis, secretions/plugging, pneumothorax or enlarging space, edema, residual block, aspiration, lobar torsion.
Most likely. Secretions and atelectasis in a splinting COPD lung with a chronic productive cough.
Studies. CXR, ABG; bronchoscopy if plugging suspected.
LLL collapse. Sit him up, bronchodilator, chest physio and incentive spirometry once analgesia works; bedside bronchoscopy for a lobar collapse that does not clear within an hour or so — waiting all night is the flag.
Unilateral epidural. Pull the catheter back 1-2 cm and re-bolus; a poorly working epidural is a remediable cause of the whole picture.

3. Persistent air leak

POD 1: continuous right chest-tube air leak through the whole respiratory cycle, right lung incompletely expanded on film. What does a continuous leak tell you? Surgeon wants suction raised from -20 to -40. Agree? Why/why not? Suction is raised anyway; the leak gets louder and the lung drops further. Now what? He is tiring, RR 32, PaCO2 60. Ventilatory support — NIV or reintubate? Settings? What findings would make you suspect the stump itself?

Considerations and pitfalls AI draft

Continuous leak. A leak through both inspiration and expiration in a spontaneously breathing patient means a sizable parenchymal leak or a stump problem, not a small alveolar leak.
Suction. More suction increases flow through the leak and can hold it open; balance expansion against leak; reflexively raising it is the error.
Worse on -40. Return to low suction or water seal, reimage, involve the surgeon; consider a second tube if the space is not draining.
Support. NIV at low pressure is acceptable; if reintubated, low tidal volume, low PEEP, spontaneous mode as soon as possible; a DLT or blocker to isolate the leaking side if the leak steals minute ventilation.
Stump. A massive leak, new pneumothorax after a period of expansion, fever, fluid in the airway; bronchoscopy shows the dehiscence.

4. Post-thoracotomy atrial fibrillation

POD 1 evening: AF at 150, BP 92/56, on the NIV. Why does this matter in him? Triggers you correct first? K+ 3.2, Mg 1.6. Rx? Rate or rhythm? Which? Agent? Dose? Diltiazem? Why/why not? He drops to 78/44. Now what? Energy? Sinus rhythm at 90 after one shock. Anticoagulate?

Considerations and pitfalls AI draft

Why it matters. A fast rhythm loses atrial kick and shortens filling on a strained RV with a fixed coronary supply; demand ischemia and RV decompensation.
Triggers. K+ to >4, Mg to >2, hypoxemia, pain, hypovolemia, mediastinal irritation; magnesium 2 g IV and potassium replacement come before the antiarrhythmic.
Rate vs rhythm. He is marginal but perfusing: amiodarone 150 mg over 10 min then 1 mg/min is the usual pick because it rate-controls and may convert with modest hemodynamic cost. Diltiazem is a negative inotrope on a failing RV; esmolol or metoprolol in small doses is defensible in a stable patient but not at 92/56.
Unstable. Synchronized cardioversion 120-200 J biphasic under brief sedation.
Anticoagulation. Not on POD 1 with an air leak and a fresh resection; reconsider if AF persists beyond 48 h.

5. Analgesia and disclosure

POD 2: epidural no longer covers the thoracic dermatomes at all, he is splinting, coughing poorly, PaCO2 climbing to 64 on NIV. Re-site the epidural, paravertebral catheter, or multimodal without a block? Which? Why? What is in your multimodal plan? Doses? Ketamine — yes/no? Dose? Two hours later PaCO2 70 and he is somnolent. Reintubate? Why/why not? His wife asks what went wrong. What will you tell her?

Considerations and pitfalls AI draft

Block. Re-site the epidural or place a paravertebral catheter if positioning allows; a poorly covered thoracotomy in a COPD lung is a remediable cause of failure; opioid-only escalation is the wrong direction.
Multimodal. Scheduled acetaminophen 1 g q6h, ketorolac 15 mg q6h if creatinine allows (1.3 — cautious), gabapentinoid optional, low-dose opioid, lidocaine or ketamine infusion.
Ketamine. Yes: 0.1-0.2 mg/kg/h, opioid-sparing without respiratory depression.
PaCO2 70, somnolent. Reintubate; NIV has failed and he can no longer protect his airway or clear secretions. Continuing NIV in an obtunded patient is a flag.
Wife. A plain account: his lungs were marginal to begin with, the pain control failed and he could not clear his secretions, he needs the breathing machine again and it is expected to be temporary; leave room for questions.

Long stem

Off-site navigational bronchoscopy and transbronchial biopsy in COPD

A 64 y.o., 95 kg, 5'7" man is scheduled for electromagnetic navigational bronchoscopy with transbronchial biopsy and fiducial placement of a peripheral right-lower-lobe nodule, in the off-site interventional pulmonology suite.

HPIA 2.2 cm peripheral RLL nodule found on CT. Moderate COPD with dyspnea on climbing one flight and a chronic cough. No hemoptysis. The case is booked in the bronchoscopy suite, a corridor and an elevator away from the main operating rooms.

PMHModerate COPD. Atrial fibrillation on apixaban, last dose 48 hours ago per instruction. Obstructive sleep apnea on CPAP, obesity (BMI 33), hypertension. Former heavy smoker.

MEDSApixaban (held), metoprolol, tiotropium, inhaled fluticasone-salmeterol, albuterol prn, lisinopril.

PHYS EXAMHR 78 (irregular); BP 142/86; RR 16; SpO2 93% on room air; T 36.7°C. Prolonged expiratory phase with scattered wheeze; short neck, Mallampati III.

PFTsFEV1 1.6 L (60% predicted); FEV1/FVC 0.58; DLCO 60% predicted.

IMAGINGCT chest: 2.2 cm peripheral RLL nodule abutting the pleura; diffuse emphysema with apical bullae.

LABSHgb 15.1 g/dL; platelets 210 K/uL; INR 1.2; K+ 4.0 mEq/L; creatinine 1.0 mg/dL.

SUITEOff-site bronchoscopy suite. Anesthesia machine, standard monitors, suction, and a code cart are present; the difficult-airway cart and blood bank are in the main OR block. The proceduralist plans a shared airway through an endotracheal tube and may use cautery and argon plasma coagulation for hemostasis.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Setting up and choosing an anesthetic for a remote location; sharing the airway and ventilating an obstructed lung during bronchoscopy; managing brisk endobronchial hemorrhage off-site; and an airway fire during endobronchial ablation in an oxygen-rich field.

1. Off-site setup and anesthetic choice

You walk into the suite. What do you check before he comes in? MAC with a natural airway, LMA, or GA with an ETT? Which? Why? Tube size? Why that size? TIVA or volatile? Why? Propofol and remifentanil — starting rates? Muscle relaxant — yes/no? Why? He is asleep; SpO2 dips to 86% before the tube is in. Next?

Considerations and pitfalls AI draft

Check. Oxygen supply and backup cylinder, suction, scavenging, monitoring including capnography, a working machine check, drugs, the route and phone number for help, how long the difficult-airway cart and blood take to arrive. The environment is the first hazard.
Airway. GA with an ETT is the expected commit: an obese OSA patient with moderate COPD, a Mallampati III airway, a shared airway, and navigation that needs a still, controlled chest. Sedation with a natural airway off-site is worth challenging; an LMA is defensible but limits tool passage and is loose with cough.
Tube size. 8.5-9.0 mm so the navigation catheter and a therapeutic scope pass with room to ventilate around them; a 7.0 is the trap.
Maintenance. TIVA — propofol 100-150 mcg/kg/min with remifentanil 0.05-0.2 mcg/kg/min; no volatile leaking into the room from an open circuit and a steady depth through apneic pauses.
Relaxant. Yes, rocuronium 0.6 mg/kg with sugammadex available; a cough during registration or biopsy loses the map and risks trauma.
Desat on induction. Expected in obesity with OSA and a low FRC; two-hand mask with an oral airway, CPAP, intubate promptly with video laryngoscopy; preoxygenation to EtO2 >80% head-up is the prevention.

2. Shared airway and ventilation

Scope in the tube. SpO2 88%, peak pressure 36 from 22. DDx? First move? Flow tracing never returns to zero before the next breath. Dx? Fix — settings? Proceduralist wants a 45-second breath-hold at end-inspiration for registration. How do you set it up? SpO2 floor? He asks to use argon plasma coagulation for a small ooze. FiO2 for that? Why? SpO2 89% at your FiO2. Ablate anyway, or wait? Why?

Considerations and pitfalls AI draft

DDx. The scope occupying the tube lumen, breath-stacking and auto-PEEP, bronchospasm, secretions, tube kink or migration, hypoventilation.
First move. Ask the proceduralist to withdraw the scope for a moment, hand-ventilate, listen, suction; then look at the flow-time tracing.
Flow not reaching zero. Auto-PEEP: drop the rate to 8-10, I:E 1:3-1:4, lower tidal volume, accept PaCO2 in the 50s; adding PEEP without recognizing trapping is the flag.
Breath-hold. FiO2 1.0 for a few breaths beforehand, hold at a set inspiratory pressure (not a paralyzed collapse), a named SpO2 floor of ~90% at which you reventilate, and one person watching the monitor and calling it.
FiO2 for APC. Lower to 0.3 or less (at most 0.4) before the energy goes on; an oxygen-rich tube plus a spark is an airway fire. Turning the FiO2 down only when the fire starts is the error.
SpO2 89% at low FiO2. Wait: recruit, re-oxygenate briefly at high FiO2, wash out to a low FiO2 again, then ablate in short bursts; ablating at FiO2 1.0 because the saturation is marginal is the trap.

3. Massive endobronchial hemorrhage

During the biopsy, brisk blood wells up the tube and SpO2 falls to 80%. First three actions? Which side is bleeding? Position him — which side down? Why? Isolate the bleeding lung — how, with what you have in this suite? How deep does the tube go, and how do you confirm? Through the scope — what maneuvers, what drugs? Iced saline and epinephrine — concentration? Volume? SpO2 90% isolated, HR 120, BP 90/55, Hgb 12. Transfuse? Bronchoscopic control alone, or bronchial artery embolization? Where does he go from here?

Considerations and pitfalls AI draft

First actions. 100% O2, continuous suction through the scope and tube, call for help and the difficult-airway cart, keep the patient deep and paralyzed; asphyxia is the killer, not exsanguination.
Side / position. The right lower lobe was biopsied; right side down so blood does not soil the left lung, balanced against oxygenation.
Isolate. Advance the single-lumen tube into the left main bronchus over the scope — turn the head right, bevel to the left, scope-guided; or a bronchial blocker down the right main if one is in the suite. A DLT exchange in a blood-filled airway off-site is a poor first move.
Confirm. Scope through the tube seeing the left upper/lower split; breath sounds left only.
Through the scope. Wedge the scope into the RLL segment to tamponade, iced saline 20-50 mL aliquots, epinephrine 1:10,000 to 1:20,000 in 2-5 mL aliquots, a balloon blocker if available, tranexamic acid 500 mg topical or 1 g IV; APC for a visible bleeder.
Logistics. Hemodynamics are early hemorrhage plus hypoxemia; volume, T&C, blood en route; transfuse to the trajectory, not to a Hgb of 12. Interventional pulmonology, thoracic surgery, IR for bronchial artery embolization; transfer to the OR or IR intubated and isolated.

4. Airway fire during ablation

Bleeding controlled. The proceduralist uses argon plasma coagulation on a persistent ooze and a flash appears at the tube tip inside the airway. First move? Second? Third? What fed it? Tube is out, fire is out, he is apneic, SpO2 84%. Now what? Reintubate — how? What size? Bronchoscopy: soot in the trachea, mild mucosal erythema, no deep burn. FiO2 now? Off-site, intubated after a fire and a bleed — ICU, OR, or recovery? Why?

Considerations and pitfalls AI draft

Sequence. Stop the APC, disconnect the circuit and stop the oxygen, pull the burning tube and scope together, saline down the airway; then mask-ventilate and re-establish the airway. Leaving oxygen flowing through a burning tube is the lethal error.
What fed it. Oxidizer (the FiO2 that crept back up to oxygenate after the bleed), ignition (argon plasma), fuel (the PVC tube, blood, secretions).
Apneic. Mask with an oral airway, two hands, and reintubate promptly with video laryngoscopy before edema; anticipate a bloody, sooty view.
Reintubation. A tube 0.5-1 mm smaller than before, over a scope or with video laryngoscopy, cuff below any injury; then bronchoscopy for injury depth and retained fragments.
FiO2. The lowest that keeps SpO2 >92%; high FiO2 is no longer a fire risk once the energy is out of the room but worsens absorption atelectasis — no reason for 1.0.
Disposition. ICU intubated: airway burn plus a bleed plus emphysema off-site; airway edema evolves over 12-24 h. Extubating in the suite is the flag.

B. POST-OPERATIVE CARE

Teaching focus. Waking and transporting a patient from a remote site; managing a pneumothorax in emphysematous lungs; post-procedure respiratory failure in COPD; recurrent bleeding and the anticoagulation decision; disclosing an unexpected admission; and a POD 3 fever with a real differential, chest-tube removal, and discharge readiness with OSA and held anticoagulation.

1. Emergence and transport off-site

He is stable, intubated, sedated. Extubate here and go to PACU, or transport intubated to the ICU? Why? Before you move him — what has to be true? What goes on the bed for a corridor-and-elevator trip? Sedation for the trip — agent? Rate? In the elevator SpO2 drops to 86%, capnography flat. First move? Tube at 23 cm at the teeth, breath sounds absent on the right. Dx? Fix? He is on the ventilator in the ICU. Dexamethasone for the burned airway — yes/no? Why?

Considerations and pitfalls AI draft

Extubate or not. Transport intubated: an airway fire with a sooty trachea, a fresh bleed, OSA, and emphysema — edema and rebleeding evolve over hours. Waking him in the suite is the flag; a committed 'intubated to ICU' with reasons is the expected answer.
Before moving. Stable gas exchange on a transport ventilator or bag with PEEP, hemodynamics off or on a known pressor, a full oxygen cylinder with enough minutes for the trip twice over, secure tube with depth documented, monitoring, a second set of hands, drugs drawn.
Kit. Oxygen, self-inflating bag with PEEP valve, suction, an intubation kit with a smaller tube and video laryngoscope, propofol/pressor syringes, a phone.
Sedation. Propofol 50-75 mcg/kg/min plus a small opioid bolus; he must not cough on a burned airway.
Flat capnography. Disconnect from the transport vent and bag by hand, check the circuit and the tube; a flat trace is dislodgement or disconnection until proven otherwise.
Absent right breath sounds. Right mainstem or a right pneumothorax in emphysematous lungs; with the tube at 23 cm in a 5'7" man, mainstem is likely — pull back 2 cm and listen. If unchanged, treat as pneumothorax on arrival.
Dexamethasone. No evidence that steroids change outcome in inhalation injury; a committed 'no' with a plan to watch for symptomatic edema and treat it with humidified oxygen, racemic epinephrine, and a delayed extubation is the stronger answer; a single dose before a planned extubation is defensible.

2. Pneumothorax in emphysematous lungs

ICU film: moderate right pneumothorax, ~30%. Peak pressure 32, SpO2 92% on FiO2 0.6, BP 118/74. Observe, aspirate, or chest tube? Why? Chest tube in; a continuous air leak, lung re-expanded. Ventilator changes? Six hours later: SpO2 94% on 0.4, awake, follows commands, repeat bronchoscopy shows soot only. Extubate? Why/why not? What must be true first? Extubated. Leak persists on water seal. Send to the floor with the tube?

Considerations and pitfalls AI draft

Chest tube. A moderate pneumothorax under positive pressure in emphysematous lungs with bullae: chest tube, not observation — positive pressure can tension it. Observation is defensible only in a spontaneously breathing stable patient.
Ventilator. Minimize airway pressure: low tidal volume, PEEP 5 or less, low rate with long expiration, permissive hypercapnia; a spontaneous mode as soon as he tolerates it.
Extubate. Yes once the airway is examined and clean, cuff-leak present, gas exchange fine on modest support, awake, secretions manageable, surgeon or IP aware; the chest tube in place makes positive pressure safer, not more dangerous.
Persistent leak. A monitored bed, not the floor; a fresh air leak in emphysema plus OSA off CPAP needs continuous oximetry.

3. Post-procedure respiratory failure

Two hours after extubation: wheezing, RR 30, PaCO2 58, pH 7.29, accessory muscle use. DDx? Most likely in him? First-line Rx? Doses? Steroid — yes/no? Which? Dose? NIV — yes/no, with a chest tube in and a fresh pleural breach? Settings? One hour on NIV: PaCO2 52, RR 22, more comfortable. Continue? What would make you reintubate now? If you did, ventilator settings for his lungs?

Considerations and pitfalls AI draft

DDx. Bronchospasm and COPD exacerbation after airway instrumentation and a burn, mucus plugging, recurrent pneumothorax or tube malfunction, upper-airway edema from the burn, residual sedation, aspiration of blood.
Most likely. Bronchospasm after instrumentation in COPD; check the chest tube is swinging and bubbling and that the film shows the lung up before calling it that.
Rx. Albuterol 2.5-5 mg nebulized repeated, ipratropium 0.5 mg, methylprednisolone 40-60 mg IV or prednisone 40 mg; oxygen to SpO2 88-92%.
NIV. Yes: the chest tube vents the pleura, so a fresh breach is not a contraindication; IPAP 10-12, EPAP 4-5, watch for stridor that would point to the airway rather than the small airways.
Improving. Continue with an hourly reassessment; reintubate for pH <7.25 despite NIV, somnolence, inability to clear secretions, or stridor. Settings: TV 6 mL/kg PBW, rate 10-12, I:E 1:4, PEEP ≤5, accept hypercapnia; the learner who dials a rate of 20 is the flag.

4. Recurrent bleeding and anticoagulation

POD 1 morning, off NIV: he coughs up ~100 mL of fresh blood, then it settles. HR 104, BP 128/80, SpO2 93%. What do you do in the next 10 minutes? What do you set up at the bedside? Hgb 12.6 from 15.1. Transfuse? Bronchoscopy now — yes/no? Apixaban is due today. Restart? Why/why not? When? He rebleeds 300 mL that afternoon. Rx? Where does he go? Later, he asks whether all of this could have been avoided. What will you tell him?

Considerations and pitfalls AI draft

Next 10 minutes. Sit him bleeding side down (right), oxygen, suction, IV access checked, T&S/crossmatch, call IP and thoracic surgery; monitor the airway, not the volume.
Bedside. Intubation kit with a large tube and a bronchial blocker, video laryngoscope, suction, a plan to mainstem the left if it recurs.
Hgb 12.6. No transfusion; the drop is the earlier bleed plus dilution; the danger is airway, not anemia.
Bronchoscopy. Reasonable to look for the source and clot at the biopsy site while stable; not mandatory if it has settled — commit either way.
Apixaban. Hold; a bleed within 24 h of a transbronchial biopsy trumps a few days of stroke risk in AF; revisit at 48-72 h without bleeding with cardiology and IP. A reflex restart or an indefinite hold are both flags.
Rebleed 300 mL. Intubate and isolate (left mainstem or right blocker), IP for bronchoscopic control, IR for bronchial artery embolization; ICU. Apixaban has been held so there is nothing to reverse; if he had been dosed, 4-factor PCC 50 U/kg (andexanet alfa was withdrawn from the US market in December 2025).
Avoidable. An honest account: bleeding and pneumothorax are recognized risks of a transbronchial biopsy, and the fire was a recognized hazard of energy in the airway; say what happened and what is being done, without false reassurance or blame; name who will bring the biopsy result.

5. POD 3: fever after embolization, the chest tube, and discharge

POD 3: bronchial artery embolization POD 1, extubated POD 2, no hemoptysis since. Temp 38.6, WBC 16, new RLL consolidation, SpO2 91% on 3 L. DDx? Most likely? What separates them at the bedside? Antibiotics now, or cultures and wait? Which agent? Chest tube: no leak on water seal for 24 hours, 60 mL serous per day. Pull it? Clamp trial first? Why? Film four hours after removal: 10% apical pneumothorax. Replace the tube? Why/why not? Tonight: his CPAP with that pneumothorax — yes/no? Pressure? POD 4: afebrile, SpO2 92% at rest on air, 87% walking the hall. Home oxygen? How much? Apixaban held five days. Restart before he leaves, or at follow-up? Why? Discharge — what must be true?

Considerations and pitfalls AI draft

DDx. Aspiration pneumonia from blood in the RLL after two bleeds and an intubation, post-embolization syndrome (fever and leukocytosis within 48 h, self-limited), atelectasis behind retained clot, empyema tracking from the chest tube, lung infarction after embolization (rare), drug fever.
Most likely. Pneumonia in the aspirated, clot-filled lobe; post-embolization fever does not usually come with hypoxemia and a consolidation. Bedside: purulent versus old-blood sputum, tube drainage character, and whether the consolidation is new versus the earlier bleed.
Antibiotics. Yes — hospital-acquired coverage (e.g., piperacillin-tazobactam or cefepime, add MRSA coverage if risk factors) after blood and sputum cultures; waiting on cultures in a hypoxemic COPD patient with a fresh consolidation is the flag. Bronchoscopy for retained clot if he does not improve in 48 h.
Chest tube. Remove — no leak for 24 h, output <200 mL/day, lung up. A 4-6 h clamp trial with a film is reasonable in emphysema and defensible either way; commit. Remove at end-expiration or Valsalva, occlusive dressing, film 2-4 h later.
10% apical pneumothorax. Observe — asymptomatic, small, spontaneously breathing; repeat film at 6-12 h, oxygen. Replace only if it enlarges or he becomes symptomatic. A reflex second tube is the error.
CPAP. Yes with the lower pressure of his range (about 8 cm H2O) and a morning film — untreated OSA with opioids and hypercapnic COPD is the larger risk; low-pressure CPAP rarely expands a small stable pneumothorax. Skipping it for the night with continuous oximetry is defensible; commit either way.
Home oxygen. Yes — exertional desaturation ≤88% qualifies; 2 L with ambulation and sleep, titrate to 88-92% (not higher in a CO2 retainer), reassess at 30 days once the pneumonia has cleared.
Apixaban. Restart with a date, not open-ended: 72 h without bleeding after embolization and a CHA2DS2-VASc of 1 (hypertension) mean the stroke risk of another week off is small; restart at about 7 days from the last bleed, agreed with IP and cardiology, and written into the discharge plan. Restarting today into a fresh biopsy site and a retained clot is the flag.
Discharge. Afebrile 24 h on oral antibiotics, no hemoptysis 72 h, no progression of the pneumothorax on a film after removal, oxygen prescribed and delivered, CPAP plan, anticoagulation restart date, and who will call with the biopsy result.

Long stem

Right pneumonectomy with borderline pulmonary function and coronary disease

A 66 y.o., 72 kg, 5'10" man is scheduled for a right pneumonectomy for a central non-small-cell lung cancer involving the right main bronchus.

HPIA 45 pack-year smoker who quit at diagnosis. Completed neoadjuvant chemoradiation to the mediastinum six weeks ago. Dyspnea on climbing two flights, with a chronic cough; 6 kg of unintentional weight loss over three months.

PMHCoronary artery disease with a drug-eluting stent to the LAD 18 months ago; clopidogrel stopped two weeks ago on cardiology advice, aspirin continued. Moderate COPD. Hypertension. The mediastinal radiation field included the heart.

MEDSAspirin 81 mg, metoprolol, lisinopril, atorvastatin, tiotropium, albuterol prn.

PHYS EXAMHR 82; BP 138/84; RR 16; SpO2 94% on room air; T 36.9°C. Thin, mild expiratory wheeze, no JVD or edema.

PFTsFEV1 1.9 L (58% predicted); FEV1/FVC 0.62; DLCO 50% predicted. Stair-climb three flights; CPET VO2max 16 mL/kg/min.

CARDIACEchocardiogram: LVEF 50%, mild RV dilation, estimated PA systolic pressure 42 mmHg. A recent stress study showed no reversible ischemia.

ECGSinus rhythm with frequent atrial premature beats; old anteroseptal Q waves.

IMAGINGCT and PET: right hilar mass involving the right main bronchus, no contralateral disease; post-radiation changes in the mediastinum. The surgeon anticipates intrapericardial division of the pulmonary vessels.

LABSHgb 11.8 g/dL; platelets 190 K/uL; INR 1.1; K+ 3.6 mEq/L; creatinine 1.1 mg/dL; albumin 3.0 g/dL.

OR ARRIVALThoracic epidural placed at T6-7, test dose negative, not yet dosed. Left-sided 39 Fr double-lumen tube planned. Radial arterial line and two large-bore IVs.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Lung isolation and an induction that respects a fixed coronary lesion; recognizing and fixing a malpositioned tube during one-lung-ventilation hypoxemia; reading the right-pulmonary-artery clamp trial; and a fluid strategy that protects the one remaining lung.

1. Isolation and induction

Left DLT, right DLT, or bronchial blocker for a right pneumonectomy? Why? The surgeon is about to fire the stapler across the right main bronchus. What do you do with the tube? Induction agent? Dose? Target HR and BP through laryngoscopy? Why those? Tube in. Confirm — how? OLV started: peak pressure 34, BP 90/52. DDx? First move? Disconnect for 20 seconds; BP 112/68. Dx? Settings now — rate? I:E? PEEP?

Considerations and pitfalls AI draft

Isolation. Left DLT: the bronchial cuff stays out of the right main bronchus, which the surgeon will staple; a right DLT or a right-sided blocker sits in the field. Want a committed, defended choice.
At the staple. Pull any blocker or scope out of the right main and confirm the tracheal cuff is above the line; the surgeon may ask you to confirm the tube is clear by scope before the stapler fires.
Induction. Etomidate 0.2-0.3 mg/kg or propofol in 30-50 mg increments with fentanyl 1-2 mcg/kg and lidocaine; rocuronium 0.6-1 mg/kg; pressor in hand.
Targets. HR 60-80, MAP 75-95; tachycardia and hypotension both threaten the LAD stent; ignoring the coronary history is a flag.
Confirm. Fiberoptic: bronchial cuff just below the carina in the left main; view the LUL/LLL split through the bronchial lumen. Auscultation alone is worth challenging.
Peak 34, BP 90/52. Breath-stacking/auto-PEEP, malposition, RV strain; disconnect before pressor or fluid. Recovery on disconnect is the diagnosis.
Settings. TV 5-6 mL/kg PBW, rate 10-12, I:E 1:3, PEEP 3-5 after checking intrinsic PEEP, permissive hypercapnia.

2. Hypoxemia during one-lung ventilation

20 min into OLV, SpO2 84% on FiO2 1.0. DDx? First move? Fiberoptic: the bronchial cuff is herniating over the carina. What is that doing? Fix it — how, step by step? SpO2 81% while you work. Keep going, or hand-ventilate both lungs first? Why? Tube reseated. What confirms the fix? SpO2 91%. Add what?

Considerations and pitfalls AI draft

DDx / first move. Malposition or migration, secretions, shunt through the nonventilated lung, dependent atelectasis, low cardiac output; FiO2 is maximal, so scope first.
Herniated cuff. The tube has ridden up; the bronchial cuff is partly obstructing the trachea and the left lung is under-ventilated while the right lung is not isolated — worse shunt and worse ventilation at once.
Fix. Deflate the bronchial cuff, advance under scope vision until the cuff is just below the carina in the left main, reinflate to the minimum that seals, reconfirm through both lumens.
SpO2 81%. Deflate both cuffs and ventilate both lungs for a minute; then reposition. Pressing on while the saturation falls is the flag.
Confirm. Scope view of the LUL/LLL split through the bronchial lumen, left chest rise, right lung collapsing in the field.
SpO2 91%. CPAP 5 to the right lung or a dependent-lung recruitment plus PEEP 5; ask the surgeon how close he is to the PA.

3. Right PA clamp trial

Surgeon test-clamps the right pulmonary artery. What are you watching in the next two minutes? SpO2 rises to 97%. Why? BP 85/50, HR 120, CVP 16 from 9, EtCO2 falling from 34 to 26. Dx? Rx — norepinephrine, vasopressin, or phenylephrine? Which? Why? Rate? BP 92/54 on the pressor, CVP still 16. Add what? Dose? Inhaled vasodilator — which, and how do you deliver it on OLV? Surgeon asks to divide the PA now. Yes or no? Why?

Considerations and pitfalls AI draft

Watching. The clamp sends the whole cardiac output through the left lung and roughly doubles RV afterload; watch arterial pressure, CVP, EtCO2 as a cardiac-output proxy, ST segments, and the TEE if present.
SpO2 up. Clamping removes shunt through the nonventilated right lung; this is the expected physiology.
Dx. Acute RV strain from the afterload step on a mildly dilated, irradiated RV: rising CVP, falling output (EtCO2), tachycardia.
Pressor. Norepinephrine 0.05-0.1 mcg/kg/min or vasopressin 0.03-0.04 U/min to restore RV coronary perfusion; phenylephrine raises PVR and should be named as such if chosen.
CVP 16 on pressor. Inotrope for the RV — epinephrine 0.03-0.05 mcg/kg/min or dobutamine 3-5 mcg/kg/min; not volume.
Inhaled vasodilator. INO 20 ppm or epoprostenol 50 ng/kg/min nebulized into the ventilated (bronchial) limb.
Divide?. Not yet: the clamp trial is the go/no-go test; if he needs an inotrope and a pulmonary vasodilator to tolerate the clamp, the pneumonectomy may not be survivable. Ask for a few minutes to optimize and reassess; tell the surgeon plainly. Waving him on regardless is the flag.

4. Fluid and transfusion strategy

RV settles; vessels divided. Two hours in: EBL 900 mL through friable irradiated tissue, 1.2 L crystalloid in, BP 96/58 on norepinephrine 0.06, urine 20 mL/hr. Total fluid target for this case? Why that number? Hgb 8.6. Transfuse? Trigger in him? Why? Pressor or fluid for this pressure? How do you decide? 250 mL bolus: no change in pulse-pressure variation, urine still 20 mL/hr. More fluid? Why/why not? MAP target? Hgb 7.4 an hour later, oozing. Now?

Considerations and pitfalls AI draft

Fluid target. Conservative: roughly 1-2 L crystalloid intraop and under 20 mL/kg in the first 24 h; excess fluid is a recognized contributor to post-pneumonectomy pulmonary edema, which is often fatal. A learner who chases urine with liters is the lesson.
Transfusion. 8.6 with a stented LAD and active bleeding: transfuse toward ~8-9 rather than waiting for 7; defend a trigger with reasons, not a reflex.
Pressor vs fluid. Pulse-pressure variation or stroke-volume response to a small bolus, the field, CVP trend; norepinephrine to MAP 65-70 rather than filling the remaining lung.
Nonresponder. Stop; oliguria of 20 mL/hr (~0.3 mL/kg/h) is tolerable for a short period in a pneumonectomy; do not chase it.
Hgb 7.4 oozing. Transfuse red cells; check platelets and fibrinogen (aspirin, recent clopidogrel, radiation); TXA 1 g if surgical oozing with normal labs.

B. POST-OPERATIVE CARE

Teaching focus. Extubation onto a single lung; recognizing acute cardiac herniation; post-thoracotomy atrial fibrillation; post-pneumonectomy pulmonary edema; and a bronchopleural fistula with honest disclosure.

1. Extubation onto one lung

Case done; norepinephrine 0.04, Hgb 9.2, temp 36.4. Extubate in the OR? Why/why not? What has to be true first? Epidural — dose now? Agent? Volume? Why does positive pressure worry you more here than after a lobectomy? You extubate. 30 min later: RR 30, PaCO2 60, pH 7.27, tiring. First fix? NIV in a fresh pneumonectomy — yes/no? Pressures? PaCO2 68, drowsy an hour later. Reintubate? Which tube, and where does the cuff sit?

Considerations and pitfalls AI draft

Extubate or not. Early extubation spares a fresh bronchial stump from positive pressure; pressor need and marginal reserve argue caution. Either is defensible if the conditions are named.
Preconditions. Quantitative TOF ratio >0.9, normothermic, PaCO2 near baseline, stable on minimal pressor, epidural working, surgeon happy with the stump.
Epidural. Bupivacaine 0.125% or ropivacaine 0.2% with fentanyl 2 mcg/mL, 5-8 mL then 5-6 mL/h; not a dense bolus on a pressor.
Positive pressure. The stump is sutured airway under pressure with no lung to buttress it; and the one remaining lung takes the whole tidal volume — stump dehiscence and volutrauma are both on the table.
Tiring. Analgesia and toilet first; NIV at low pressure (IPAP 10, EPAP 4) is defensible for a short trial; uncritical high pressures on a fresh stump deserve a probe.
Reintubate. Yes at PaCO2 68 and drowsy; a single-lumen tube with the cuff well above the carina, or a left DLT/left mainstem placement if the stump is a concern; low tidal volume for one lung.

2. Sudden collapse in the PACU

Reintubated, stable. In the PACU he is turned toward the left for a film. Within a minute: BP 60/35, HR 140, SpO2 82%, CVP 22. Dx until proven otherwise? Why him? What do you do in the next 60 seconds? Which way do you turn him? Why? What is the definitive fix? ST depression 2 mm in II and V5 as you move. Does that change anything? Pressor while you wait for the OR — which? What endpoints on the way?

Considerations and pitfalls AI draft

Dx. Cardiac herniation through the intrapericardial defect into the empty right hemithorax; a position change after intrapericardial pneumonectomy is the classic trigger; recognition is the test.
Mechanism. The heart rotates into the pneumonectomy space, kinking the cavae and great vessels — obstructive shock with a high CVP.
60 seconds. Call the surgeon and book the OR, 100% O2, turn him operative side up (right side up, left lateral), stop any suction on the right chest, volume and pressor; the fix is surgical.
ST changes. Demand ischemia from hypotension and tachycardia on a fixed LAD supply; restoring perfusion treats both — do not tunnel on the herniation, keep ST monitoring going. Ischemia stays on the differential if repositioning does not help.
Pressor / endpoints. Norepinephrine or epinephrine to a MAP >60 and SpO2 >90% while moving; a definitive fix is re-exploration and pericardial repair, not a drug.

3. Post-thoracotomy atrial fibrillation

Re-explored, pericardium repaired, back in the ICU. POD 1 evening, extubated that morning: AF at 150, BP 96/58. Why does it matter in him? What do you correct first? K+ 3.3, Mg 1.7. Doses? Rate or rhythm? Agent? Dose? Diltiazem? Why/why not? BP 80/44. Now what? Energy? Sinus at 88. Anticoagulate him — yes/no? Why?

Considerations and pitfalls AI draft

Why it matters. A fast rhythm loses atrial kick and shortens filling on a strained RV with a fixed coronary supply; the whole cardiac output crosses one lung.
Triggers. K+ to >4 (KCl 20-40 mEq), Mg 2 g IV, hypoxemia, pain, hypovolemia, mediastinal irritation.
Agent. Amiodarone 150 mg over 10 min then 1 mg/min; diltiazem depresses a failing RV; small esmolol or metoprolol doses are defensible only if BP allows.
Unstable. Synchronized cardioversion 120-200 J biphasic.
Anticoagulation. Not now: two chest operations in 24 h and a stump; reassess if AF persists beyond 48 h, weighing the stent (already on aspirin) and stroke risk.

4. Progressive hypoxemia, POD 2

POD 2: PaO2 75 on FiO2 0.5 by mask, RR 28, new diffuse infiltrate in the left lung, fluid balance +3.5 L since surgery. DDx? Most likely in him? Echo: LVEF 50%, no valve lesion, CVP 8. Does that change your list? Rx? Diuretic — yes/no? Dose? PaO2 58 on 100% non-rebreather. Intubate? Ventilator settings for one lung? Tidal volume — number? He worsens over 24 hours on those settings. VV ECMO — yes/no? Why? What are you bridging to?

Considerations and pitfalls AI draft

DDx / most likely. Post-pneumonectomy pulmonary edema in the remaining lung; also cardiogenic edema, pneumonia, aspiration, transfusion-related lung injury.
Echo normal. Makes it non-cardiogenic edema — PPE or TRALI — rather than pump failure; PPE is a diagnosis after excluding the others.
Rx. Conservative fluids, furosemide 20-40 mg IV if the pressure tolerates it, oxygen, treat pneumonia if any doubt; supportive care is the substance.
Ventilator. Lung-protective settings scaled to one lung: TV ~4-5 mL/kg PBW (~300 mL), PEEP 5-8, plateau ≤25, permissive hypercapnia, prone not feasible.
Limits. PPE carries ~50% mortality; ECMO (VV) is a bridge only if there is something to bridge to; honest conversation with the family belongs here.

5. POD 5 fever with a new air-fluid level

POD 5, extubated the day before after a 48-hour ventilator course: fever 38.9, coughing up thin brown fluid, the air-fluid level on the right has dropped 3 cm, SpO2 89% on 6 L. Dx until proven otherwise? What do you do in the first two minutes? Which side down? Why? He needs intubation. How do you do it so the left lung stays dry? Tube? Ventilator settings after? Chest drain on the right — suction or not? He asks what has happened. What will you tell him?

Considerations and pitfalls AI draft

Dx. Bronchopleural fistula from stump dehiscence with the pneumonectomy space draining into the remaining lung; empyema is usually with it.
First two minutes. Sit him up and lean him to the right (fistula side down), oxygen, call thoracic surgery, nothing by positive-pressure mask.
Intubation. Awake fiberoptic or rapid sequence with the patient kept operative side down, and a left DLT (or a left mainstem single-lumen tube) placed under scope guidance so the left lung is isolated before positive pressure starts; fiberoptic confirmation is mandatory.
Ventilator. Low tidal volume to one lung, low PEEP, minimal airway pressure; spontaneous ventilation as soon as possible.
Drain. A right chest tube to water seal, not suction, to drain the space; suction pulls the mediastinum and worsens the leak.
Counsel. A plain account: the stitched airway has opened and fluid has spilled into his good lung; he needs the tube and likely another operation; it is serious and the team will keep him informed.

Long stem

Tracheal resection and reconstruction for post-intubation stenosis

A 55 y.o., 98 kg, 5'8" man is scheduled for tracheal resection and end-to-end reconstruction for a post-intubation tracheal stenosis.

HPIProlonged intubation and then a tracheostomy during an ICU stay for ARDS last year; decannulated four months ago. Since then, worsening exertional dyspnea and noisy breathing, now with stridor audible at rest and difficulty clearing secretions; he can climb less than one flight.

PMHObesity (BMI 33), obstructive sleep apnea on CPAP, hypertension, GERD. Former smoker.

MEDSLisinopril, amlodipine, omeprazole, CPAP nightly.

PHYS EXAMHR 92; BP 146/88; RR 20 with biphasic stridor at rest, worse supine; SpO2 95% on room air; T 36.8°C. Short, thick neck; healed tracheostomy scar; Mallampati III.

IMAGINGCT neck and chest: a 1.5 cm segment of mid-tracheal stenosis narrowing the lumen by roughly 70%, beginning about 4 cm below the cords; no distal disease.

FLOW / SCOPEFlow-volume loop with fixed obstruction. Awake nasendoscopy: mobile vocal cords, narrow subglottic-to-mid-tracheal airway.

LABSHgb 14.2 g/dL; platelets 230 K/uL; INR 1.0; K+ 4.1 mEq/L; creatinine 0.9 mg/dL.

OR ARRIVALPlan made jointly with the surgeon. Rigid bronchoscope, an array of small cuffed and armored tubes, sterile cross-field tubing, and a jet ventilator are in the room; perfusion is on standby. Radial arterial line and two large-bore IVs.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. An induction that keeps a critically narrowed airway open; sharing the airway with the surgeon during resection; an airway fire in an oxygen-rich field; and rescuing a lost distal airway in the open field.

1. Induction across the stenosis

Awake fiberoptic, inhalational induction breathing spontaneously, or IV induction with paralysis? Which? Why? Premedication — anything? Why/why not? Rigid bronchoscope open and the surgeon scrubbed before you induce — necessary? Why? Induced; mask ventilation is easy. Muscle relaxant now — yes/no? Why? Tube size? Sit it above the stenosis, or pass it through? You pass a 6.0 through the narrowing; it will not advance and SpO2 drops to 85%. Next? SpO2 78% with the tube pulled back above the lesion. Now?

Considerations and pitfalls AI draft

Induction. The loop shows a fixed stenosis — it will not collapse with paralysis the way a mediastinal mass does. IV induction after confirming mask ventilation, or an inhalational induction keeping him breathing, are both defensible with the surgeon and rigid scope in the room. Awake fiberoptic through a 70% stenosis buys little and can obstruct. The flag is paralysis before anyone has confirmed the lungs can be ventilated.
Premed. An antisialagogue (glycopyrrolate 0.2 mg) is reasonable; sedatives that blunt drive in a stridulous OSA patient are not.
Surgeon. Scrubbed and at the head with the rigid scope; not down the hall.
Relaxant. Yes once mask ventilation is confirmed; rocuronium; a fixed stenosis is not made worse by paralysis, and a still patient is safer for rigid bronchoscopy.
Tube. A 6.0-6.5 above the stenosis with a plan to have the surgeon dilate or rigid-scope and then pass a small tube through, or to proceed with the tube above the lesion until the trachea is opened; forcing a tube blindly through a 70% stenosis is the trap.
Stuck at 85%. Pull back above the lesion, ventilate, hand to the surgeon for rigid bronchoscopy and dilation; that is what the room is set up for.
78% above the lesion. Obstruction by edema or secretions at the stenosis: rigid scope now, jet through the rigid scope past the lesion, perfusion on notice.

2. Ventilation during the open phase

Rigid dilation done; a 6.0 sits above the stenosis. The surgeon divides the trachea below the lesion and is ready to ventilate the distal segment. Cross-field tube or jet? Which? Why? Cross-field tube in: how do you ventilate a 98 kg man through a 6.0 armored tube? Settings? EtCO2 climbs to 58 over 20 minutes. Accept it? Ceiling? The surgeon needs the cross-field tube out for the posterior suture line. FiO2 before you pull it? SpO2 floor for each apneic interval — number? SpO2 hits your floor at 90 seconds with three sutures left. Reventilate now, or give him the three sutures? Why?

Considerations and pitfalls AI draft

Cross-field vs jet. A sterile cross-field armored tube gives a secure cuffed airway but sits in the field; jet ventilation through a catheter keeps the field open but risks barotrauma, CO2 retention, and blood aerosolization. Either is defensible if reasoned; commit.
Small tube. Pressure-controlled ventilation, longer inspiratory time, rate 14-18, accept small tidal volumes; a 6.0 has high resistance so peak pressure will read high — plateau matters.
EtCO2 58. Permissive hypercapnia is acceptable to roughly 60-65 with a pH above ~7.20; chasing normocapnia at the cost of the field is the error.
Before the apneic interval. FiO2 1.0 for several minutes to an EtO2 >80%, then the tube out; a named floor of ~90%, and one person (the anesthesiologist) calls 'reventilate' while the surgeon confirms. No floor and no assigned caller is the flag.
Floor at 90 s. 'I need the tube back in now'; reventilate, then resume. Negotiating three more sutures is the trap; the closed-loop callout exists for this.

3. Airway fire in the field

Anterior wall being trimmed; cautery near the open trachea while the cross-field tube is in; a flash and flame. First move? Second? Third? What fed it? Fire out. He is apneic; SpO2 80%. How do you re-establish ventilation? Bronchoscopy shows soot to the carina, blistering at the cut edge, no deeper injury. Complete the reconstruction now, or stage? Why? What FiO2 for the rest of the case?

Considerations and pitfalls AI draft

Sequence. Stop the cautery, disconnect the oxygen source and pull the burning cross-field tube from the field, saline on the field and down the airway; then re-establish ventilation. Oxygen off before anything else.
FiO2. The trap is leaving FiO2 at 1.0 from the last apneic interval; before cautery near an open airway it should be ≤0.3 and no nitrous; with an open trachea, oxygen pools in the field.
Re-establish. The surgeon reinserts a fresh cross-field tube into the distal trachea, or advance the oral tube across the field under vision; hand-ventilate at low FiO2 once the flame is out; scope.
Proceed or stage. With a superficial injury and a stable patient, completing the anastomosis is reasonable — the resected margins are the burned tissue; deep injury, hemodynamic instability, or a contaminated field argue for staging with a tracheostomy or T-tube. Commit.
FiO2 after. The lowest that keeps SpO2 >92%; no cautery near the airway without the oxygen turned down.

4. Lost distal airway

Posterior anastomosis half done. The cross-field tube slips out of the distal trachea into the field; SpO2 falls to 82% and you cannot ventilate. First move? What are you doing while the surgeon reaches for the distal trachea? Surgeon cannot get the tube back in — the distal segment has retracted. Options? Advance your oral tube across the gap — how, and how do you know it is in? SpO2 75%, HR 130. How long do you persist before calling perfusion? Cannulation — where? What is the last thing you try before that?

Considerations and pitfalls AI draft

First move. 100% O2 to both the oral tube and the field tube, and one sentence to the room — 'I cannot ventilate, SpO2 82' — so the surgeon stops and reaches for the distal trachea.
Meanwhile. Hand-ventilate through the oral tube above the anastomosis in case some gas passes the gap; suction; have the fiberoptic scope loaded in the oral tube; call for help and perfusion to the room.
Retracted segment. The surgeon grasps and delivers the distal trachea with stay sutures and reinserts the cross-field tube; or you advance the oral tube over a fiberoptic scope through the open anastomosis into the distal trachea under the surgeon's direct vision.
Confirm. Capnography and the surgeon seeing the tube in the distal lumen; chest rise.
Escalation. Do not persist into arrest: at a saturation in the 70s with a rising HR and no airway, call for cannulation now; the standby perfusion team is for exactly this. Femoral VA ECMO or VV via femoral-jugular; the last thing to try is a rigid bronchoscope or jet catheter into the distal segment by the surgeon.

B. POST-OPERATIVE CARE

Teaching focus. Early extubation onto a fresh anastomosis with the neck flexed; post-extubation airway compromise and the danger of blind reintubation; sedation against a protected neck; POD 2 liberation from the ventilator onto a flexed neck, with steroids and swallowing; anastomotic dehiscence with honest disclosure.

1. Extubation with the neck flexed

Reconstruction complete, a chin-to-chest guardian suture in, oral 6.5 tube with the cuff below the anastomosis. Extubate in the OR? Why/why not? What has to be true first? What do you check with the scope before pulling it? Deep or awake? Why? He is awake, flexed, and stridorous within two minutes of extubation. Rx? Doses? Stridor eases; SpO2 95% on 4 L. Where does he go? He is comfortable at 30 minutes. His home CPAP tonight — yes/no? Why?

Considerations and pitfalls AI draft

Extubate or not. Yes, early extubation is the goal — a cuff sitting on or near the anastomosis and positive pressure both threaten it; edema and OSA argue for care, not for staying intubated.
Preconditions. Fully awake and following commands, reversed with quantitative TOF >0.9, normothermic, minimal secretions, surgeon at the bedside, small tubes and a fiberoptic scope ready; a cuff-leak test.
Scope check. The anastomosis intact, no significant edema or blood at the suture line, cords mobile.
Awake. Awake with the neck flexed; a deep extubation risks obstruction in an OSA patient with a fresh anastomosis and no way to lift the chin.
Stridor. Sit up (while flexed), humidified oxygen, racemic epinephrine 0.5 mL of 2.25% nebulized, dexamethasone 8-10 mg, heliox 70:30 as a bridge; an anastomotic edema problem, not laryngospasm.
Disposition. ICU with continuous oximetry, CPAP available at low pressure if needed for OSA.
CPAP. Untreated OSA in a flexed, edematous airway obstructs; low-pressure CPAP with the surgeon's agreement is the usual compromise, and a committed answer either way with a named pressure is what is wanted. High pressures on a fresh suture line are the concern; note that reintubation here would need a fiberoptic-guided 5.5-6.0 tube with the surgeon and a rigid scope present — never blind.

2. Post-extubation airway compromise

Two hours later in the ICU: stridor worse, voice weak, RR 28, SpO2 92% on 6 L. DDx? Most concerning? How do you look without making it worse? Flexible scope through the nose: cords mobile, the anastomosis edematous with a slit lumen. Heliox and racemic epinephrine again — worth it? Why? He tires, SpO2 86%, drowsy. Secure the airway — how exactly? Tube size? Backup if the fiberoptic fails? Tube in below the anastomosis; SpO2 97%. Ventilator settings?

Considerations and pitfalls AI draft

DDx / most concerning. Anastomotic edema, recurrent laryngeal nerve injury with cord dysfunction, hematoma, secretions, early dehiscence; a tight edematous anastomosis or bilateral cord palsy obstructs.
Look. Awake nasal fiberoptic assessment with topical anesthesia, sitting up, gentle; no repeated laryngoscopy.
Temporizing. Heliox and racemic epinephrine buy minutes for a mechanical problem, not a fix; use them while the airway is set up, not instead of setting it up.
Secure. Awake or lightly sedated (dexmedetomidine, ketamine) fiberoptic intubation through the nose or mouth with a 5.5-6.0 tube railroaded under vision past the anastomosis, cuff below it; the surgeon at the bedside with a rigid bronchoscope and a tracheostomy tray as backup; no paralysis until the tube is in. Blind reintubation is the flag.
Settings. Low tidal volume and pressure, PEEP ≤5, keep the cuff pressure <25; light sedation and early plan to extubate once edema settles.

3. Sedation versus a protected neck

POD 1, intubated, on propofol 30 mcg/kg/min. He wakes agitated, bucks on the tube, and extends his neck against the guardian suture. What is at risk? Right now — what do you give? Dose? Sedation target for the day? Deeper? Why/why not? Dexmedetomidine, propofol, or a benzodiazepine infusion? Which? Rates? Analgesia — what? Fentanyl at 100 mcg/h makes him apneic on pressure support. Adjust how? He is calm and breathing. Extubate today — what has to be true, beyond the usual?

Considerations and pitfalls AI draft

Risk. Neck extension and violent coughing put tension on the fresh anastomosis; the cuff moving on the suture line; self-extubation into an airway nobody can easily reintubate.
Right now. Propofol 30-50 mg bolus and a hand on the tube; then fix the infusion.
Target. RASS 0 to -1: calm, follows commands, keeps the neck flexed, breathes spontaneously; deep sedation invites ventilator dependence and hypoventilation with OSA.
Agents. Dexmedetomidine 0.4-1.2 mcg/kg/h as the base — calm without respiratory depression; low-dose propofol 10-30 mcg/kg/min as needed; benzodiazepine infusions delay extubation and cause delirium.
Analgesia. Scheduled acetaminophen, ketorolac if renal function allows, low-dose opioid; fentanyl 25-50 mcg/h or hydromorphone PCA once awake.
Apneic on fentanyl. Halve the opioid, lean on dexmedetomidine and non-opioids; the coughing is from the tube, not pain.
Extubation criteria. Repeat scope showing the anastomosis and cords, surgeon present, a cuff leak, the same rescue setup as in the OR.

4. POD 2 liberation onto a flexed neck

POD 2, calm on pressure support 5/5, FiO2 0.3, awake and flexed. Repeat scope: anastomosis intact, mild edema, cords mobile. Cuff-leak test: no leak. Extubate now? Why/why not? Dexamethasone before the tube comes out — yes/no? Dose? How many doses after? Extubated uneventfully. Sips of water at four hours: he coughs, voice wet. Cause? Oral intake — continue, stop, or thicken? Why? Guardian suture — stays how long? Repeat bronchoscopy — when? Why? POD 3: 2 L, swallowing cleared. Floor or ICU tonight? What has to be true before he leaves the ICU?

Considerations and pitfalls AI draft

No cuff leak. The leak test is unreliable after tracheal resection — a small tube in a narrowed, edematous lumen fails it — and the scope is the better test; anastomosis intact with mild edema and mobile cords is a go, with the surgeon present and the same rescue setup as in the OR. Either commit is defensible (extubate now, or 12-24 h more steroids and re-scope); a cuff sitting on the suture line has its own cost, so 'no leak, stay intubated' by reflex is the flag.
Dexamethasone. Yes; 8-10 mg IV before extubation, then 4-8 mg q8h for 24-48 h; modest evidence for airway edema, low cost.
Cough with water. Aspiration from laryngeal dysfunction: reduced laryngeal elevation with the neck fixed in flexion (worse after a laryngeal release), recurrent or superior laryngeal nerve injury, glottic edema and blunted sensation after the tube.
Oral intake. Stop — NPO and a formal swallow evaluation (bedside speech pathology, then FEES or a modified barium swallow); thickening without an evaluation is guessing; aspiration onto a fresh anastomosis invites pneumonia and dehiscence.
Guardian suture. About 7 days, removed by the surgeon, then gradual extension; the patient is told not to extend before then.
Bronchoscopy. Surgeon's call; typically at suture removal around POD 7 and immediately for any change in voice, stridor, or secretions; granulation and restenosis declare over weeks, so surveillance continues at 1 and 3 months.
Disposition. Floor once swallowing is cleared, oxygen ≤2 L, no stridor, secretions handled, with the CPAP plan set and the ward staff holding a written reintubation plan (small tube, fiberoptic, surgeon called); nothing about the operation requires ICU by default.

5. POD 4 fever with neck emphysema and air leak

POD 4, extubated on POD 2: fever 38.8, new subcutaneous emphysema across the neck and chest, SpO2 90% on 6 L, RR 30. Dx until proven otherwise? Anything else on the list? OR now, or CT first? Why? Positive pressure — what would it do here? BiPAP to buy time — yes/no? He is tiring, PaCO2 62. Secure the airway — how? Where must the cuff sit? Tube in with the cuff below the disruption; ventilating well. Where does he go next? MAP and SpO2 targets on the way? His wife asks what went wrong. What will you tell her?

Considerations and pitfalls AI draft

Dx. Anastomotic dehiscence with air leak into the neck and mediastinum; mediastinitis follows; also wound infection or pneumonia without dehiscence.
OR vs CT. The thoracic surgeon and the OR — the fix is surgical; CT confirms only if he is stable, and a tiring patient with a threatened airway does not go to the scanner.
Positive pressure. Mask pressure forces gas through the disruption and expands the emphysema and mediastinal contamination; BiPAP is the wrong move — no.
Secure. Fiberoptic-guided intubation (awake or with ketamine/dexmedetomidine, no paralysis until in), surgeon present with a rigid scope; the cuff must sit distal to the disruption so ventilation bypasses the leak; confirm with the scope; cuff pressure minimal.
Support. OR for exploration, revision, or a tracheostomy/T-tube through the dehiscence; until then low airway pressures, SpO2 >90%, MAP >65, antibiotics for mediastinitis.
Wife. A plain account: the joined ends of the windpipe have come apart, it is a known and serious complication of this operation, he needs another operation and may need a tracheostomy, and the team will keep her updated through it; no false reassurance and no blame.

Short stem

VATS wedge resection in an active smoker with a known difficult airway

A 64 y.o., 5'2", 58 kg woman is scheduled for a right video-assisted thoracoscopic (VATS) wedge resection of a 1.8 cm peripheral right lower lobe nodule, with a right lower lobectomy under the same anesthetic if frozen section shows lung cancer. She smokes one pack a day (45 pack-years), including this morning, has a daily cough with clear sputum, and uses an albuterol inhaler a few times a week. PFTs: FEV1 1.45 L (62% predicted), FEV1/FVC 0.64, DLCO 55% predicted. She takes clopidogrel for a femoral artery stent placed two years ago; her last dose was three days ago. After a hysterectomy six years ago she was told she was a difficult intubation; the letter she brings describes easy mask ventilation, a grade 3 view and failed first attempt with direct laryngoscopy, and success with a video laryngoscope and bougie. HR 84; BP 146/88; RR 16; SpO2 95% on room air; scattered expiratory wheezes; Mallampati 3; thyromental distance 5 cm.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Pulmonary risk assessment sized to the largest resection she might get; what a cigarette this morning and active wheezing change on the day of surgery; choosing and backing up lung isolation in a known difficult airway; regional analgesia when an antiplatelet agent was stopped only three days ago.

1. Pulmonary evaluation

Her PFTs. Enough to proceed with this operation? Why/why not? Predicted postop FEV1? Predicted postop DLCO? Further testing? Which test? Why? Stair climb: 24 m without stopping, SpO2 nadir 93%. Lobectomy acceptable today? Why/why not? Cardiac testing first? Why/why not? Preop ABG? Why/why not?

Considerations and pitfalls AI draft

Enough to proceed?. A wedge barely changes her function, but the plan allows a lobectomy, so the evaluation has to be sized to the lobectomy. Clearing her on the wedge alone is the miss (and a DLCO of 55% sits under 60% even before any resection).
ppoFEV1. Segment method: the RLL is 5 of 19 segments, so 62% x (1 - 5/19) is about 46% (about 1.07 L); the 42-subsegment method (12 of 42) gives about 44%. Either is fine if the arithmetic is shown. Use the postbronchodilator value.
ppoDLCO. 55% x 0.74 is about 40%. Both values sit between 30% and 60%, which calls for a low-technology exercise test rather than clearance or formal CPET. A learner who stops at FEV1 and ignores DLCO is missing half the risk estimate.
Further testing. Stair climb or shuttle walk as the screen; CPET if either ppo value is 30% or below, or if the screening test is unsatisfactory.
24 m, nadir 93%. A stair climb of 22 m or more is a satisfactory result; she can proceed to lobectomy at acceptable risk. Desaturation of more than about 4% on exercise would have raised concern.
Cardiac testing. Thoracic RCRI is 0 (no ischemic heart disease, stroke, creatinine over 2, or pneumonectomy) and she just climbed 24 m, so no further cardiac testing. PAD earns a careful history for angina and a baseline ECG, not a stress test by reflex.
ABG. Not required. A raised PaCO2 is a marker of risk, not an exclusion; reasonable to obtain if her history or exam suggested CO2 retention.

2. Morning cigarette and wheeze

Last cigarette two hours before arrival. Significance? Proceed today? Why/why not? Any test before induction? Which? Why? Treat the wheezes before induction? Agent? Dose? Systemic steroid? Why/why not? Postpone a few weeks to optimize her lungs? Why/why not? She asks if it is too late for quitting to matter. What will you tell her?

Considerations and pitfalls AI draft

Significance. Carbon monoxide from recent smoking: carboxyhemoglobin reads as oxyhemoglobin on a standard two-wavelength oximeter, so her true saturation is lower than displayed (smokers often carry 5-10% COHb), and her O2 reserve at induction is smaller than it looks. Also a more reactive airway. COHb half-life is roughly 4-6 hours on room air and about 1-1.5 hours on 100% O2. A learner who sees no significance beyond 'she should have quit' is missing the oximeter.
Proceed. Yes. A cigarette this morning is not a reason to cancel a cancer resection; it changes how you read her oximeter and how long you preoxygenate.
Test. Co-oximetry on a blood gas gives the real COHb and saturation; reasonable, not mandatory. A blood gas without co-oximetry reports a calculated saturation that misses COHb.
Wheezes. Short-acting beta-agonist before induction: albuterol 2.5 mg nebulized or 4-8 puffs by MDI; continue any maintenance inhaler. A learner who plans to manipulate the airway of a wheezing smoker without bronchodilator first is a flag.
Steroid. Not routine for mild, baseline wheeze that clears with albuterol. A short course belongs to a true exacerbation (more dyspnea, sputum change, poor response), and that picture would also argue for delay.
Postpone. Not for her baseline. Waiting weeks to optimize stable obstructive disease delays a cancer operation for little gain; postponement is for an active exacerbation or infection.
Quitting now. Not too late: stopping now and staying off lowers wound and pulmonary complications and improves how she tolerates further cancer treatment; quitting right before surgery does not raise complications. The biggest pulmonary benefit takes about 4-8 weeks, but it starts today. Offer nicotine replacement in the hospital and a referral. A plain, nonjudgmental answer, not a lecture.

3. Lung isolation plan

Lung isolation: DLT or single-lumen tube with a bronchial blocker? Which? Why? Assume a DLT. Left or right? Why, for a right-sided resection? Size? Why? Awake fiberoptic intubation? Why/why not? Device for the first attempt? Why? Backup if the DLT fails? What does a blocker cost you compared with a DLT?

Considerations and pitfalls AI draft

Choice. Either is defensible. A left DLT gives the fastest, most reliable isolation and suction of the operative lung; a single-lumen tube plus blocker is the easier tube to place in a known difficult airway and needs no exchange at the end. The commit has to engage her airway history.
Left or right. Left DLT: the left main bronchus is long, so the bronchial cuff sits well clear of the left upper lobe takeoff; the right main bronchus is short and the right upper lobe takeoff makes a right DLT harder to seat. For a right-sided operation the left DLT ventilates the dependent lung and leaves the right lung free.
Size. 35 Fr for a woman under about 160 cm; 37 Fr is acceptable. Choosing a large tube to make suctioning easier, in a known grade 3 view, is worth challenging.
Awake. Not required: documented easy mask ventilation and a documented video laryngoscope success. Awake intubation is defensible if her airway exam has worsened or the learner has a reason; it does not solve lung isolation by itself.
First attempt. Video laryngoscope, since that is what worked last time; direct laryngoscopy repeats a known failure.
Backup. A single-lumen tube with a bronchial blocker, or a single-lumen tube exchanged for a DLT over an exchange catheter; a learner with no backup plan for a difficult DLT is a flag.
Blocker cost. Slower and less complete collapse, a small lumen that barely suctions, easier dislodgement (especially in the short right main bronchus), and harder to switch sides. Gains: one easy tube and no exchange at the end.

4. Analgesia plan

Analgesia plan. Thoracic epidural? Why/why not? Paravertebral? Why/why not? Erector spinae or serratus plane block? Which? Why? Before induction or after? Why? Local anesthetic? Concentration? Volume? Maximum dose at her weight? Systemic adjuncts? Doses? Ketorolac? Why/why not?

Considerations and pitfalls AI draft

Thoracic epidural. No. Clopidogrel stopped three days ago is inside the 5-7 day hold for neuraxial techniques, so an epidural is contraindicated today; VATS rarely needs one anyway.
Paravertebral. No for the same reason. It is a deep, noncompressible block close to the neuraxis and is held to the neuraxial antiplatelet rules.
Plane block. An erector spinae plane block or a serratus anterior plane block is a superficial plane block that many accept on clopidogrel after a risk-benefit judgment; either is defensible. Surgeon-placed intercostal blocks under direct view are also reasonable.
Timing. After induction in the lateral position is common and avoids moving a sedated difficult airway; before induction allows a check of the block. Either is defensible. Single shot is usually enough for a wedge; a catheter is reasonable if a lobectomy is likely.
Local anesthetic. E.g., ropivacaine 0.375-0.5%, 20-30 mL. Maximum about 3 mg/kg for ropivacaine (about 174 mg at 58 kg) or 2.5 mg/kg for plain bupivacaine (about 145 mg); 30 mL of 0.5% ropivacaine is 150 mg, close to the ceiling, so account for any surgeon local.
Systemic. Scheduled acetaminophen 1 g every 6 hours; dexamethasone 4-8 mg after induction; low-dose ketamine (e.g., 0.25-0.5 mg/kg at induction) is reasonable; opioid as a supplement only. Gabapentinoids are optional and add sedation in an older patient.
Ketorolac. A judgment call: an NSAID adds bleeding risk on top of residual clopidogrel effect after a lung resection; many would avoid it or give a single 15 mg dose only with the surgeon's agreement.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. A failed DLT placement and the move to a blocker; what lateral positioning does to a right-sided blocker; ventilating and oxygenating on one lung in a smoker; restrictive fluids and permissive hypercapnia once the case becomes a lobectomy; reversal and extubation of a known difficult airway.

1. Induction and intubation

Assume you plan a left DLT. Induction agent? Dose? Preoxygenation end point? Why? Video laryngoscope: grade 3 view; the DLT tip will not pass the arytenoids. Next? Two attempts; SpO2 93%, mask ventilation easy. Third attempt with the DLT, or a single-lumen tube? Why? A 7.5 single-lumen tube goes in over a bougie. Isolate now: bronchial blocker, or exchange to a DLT over a catheter? Why? Assume a blocker. Confirm position: how? Where should the balloon sit?

Considerations and pitfalls AI draft

Induction. Propofol 1.5-2 mg/kg (about 90-115 mg) with fentanyl 1-2 mcg/kg and rocuronium 0.6 mg/kg (about 35 mg); a volatile or deep plane before airway instrumentation helps the reactive airway. Ketamine is a reasonable alternative.
Preoxygenation. End-tidal O2 of 0.9 or more, head up. Her oximeter overreads, so the real reserve is smaller than the number suggests.
Tip will not pass. Rotate the tube, withdraw the stylet slightly, railroad the DLT over an airway exchange catheter sized for the bronchial lumen (a standard adult bougie will not pass through a 35 Fr bronchial lumen), or drop to a smaller DLT; one adjusted attempt is reasonable.
After two attempts. Stop chasing the DLT; a single-lumen tube over a bougie is the more reliable tube in this airway. Repeated DLT attempts while she desaturates is the flag, and her 93% is optimistic because the oximeter reads COHb as oxyhemoglobin.
Blocker vs exchange. Blocker keeps the tube that is already in a hard airway; exchanging over a catheter risks losing it. Exchange under video laryngoscopy with a long catheter is defensible if a DLT is strongly preferred.
Confirm. Fiberoptic through the tube, watching the blocker enter the right main bronchus and the balloon inflate under direct view. Listening alone is not adequate.
Balloon. Just below the carina, fully inside the right main bronchus and above the right upper lobe takeoff (a balloon past that orifice leaves the upper lobe ventilated), inflated under vision with the smallest volume that seals (usually about 4-8 mL); overinflation risks bronchial injury and pushes the balloon back toward the carina.

2. Lateral position and lung collapse

Turned to left lateral decubitus. Recheck the blocker? Why? How? One-lung ventilation started. Tidal volume in mL? Rate? PEEP? FiO2? Five minutes later the surgeon says the right lung is not collapsing. DDx? Rx? Lung down. Twenty minutes later, during hilar dissection: peak pressure from 24 to 48 cm H2O, ETCO2 trace lost, SpO2 falling. Most likely cause? First move? Balloon deflated; two-lung ventilation; SpO2 back to 96%. Next?

Considerations and pitfalls AI draft

Recheck. Yes, every time she moves: turning and neck flexion or extension shift the blocker, and the short right main bronchus leaves little margin. Fiberoptic again after positioning.
Settings. PBW about 50 kg, so tidal volume 4-6 mL/kg (about 200-300 mL), rate up to keep minute ventilation reasonable, PEEP 5, FiO2 high to start then titrated down; watch the expiratory flow curve for breath-stacking in an obstructed patient.
Not collapsing. Balloon not sealing or sitting too proximal, slow absorption atelectasis through a small blocker lumen, air (nitrogen) in the lung at isolation, emphysematous lung that empties slowly. A learner who does not recheck the blocker first is missing the most likely fix.
Rx. Confirm the seal by fiberoptic, deflate the balloon, disconnect the circuit briefly so the right lung empties (after a period on 100% O2 to wash out nitrogen), then reinflate the balloon; gentle suction on the blocker lumen; surgeon can compress gently. Collapse with a blocker is slower than with a DLT.
Most likely cause. The blocker balloon has backed out into the trachea and is occluding it, a recognized danger with right-sided blockers during hilar manipulation. Kink, plug, and severe bronchospasm are on the list, but loss of all ventilation points to the balloon.
First move. Deflate the balloon now and ventilate both lungs with 100% O2; tell the surgeon. Reaching for bronchodilators while the trachea is occluded is the flag.
Next. Re-site the blocker under fiberoptic, a little deeper, and reinflate under vision once she has recovered.

3. Desaturation on one-lung ventilation

Blocker re-sited, isolation restored. Forty minutes into OLV: SpO2 87% on FiO2 0.8, BP 124/72, peak 26. DDx? First move? FiO2 1.0. Fiberoptic: blocker in place; thick secretions plugging the left lower lobe bronchus. Rx? Suctioned; SpO2 90%. Next? Oxygen through the blocker lumen to the right lung? Why/why not? Recruit the left lung? Pressure? How long? PEEP after? SpO2 93%. Surgeon asks for ten more minutes of collapse to finish the wedge. Agree? Why/why not? Lowest SpO2 you accept?

Considerations and pitfalls AI draft

DDx. Blocker malposition, secretions or a plug in the ventilated lung, shunt through the collapsed right lung, dependent-lung atelectasis, bronchospasm, low cardiac output.
First move. FiO2 to 1.0, then look with the fiberoptic; with a blocker that has already moved once, malposition comes first. A daily-cough smoker makes secretions likely.
Secretions. Suction through the tube with the fiberoptic or a catheter; saline lavage if thick; a bronchodilator if wheeze is present.
O2 through the blocker lumen. Low-flow O2 insufflation into the right lung can reduce shunt, but it can partly reinflate the lung in the surgeon's field; CPAP through a blocker lumen is less practical than through a DLT. Defensible if the surgeon agrees.
Recruit. About 30 cm H2O for 20-30 seconds to the dependent lung, then PEEP 5-10, watching BP during the maneuver.
Ten more minutes. Reasonable while SpO2 holds above about 90% and she is stable; a falling trend, arrhythmia, or ST change means two-lung ventilation now. Intermittent reinflation with the surgeon is the fallback.
Lowest SpO2. Most accept SpO2 around 90% briefly; her COHb has partly cleared on high FiO2 by now, but the displayed number still reads a little high; the learner should name a number and the action at that number, not a vague 'if it gets worse.'

4. Conversion to lobectomy

Frozen section: adenocarcinoma. RLL lobectomy proceeds by VATS. Fluid plan for the rest of the case: restrictive or liberal? Why? Crystalloid limit? Two hours later: urine 10 mL/h over those two hours, MAP 60, HR 88, EBL 200 mL. Bolus? Pressor? Which? Why? ABG on OLV: pH 7.27, PaCO2 56, PaO2 140 on FiO2 0.6. Of concern? Rx? FiO2 now? Target SpO2?

Considerations and pitfalls AI draft

Restrictive or liberal; limit. Restrictive, not dry. Lung resection patients are prone to postoperative lung injury and edema, and the lymphatics of the operated side are disrupted; a common ceiling is a positive balance under about 20 mL/kg (about 1.2 L at 58 kg) in the first 24 hours, with no fluid for third-space losses. Replace blood loss. Running her dry enough to cause hypovolemia or AKI is also a miss.
Bolus?. Low intraoperative urine output is common under anesthesia and is a poor guide to volume here; it is not by itself a reason to bolus.
Pressor. Too low for her baseline pressures, so it gets treated. With modest blood loss this is most likely anesthetic vasodilation: a low-dose vasopressor (phenylephrine boluses or a norepinephrine infusion) first, with a modest bolus (e.g., 250 mL) only if there is a sign of hypovolemia. Liters of crystalloid to fix a number is the flag.
ABG. Acceptable permissive hypercapnia during OLV with protective tidal volumes if oxygenation and hemodynamics are fine (pH 7.27 fits acute CO2 retention alone); acidosis raises PVR and can add to vasodilation, so a falling pH toward 7.20, arrhythmia, or RV strain pushes to act; raise the rate if it climbs, watching for auto-PEEP rather than increasing tidal volume.
FiO2; target SpO2. Come down from 0.6 toward the lowest FiO2 that keeps SpO2 about 92-96%; high FiO2 on the ventilated lung adds absorption atelectasis without benefit when PaO2 is 140.

5. Emergence and PACU

Lobectomy done; one chest tube; blocker out. TOF count 2. Reversal? Dose? End point before extubation? Extubate in the OR? Why/why not? Awake or deep? Why? Airway exchange catheter? Why/why not? PACU, 40 minutes later: RR 28, shallow, SpO2 89% on 4 L, pain 8/10 on breathing. DDx? CXR: lungs expanded, no pneumothorax, small right basal atelectasis. Rx?

Considerations and pitfalls AI draft

Reversal. Sugammadex 2 mg/kg (about 116 mg) at TOF count 2; quantitative TOF ratio of 0.9 or more before extubation. Neostigmine at this depth is likely to leave residual block.
Extubate. Yes in most cases: good gas exchange, reversed, warm, and positive pressure is bad for a fresh stump. The learner should name the conditions first.
Awake. Awake and upright. Deep extubation in a known difficult airway is the flag.
Exchange catheter. Defensible in a known difficult intubation (a grade 3 view twice); many would leave one in place briefly. Not using one is defensible if the learner names the reintubation plan (video laryngoscope, bougie, help at hand).
PACU DDx. Splinting from pain, atelectasis or retained secretions, residual block or opioid effect, pneumothorax or hemothorax, bronchospasm.
Rx. Treat the pain: bolus the catheter if one is in, otherwise titrated IV opioid with the scheduled multimodal plan; sit her up, incentive spirometry, cough, bronchodilator, supplemental O2. A worsening picture despite analgesia means bronchoscopy for secretions or a recheck of the chest tube.

Long stem

Healthy young adult for urgent laparoscopic appendectomy

A 23 y.o., 60 kg, 5'5" woman is scheduled for urgent laparoscopic appendectomy.

HPIPeriumbilical pain since yesterday afternoon, moving to the right lower quadrant overnight. No appetite; nauseated; vomited twice, last at 4 AM. Last meal (pizza) at 7 PM last night; sips of water since. CT: acute appendicitis without perforation or abscess. In the ED at 6 AM she received morphine 4 mg IV and ondansetron 4 mg IV, then ceftriaxone and metronidazole IV and 1 L lactated Ringer's. It is now 11 AM.

PMHWisdom teeth removed under general anesthesia at age 18; vomited through most of that evening. Otherwise healthy. Nonsmoker; drinks socially; runs three times a week. No known drug allergies.

MEDSCombined oral contraceptive pill, one tablet nightly.

PHYS EXAMHR 102; BP 116/70; RR 16; SpO2 99% on room air; T 38.1°C. Mallampati 1, full mouth opening, thyromental distance three fingerbreadths, full neck extension, intact dentition. Lungs clear. Right lower quadrant tenderness with guarding.

LABSWBC 14.6 K/uL; Hgb 13.2 g/dL; platelets 260 K/uL; Na+ 138 mEq/L; K+ 3.7 mEq/L; creatinine 0.7 mg/dL; glucose 98 mg/dL. Urine hCG sent; result pending.

OR ARRIVAL20 g IV in the left hand with lactated Ringer's running. Standard monitors on. Rates her pain 6/10.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. One complete general anesthetic in a healthy patient: full-stomach reasoning despite long fasting hours, the checks and equipment owed before every induction, RSI dosing and tube confirmation, a maintenance choice tied to PONV risk, pneumoperitoneum physiology, monitor-guided reversal, and extubation criteria.

1. Before induction

11:15. Surgeon is ready; urine hCG still pending. Start? Why/why not? hCG returns negative. The machine was checked out at 7 AM. Repeat any of it yourself before this induction? Which checks? Airway equipment within reach for this induction? What? Rapid sequence? Standard induction with mask ventilation? Which? Why? Assume RSI. Cricoid pressure? Why/why not? Gastric tube before induction? Why/why not? Preoxygenation: how? End point?

Considerations and pitfalls AI draft

Start before hCG. Most would wait. This is urgent, not emergent, and a non-perforated appendix tolerates the few minutes a urine test takes. A positive result would not cancel the operation, but it changes consent, brings in obstetrics, and changes some drug and monitoring choices. Starting without the result to keep the room moving is the flag.
Machine checks. A morning checkout does not cover every case. Before each induction: suction working and within reach, monitors and alarms working, a circuit leak and pressure test, flow through the circuit with intact unidirectional valves, vaporizer filled and seated, ventilator settings, and a self-inflating bag and backup oxygen in the room. Treating the 7 AM check as covering the whole day is the weak answer.
Airway equipment. Suction on and under the pillow, laryngoscope with a second blade or a video laryngoscope, the planned tube plus one size smaller with a stylet, a bougie, oral airways, and a sized supraglottic airway. The exam is reassuring; the setup still assumes the first attempt can fail.
RSI vs standard. Most would choose RSI. Sixteen hours since her meal does not make her stomach empty: appendicitis slows gastric emptying, she vomited 7 hours ago, she is still nauseated, and she has had morphine. Fasting guidelines are written for healthy elective patients, not an inflamed abdomen. A standard induction because she has been NPO since 7 PM misses the point. A modified RSI with gentle, low-pressure mask ventilation is defensible if defended. Gastric ultrasound, where available, can inform the call but does not need to delay it.
Cricoid pressure. Either, if defended. It is traditional (about 30 N once she loses consciousness), but evidence of benefit is weak and it can worsen the view and mask ventilation. A learner who applies it should say it comes off if the view or ventilation is poor, and stays on until ETCO2 confirms tracheal placement.
Gastric tube before induction. Not here. Pre-induction decompression matters in bowel obstruction with a fluid-filled stomach; she has no obstruction, an awake nasogastric tube is miserable, and it will not remove solids. An orogastric tube after intubation, to decompress the stomach before trocar placement, is reasonable.
Preoxygenation. Tight mask seal, FiO2 1.0 with high fresh gas flow, head up 20-30 degrees, 3 minutes of tidal breathing or 8 deep breaths over a minute. End point: end-tidal O2 of 0.9 or higher. Naming a time without an end point is the weak answer; a leaking mask makes the time meaningless.

2. Induction and the tube

Induction agent? Dose? Opioid with it? Dose? Rocuronium or succinylcholine? Why? Dose? Grade 1 view; a 7.0 tube passes the cords. Placement confirmed how? ETCO2 36 with a steady square waveform for six breaths; SpO2 100%. Enough? Why/why not? Cuff pressure reads 60 cmH2O. Target? Why? Three minutes later: BP 80/42, HR 114. Rx? Phenylephrine? Ephedrine? Volume? Which first? Dose?

Considerations and pitfalls AI draft

Induction agent. Propofol 1.5-2 mg/kg (90-120 mg) is standard in a healthy adult; she is febrile, tachycardic, and has been fasting and vomiting, so many would go toward the lower end. Etomidate or ketamine are defensible but not needed. In an RSI the dose is given as a single predetermined bolus, not titrated slowly.
Opioid. Fentanyl 1-1.5 mcg/kg (60-90 mcg) to blunt the response to laryngoscopy. The 6 AM morphine has largely worn off and changes the induction dose little. Large opioid doses at induction add hypotension without much benefit in a short case.
Rocuronium vs succinylcholine. Either, if defended. Rocuronium 1.2 mg/kg (about 70 mg) gives intubating conditions in about a minute with sugammadex available. Succinylcholine 1-1.5 mg/kg (60-90 mg) has the fastest onset and offset and she has no contraindication, but it brings myalgias and MH triggering. Rocuronium at the standard 0.6 mg/kg for an RSI is the error: onset is too slow.
Confirmation. Sustained ETCO2 over several breaths is the standard. Add bilateral breath sounds and chest rise, nothing over the stomach, depth at the lip (about 21 cm for an average adult woman), and SpO2. Seeing the tube pass the cords supports it but is not proof.
Enough?. ETCO2 proves the tube is in the airway, not that it sits above the carina; a mainstem tube gives a normal waveform. Listen to both sides and check depth before calling it done.
Cuff pressure. 20-30 cmH2O, measured with a manometer. At 60 the cuff exceeds tracheal mucosal perfusion pressure and risks ischemia and sore throat; too low allows aspiration around the cuff. Judging by feel of the pilot balloon is unreliable.
Hypotension. Expected after propofol in a febrile, fasting, vomiting patient: vasodilation on a contracted volume, plus loss of the stimulation of laryngoscopy. Phenylephrine 50-100 mcg IV or ephedrine 5-10 mg IV, plus a crystalloid bolus. With HR 114, phenylephrine is a reasonable first choice; ephedrine is acceptable. Lighten the anesthetic and glance at airway pressures and the rhythm. A pressor without volume is half the answer.

3. Maintenance and insufflation

Maintenance: sevoflurane? Propofol infusion? Which? Why? Nitrous oxide? Why/why not? Dexamethasone? Why/why not? Dose? Assume sevoflurane. End-tidal 2.0%; BP 104/62, HR 86. Depth adequate? What tells you? Insufflation to 15 mmHg: HR 38, BP 78/40. Rx? Atropine? Glycopyrrolate? Dose? HR 84 after re-insufflation; head down, right side up. Twenty minutes later: ETCO2 47 from 35, peak pressure 33 from 21 cmH2O, SpO2 96%. DDx? Ventilator change? Rate? Tidal volume? Which? To what?

Considerations and pitfalls AI draft

Sevoflurane vs propofol. Either is defensible. Her Apfel score is 4 (female, nonsmoker, prior PONV, postoperative opioids expected), a baseline risk of roughly 80%. Propofol TIVA removes the volatile, one of the larger anesthetic drivers of PONV, and counts as one of her prophylactic measures. Sevoflurane with a full antiemetic regimen is also reasonable. A learner who does not connect the maintenance choice to her PONV history has missed a stem hook.
Nitrous oxide. No. It adds PONV risk, distends bowel in a laparoscopic case, and adds little in a short case in a healthy patient.
Dexamethasone. Yes: 4-8 mg IV after induction (given awake it can cause perineal burning). It is one of the agents for a high-risk patient and helps pain and fatigue a little too. One dose in a healthy, nondiabetic patient carries little risk.
Depth. End-tidal sevoflurane 2.0% is about 0.9 age-adjusted MAC at 23, adequate with opioid on board. She is paralyzed, so movement is masked; depth rests on end-tidal agent levels, a low-agent alarm, hemodynamics, and processed EEG if used. Processed EEG matters more with TIVA plus paralysis. "She isn't moving" is the flag.
Bradycardia on insufflation. Vagal reflex from peritoneal stretch. The fastest fix is to have the surgeon release the pneumoperitoneum. Then glycopyrrolate 0.2-0.4 mg IV or atropine 0.5-1 mg IV; atropine acts faster when the rate is very low. If asystole: desufflate, atropine, CPR if the rhythm does not return at once. Re-insufflate more slowly. Waiting to see if it passes is the error.
DDx for the rising ETCO2 and peak pressure. Largely expected: CO2 absorbed from the peritoneum, and pneumoperitoneum plus head-down position pushing the diaphragm up and lowering compliance. But rule out: the tube migrating into a mainstem bronchus (the carina moves toward the tube with head-down and insufflation), subcutaneous emphysema, a kinked or obstructed tube, bronchospasm, capnothorax. Listen to both sides, check depth and the circuit, ask the insufflation pressure. A large CO2 embolism drops ETCO2 and BP rather than raising ETCO2 alone.
Ventilator change. Raise minute ventilation mainly with rate (for example 12 to 16-18), keeping Vt at 6-8 mL/kg predicted body weight; her PBW is about 57 kg, so roughly 340-460 mL. Check plateau, not just peak, and keep it under 30 cmH2O; modest PEEP helps oxygenation. Pushing Vt to 600 mL to chase the CO2 is the weak answer. Lower insufflation pressure is an option to raise with the surgeon if pressures climb further.

4. Closing and emergence

Appendix out; port sites closing. Acetaminophen? Ketorolac? Why/why not? Doses? Opioid now? Which? Dose? Antiemetic now? Which? Dose? Assume rocuronium; last dose 15 mg, 30 minutes ago; quantitative TOF count 2 at the adductor pollicis. Neostigmine? Sugammadex? Which? Dose? Assume sugammadex: TOF ratio now 0.96. Extubate deep? Awake? Which? Why? Assume awake. Agent off; eyes open, reaching for the tube, RR 18, Vt 380 mL. Extubate now? Why/why not?

Considerations and pitfalls AI draft

Acetaminophen, ketorolac. Both, as the base of multimodal analgesia: acetaminophen 1 g IV and ketorolac 15-30 mg IV near the end, with normal renal function and no bleeding concern (confirm hemostasis with the surgeon). Port-site infiltration with local anesthetic by the surgeon is simple and worth asking for; a TAP block is an option but not needed for most.
Opioid. A modest dose titrated to her breathing, for example hydromorphone 0.2-0.5 mg or fentanyl 25-50 mcg increments as spontaneous ventilation returns. A large long-acting dose in a 4-point PONV patient worsens nausea and breathing; none at all leaves her waking in pain. Either extreme without a reason is the flag.
Antiemetic. Ondansetron 4 mg IV at the end of surgery. With four risk factors, three or four interventions are reasonable: dexamethasone, ondansetron, and TIVA or a third agent (scopolamine patch, aprepitant, low-dose droperidol or haloperidol, amisulpride); a scopolamine patch has a slow onset and works best placed early. The ED ondansetron was 7 hours ago and was treatment, not prophylaxis; it does not rule out a dose now. Two agents for a 4-point patient is undertreatment.
Reversal. TOF count 2 is a moderate block. Sugammadex 2 mg/kg (120 mg) is recommended over neostigmine at this depth. Neostigmine (0.04-0.07 mg/kg, max 5 mg, with glycopyrrolate) is a reasonable alternative only at minimal block, a TOF ratio of 0.4 to below 0.9; given at a count of 2 it may not reach 0.9. Reversing on clinical signs, or skipping reversal because it has been 30 minutes, is the error.
Deep vs awake. Awake. The aspiration risk that justified RSI is the same at emergence; a deep extubation leaves an unprotected airway over a possibly full stomach. Suction the oropharynx and the orogastric tube, then remove it, before extubation. The TOF ratio of 0.96 at the adductor pollicis meets the 0.9 target.
Extubate now?. Not yet. Breathing is adequate (Vt 380 mL is about 6.7 mL/kg PBW), but reaching for the tube is not the same as following commands; she may be in the excitement phase, where extubation invites laryngospasm. Wait for a command followed (squeeze, open eyes, lift head), with stable hemodynamics, adequate SpO2 and ETCO2, and the airway suctioned. Extubating because she is pulling at the tube is the flag.

B. POST-OPERATIVE CARE

Teaching focus. PACU care after a routine case: oxygenation and opioid effect on arrival, what the handoff must carry, PONV rescue, laparoscopic pain, a tachycardia with a benign cause that still needs a cause, and same-day discharge including the sugammadex and oral contraceptive interaction.

1. Arrival in PACU

Extubated awake; uneventful. Assume hydromorphone 0.5 mg at closing. Oxygen for the trip to PACU? Why/why not? PACU arrival: drowsy, rouses to voice, RR 8, SpO2 92% on 2 L nasal cannula. DDx? First move? Naloxone? Why/why not? Dose? Ten minutes later: RR 14, SpO2 97% on 2 L, BP 112/68, follows commands. Leave her with the PACU nurse now? Why/why not? Monitoring for the next hour: continuous pulse oximetry? RR and sedation checks how often?

Considerations and pitfalls AI draft

Oxygen for transport. Most would give it: residual anesthetic and opioid, atelectasis after pneumoperitoneum and head-down position, and a trip with less monitoring. Room air is defensible for a short trip in a fully awake patient with good saturation off oxygen in the OR, but that is not this patient.
DDx. Opioid effect (mostly the closing dose; the 6 AM morphine has largely worn off), residual volatile, atelectasis, upper airway obstruction from sedation. Residual blockade is unlikely after a measured TOF ratio of 0.96 with sugammadex; recheck if in doubt rather than assume.
First move. Wake her up: stimulate, ask for deep breaths, sit her up, apply oxygen, chin lift or jaw thrust if obstructing. Most cases like this resolve with that.
Naloxone. Not if she responds to stimulation and oxygen. If she does not, small titrated doses: 40 mcg IV every 2-3 minutes to RR, not to full wakefulness. A full 0.4 mg dose strips analgesia and can cause severe pain, hypertension, and occasionally pulmonary edema. Naloxone lasts 30-90 minutes, so she needs to be watched after a dose.
Leave now. Yes, once she is on PACU monitors with a first set of vitals, the nurse has accepted her, and the handoff is complete. Leaving before the first vitals, or while she still needs stimulation to breathe, is the flag.
Monitoring. After an episode of opioid hypoventilation: continuous pulse oximetry (capnography if available; on supplemental oxygen, SpO2 falls late and can miss hypoventilation), and RR and sedation level checked often, for example every 15 minutes for at least the next hour, longer if naloxone was given, since it can wear off before the opioid. Any further opioid only once she is fully awake, at a reduced dose, with sedation checked first. The nurse needs the event and the timing of every opioid and antiemetic to act on this. Resuming standard PACU checks as if nothing happened is the flag.

2. Retching at 40 minutes

Assume dexamethasone 4 mg after induction and ondansetron 4 mg at closing. 40 minutes in: retching, then vomits 100 mL. BP 110/66, HR 96, SpO2 97% on 2 L, pain 3/10. Immediate priorities? Ondansetron again? Why/why not? Which drug instead? Dose? Twenty minutes later: still nauseated, no more vomiting. Next? Drug? Dose? She asks for the scopolamine patch her friend used. Now? Why/why not?

Considerations and pitfalls AI draft

Immediate priorities. Airway first (turn her to the side, suction). Then look for a cause beyond PONV: hypotension, hypoxemia, pain, hypoglycemia, opioid effect, a distended stomach. Vitals here are reassuring.
Ondansetron again. No. A repeat of the class that just failed as prophylaxis adds little; rescue should come from a different class. Repeating a 5-HT3 antagonist is reasonable only if more than about 6 hours have passed.
Drug instead. A dopamine antagonist (haloperidol 0.5-1 mg IV, droperidol 0.625 mg IV, or amisulpride 10 mg IV) or an antihistamine (promethazine 6.25 mg IV, which sedates). Low doses are safe in a healthy patient with a normal QT. Dexamethasone is not a rescue drug (slow onset), and she already had it. Note that she got two prophylactic agents with a volatile anesthetic; with four risk factors a third was owed in the OR, which is part of why she is vomiting now.
Next. A drug from yet another class (antihistamine or anticholinergic if a dopamine antagonist was used); a small propofol dose (10-20 mg) in a monitored setting is a short-lived rescue; IV fluid if she is dry. Persistent vomiting may change whether she goes home today.
Scopolamine patch now. Limited value for the next hour: onset takes several hours. It can help later nausea at home, at the cost of dry mouth, blurred vision, drowsiness, and confusion; she must wash her hands after touching it (a dilated pupil can be mistaken for a neurologic sign). Reasonable if she goes home still nauseated, not as immediate rescue.

3. Pain at one hour

One hour in: pain 8/10, mostly the right shoulder, worse with deep breaths. SpO2 97% on 2 L, BP 124/76, HR 104. DDx? Most likely? Why? Rx? Opioid? Which? Dose? Interval? 15 minutes and two doses later: pain 4/10, RR 12, eyes closing between sentences. More opioid? Why/why not? Ketamine? Why/why not?

Considerations and pitfalls AI draft

DDx. Referred pain from CO2 and peritoneal stretch irritating the diaphragm (phrenic, C3-5); incisional pain; less often subdiaphragmatic blood, pneumothorax or capnothorax. Cardiac ischemia is unlikely at 23 with no risk factors.
Most likely. Referred diaphragmatic pain after pneumoperitoneum. Normal SpO2 and stable vitals argue against pneumothorax, but listen to both sides before reassuring.
Rx. Reassure (it fades over 24-48 hours), sit her up, heat to the shoulder. Acetaminophen and ketorolac are already in; do not redose either early. Then titrated opioid.
Opioid. Hydromorphone 0.2-0.4 mg IV every 10 minutes (its peak effect takes 10-20 minutes, so faster dosing stacks), or fentanyl 25 mcg every 5 minutes, titrated to pain and sedation, with RR and sedation checked between doses.
More?. Not now. Increasing sedation is the warning sign; more opioid at this point buys respiratory depression more than relief. Pain 4/10 with drowsiness is a reasonable place to stop and reassess in 15-30 minutes. Chasing a pain score of zero with stacked doses is the error.
Ketamine. Not needed. She is responding to standard multimodal therapy. Low-dose ketamine (0.1-0.3 mg/kg) is a reasonable add-on for opioid-tolerant patients or pain that does not respond to opioids, at the cost of dysphoria and more nausea in a patient who is already nauseated.

4. Tachycardia at 90 minutes

90 minutes in: HR 122, BP 94/56, T 38.4°C. DDx? First check? Abdomen soft, port sites dry, SpO2 97% on 2 L, point-of-care Hgb 12.5. 1.6 L crystalloid in the OR. Rx? Esmolol? Fluid? Which? How much? 1 L later: HR 94, BP 114/70. More fluid? Why/why not?

Considerations and pitfalls AI draft

DDx. Tachycardia with a soft BP after surgery needs a cause, not a beta blocker or watchful waiting. Hypovolemia is the front runner: fever, an overnight fast, vomiting, and insensible loss. Bleeding (mesoappendix, port site, abdominal wall vessel), pain, sepsis, and pulmonary embolism (she takes a combined oral contraceptive) belong on the list.
First check. Examine her: abdomen (distension, worsening pain), port sites, repeat vitals and SpO2; review intraoperative fluids and EBL; a point-of-care Hgb. A soft abdomen, dry port sites, and normal SpO2 make bleeding and embolism less likely. An early Hgb can lag acute bleeding until fluid redistributes, so a near-normal value does not rule it out; if the picture does not settle, repeat it. A learner who goes straight to CT angiography for PE without examining her has skipped the basics.
Esmolol. No. The tachycardia is compensating for low volume and a soft BP; slowing it drops cardiac output and BP further. Treat the cause first.
Fluid. A balanced crystalloid bolus, 500-1000 mL, then reassess. She is young with normal heart and kidneys. Albumin and blood are not indicated with Hgb 12.5 and no sign of bleeding.
More fluid. Not automatically. She has responded; recheck vitals, start oral fluids, and give another bolus only if HR climbs or BP falls again. Tachycardia that persists after fluid, or new abdominal findings, calls the surgeon back to look for bleeding or another cause.

5. Going home

Three hours in: HR 86, BP 112/70, pain 3/10 at rest, nausea gone, sipping water, walked to the chair with help. Surgeon wants her home today. Agree? Why/why not? She has not voided. Discharge anyway? Why/why not? Home analgesia: which drugs? Doses? Opioid prescription? Why/why not? How many tablets? Getting dressed, she asks: "Can I take my birth control pill tonight?" What will you tell her?

Considerations and pitfalls AI draft

Home today. Reasonable. Same-day discharge after uncomplicated laparoscopic appendectomy is common once she meets discharge criteria: stable vitals, awake and oriented, pain and nausea controlled on oral medication, walking, and a responsible adult to take her home and stay with her. The tachycardia resolved with fluid; if it recurs, she stays.
Voiding. Not mandatory for a low-risk patient: no spinal, no pelvic or urologic surgery, no history of retention. Discharge with instructions to return if she cannot void within 6-8 hours. Requiring every patient to void delays discharge without benefit.
Home analgesia. Scheduled acetaminophen (1 g every 6-8 hours, no more than 3-4 g a day) and an NSAID (ibuprofen 400-600 mg every 6 hours with food) for several days, with opioid only for breakthrough pain.
Opioid prescription. Small or none: for example up to 10 tablets of oxycodone 5 mg, with storage and disposal instructions. Many patients use few or none after this operation. A reflexive 30-tablet prescription is the error.
Birth control. Yes, keep taking it on schedule, but it may not protect her fully this week. Sugammadex binds progestogen, so a dose counts as missing pills: she should use a nonhormonal backup method (condoms) for the next 7 days. Telling her to stop the pill, or not mentioning the interaction, are both flags. The scheduled ibuprofen and acetaminophen do not interact with it.

Short stem

Unexpected difficult mask ventilation after induction in a bearded man for outpatient hernia repair

A 52 y.o., 5'10", 104 kg man is scheduled for elective outpatient laparoscopic bilateral inguinal hernia repair. He has a full beard. His wife says he snores loudly and sometimes stops breathing in his sleep. He had a knee arthroscopy under general anesthesia 12 years ago with "no problems" and has gained 25 kg since; those records are not available. He takes no medications and has no allergies. BP 132/82; HR 74; SpO2 96% on room air. Mallampati II, mouth opening three fingerbreadths, full dentition, thyromental distance three fingerbreadths, full neck extension, neck circumference 44 cm.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. An airway assessment that weighs mask ventilation as well as laryngoscopy; fasting status and aspiration risk; preoxygenation in a bearded, heavier patient; an induction and rescue plan set before any drug goes in.

1. Airway assessment

Airway plan for this man. Asleep induction or awake intubation? Why? Difficult laryngoscopy likely? Why/why not? Difficult mask ventilation likely? What tells you? Prior anesthetic 'with no problems': reassured? Why/why not? Further exam? What? Shave the beard before surgery? Why/why not? He declines to shave. Options? Video or direct laryngoscope for the first attempt? Why?

Considerations and pitfalls AI draft

Asleep vs awake. Asleep IV induction is a reasonable commit: elective, cooperative, no documented difficulty, Mallampati II with good mouth opening and neck extension. Awake intubation is favored when difficult ventilation is predicted together with difficult intubation, or when aspiration risk is high, apnea will be poorly tolerated, or front-of-neck rescue is expected to be hard; his predictors make awake intubation a defensible choice too. Either is defensible if reasoned; what matters is that the asleep plan comes with a stated rescue sequence. Choosing asleep without ever mentioning mask ventilation is the flag.
Laryngoscopy. Less likely but not excluded. Mallampati II, three fingerbreadths of mouth opening and thyromental distance, and full extension are reassuring; neck circumference 44 cm and probable OSA push the other way. No single bedside test predicts well, so the plan cannot rest on the exam.
Mask ventilation. Yes, a real risk. Beard, BMI about 33, loud snoring with witnessed apneas, male sex, and a thick neck are each classic predictors of difficult mask ventilation, and several together raise the risk substantially. A good laryngoscopy exam says little about mask ventilation. A learner who discusses only Mallampati and thyromental distance has missed the main hook.
Prior anesthetic. Weak reassurance. He is 25 kg heavier and may have developed OSA since; 'no problems' may mean a supraglottic airway with no one ever testing mask ventilation or laryngoscopy. Try to get the record if it can be found in time.
Further exam. Jaw protrusion (upper lip bite test), cervical range already noted, dentition, and palpation of the cricothyroid membrane. Also ask about daytime sleepiness.
Shave. It improves the mask seal, but it is his choice and not mandatory; offer it with the reason.
Declines. Water-soluble gel worked into the beard, a clear adhesive dressing over the beard and lower face, a two-hand mask hold from the start, oral and nasal airways at hand, and an early move to a supraglottic airway if the seal fails.
VL vs DL. Current guidance favors videolaryngoscopy as the first device where available because it improves first-pass success; direct laryngoscopy is acceptable in skilled hands. A hyperangulated blade needs a stylet. The point is the best chance on the first attempt, with a bougie ready.

2. Fasting and aspiration risk

Last solid food 10 p.m. last night; black coffee at 6 a.m.; surgery at 11 a.m. Proceed on schedule? Why/why not? He mentions heartburn after large meals, a few times a month, no medication, none today. Of concern? Premedicate? With what? Why? Rapid sequence induction? Why/why not? Cricoid pressure? Why/why not? Mask ventilation before the tube goes in: peak pressure limit? Why? Gastric tube after intubation? Why/why not?

Considerations and pitfalls AI draft

Proceed on schedule. Yes. More than 8 hours since solids, and black coffee without milk counts as a clear liquid, allowed up to 2 hours before. A learner who cancels for the coffee, or who does not ask about fasting at all, needs a nudge.
Heartburn. Occasional, untreated, asymptomatic today: a minor risk factor, not a reason to change the plan on its own. Daily symptoms, regurgitation, or symptoms lying flat would weigh more. Ask about GLP-1 agonists and other drugs that slow gastric emptying as routine; he takes none.
Premedicate. Not required. Routine H2 blockers, proton pump inhibitors, or antacids are not recommended for patients without a clear increase in aspiration risk; giving one here is harmless and defensible if reasoned.
RSI. Not required on these facts: he is fasted and his reflux is occasional and quiet today. A classic RSI skips mask ventilation, and in a patient predicted hard to mask, gentle ventilation before and between attempts matters. A modified RSI (relaxant right after the induction agent, gentle low-pressure mask ventilation) is also defensible given BMI 33 and some reflux. A learner who chooses a classic RSI should be asked what happens if the first attempt fails.
Cricoid pressure. Not here. Without an RSI indication it adds nothing, and it can worsen mask ventilation and the laryngoscopic view. Even when used, it is released if it hinders ventilation or intubation.
Peak pressure limit. Keep mask pressures at or below about 20 cmH2O where possible; above that, more gas passes the esophageal sphincters into the stomach, raising regurgitation risk and making ventilation harder. It is a target, not an absolute: if he cannot be oxygenated at 20, higher pressure is accepted while technique is fixed.
Gastric tube. Reasonable, and most would after any difficult mask ventilation: an orogastric tube decompresses a stomach inflated by mask ventilation and lowers the risk of a distended stomach in the laparoscopic field. For a lower-abdominal laparoscopy after easy masking it is optional. Remove before emergence.

3. Preoxygenation

Preoxygenation. Position? Why? FiO2? Fresh gas flow? End point? How long? Three minutes of tidal breathing on the face mask: EtO2 68%. Interpretation? Rx? EtO2 now 91%. Safe apnea time in him compared with a lean adult? Why? Nasal cannula O2? Start when? Flow? Why? CPAP during preoxygenation? Why/why not?

Considerations and pitfalls AI draft

Position. Head up 25-30 degrees or ramped (ear level with the sternal notch). Raises FRC, lengthens safe apnea time, and improves both mask ventilation and the laryngoscopic view.
FiO2, flow, end point. FiO2 1.0, fresh gas flow above his minute ventilation (10-15 L/min), tight seal. End point EtO2 of at least 90%. About 3 minutes of tidal breathing or 8 deep breaths over 60 seconds.
EtO2 68%. A leak, most likely around the beard, letting room air in. Check that the reservoir bag moves and the capnogram is square; fix the seal (two hands, gel, dressing, mask size) and keep going to 90% or more. Inducing at 68% throws away apnea time; doing so is the flag.
Safe apnea time. Shorter. Lower FRC and higher O2 consumption mean he desaturates sooner than a lean, well-preoxygenated adult (who may tolerate several minutes), and the fall is steep once SpO2 drops below about 90%.
Nasal cannula. Yes, for apneic oxygenation. Put the cannula on before induction, under the mask, so it is already in place: run it at a tolerable low flow (about 5 L/min) during preoxygenation and turn it up to 15 L/min once he is asleep, since 15 L/min is uncomfortable awake. High-flow nasal O2, started during preoxygenation and kept on through laryngoscopy, is an alternative where available. Watch that the tubing does not break a seal the beard has already made poor; recheck EtO2 after placing it. Cheap and lengthens time to desaturation, but it only works through a patent upper airway. Placing it only after the first failed attempt is the weak answer.
CPAP. 5-10 cmH2O during preoxygenation reduces atelectasis in heavier patients and is reasonable if the seal allows; PEEP carries into mask ventilation.

4. Induction plan

Induction agent? Dose? Dosed to what weight? Why? Relaxant: rocuronium or succinylcholine? Dose? Dosed to what weight? Give it right after the induction agent, or only after mask ventilation is confirmed? Why? Assume rocuronium 1.2 mg/kg. Sugammadex in the room? Dose for immediate reversal? Airway equipment open before induction? What? The cricothyroid membrane is hard to feel. Ultrasound it before induction? Why/why not?

Considerations and pitfalls AI draft

Agent and dose. Propofol is standard. Induction dose 1.5-2.5 mg/kg on lean body weight (about 70 kg for him), so roughly 100-170 mg, titrated. Total-weight dosing overshoots and drops BP. At BMI 33 the weights are close; the reasoning matters more than the number.
Relaxant. Either works. Rocuronium 0.6 mg/kg for routine intubation, 1.2 mg/kg for fast onset, dosed on ideal or lean body weight (about 70-73 kg), so roughly 45 mg or 85-90 mg. Succinylcholine 1-1.5 mg/kg on total body weight, about 100-150 mg. Some choose high-dose rocuronium here for fast, reliable conditions with sugammadex available.
Before or after mask check. Confirming mask ventilation before giving a relaxant is a common habit, not a requirement. A relaxant usually makes mask ventilation easier or leaves it unchanged; withholding it leaves you without the best conditions for mask, supraglottic airway, and laryngoscopy; and after an induction dose of propofol you cannot wake him before he desaturates. Current difficult airway guidance advises not delaying the relaxant to test the mask. A learner who says 'if I can't mask him I'll wake him up' should be asked how long the propofol lasts compared with his safe apnea time.
Sugammadex. In the room. For immediate reversal after rocuronium 1.2 mg/kg: 16 mg/kg on actual body weight (the label doses on actual weight), about 1,660 mg, roughly 17 mL from several vials, so it should be drawn up or immediately at hand, not 'somewhere in the department.' It reverses the block only, not the propofol and not an obstructed airway, so it is not a reliable rescue.
Equipment. Suction on; oral and nasal airways in several sizes; videolaryngoscope with stylet; bougie; second-generation supraglottic airway in his size (size 5) and one size down; difficult airway cart in the room; front-of-neck kit (10 blade scalpel, bougie, 6.0 cuffed tube); waveform capnography; a second experienced person reachable at once.
Ultrasound. Reasonable and increasingly recommended where an ultrasound and someone skilled with it are at hand. Marking the cricothyroid membrane (neck extended) takes a minute and makes front-of-neck access faster and more accurate if it is ever needed; palpation is unreliable in a thick neck. It is not yet universal practice, so skipping it is defensible; dismissing the impalpable membrane as irrelevant because the airway 'looks fine' is the flag.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Escalating mask technique after induction; the relaxant decision when masking is hard; limits on laryngoscopy and supraglottic airway attempts; recognizing cannot intubate, cannot oxygenate and performing front-of-neck access; what follows: disposition, anesthetic depth, documentation, the next anesthetic, and telling the patient.

1. After induction

Head up, EtO2 91%, nasal cannula O2 at 15 L/min. Propofol 170 mg. Assume no relaxant yet. One-hand mask: no chest rise, flat capnogram. SpO2 99%. Of concern? First moves? Jaw thrust, oral airway in: small irregular capnogram, Vt 120 mL at 30 cmH2O. Next? Two-hand mask. Bag or ventilator? Why? SpO2 93%. Call for help now, or wait? Why? Relaxant now? Why/why not? Agent? Dose in mg? Wake him up instead? Why/why not?

Considerations and pitfalls AI draft

Of concern. Yes, despite SpO2 99%. A flat capnogram means no ventilation; saturation lags and the clock has started. Being reassured by the oximeter is the flag.
First moves. Reposition (head extension, chin lift, jaw thrust), check the seal and the circuit (APL valve, leaks), oral airway sized from the corner of the mouth to the angle of the jaw, nasal airways. Consider whether he is light enough to have laryngospasm.
Vt 120 at 30. Still inadequate. Escalate to a two-hand hold (both thumbs and thenar eminences on the mask, fingers lifting the jaw), add nasal airways and PEEP. Pressures above about 20 cmH2O increasingly inflate the stomach, so technique, not pressure, is the fix.
Bag or ventilator. Either. Pressure control on the ventilator (for example 15-20 cmH2O with PEEP) lets the operator keep both hands on the mask; an assistant squeezing the bag also works. The goal is two hands on the mask.
Help. Now. Difficult mask ventilation in a patient with predictors is reason enough; calling once SpO2 is falling fast is late.
Relaxant. Most would give it now. Once basic technique has been optimized and failed, relaxation usually improves mask ventilation (removes laryngeal and chest wall tone and any laryngospasm) and gives the best conditions for a supraglottic airway or laryngoscopy. Rocuronium 1.2 mg/kg on ideal weight, about 90 mg, or succinylcholine 1.5 mg/kg on total weight, about 150 mg.
Wake him. Not realistic now. He will stay apneic for minutes after 170 mg of propofol, and at SpO2 93% and falling he will desaturate badly before spontaneous breathing returns; waking also does not guarantee an open airway. Waking becomes the right move once oxygenation is restored, not before.

2. Laryngoscopy

Rocuronium 90 mg. Two-hand mask now moves 300 mL; SpO2 92%. Laryngoscopy now, or mask first? Why? First look, video laryngoscope with a standard-geometry blade: epiglottis only; tube will not pass. SpO2 88%. Next? Second attempt: what do you change? Hyperangulated blade, stylet, laryngeal manipulation: arytenoids only. Bougie? Why/why not? Bougie passes, tube railroaded. Flat capnogram, no chest rise. Interpretation? Rx? Two-hand mask; SpO2 85%. Third attempt? Why/why not? An experienced colleague has arrived and makes the third attempt; it fails. SpO2 82%. Next?

Considerations and pitfalls AI draft

Mask first. Mask first and let SpO2 climb while the nasal O2 runs; going in at 92% in a predicted-difficult patient leaves little margin. Do not mask indefinitely if SpO2 is not rising; that is a signal to move to a device that will oxygenate.
After attempt 1. Stop, back to two-hand mask, and tell the room this is a difficult airway. A second attempt only if something will be different.
What changes. Position (more ramp, head extension), blade (hyperangulated with a stylet), external laryngeal manipulation, adjunct (bougie), or operator. Repeating the same attempt is the error; each attempt adds edema and bleeding that make rescue harder.
Bougie. Reasonable with the arytenoids in view, aimed just anterior to them. Blind passage with an epiglottis-only view risks trauma. A straight bougie is hard to steer around a hyperangulated blade; an angled-tip or pre-shaped bougie, or sticking with the stylet, is the usual fix. Clicks and hold-up are not reliable confirmation.
Flat capnogram. Esophageal placement until proven otherwise ('no trace, wrong place'), with cardiac arrest and disconnection the other causes. Pull it and re-oxygenate by mask. Leaving it in while puzzling over breath sounds is the flag.
Third attempt. Defensible only with a real change and adequate oxygenation, and best made by the most experienced person present. DAS guidance caps tracheal intubation at three attempts, with a fourth and final attempt allowed only by a more experienced colleague; ASA guidance says to limit attempts without setting a number. Declaring failure earlier is right if nothing new is available or oxygenation is poor; at 82% after three failed attempts, a fourth is not justified.
Next. Failed intubation: declare it aloud and move to a supraglottic airway. More laryngoscopy is the classic slide toward CICO.

3. Ventilation after failed laryngoscopy

Supraglottic airway? Why/why not? Device? Size? Second-generation device, size 5, in: Vt 80 mL, large leak at 20 cmH2O. SpO2 79%. Next? Reseated, then size 4: no capnogram. SpO2 72%, HR 52. Next? Final two-hand mask with oral and nasal airways, full block: no chest rise. SpO2 65%. Interpretation? Next? Sugammadex now? Why/why not? HR 46. Atropine? Why/why not?

Considerations and pitfalls AI draft

Supraglottic airway. Yes, the next step after failed intubation. Second-generation device (higher seal pressure, gastric drain), size 5 for his weight. DAS allows up to three insertion attempts, each with a change (size, device type, or depth of block), with face-mask oxygenation between attempts; moving on before three is right if he is desaturating.
Leak and low Vt. Reseat, check depth and cuff pressure, confirm full block, change size or device. Each change counts toward the limit; at 79% there is little time.
After the second device fails. One last optimized face-mask attempt: two people, oral and nasal airways, full block. Not more laryngoscopy.
Interpretation. Cannot intubate, cannot oxygenate. Declare it aloud and open the front-of-neck kit now. Repeated attempts have likely added edema and bleeding, which is why rescue devices are failing. Delaying the neck for one more attempt from above is the classic fatal error.
Sugammadex. Not now. It reverses the rocuronium but not the propofol, the obstruction, or the swelling; spontaneous breathing through this airway is unlikely to oxygenate him, and a full block is wanted for the neck. Giving it is acceptable only if it delays nothing.
Atropine. Hypoxic bradycardia heralds arrest; the treatment is oxygen through the neck. Atropine may be given but will not fix it. If he loses a pulse, start CPR and continue the airway.

4. Front-of-neck access

Assume the membrane was not marked and you cannot feel it. Scalpel or needle? Why? Position? Incision: where? Then? Tube size? Tube in; capnogram trace; SpO2 climbs to 94%, HR 88. What else confirms placement? Propofol 170 mg was 12 minutes ago, nothing since. Anything to give now? Why? Surgery: proceed or cancel? Why? Disposition? The cricothyroidotomy tube: keep it, or convert? When?

Considerations and pitfalls AI draft

Scalpel or needle. Scalpel-bougie-tube cricothyroidotomy is the default. Needle cricothyroidotomy with jet ventilation fails more often, needs equipment that may not be at hand, and depends on an upper airway open enough to exhale.
Position. Neck fully extended (shoulder roll or drop the head), full block, O2 continued from above by mask or supraglottic airway.
Incision. Vertical midline skin incision about 8-10 cm, caudad to cephalad (from near the sternal notch toward the chin); current DAS guidance makes the vertical incision the default whenever the membrane is impalpable or was not marked. Blunt finger dissection with both hands to find the larynx and the membrane; then a transverse stab through the membrane with a 10 blade, rotate the blade 90 degrees with the sharp edge caudad, slide the bougie along it into the trachea, railroad the tube, inflate the cuff.
Tube. 6.0 cuffed tracheal tube.
Confirmation. Sustained waveform capnography first; bilateral chest rise and breath sounds; avoid passing too far (a short distance takes it endobronchial); chest X-ray for position, pneumothorax, and subcutaneous emphysema; control bleeding.
Anesthetic depth. Yes. He has been paralyzed on a single induction dose for 12 minutes and may be aware. Give more hypnotic now (propofol bolus and infusion, or volatile through the new airway), plus an opioid for the incision. Forgetting depth during the crisis is common and the reason to ask about recall later.
Surgery. Cancel. It is elective, the airway is a surgical one, and the upper airway is traumatized. Reschedule after a definitive airway plan.
Disposition. ICU, sedated and ventilated through the cricothyroidotomy tube, secured well because losing it would be a second crisis; further relaxant only if needed to protect the tube, with sedation adequate whenever he is paralyzed; neuro assessment once sedation lightens.
Convert. A cricothyroidotomy is a temporary airway. Convert to a formal tracheostomy by ENT or surgery once he is stable, as a planned daytime OR case (usually the next day, traditionally within about 72 hours), not as an overnight emergency. The traditional reason is subglottic stenosis; the evidence for a strict deadline is weak, and conversion carries its own risk, but a formal tracheostomy is also easier to secure and change while the upper airway heals.

5. Two days later

ENT converted the cricothyroidotomy to a tracheostomy in the OR yesterday. Today he is awake on a trach collar, following commands, writing notes. Neuro exam: looking for what? Anything to ask him about the event? What? Your note on the airway: what goes in it? Airway alert: letter? Registry? Bracelet? Which? Why? He writes: 'What happened? Did someone make a mistake?' What will you tell him? He is decannulated before discharge. Two months later the stoma has healed and he is back for the hernia repair. Airway plan? Why?

Considerations and pitfalls AI draft

Neuro exam. Signs of hypoxic injury after a few minutes of severe desaturation with bradycardia: confusion, memory gaps, focal deficits, visual change. Most patients recover fully from a brief episode; a new deficit needs imaging and neurology.
Ask him. Awareness. Structured questions: last thing remembered before sleep, first thing on waking, anything in between, dreams, worst part. He was paralyzed for a stretch on a single induction dose. If he reports recall, acknowledge it, believe him, and offer psychological follow-up.
Note. Factual and specific: mask ventilation and what improved it, laryngoscopes and blades used, best view, number of attempts and by whom, adjuncts, supraglottic devices and sizes, the front-of-neck technique and tube, SpO2 nadir and HR, drugs and timing, what worked, and a recommendation for future anesthetics. No blame or speculation. File a safety report through the usual system.
Alert. Difficult airway guidance (ASA and DAS) asks that the patient be told in person and in writing. The expected minimum is a letter to him and his primary care doctor describing what happened and what worked, and an alert in the medical record. A national registry or a medical alert bracelet is strongly encouraged because it reaches a team at another hospital before induction. Relying on the chart alert alone is the weak answer.
What to tell him. Plain and honest: his airway proved very difficult to ventilate and intubate despite an exam that looked reassuring; the team went through the standard backup steps; when none worked, an emergency opening in the neck delivered oxygen, and that is why he has a tracheostomy. Say you are sorry for what he went through. On 'a mistake': do not defend or blame; say the event will be reviewed and he will be told what is learned. Tell him what it means for future anesthetics and give him the letter.
Next anesthetic. Awake tracheal intubation (flexible bronchoscope or awake videolaryngoscopy) with topical anesthesia and minimal sedation, after checking the healed airway for stenosis; or a regional or local technique if the surgeon can do the repair that way. The asleep plan he had last time is no longer defensible. Also: refer him for a sleep study if not yet done.

Long stem

Symptomatic carotid stenosis with coronary disease for carotid endarterectomy

A 72 y.o., 84 kg, 5'9" man is scheduled for left carotid endarterectomy.

HPITen days ago, two episodes a day apart of right hand weakness and trouble finding words, each lasting about 20 minutes and resolving fully. Seen by neurology after the first episode. Walks his dog two miles every morning and climbs two flights of stairs without chest pain or dyspnea. Home BP readings run 140s to 150s systolic.

PMHCoronary artery disease: drug-eluting stent to the LAD 3 years ago for exertional angina; no angina since. Hypertension for 20 years. Type 2 diabetes, HbA1c 7.4%. Right-handed. No prior anesthetic problems. No known drug allergies.

MEDSAspirin 81 mg daily. Clopidogrel 75 mg daily, started by neurology 10 days ago. Atorvastatin 80 mg daily. Metoprolol succinate 50 mg daily. Lisinopril 20 mg daily. Amlodipine 10 mg daily. Metformin 1000 mg twice daily. This morning he took all of them except metformin with a sip of water.

PHYS EXAMHR 58; BP 182/96 right arm, 154/82 left arm; RR 14; SpO2 97% on room air. Anxious. Neurologic exam normal. Left carotid bruit. Mallampati 2, full dentition, normal neck mobility. Lungs clear. Regular rhythm, no murmur.

CT ANGIOGRAMLeft internal carotid artery 85% stenosis at the bifurcation with ulcerated plaque. Right internal carotid artery occluded. No intracranial hemorrhage.

ECGSinus bradycardia at 58. Left ventricular hypertrophy by voltage. No Q waves or ST changes.

ECHO (1 year ago)LVEF 55%. Mild concentric LV hypertrophy. No significant valve disease.

LABSHgb 13.6 g/dL; platelets 228 K/uL; INR 1.0; Na+ 138 mEq/L; K+ 4.4 mEq/L; creatinine 1.2 mg/dL; glucose 168 mg/dL.

OR ARRIVALTwo 18 g peripheral IVs. Standard monitors. EEG monitoring is available. The surgeon shunts selectively and wants to start within the hour.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Deciding to proceed in a recently symptomatic patient with coronary disease and a high BP; choosing anesthetic technique and arterial line site; holding cerebral perfusion through induction, dissection, and clamping; reading and acting on an EEG change; shunt, glucose, and reperfusion BP decisions.

1. Before induction

Proceed today? Why/why not? Stress test first? Why/why not? Lower his BP in holding? Why/why not? To what? Operate on clopidogrel? Why/why not? Anesthetic technique: GA? Cervical plexus block with sedation? Which? Why? If regional: superficial or deep cervical plexus? Which? Why? Arterial line: before or after induction? Why? Which arm? Why?

Considerations and pitfalls AI draft

Proceed today. Most would proceed. Recent TIAs from a high-grade, ulcerated stenosis carry a high early stroke risk, and the benefit of endarterectomy is greatest when it is done within about two weeks of symptoms. Delay itself is a risk. A learner who postpones for routine optimization without weighing that stroke risk has the trade-off backwards.
Stress test. Most would not. Carotid endarterectomy is an elevated-risk operation, but he has known, previously treated coronary disease, no angina, and better than 4 METs of functional capacity (two miles of walking, two flights of stairs). Stress testing is indicated only when the result would change management on its own merits; here it would only delay a time-sensitive operation. Ordering one reflexively because he has a stent is the flag.
BP in holding. Recheck after he settles and use the right-arm reading (see arm choice below). His usual systolic is 140s to 150s; 182/96 is above that but not a reason to cancel a symptomatic carotid case. If treated, small titrated doses only, aiming back toward his usual range, not toward normal. With the right ICA occluded, flow to the brain is pressure-dependent and a large preoperative drop risks hypoperfusion. Aggressive lowering to 120s is unsafe here.
Operate on clopidogrel. Proceeding is defensible and common. Neurology started it for recent TIAs; stopping it this morning does nothing for bleeding today, because its platelet effect lasts 5-7 days, so the only way to operate off it is to delay surgery and lose both the added stroke protection and time in the two-week window. The cost is more neck bleeding and hematoma, so meticulous hemostasis, protamine at closure, and close neck checks afterward matter. Practice varies; some surgeons operate on aspirin alone. Aspirin continues either way. Stopping both drugs is the flag.
GA vs regional. Either is defensible. Regional (superficial or intermediate cervical plexus block plus surgeon's local infiltration, light sedation) gives the best neuro monitor there is, the awake patient, and avoids induction and emergence swings; it needs a cooperative patient who can lie still with drapes over his face, and a plan to convert. GA gives a still field, airway control, and control of CO2, with neuro monitoring by EEG or other surrogates. Neither has shown a difference in stroke or death. A learner who picks either without addressing how they will monitor the brain during the clamp has not finished the answer.
Superficial vs deep plexus. Superficial or intermediate. The deep block is placed near the vertebral artery and transverse processes, a deep, noncompressible site, so most apply the same caution on clopidogrel as for other deep blocks and neuraxial (clopidogrel stopped 5-7 days). Superficial or intermediate cervical plexus blocks are subcutaneous or just deep to the investing fascia, compressible, and acceptable on clopidogrel. The deep block also carries phrenic nerve block, vertebral artery injection, and intrathecal or epidural spread. A learner who chooses a deep block without mentioning the clopidogrel is the flag.
Arterial line timing and arm. Before induction, in the right arm. Induction and laryngoscopy swing BP both ways in a hypertensive patient on an ACE inhibitor, and the operative hemisphere depends on that pressure. A 28 mmHg difference between arms points to left subclavian stenosis, so the left arm reads falsely low; the higher-reading arm is closer to aortic pressure. A learner who places it in the left arm and then chases a falsely low number will run the brain at a higher pressure than they think, or treat a low reading that is not real.

2. Induction and maintenance

Assume GA. Right radial arterial line in. BP goal through induction? Induction agent? Dose? Laryngoscopy: BP 208/112, HR 98. Rx? Dose? Ten minutes later, during positioning: BP 82/44, HR 56. Possible causes? Rx? Phenylephrine? Ephedrine? Which? Why? Maintenance: volatile? TIVA? Which? Why?

Considerations and pitfalls AI draft

BP goal. Within about 20% of his baseline: roughly SBP 120-180 with a MAP of at least 80-90, aiming for the upper part of that range because the right ICA is occluded. Both ends matter: hypotension risks cerebral and myocardial ischemia; surges risk myocardial ischemia and bleeding.
Induction agent. A titrated, hemodynamically stable induction: propofol 1-1.5 mg/kg (about 80-125 mg) given slowly, or etomidate 0.2-0.3 mg/kg (about 17-25 mg), with an opioid (fentanyl or remifentanil) to blunt laryngoscopy and a vasopressor drawn up. Rocuronium for relaxation. A full propofol dose given as a bolus in a 72-year-old on lisinopril is the classic setup for the drop that follows.
Laryngoscopy surge. Treat quickly with short-acting drugs and deepen the anesthetic: esmolol 0.5 mg/kg (about 40 mg), more opioid or propofol, small labetalol doses (5-10 mg). Avoid long-acting agents that will add to the post-stimulation hypotension that follows in a few minutes. The surge raises myocardial oxygen demand in a man with a coronary stent; leaving it untreated is the flag.
Hypotension causes. Most likely: induction drugs plus the lull between laryngoscopy and incision, on top of lisinopril and amlodipine taken this morning and metoprolol blunting the heart rate response. Also check anesthetic depth, a kinked or damped arterial line, and volume status. Myocardial ischemia belongs on the list in a coronary patient; look at the ST segments.
Rx for 82/44; phenylephrine vs ephedrine. Lighten the anesthetic and give a vasopressor now: phenylephrine 50-100 mcg boluses, then an infusion if needed; ephedrine 5-10 mg is reasonable with HR 56. A modest fluid bolus helps but will not fix ACE-inhibitor vasodilation alone. Vasopressin in small doses (1-2 units) if hypotension is refractory to phenylephrine, a known pattern with ACE inhibitors. MAP 60 is not acceptable for this brain; the goal is back to his baseline range.
Maintenance. Either, if it suits the monitor. Volatile at or below about 1 MAC (many aim for 0.5-0.75 MAC with an opioid infusion) or propofol-remifentanil TIVA both allow an interpretable EEG; the requirement is a steady anesthetic depth, especially around the clamp, so that an EEG change means ischemia and not a drug change. If SSEPs are used, keep volatile low or use TIVA. Fast emergence for an early neuro exam favors short-acting agents.

3. Dissection and clamping

Cerebral monitoring for the clamp: EEG? Stump pressure? Cerebral oximetry? Which? Why? During dissection: HR 38, BP 76/40. Cause? Rx? Dose? It recurs twice more over five minutes. Next? Heparin before the clamp: dose? Target BP during the clamp? Why? Target PaCO2? Why?

Considerations and pitfalls AI draft

Cerebral monitoring. Under GA, EEG is a common choice: continuous, sensitive to cortical ischemia, and fast. Stump pressure (back pressure from the ICA after clamping, often under 40-50 mmHg taken as low) is cheap but a single, imperfect number. Cerebral oximetry (a relative drop of more than about 20% is commonly used) is easy but has poor specificity. SSEPs are an option. None matches an awake patient's exam. Choosing no cerebral monitoring with a selective shunting surgeon and an occluded right ICA is the flag.
Cause. Carotid sinus baroreceptor reflex from manipulation at the bifurcation: increased vagal tone and reduced sympathetic output. Also check the obvious: depth, a damped line, bleeding.
Rx and dose. Tell the surgeon to stop manipulating; it usually resolves at once. If it does not, or BP stays low: glycopyrrolate 0.2-0.4 mg or atropine 0.4-1 mg IV, plus a vasopressor for the BP. Atropine is faster; glycopyrrolate causes less tachycardia, which matters in a coronary patient.
Recurs. Ask the surgeon to infiltrate the carotid sinus with local anesthetic (1% lidocaine, a few mL) to block the reflex. Avoid blind repeated anticholinergic dosing that leaves him tachycardic later. Pre-treating with an anticholinergic is an option if it keeps happening.
Heparin dose. Commonly a fixed 5000 units or about 75-100 units/kg (about 6300-8400 units at 84 kg), given a few minutes before the clamp so it has circulated. Practice varies by surgeon. Many check an ACT before clamping (often aiming for about 250 seconds or about twice baseline); some surgeons do not. Nobody clamps without a documented dose given through a running line.
BP during the clamp. His baseline to about 20% above it: roughly SBP 150-180, MAP about 100-110. With the left ICA clamped and the right ICA occluded, the left hemisphere depends on collateral flow through the circle of Willis, which is pressure-dependent. Phenylephrine is the usual tool. The cost is more myocardial work in a coronary patient, so watch the ST segments; blind escalation to very high pressures is not the answer either.
PaCO2. Normocapnia, PaCO2 about 35-40. Hypocapnia constricts cerebral vessels and cuts collateral flow. Hypercapnia dilates vessels in normal brain and can steal flow away from maximally dilated ischemic territory, and it raises sympathetic tone. Deliberate hyper- or hypoventilation to 'help' the brain is the flag.

4. Ninety seconds after the clamp

EEG in use. Ninety seconds after the clamp: EEG shows loss of fast activity and reduced amplitude over the left hemisphere. BP 134/70. Of concern? Rx? Drug? Two minutes later, EEG unchanged at SBP 172. Shunt? Why/why not? Shunt in; EEG back to baseline within a minute. Glucose 196. Rx? Target? Endarterectomy done, shunt out, clamp off. BP target now? Why? Protamine? Why/why not? Dose?

Considerations and pitfalls AI draft

Of concern. A new unilateral EEG change on the clamped side right after clamping is cerebral ischemia until proven otherwise. Confirm nothing else changed: no new anesthetic bolus, no change in volatile, no drop in BP or CO2, no artifact. A global (both sides) change suggests a drug or physiologic cause instead.
Rx and drug. Tell the surgeon at once, raise BP about 20% above baseline (SBP into the 170s, MAP about 110) with phenylephrine, confirm normocapnia and oxygenation. 134/70 is below his usual range, and with an occluded right ICA collateral flow will not keep up at that pressure.
Shunt. Most would shunt now. An EEG change that persists despite BP augmentation means collateral flow is not enough; the surgeon should shunt. Waiting longer increases the risk of infarction. Shunts carry their own risks (embolism, intimal injury, a cramped field), which is why this surgeon shunts selectively, but those do not outweigh a persistent ischemic EEG. A learner who keeps raising the BP without asking for a shunt has missed the point of the monitor.
Glucose 196. Treat: IV insulin (a bolus of a few units, or an infusion), with a target of about 140-180 mg/dL and recheck in 30-60 minutes. Hyperglycemia worsens ischemic brain injury, and this brain was just ischemic. Avoid hypoglycemia, which is at least as harmful; aiming for normal glucose under anesthesia is not the goal.
BP after clamp release. Bring it back down to his baseline range, roughly SBP 120-160, and stop the phenylephrine augmentation. The left hemisphere now has full flow through a vessel whose bed has adapted to low pressure for months; contralateral occlusion and a high-grade stenosis raise the risk of hyperperfusion (headache, seizures, intracerebral hemorrhage). Leaving the clamp-period pressure in place is the flag.
Protamine. Reasonable and often used, especially on clopidogrel: it reduces neck bleeding and hematoma without a clear increase in stroke. It is the surgeon's call with you. Dose from the heparin still circulating: about 1 mg per 100 units, reduced for time since dosing; many give 25-50 mg in partial reversal here. Give slowly over 10 minutes and watch for hypotension; ask about prior protamine, NPH insulin, or fish allergy, which raise reaction risk.

B. POST-OPERATIVE CARE

Teaching focus. Emergence and the first neuro exam; post-endarterectomy BP lability in both directions; the airway threat of a neck hematoma; BP targets and a new headache on the first postoperative day; resuming home medications, discharge readiness, and a disclosure conversation.

1. End of the case

Skin closing. Extubate deep or awake? Why? Assume awake. Anything to smooth emergence? What? Dose? Bucking on the tube: BP 206/104, HR 94. Rx? Dose? Extubated. Neuro exam: in the OR or in PACU? Why? Exam intact. After PACU: ICU? Step-down? Floor? Which? Why?

Considerations and pitfalls AI draft

Deep vs awake. Awake is the usual choice: it gives an immediate neuro exam and a protected airway in a man with a fresh neck incision. Deep extubation (or exchange to an LMA) avoids coughing and BP surges but delays the exam and leaves an unprotected airway with possible early neck swelling. Either can be defended; a learner who extubates deep without a plan for the early neuro exam has missed why this case is different.
Smoothing emergence. Remifentanil continued at a low rate (0.03-0.05 mcg/kg/min) through emergence, IV lidocaine 1-1.5 mg/kg, or dexmedetomidine 0.2-0.5 mcg/kg over 10 minutes. Have esmolol or labetalol ready. Full reversal of neuromuscular blockade with a quantitative twitch check before extubation (sugammadex 2 mg/kg, about 170 mg, after rocuronium at moderate block).
BP 206/104. Treat now: esmolol 0.5 mg/kg (about 40 mg) or labetalol 5-10 mg boluses, more remifentanil or lidocaine, and extubate promptly once criteria are met. The fresh arteriotomy and the newly reperfused hemisphere are both at risk at this pressure, and so is the myocardium. Hydralazine is too slow and unpredictable here.
Where to examine. In the OR, before leaving, while the field and the surgeon are still there. A deficit present at emergence after CEA is assumed to be a technical problem at the endarterectomy site (thrombosis, intimal flap, embolus) until proven otherwise, and most surgeons re-explore at once or get an on-table duplex rather than wait for CT. Finding it only in PACU loses time.
Disposition. A monitored bed overnight (step-down or ICU, depending on the hospital) with arterial or frequent BP monitoring, hourly neuro and neck checks, and BP orders with explicit limits: BP lability, neck hematoma, and new deficits cluster in the first hours. ICU if he needs vasoactive infusions. An unmonitored floor bed after an intraoperative EEG change in a man with an occluded contralateral ICA is the flag.

2. PACU, 45 minutes

PACU, 45 minutes: awake, comfortable, BP 186/94, HR 82. Treat? Why/why not? Possible causes? Agent: labetalol? Hydralazine? Nicardipine? Which? Dose? Target SBP? Why that number? Assume labetalol: 20 mg in total. An hour later: BP 84/46, HR 48, alert, no chest pain. DDx? Rx? Target? ECG unchanged from preop. Troponin? Why/why not?

Considerations and pitfalls AI draft

Treat. Most would treat. Hypertension after CEA is common, and SBP above about 160 is the usual treatment threshold (lower if he develops headache or a neuro symptom). It risks neck bleeding, myocardial ischemia, and hyperperfusion injury, and his contralateral occlusion makes hyperperfusion more likely.
Possible causes. Surgical disruption of the carotid sinus baroreceptor (loss of the reflex brake), pain, bladder distension, hypoxia or hypercarbia, emergence agitation, and his chronic hypertension with the lisinopril taken this morning wearing off. Check the treatable ones before reaching only for drugs.
Agent and dose. Labetalol 5-10 mg IV every 5-10 minutes is the common first choice (rate and pressure control, fast). Nicardipine infusion (5 mg/h, titrated by 2.5 mg/h every 5-15 minutes to 15 mg/h) is smooth and predictable if it persists. Hydralazine 5-10 mg acts slowly and unpredictably and causes reflex tachycardia, a poor fit in coronary disease. With HR 82 and a beta-blocker already on board, watch for bradycardia with labetalol.
Target SBP. Roughly 120-160, near his usual home range. High enough to perfuse the brain (he still has an occluded right ICA) and the coronaries, low enough to protect the repair and avoid hyperperfusion. Pushing to the low 100s is overtreatment.
DDx for 84/46, HR 48. DDx: overshoot from labetalol on top of metoprolol; baroreceptor hypersensitivity (the carotid sinus now sees full pulsatile pressure after the plaque is gone, a common cause of hypotension after CEA); hypovolemia; bleeding, including into the neck; myocardial ischemia or infarction; residual effects of his morning antihypertensives. Look at the neck.
Rx and target. Stop further antihypertensives, lay him flat, give a fluid bolus, and treat the low HR and BP: glycopyrrolate 0.2-0.4 mg or ephedrine 5-10 mg fit the bradycardia; phenylephrine boluses or a low-dose infusion if needed. Target back to his baseline range, SBP above about 120. This patient's brain depends on pressure more than most; accepting 84/46 because he is alert is the flag.
Troponin. Reasonable to check. Myocardial injury after noncardiac surgery is common in vascular patients, is usually silent (beta-blocked, post-anesthetic, no chest pain), and hypotension with bradycardia in a man with a coronary stent is exactly the setup. An unchanged ECG does not exclude it. Many centers check troponin routinely after vascular surgery in patients with coronary disease.

3. Neck swelling

BP back to 138/74 on low-dose phenylephrine. Hour 3: left neck swelling, muffled voice, RR 26, SpO2 94% on 2 L. Immediate priorities? Open the wound at the bedside? Why/why not? Swelling increasing; new inspiratory stridor. Next? Skin and platysma opened at the bedside; clot evacuated; stridor eases. To the OR. Airway: awake fiberoptic? Video laryngoscopy after induction? Inhalational induction? Which? Why? Neuromuscular blocker: when? Why? Suture-line bleed repaired. Extubate at the end? Why/why not? What do you check first?

Considerations and pitfalls AI draft

Immediate priorities. Expanding neck hematoma after CEA is an airway emergency, made more likely by clopidogrel and the recent hypertension. Sit him up, 100% oxygen, call the surgeon and the OR now, keep BP in his target range without surges, get airway equipment (video laryngoscope, fiberoptic, surgical airway kit) and help to the bedside. Do not send him for imaging.
Open at the bedside. Not yet while he is oxygenating and the surgeon and OR are minutes away, but the threshold is low. Open it at the bedside as soon as there is airway compromise that will not wait for the OR: stridor, worsening respiratory distress, or falling SpO2. Waiting for the OR while he obstructs is the error.
Stridor. Open the wound now (cut skin sutures and the platysma layer, evacuate the clot), whoever is at the bedside. That relieves the external compression. The airway may not fully open, because venous and lymphatic congestion leave the pharynx and larynx edematous even after the clot is out.
Airway plan. With the clot decompressed and him oxygenating, an approach that keeps spontaneous ventilation is the safer default: awake fiberoptic with topical local if he can cooperate, or a carefully titrated induction with video laryngoscopy and the surgeon scrubbed and ready for a surgical airway. Inhalational induction is slow with an obstructed airway and can lose the airway at depth. Expect edema and distorted anatomy; have a smaller tube ready. Any of these can be defended if the backup plan is stated.
Neuromuscular blocker timing. Not before you know you can ventilate or have the tube in, as a general rule: paralysis removes his own muscle tone holding the airway open, and mask ventilation may fail with an edematous pharynx. If induction with video laryngoscopy is chosen and the airway looks favorable, giving rocuronium with sugammadex available is a defensible variation; the danger is a reflex full RSI without a front-of-neck plan.
Extubate at the end; what to check. Not automatically. Airway edema often persists after the hematoma is evacuated. Check for a cuff leak first and look at the airway (direct or fiberoptic view of edema) before deciding; if the leak is absent or the tissues are swollen, keep him intubated with the head up and reassess in hours. Extubating with an exchange catheter and full difficult-airway backup is an option when the leak is present but the airway was difficult.

4. Postoperative day 1

Assume he was extubated at the end of the re-exploration. Phenylephrine off at 2 a.m.; a quiet night. POD 1, 7 a.m.: BP 164/84, HR 66, neuro exam intact, neck soft, eating breakfast. Target SBP today? Why? Home metoprolol and amlodipine this morning? Why/why not? 10 a.m.: new left-sided headache, frontal and behind the eye, throbbing, 6/10. BP 184/94, HR 70. Neuro exam unchanged. DDx? CT head now? Why/why not? Noncontrast CT: no hemorrhage, no edema. BP target now? Why? Agent? Dose? Headache Rx: acetaminophen? Ketorolac? Opioid? Which? Why? Seizure prophylaxis? Why/why not?

Considerations and pitfalls AI draft

Target SBP today. Roughly 120-160, as in PACU, and many would aim for the lower part of that range in him: a high-grade stenosis, a contralateral occlusion, long-standing hypertension, and labile BP after surgery all raise the risk of hyperperfusion. Not too low either: 84/46 yesterday was too low for this brain. 164 is just above that range; treating it is reasonable, starting with his own oral drugs. A learner who reads 164 as 'his baseline' without the post-CEA context, or who aims for the low 100s, has missed the target.
Home metoprolol and amlodipine. Most would give both. Stopping a chronic beta-blocker risks rebound tachycardia and ischemia in a coronary patient, and HR 66 allows it; yesterday's HR 48 after labetalol on top of metoprolol is a reason to watch the rate, not to stop it. Amlodipine restores his usual control smoothly. Lisinopril can reasonably wait another day after yesterday's hypotension; restarting it today is also defensible if BP stays up and creatinine and potassium are stable.
DDx. Most concerning: cerebral hyperperfusion (new headache on the operated side with hypertension, after opening a high-grade stenosis with a contralateral occlusion, most often in the first days to a week) and intracerebral hemorrhage, which hyperperfusion can progress to. Also ischemic stroke (less likely with an unchanged exam), hypertension alone, and ordinary causes: caffeine withdrawal, poor sleep, incision pain, a migraine history. Ask about prior headaches and caffeine. A learner who calls it a tension headache and gives acetaminophen without addressing the BP has missed the post-CEA context.
CT head. Most would get a noncontrast head CT now and call the surgeon: a new headache on the operated side with BP 184 after CEA needs hemorrhage excluded, because hemorrhage changes the BP target, the antiplatelet plan, and who else is involved. A normal CT does not exclude hyperperfusion, which is a clinical diagnosis. MRI shows edema better if symptoms persist or the exam changes; transcranial Doppler, where available, can show a large rise in middle cerebral artery velocity. Contrast imaging of the neck is for a changed exam, not for a headache with an intact exam.
BP target now. Lower it promptly but not abruptly: most would aim for SBP under about 140, and some lower (toward 120) once hyperperfusion seems likely, reached over an hour or so with titratable doses and close monitoring in a monitored bed. Avoid overshooting into hypotension; yesterday he dropped to 84/46 after 20 mg of labetalol. The permissive pressures used after an untreated acute ischemic stroke do not apply after revascularization.
Agent and dose. Labetalol and clonidine are commonly preferred because they lower BP without dilating cerebral vessels. Labetalol in small steps (5-10 mg IV every 10 minutes), given yesterday's response; clonidine 0.1-0.2 mg PO is an option, at the cost of sedation that clouds the neuro exam. Many avoid direct vasodilators (hydralazine, nitroglycerin, nitroprusside) because they dilate cerebral vessels and could worsen hyperperfusion; hydralazine is also slow, unpredictable, and causes reflex tachycardia. A nicardipine infusion is used in many centers for smooth titration, though some avoid calcium channel blockers on the same cerebral-vasodilation argument; it is defensible with that trade-off stated. Practice varies.
Headache Rx. Acetaminophen 1 g first; treating the BP often treats the headache. Avoid ketorolac and other NSAIDs: he is on aspirin and clopidogrel, bled into his neck last night, and hemorrhage is the complication being guarded against. Opioids sparingly if at all: sedation blurs the neuro exam, and hypoventilation raises PaCO2 and cerebral blood flow.
Seizure prophylaxis. Most would not give it routinely; seizures occur in a minority of patients with hyperperfusion and prophylaxis is not standard. Control BP, keep frequent neuro checks, and treat a seizure if one occurs (a benzodiazepine, then a loading dose of levetiracetam or similar) with repeat imaging. A learner who starts an antiseizure drug but leaves the BP at 184 has the priorities backwards.

5. Postoperative day 2

POD 2. No headache since yesterday evening. BP 132-150 systolic on metoprolol and amlodipine; no labetalol since yesterday afternoon. Neck soft, eating, walking the hall. Creatinine 1.2. Lisinopril still held. Restart? Why/why not? BP target over the next few weeks? Why? Metformin: restart today? Why/why not? Clopidogrel at discharge? Why/why not? Home today? Why/why not? His wife asks you: 'Why did he have to go back to surgery that night? Did something go wrong?' What will you tell her?

Considerations and pitfalls AI draft

Restart lisinopril. Most would restart it now or within a day: he is eating, BP is above his low range, creatinine is at baseline, and he has hypertension, a coronary stent, and diabetes. Check potassium; a lower starting dose with BP checks is reasonable after the post-op hypotension. Leaving it off indefinitely undertreats him.
BP target over the next few weeks. Gradually toward under about 130/80 for secondary stroke prevention, his coronary disease, and his diabetes. In the first couple of weeks the priority is avoiding both hypertension (hyperperfusion can still appear after discharge) and hypotension, so a home cuff and a clear number to call about (for example SBP above about 160, or a headache) matter more than reaching 130 this week.
Metformin. Most would restart it today: he is eating, hemodynamically stable, and his renal function is at baseline (creatinine 1.2, eGFR about 60). The preoperative CT angiogram is not a reason to keep holding it: current ACR contrast guidance does not call for stopping metformin around IV contrast, or rechecking renal function afterward, in a patient with eGFR 30 or above and no AKI; holding is reserved for AKI or eGFR under 30. Holding it another 48 hours 'for the contrast' is an outdated reflex. Restarting it in the face of AKI or ongoing hypotension, or discharging him on sliding-scale insulin alone, are the flags.
Clopidogrel at discharge. Continue aspirin long term. Clopidogrel is defensible either way, decided with neurology and the surgeon: continuing it for a short course after his recent TIAs and then dropping to a single agent, or stopping it now that the source plaque is removed and after last night's hematoma. His stent is 3 years old and does not require dual therapy. Stopping all antiplatelet therapy is the flag.
Home today. Defensible either way. Usual discharge after CEA is POD 1-2 once BP is in range on oral drugs, the neck is soft, and he is eating, voiding, and walking. After a re-exploration and yesterday's headache, many would keep him one more day to see BP hold on his oral regimen with no rescue doses. If he goes: home BP checks with a number to call above, early follow-up, and the warning signs. Discharging him while BP still needs IV doses, or without a BP plan, is the flag.
What to tell her. Honest and specific, in plain words: bleeding from the artery repair collected in his neck and pressed on his airway; that is a known risk of this operation and more likely on the blood thinners he needs to prevent a stroke. It was recognized, the pressure was relieved, he went back to the operating room where the bleeding point was repaired and his breathing was kept safe, and his neck is now soft. Acknowledge that it was frightening. Tell her what to watch for at home and to call or come in at once: neck swelling, trouble breathing or swallowing, a severe headache, weakness or trouble speaking. The team reviews every return to the OR and she can ask the surgeon as well. A learner who says flatly that nothing went wrong, or who guesses at whose fault it was, has overstepped.

Long stem

Open infrarenal AAA repair with aortic cross-clamp physiology in a high-risk vasculopath

A 71 y.o., 82 kg, 5'10" man is scheduled for elective open repair of a 6.2 cm infrarenal abdominal aortic aneurysm.

HPIAneurysm found on surveillance ultrasound and enlarging over the past year. Two flights of stairs bring on dyspnea and occasional chest tightness relieved by rest. A 60 pack-year smoker, still smoking. Chronic productive cough.

PMHCoronary artery disease with an inferior myocardial infarction three years ago, treated with a drug-eluting stent to the RCA; stable angina since. COPD. Longstanding, poorly adherent hypertension. Type 2 diabetes. Chronic kidney disease.

MEDSAspirin 81 mg; clopidogrel, last dose seven days ago per surgical instruction; metoprolol; lisinopril (held this morning); atorvastatin; metformin (held); tiotropium and albuterol prn.

PHYS EXAMHR 82; BP 186/98; RR 18; SpO2 92% on room air; T 36.6°C. Prolonged expiratory phase with scattered expiratory wheezes; pulsatile epigastric mass; distal pulses intact.

ECGSinus rhythm; old inferior Q waves; left ventricular hypertrophy with baseline lateral ST-T flattening.

ECHO / IMAGINGCT: 6.2 cm infrarenal AAA with an adequate neck below the renal arteries; heavy aortoiliac calcification. Echo: LVEF 40%, inferior hypokinesis, mild diastolic dysfunction, no significant valvular lesion.

PFT / ABGFEV1 1.6 L (52% predicted); FEV1/FVC 0.60. ABG room air: pH 7.37; PaCO2 47; PaO2 63; HCO3 27 mEq/L.

LABSHgb 12.4 g/dL; platelets 205 K/uL; INR 1.1; creatinine 1.7 mg/dL (eGFR ~44); K+ 4.2 mEq/L; glucose 172 mg/dL.

OR ARRIVALThoracic epidural placed at T8-9, test dose negative, not yet dosed. Radial arterial line planned. Two 16 g peripheral IVs; cell salvage set up and 4 units crossmatched.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Monitoring and access matched to a low-EF, fixed-coronary patient; an induction that protects the coronary supply; recognizing and treating the afterload and ischemic load of aortic cross-clamping; renal preservation during the clamp; and surviving the declamp.

1. Monitoring and induction

Arterial line before or after induction? Why? BP 186/98 on the table. Induce at that pressure, or treat it first? With what? PA catheter, TEE, or neither? Which? Why? Induction agent and dose? Target HR and MAP through laryngoscopy? BP 78/44, HR 98, 1 mm ST depression in II after induction. Rx — phenylephrine, ephedrine, or volume? Which? Dose? BP 105/60, HR 90, ST depression still 1 mm. Next? Nitroglycerin now — yes/no? Why?

Considerations and pitfalls AI draft

Arterial line. Before induction: labile hypertension, a fixed RCA lesion, and an EF of 40% — beat-to-beat pressure through the riskiest minutes. After induction is worth challenging.
186/98. Do not induce into a 186 systolic with a sympathetic surge to follow: small doses of labetalol or a nitroglycerin infusion and a moment; but the bigger hazard is the fall after induction, so the induction itself must be slow.
PA vs TEE vs neither. Commit to this ventricle: TEE for volume and wall motion under clamp and declamp is the strongest pick; a PA catheter for filling pressures and CO is defensible; neither, with arterial waveform and judgment, is thin for an open aorta at EF 40%. A reflexive 'PA catheter because it's an aorta' without reasoning is a flag.
Induction. Etomidate 0.2 mg/kg or propofol in 20-30 mg increments, fentanyl 2-3 mcg/kg, lidocaine, rocuronium 0.6-1 mg/kg; esmolol 20-30 mg ready for the laryngoscopy surge.
Targets. HR 60-75, MAP 75-95; coronary perfusion pressure is diastolic minus LVEDP, so hypotension and tachycardia together are the worst combination for the RCA territory.
78/44 with ST depression. Phenylephrine 100-200 mcg (or vasopressin 1-2 U) to restore diastolic pressure now, a modest 250 mL bolus, back off the anesthetic; ephedrine raises rate. Target MAP ≥75. 'Give fluid' alone deserves a probe.
Persistent ST. Rate down to the 60s (esmolol if pressure allows), check oxygenation and hemoglobin, TEE for new wall-motion abnormality; nitroglycerin 10-20 mcg/min only now that pressure tolerates it. Treat the ischemia, not just the number.

2. Aortic cross-clamp

TEE probe in. The surgeon is ready to clamp the infrarenal aorta. What do you do in the two minutes before it goes on? Clamp on: BP 214/108, ST depression 2 mm in V5-6. Why is this happening? Rx — nitroglycerin, nicardipine, clevidipine, or deepen the anesthetic? Which? Why? Starting dose? Target BP? BP 150/80, ST depression 1 mm. Good enough? TEE now shows a dilated, poorly contracting LV; cardiac index 1.4. What is the problem? Rx — inotrope, or back off the vasodilator? Which? Dose?

Considerations and pitfalls AI draft

Before the clamp. Deepen the anesthetic, have a vasodilator running or in hand, heparin given and confirmed, tell the surgeon you are ready, blood in the room; a learner caught flat-footed by a predictable event is the teaching point.
214/108 with ST. The abrupt afterload rise on an EF of 40% and fixed coronaries drives wall stress and subendocardial ischemia; pressure and ischemia are one problem.
Agent. Nitroglycerin 0.5-2 mcg/kg/min is favored when ischemia dominates (venodilation lowers wall stress); clevidipine 1-2 mg/h or nicardipine 5 mg/h for pure afterload control; deepening as an adjunct. Commit and defend; overshooting into hypotension on a fixed coronary is the pitfall.
Target. MAP 80-95, systolic 120-140 — a number, not 'lower it'.
150/80, 1 mm. ST depression that persists means the LV is still stressed; continue titrating and reassess on TEE.
CI 1.4 with a dilated LV. This is pump failure under afterload, not over-vasodilation (the LV would be small and empty); inotrope — dobutamine 3-5 mcg/kg/min or milrinone 0.25-0.375 mcg/kg/min — while keeping the vasodilator on; stopping the vasodilator would raise afterload on a failing ventricle. Reaching for an inotrope while the LV is underfilled would be the opposite error; TEE settles it.

3. Renal preservation during the clamp

Clamp on 40 minutes; urine output zero for 30 minutes. Why does this worry you in him? Causes? TEE: LV now adequately filled, CI 2.4, MAP 78. Fluid bolus — yes/no? Mannitol — yes/no? Why? Furosemide? Fenoldopam? Surgeon says 'protect the kidneys.' What do you actually do? MAP target during the clamp? Clamp at 70 minutes; surgeon says 20 more. What changes in your plan?

Considerations and pitfalls AI draft

Why him. Even an infrarenal clamp drops renal blood flow ~40% by neurohumoral mechanisms; baseline creatinine 1.7 leaves no margin; AKI after open AAA is common and carries mortality.
Causes. Reduced renal perfusion from the clamp plus hypovolemia or low output, embolization of aortic debris to the renal arteries, a clamp placed higher than intended; not simply 'the clamp'.
Fluid. No — the TEE says he is filled; fluid into a full, low-EF ventricle buys pulmonary edema, not urine.
Mannitol / loop / fenoldopam. No drug has been shown to prevent AKI here; mannitol before the clamp is common practice with weak evidence; furosemide makes urine without protecting nephrons; fenoldopam is unproven. A learner who promises mannitol 'protects the kidney' should be probed.
'Protect the kidneys'. Euvolemia confirmed, MAP ≥75-80 (higher than a generic 65 for a chronically hypertensive kidney), avoid nephrotoxins, and ask the surgeon to limit clamp time; the ritual is not the substance.
70 minutes. Rising ischemic burden to kidneys, gut, and legs; expect a bigger declamp hit — volume ahead, pressor ready, calcium and bicarbonate available, ask for a staged release. A learner unmoved by 70 minutes is under-concerned.

4. Declamping

Surgeon ready to release the clamp. What do you want done in the minute before? How do you want the clamp released? Clamp off: BP 62/38, EtCO2 up from 32 to 44, ST depression returns. What is happening? Rx — volume, pressor, or ask for the clamp back? In what order? Pressor — which? Dose? BP 70/40 after 500 mL and pressor. Reclamp — partial or full? ABG: pH 7.22, K+ 5.6, lactate 5.1. Calcium — dose? Bicarbonate — yes/no? Why? BP 95/60 ten minutes later. What are you watching for next?

Considerations and pitfalls AI draft

Before release. Volume loaded to a full LV on TEE, vasodilators off, anesthetic lightened, pressor and calcium in the line, blood checked; ask for gradual, one-limb-at-a-time release. Letting a fully clamped aorta open into an empty tank is the lesson.
What is happening. Declamp hypotension: central hypovolemia into a dilated lower body, reactive hyperemia, and washout of acid, potassium, and vasodilating metabolites; EtCO2 rises because CO2 returns from the reperfused tissues. Naming the mechanism of this event is reasoning, not recall.
Rx order. Volume first (crystalloid/colloid/blood already hanging), pressor to bridge — phenylephrine 100-200 mcg or norepinephrine 8-16 mcg boluses then an infusion, and ask for partial reclamping if it does not respond within a minute or two. A reflexive escalating pressor without refilling is a flag.
Reclamp. Yes at 70/40 despite volume and pressor: partial or single-limb reclamp, refill, release again slowly.
Calcium / bicarbonate. Calcium chloride 500 mg-1 g for the ionized drop and to protect the myocardium from K+ 5.6; bicarbonate is not routine — the acidosis clears with perfusion; 50 mEq is defensible for pH <7.2 with hemodynamic compromise. Want reasoning, not reflex.
Potassium. Calcium, hyperventilate briefly, insulin 10 U with dextrose if it climbs; recheck in 15 min.
After. A second dip as more limbs are released, bleeding at the anastomoses, urine output, distal pulses, and the ST segments — the ischemic ventricle just took another hit.

B. POST-OPERATIVE CARE

Teaching focus. Extubation judgment in a marginal-reserve patient after a large aortic case; postoperative acute kidney injury on a chronic baseline; distinguishing surgical bleeding from coagulopathy after massive transfusion; postoperative myocardial ischemia and the antiplatelet dilemma; and recognizing bowel ischemia with honest disclosure.

1. Extubation decision

Case done at 6 hours: EBL 2.5 L, 4 units PRBC given, norepinephrine 0.05 mcg/kg/min, temp 35.4, epidural dosed and working. Extubate in the OR? Why/why not? What has to be true first? 35.4 — what does it do to him? Warm him how, and to what? He is 36.2 an hour later and extubated. 20 min on: RR 32, shallow, PaCO2 58, pH 7.28 on 40%. Interpretation? First fix? NIV — yes/no? PaCO2 66, pH 7.22, drowsy. Reintubate? Why/why not? The epidural — does it help or hurt you now?

Considerations and pitfalls AI draft

Extubate or not. The case, pressor need, hypothermia, and COPD argue for a period of ventilation; a working epidural argues you can extubate once warm and stable. Either is defensible if the conditions are named and met; extubating cold on a pressor is the flag.
Preconditions. Temp ≥36, hemoglobin and coagulation acceptable, hemodynamics stable on minimal support, quantitative TOF >0.9, PaCO2 near his baseline of 47, analgesia for deep breathing.
35.4. Coagulopathy (platelet and enzyme dysfunction), shivering that multiplies oxygen demand on an ischemic heart, slowed drug clearance; forced-air warming, warmed fluids, target ≥36.
Rising CO2. COPD plus splinting and residual opioid/anesthetic; sit up, bronchodilator, check the epidural level, suction; a short NIV trial is reasonable.
Reintubate. Yes at 66 and drowsy; NIV has failed and he is tiring; delaying an obviously failing patient is the error.
Epidural. Help — thoracic analgesia enables cough and reduces splinting; the hazard is sympathectomy on a pressor-dependent patient — run a dilute solution and accept a slightly higher norepinephrine rate rather than turning it off.

2. Postoperative oliguria

POD 0, ICU, reintubated: urine 10 mL/hr for 3 hours, creatinine 2.6 from 1.7. What is your first check at the bedside? Foley flushes freely. Pre-renal or intrinsic — how do you tell? What do you send? FENa 3%, muddy brown casts. Dx? Fluid challenge — yes/no? How much? He is 3 L positive from the OR, CVP 14. More fluid? Diuretic? Dopamine? Neither? Why? Does he need dialysis now? Why/why not? K+ 6.1, peaked T waves. Rx in order? Doses?

Considerations and pitfalls AI draft

First check. The Foley and the bladder; then volume status and the pressure; a blocked catheter is the cheap miss.
Pre-renal vs ATN. Urine sodium and FENa (unreliable after diuretics), sediment, the clamp time and the hypotensive episodes; reason rather than jump to a diuretic.
Muddy casts, FENa 3%. ATN after 90 minutes of clamp, declamp hypotension, and 2.5 L of blood loss on a CKD baseline.
Fluid. No — 3 L positive, CVP 14, EF 40%: more fluid buys pulmonary edema; endless fluid in an oliguric cardiac-limited patient is the pitfall. A single 250 mL challenge with a defined endpoint is the most that is defensible.
Diuretic / dopamine. Furosemide 40-80 mg may manage volume but does not convert or shorten AKI; 'renal-dose' dopamine is not supported — a learner who reaches for it should be probed.
RRT. Refractory hyperkalemia, acidosis, volume overload with respiratory compromise, uremic complications; not the creatinine number itself.
K+ 6.1 with T waves. Calcium chloride 1 g (or gluconate 3 g) first, then insulin 10 U with 50 mL D50, albuterol 10-20 mg nebulized, bicarbonate if acidotic, and a nephrology call for dialysis since he is anuric.

3. Postoperative hemorrhage

POD 0, two hours later: 400 mL/hr from the drain, BP 88/50, HR 118, abdomen firm and distending. Surgical bleeding or coagulopathy — which do you think, and what tells you? What do you send? INR 1.8, platelets 78, fibrinogen 120, temp 35.2. Interpretation? Products — which first? Targets? Bladder pressure 24 mmHg. What does that mean? Temp 35.2, pH 7.24, still 400 mL/hr after products. What else has to change? Re-explore now, or keep correcting labs? Why? BP 70/40. What do you set up for the OR?

Considerations and pitfalls AI draft

Surgical vs coagulopathic. Brisk output with a firm distending abdomen at 400 mL/hr points surgical until proven otherwise; diffuse ooze with deranged labs points coagulopathic — after 4 units and hypothermia it is often both. Underplaying it is the flag.
Send. CBC, INR/PTT, fibrinogen, TEG/ROTEM, ionized calcium, ABG, T&C for more units.
Labs. Dilutional and consumptive coagulopathy compounded by hypothermia; fibrinogen first — cryoprecipitate 10 units or fibrinogen concentrate 3-4 g to >150-200; platelets to >100 while bleeding; plasma to INR <1.5; calcium to ionized >1.1; TXA 1 g if not already given.
Bladder pressure 24. Intra-abdominal hypertension heading toward compartment syndrome; it explains the oliguria and the pressure; decompression is a surgical decision that needs to be made now.
Cold and acidotic. Rewarm aggressively and restore perfusion — the lethal triad perpetuates the coagulopathy; a learner who only orders products misses half the problem.
Re-exploration. A firm abdomen, bladder pressure 24, and ongoing output despite correction is a surgical bleed and a compartment problem — the OR, now; correcting labs endlessly while he exsanguinates is the error.
Setup. Massive transfusion protocol activated, rapid infuser, blood in the room, calcium and pressor infusions, TEE, product ratios 1:1:1 until the TEG guides.

4. Postoperative myocardial ischemia

Re-explored overnight for an anastomotic bleeder, extubated POD 1 afternoon. POD 1 evening: chest pressure, HR 104, BP 150/85, new ST depression V4-6, troponin 2.1 and rising. Type 1 or type 2 MI? What tells you? Hgb 7.8. Transfuse? Target? Beta-blocker now — yes/no? Dose? Heparin — yes/no? Why? Restart clopidogrel now, or hold? Why? Two hours later: SpO2 88% on 6 L, crackles, BP 160/90. Dx? Rx? Nitroglycerin — dose? Cath lab — yes/no? What tips you?

Considerations and pitfalls AI draft

Type 1 vs 2. A rising troponin with anemia, tachycardia, pain, and hypertension in the highest-risk window is most often demand (type 2); ST depression rather than elevation and no ongoing pain after demand is fixed support that; a stent event stays on the list. Want the reasoning, not the label.
Hgb 7.8. Transfuse to ≥8-9 in active ischemia; anemia is the correctable supply problem.
Beta-blocker. Yes once volume and bleeding are controlled: metoprolol 2.5-5 mg IV in increments to a rate in the 70s; beta-blockade into hypovolemia or a bleeding patient is the flag.
Heparin. No, 12 hours after a bleed that needed re-exploration; the rebleeding risk outweighs the benefit for a probable demand event.
Clopidogrel. He is on aspirin; the stent is 3 years old, so thrombosis risk off clopidogrel is low, and he re-bled 12 hours ago — hold for now, revisit in 24-48 h once hemostasis is secure. Naming the competing risks and committing is the point; 'balancing the consultants' is not.
Pulmonary edema. Ischemic LV dysfunction with hypertension: sit up, oxygen and CPAP, nitroglycerin 20-50 mcg/min titrated, furosemide 40 mg IV if not hypovolemic, treat the ischemia; flooding or over-diuresing without regard to the ventricle is the lesson.
Cath. Ongoing pain or ischemic ECG changes after demand is corrected, cardiogenic shock, or evolving ST elevation; the tension is the bleeding risk of antiplatelet loading — cardiology at the bedside now.

5. Bowel ischemia and disclosure

POD 2: lactate 6, pH 7.26, abdomen distended, bloody stool, WBC 22, HR 118. Dx until proven otherwise? Why after this operation? CT, sigmoidoscopy, or straight to the OR? What decides it? BP 84/48 on norepinephrine 0.1. Which now? Surgeon books an urgent laparotomy. What do you correct in the 30 minutes before incision? Induction plan for him now — agent? Dose? Epidural — use it, hold it, or pull it? Why? Intraop: K+ 5.9, pH 7.18, BP 70/40 on norepinephrine 0.3. Rx? His wife asks whether he will survive this. What will you tell her?

Considerations and pitfalls AI draft

Dx. Colonic ischemia after open aortic repair until proven otherwise; a rising lactate and bloody stool in this patient is an alarm.
Why. The inferior mesenteric artery is ligated or excluded with the sac and the collateral supply (marginal artery, hypogastrics) was compromised by hypotension, declamp, and heavy iliac calcification; reasoning about this operation's risk, not a recited list.
Studies vs OR. A stable patient can have CT angiography or bedside flexible sigmoidoscopy; an unstable patient with peritoneal signs goes to the OR; at 84/48 on a pressor with acidosis he is unstable — OR. Delaying source control is the error.
Before incision. Blood in the room, K+ corrected, calcium, bicarbonate for pH <7.2, antibiotics, arterial line and central access confirmed, norepinephrine and vasopressin running, TEE ready; a learner who treats this like a routine laparotomy misses the physiology.
Induction. Ketamine 0.5-1 mg/kg or etomidate 0.2 mg/kg with rocuronium 1.2 mg/kg as an RSI; a full propofol dose in septic shock on a pressor is a flag.
Epidural. Hold the infusion — sympathectomy in septic shock; keep the catheter if coagulation allows and use it after; pull it only when the INR and platelets say so.
K+ 5.9, pH 7.18, 70/40. Calcium chloride 1 g, insulin/dextrose, bicarbonate 50-100 mEq now, vasopressin 0.04 U/min added, epinephrine if the TEE shows a failing LV; expect worsening as dead bowel is reperfused or resected.
Wife. Honest: the bowel has lost its blood supply, that is a serious complication of this operation, the surgery is to remove the dead part and he is critically ill with a real chance of not surviving; the team will tell her everything as it happens; no false reassurance and no foreclosing hope.

Short stem

Femoral-popliteal bypass in a diabetic with a recent coronary stent and CKD

A 67 y.o., 5'9", 98 kg man is seen in pre-op clinic one week before a right common femoral to below-knee popliteal artery bypass with ipsilateral great saphenous vein, for rest pain and a nonhealing great-toe ulcer. Four months ago a drug-eluting stent was placed in his LAD for exertional angina; he has had no chest pain since, though foot pain keeps him from walking more than half a block. Medications: aspirin 81 mg, clopidogrel 75 mg, metoprolol succinate 50 mg, atorvastatin 80 mg, lisinopril 20 mg, metformin 1000 mg BID, empagliflozin 10 mg daily, and insulin glargine 40 units at bedtime. Angiography with runoff was done two days ago. P 64; BP 152/84; SpO2 96% on room air. HbA1c 8.9%; creatinine 2.1 mg/dL (1.8 before the angiogram); K 5.0; Hgb 11.2; platelets 210.

The considerations and pitfalls notes are AI-drafted and not yet reviewed by faculty. Use them to orient yourself, not as an answer key.

A. PRE-OPERATIVE EVALUATION

Teaching focus. Cardiac risk for an infrainguinal bypass when functional capacity cannot be judged; antiplatelet management four months after a DES and its bearing on neuraxial timing; a creatinine rise after contrast in a patient with CKD; the diabetic regimen, including an SGLT2 inhibitor that was not held.

1. Cardiac risk assessment

Cardiac risk for this operation — low or elevated? Why? Functional capacity — how do you judge it in him? Cath report from four months ago: LAD lesion stented, no other obstructive disease, EF 50%. Stress test now? Why/why not? Echo? Why/why not? NT-proBNP 480 pg/mL. Interpretation? Does it change your plan? Baseline troponin — send it? Why? Metoprolol — continue? Increase the dose? Why/why not? Atorvastatin — morning of surgery? Why?

Considerations and pitfalls AI draft

Risk. Elevated: three RCRI factors (ischemic heart disease, insulin-treated diabetes, creatinine above 2.0). Infrainguinal bypass is not an RCRI high-risk operation (that point is for suprainguinal vascular, intraperitoneal, intrathoracic), but vascular patients carry high event rates regardless. A learner who scores the surgery as low risk and stops there is missing the patient.
Functional capacity. Cannot be assessed: claudication and rest pain cap his exertion, so 'walks half a block' says nothing about his heart. Ask about other activities (stairs, yard work) and anginal equivalents; treat him as poor or unknown capacity.
Stress test. Not indicated. Test only if the result would change management, and he was fully studied and revascularized four months ago. A stress test that would only lead back to the cath lab and delay a limb-threatening operation adds risk, not safety.
Echo. Not indicated without new dyspnea, signs of heart failure, a murmur, or a change since the cath-derived EF of 50%.
NT-proBNP. Above the usual 300 pg/mL low-risk cutoff, but CKD raises it. An elevated value calls for a team discussion of next steps, but here stress testing or echo would not change management; it supports postoperative troponin surveillance and frank counseling about risk.
Baseline troponin. Reasonable in an elevated-risk patient with poor or unknown capacity; a preoperative value is what makes a postoperative rise interpretable, especially when CKD lifts the baseline.
Metoprolol. Continue; do not stop a chronic beta-blocker. Do not escalate the dose before surgery to chase a heart rate already at 64; new or aggressive beta-blockade just before surgery raises stroke and hypotension risk.
Statin. Continue, including the morning of surgery.

2. Antiplatelet therapy

Clopidogrel through surgery — continue or hold? Why? Proceed next week, or delay? Why/why not? Assume you hold it. How many days before surgery? Assume an epidural is planned. Does that change the number? Why? Aspirin — continue? Why/why not? The surgeon asks you to stop the aspirin too. Agree? Why/why not?

Considerations and pitfalls AI draft

Continue or hold. Both are defensible. Many vascular surgeons operate on DAPT for an infrainguinal bypass, accepting more oozing and giving up neuraxial. Holding clopidogrel lowers bleeding and opens neuraxial, at some stent-thrombosis risk. The learner should name what each path costs.
Proceed or delay. Rest pain with tissue loss is a time-sensitive, limb-threatening indication. For a DES placed for stable disease, elective surgery waits about 6 months, but time-sensitive surgery is reasonable after 3 months when delay carries real harm. Delaying two more months risks the limb; proceeding now, with the stent timing stated explicitly, is the stronger position; a learner who delays should name what the limb risks in the meantime.
Days off clopidogrel. 5 days for surgical bleeding alone.
Epidural. It can: neuraxial guidance calls for 5-7 days off clopidogrel, so 5 days sits at the edge of the window; 7 days removes the ambiguity. A learner who plans neuraxial at fewer than 5 days is the flag.
Aspirin. Continue through surgery after any PCI. Aspirin alone does not preclude neuraxial.
Surgeon's request. No; stopping both agents four months after a DES is the setup for stent thrombosis, a high-mortality event. Aspirin's added bleeding in a peripheral bypass is modest.

3. Renal function

Creatinine — interpretation? Workup before surgery? Repeat creatinine in four days: 1.9. Proceed? Why/why not? Lisinopril — morning of surgery? Why/why not? Metformin this week — continue or hold? Why? Intraoperative fluid — type? How much? The surgeon plans a completion angiogram. Agree? Why/why not? Ketorolac for postoperative pain? Why/why not?

Considerations and pitfalls AI draft

Interpretation. A 0.3 mg/dL rise within 48 hours of contrast is AKI on CKD (eGFR roughly 34 at creatinine 2.1). Probably contrast-associated, with ACE inhibitor, SGLT2 inhibitor, and volume status as contributors.
Workup. Do not cancel reflexively, but do not proceed blind: repeat creatinine and K, assess volume status, stop nephrotoxins. A stable or falling creatinine supports going ahead with a time-sensitive limb operation.
Creatinine 1.9. Recovering; proceed.
Lisinopril. Hold the morning of surgery here: recent AKI, K 5.0, and neuraxial-plus-sedation hypotension all argue for it. Continuing an ACE inhibitor is defensible in other patients; this one has reasons to hold.
Metformin. Hold now: AKI after contrast at an eGFR in the mid-30s; resume only once renal function is stable and he is eating after surgery. Hold the morning of surgery regardless. Separately, 2,000 mg/day is above the usual 1,000 mg/day ceiling for an eGFR of 30-44; flag the dose to his primary team.
Fluid. Balanced crystalloid to euvolemia; avoid both under-resuscitation and liberal excess. Normal saline in large volume adds a hyperchloremic acidosis he does not need.
Completion angiogram. A second contrast load within the week on recovering AKI. Reasonable to agree if it is needed to judge the graft, with minimal and dilute contrast; intraoperative duplex or Doppler is an alternative. The learner should raise the kidney, not just accept it.
Ketorolac. No; recent AKI on CKD is a contraindication to NSAIDs.

4. Diabetic regimen and the morning of surgery

Glargine the night before — dose? Empagliflozin — when does he stop it? Why? HbA1c — postpone for better control? Why/why not? Day of surgery, 06:00: he took empagliflozin yesterday. Glucose 262. Proceed? Why/why not? What do you check first? Beta-hydroxybutyrate 0.3 mmol/L, bicarbonate 24, anion gap 11. Proceed? Why/why not? Glucose — treat before incision? Why/why not? SC or IV insulin? Why? Target?

Considerations and pitfalls AI draft

Glargine. About 75-80% of the usual dose the night before (30-32 units); a full dose risks morning hypoglycemia while NPO, and skipping it risks hyperglycemia and ketosis.
Empagliflozin. Hold for 3 days before surgery (last dose four days before) because of euglycemic ketoacidosis with fasting and surgical stress.
HbA1c 8.9%. Raises infection and wound risk, but this is limb-threatening disease; delaying for months of better control is not reasonable. Optimize perioperatively instead.
Took it yesterday. Check ketones and acid-base before deciding: beta-hydroxybutyrate, bicarbonate, anion gap, and the patient (nausea, abdominal pain, tachypnea). Glucose does not settle it either way; SGLT2-associated ketoacidosis can occur at near-normal glucose.
Normal ketones and gap. Proceeding is reasonable for time-sensitive surgery, with ketone and gap checks intraop and postop and the drug held until he is eating normally. For purely elective surgery practice varies: some guidance allows proceeding with normal ketones and monitoring, and many centers would postpone. Canceling despite normal ketones and a threatened limb, or proceeding without checking, are both flags.
Treat 262. Yes; it is above the usual 180 mg/dL ceiling. A long case, sedation, and variable perfusion favor an IV insulin infusion with hourly checks over SC correction; small SC correction is acceptable only if it is followed closely.
Target. Roughly 140-180 mg/dL (100-180 acceptable); avoid hypoglycemia, which a sedated patient cannot report.

B. INTRA-OPERATIVE MANAGEMENT

Teaching focus. Neuraxial versus GA after a clopidogrel hold, and the timing of puncture against systemic heparin; heparin dosing and ACT endpoints; recognizing and treating intraoperative ischemia under sedation; glucose, potassium, and protamine at closure; loss of the graft signal in PACU, then a postoperative troponin rise, the timing of clopidogrel against the epidural catheter, and the conversation with the patient.

1. Anesthetic technique

Day of surgery. Assume clopidogrel was held, last dose 7 days ago; aspirin this morning; platelets 205, INR 1.0. Anesthetic — GA? Neuraxial? Which? Why? Assume neuraxial. Single-shot spinal or epidural catheter? Why? Interspace? Target sensory level? Assume a lumbar epidural, no blood on placement, at 07:30. The surgeon wants to give heparin at 08:10. Agree? Why/why not? Arterial line — yes/no? Why? ECG leads? Sedation — agent? Depth?

Considerations and pitfalls AI draft

Technique. Neuraxial and GA are both acceptable; neither has been shown to improve graft patency or survival. Neuraxial avoids airway instrumentation and gives postoperative analgesia; GA suits a patient who cannot lie still for hours or a case likely to extend. The learner should defend one.
Spinal vs catheter. An epidural (or CSE) catheter covers a 3-4 hour case that can run long and gives postoperative analgesia; a single-shot spinal risks wearing off before the vein harvest is closed.
Interspace and level. Lumbar interspace (L2-3 or L3-4); sensory level about T10 bilaterally to cover the groin incision, with lumbar and sacral roots covered for the thigh, knee, and vein harvest. Naming a thoracic insertion site, or confusing the interspace with the block height, is the error.
Heparin at 08:10. No; wait at least 1 hour after neuraxial puncture before IV heparin, so 08:30 or later. A traumatic placement would call for a conversation with the surgeon about delaying or proceeding with closer neuro checks.
Arterial line. Yes: CAD, recent stent, expected heparinization, beat-to-beat pressure under a neuraxial sympathectomy, and serial ACT, glucose, and Hgb draws.
ECG. Leads II and V5 with ST analysis.
Sedation. Light, titrated (low-dose propofol or dexmedetomidine) so he can still report chest pain and keep his airway; heavy sedation in a long case invites hypoventilation and loses the patient as an ischemia monitor.

2. Heparin before clamping

08:40, exposure complete, surgeon ready to clamp. Heparin — dose? In units? Target ACT? ACT 5 minutes after: 182, baseline 128. Clamp now? Why/why not? Rx? Recheck when? Clamps on. An hour later, ACT 205. Redose? Why/why not? Epidural infusion — start now, or wait? Why? Drug? Rate?

Considerations and pitfalls AI draft

Dose. 70-100 units/kg; at 98 kg, about 7,000-10,000 units (commonly 8,000).
Target ACT. Roughly 200-300 s for peripheral arterial clamping, with many aiming near 250 (about twice his baseline of 128); surgeon preferences vary. The learner should name a number and confirm it with the surgeon.
ACT 182. Subtherapeutic; redose 2,000-3,000 units and recheck in about 5 minutes before clamping. Clamping on an inadequate ACT invites graft and runoff thrombosis.
Recheck interval. Every 30-60 minutes while clamped, and before any clamp release.
ACT 205 at one hour. Drifting toward the floor of the range; a small redose (about 1,000-2,000 units) is reasonable while clamps stay on. Heparin clearance continues regardless of the epidural.
Epidural infusion. Start before the initial block regresses, with a dilute local anesthetic (e.g., bupivacaine 0.1% or ropivacaine 0.1-0.2%, with or without fentanyl 2 mcg/mL) at 6-10 mL/h; a catheter can be used and dosed while heparinized.

3. Hypotension and ST change at hour 2

Hour 2, clamps on, EBL 650 mL. BP 92/50, HR 104; 1.5 mm ST depression in V5. He says his chest feels tight. Of concern? Rx first? Phenylephrine? Volume? Which? Why? Hgb 8.4. Transfuse? Why/why not? Target? Assume phenylephrine and a unit of PRBC. BP 128/70, HR 98, ST still depressed. Esmolol? Nitroglycerin? Which? Why? Convert to GA? Why/why not? Troponin — when?

Considerations and pitfalls AI draft

Of concern. Demand ischemia: low diastolic pressure, tachycardia, and falling oxygen-carrying capacity in a man with a stented LAD. Symptomatic ST depression is ischemia until proven otherwise. Stent thrombosis enters the differential with ST elevation or refractory change.
Rx first. Restore coronary perfusion pressure now: phenylephrine for the neuraxial sympathectomy, volume and blood for the loss. Phenylephrine raises diastolic pressure and slows the rate; a pure fluid bolus alone is slower and may not fix the tone. Both are reasonable together.
Hgb 8.4. Transfuse: active ischemia with ongoing loss. A threshold of about 8 g/dL applies in stable CAD; with symptomatic ischemia, transfuse and aim higher (about 9-10). Withholding blood in active ischemia is the error.
Persistent ST with HR 98. Slow the heart: esmolol titrated now that pressure is restored. Nitroglycerin is reasonable for persistent ischemia with adequate pressure, but it can drop preload and pressure in a recently bled patient; rate control first.
Convert to GA. Not for ischemia alone; induction adds hemodynamic risk and an awake patient reporting symptoms is a monitor. Convert if he cannot protect his airway, cannot tolerate the procedure, or becomes unstable.
Troponin and ECG. 12-lead now and after the event; troponin postoperatively and at 24-48 hours against the baseline. The event and its timing go into the handoff.

4. Closure

Hour 3.5. Graft complete, Doppler signals at the foot. Glucose 268. Rx? Dose? K 5.6. Of concern? Rx? Total heparin 11,000 units, last dose 90 minutes ago; ACT 176. Surgeon asks for protamine. Agree? Why/why not? Dose? Rate?

Considerations and pitfalls AI draft

Glucose 268. Treat; above target despite the morning plan. If he is not already on an IV insulin infusion, start one (about 2-3 units/h, with or without a small bolus) with hourly checks; SC rapid-acting is less predictable with shifting perfusion and temperature in a long case. If he is already on one, increase the rate per protocol.
Dose. A starting rate of about 2-3 units/h, or a protocol increase if already running; hourly glucose and K while on the infusion, aiming for the 140-180 mg/dL range set this morning, and a transition plan to basal insulin for the floor.
K 5.6. A rise from 5.0 on CKD, with transfusion, recent ACE inhibitor, and limb ischemia-reperfusion as contributors; get an ECG and a blood gas. The insulin infusion lowers it; add dextrose if glucose falls. Calcium, bicarbonate, or binders only for ECG changes or a higher value. Note it for the AKI watch.
Protamine. A shared call with the surgeon; reversal reduces bleeding but risks early graft thrombosis, so many surgeons give partial or no reversal for a vein bypass. Either answer is fine if the learner names the trade.
Dose. Based on residual heparin, not the 11,000 given: with a heparin half-life of roughly 1-1.5 hours, perhaps 3,000-4,000 units remain, so about 30-40 mg (1 mg per 100 units remaining), then recheck the ACT. Dosing to the total given (110 mg) is a gross overdose and itself anticoagulant.
Rate. Slowly, no faster than about 5 mg/min, watching for hypotension; a reaction risk factor is prior protamine exposure, including NPH insulin (glargine contains none).

5. PACU and postoperative day 1

PACU, 90 minutes: right foot cool, the dorsalis pedis Doppler signal present at closure is gone. DDx? Next? Back to the OR. Anesthetic — use the epidural? Why/why not? More heparin with the catheter in — safe? Why? Thrombectomy, signal restored. POD 1, no chest pain: hs-troponin T 94 ng/L, pre-op 22; ECG unchanged. Of concern? Rx? SC heparin 5,000 units TID started this morning. Catheter out — when? Clopidogrel restart — when? He asks whether he had a heart attack. What will you tell him?

Considerations and pitfalls AI draft

DDx. Early graft thrombosis (technical problem, inadequate heparinization or reversal, low flow from hypotension), embolus, kinked or compressed graft, spasm; low cardiac output can mimic it. A loss of signal is a surgical emergency, not something to watch. A dense block can also mask ischemic pain and compartment syndrome, a reason the infusion was kept dilute.
Next. Call the surgeon now; check pressure, Hgb, ACT; restore perfusion pressure; heparin per the surgeon; back to the OR for exploration.
Epidural. Reasonable to dose the catheter for the re-exploration if he is stable and cooperative, the level is adequate, and neuro checks are documented; GA if not.
Heparin with the catheter in. Acceptable: IV heparin with an indwelling catheter is permitted when placement was more than an hour earlier; the priority becomes serial neuro checks and planned timing of removal.
Troponin 94. A rise well above his own baseline and the assay's 99th percentile. Paired with yesterday's chest tightness and ST depression during hypotension, tachycardia, and anemia, this is most consistent with a supply-demand (type 2) MI, not a silent injury of unclear meaning; stent thrombosis (type 4b) or plaque rupture (type 1) is less likely with no symptoms now and an unchanged ECG, but it is the thing to exclude. Either way it predicts higher mortality and is not to be dismissed as CKD.
Rx. Trend troponin, repeat ECG, correct the drivers (Hgb, rate, pressure, pain); continue aspirin and statin; cardiology input; echo if new dysfunction is suspected. Heparin infusion or a cath lab for asymptomatic injury is not standard.
Catheter and clopidogrel. The stent needs clopidogrel back promptly. Sequence it: remove the catheter 4-6 hours after a SC heparin dose, the next heparin dose can follow removal, and clopidogrel 75 mg without a load can resume immediately after removal; a catheter can stay in for 1-2 days on maintenance clopidogrel, but a loading dose means waiting about 6 hours after removal.
What to tell him. Honestly: yes, a small heart attack from strain on the heart during the low blood pressure and blood loss yesterday, not from a blocked stent as far as the tests show; his heart medicines continue, the cardiology team is following it, and it changes how closely his heart is followed after discharge. Neither 'no, nothing happened' nor alarm.