ACLS adapted to the operating room
Stem
A 61-year-old man, 88 kg, is having a laparoscopic sigmoid colectomy under general anesthesia with sevoflurane and a radial arterial line. Forty minutes in, the arterial trace goes flat, end-tidal CO2 falls from 35 to 9 mmHg, and the ECG shows a narrow-complex rhythm at 38 per minute. You cannot feel a carotid pulse.
Question
What is happening, and how do you run the next few minutes?
Ideal answer
HeadlineA witnessed, monitored PEA arrest: help and the code cart, I announce it, compressions start, epinephrine as soon as feasible.
- Surgeon stops and releases the pneumoperitoneum, a possible cause that cuts venous return; roles: compressions, airway, drugs, recorder.
- Compressions 100–120 per minute, at least 5 cm but not more than 6 cm deep,1 guided by the arterial line and capnography: end-tidal CO2 at least 10 mmHg, ideally 20 mmHg or more.2
- Volatile and suspect infusions off, 100% oxygen, my drugs may be the cause; tube position confirmed by capnography.
- Epinephrine 1 mg every 3–5 minutes, for a non-shockable rhythm; VF gets immediate defibrillation.2
- Causes in this room, during CPR: drug error, local anesthetic toxicity, anaphylaxis, hemorrhage, tension pneumothorax, gas embolism from insufflation, vagal reflex, hyperkalemia.
Watch for: arterial waveform and an abrupt end-tidal CO2 rise: return of circulation.
Breaking down the answer
- Witnessed, monitored arrest — VF or pulseless VT is shocked within seconds if pads are on, because early shocks succeed most; AHA 2025 prefers a single-shock strategy to stacked shocks, compressions resuming immediately after each.2 Graded: ACLS adapted to an intubated patient under my drugs.
- Monitors I already have — the arterial line shows compression quality and return of circulation without pausing, though adult data are inadequate for a specific diastolic target; end-tidal below 10 mmHg means fix compressions, and an abrupt rise suggests ROSC, with no absolute cutoff.2
- Ventilation — with a secured airway, 10 breaths per minute asynchronous with compressions;2 no hyperventilation, because raised intrathoracic pressure cuts venous return.
- OR-specific causes first — adaptability, not recited Hs and Ts: vaporizer and pumps for overdose; local anesthetic just injected (lipid emulsion 1.5 mL/kg); neuraxial placed (high spinal: epinephrine early and generously); surgeon near a great vessel; insufflation, cement or tourniquet release just happened.
- Vagal bradycardia and asystole — peritoneal traction, oculocardiac reflex or pneumoperitoneum: the surgeon stops, atropine 0.5–1 mg or glycopyrrolate, and quick escalation to epinephrine.
- Prone patient — AHA suggests turning supine first when that is safe; if not, I compress prone over the mid-thoracic spine between the scapulae. In an ILCOR review all 12 operating-room or ICU patients given prone CPR achieved ROSC.1
- ECPR — with a reversible cause and ECMO in the institution, I activate the team early in refractory arrest, not as a last resort; AHA supports ECLS for refractory arrest after cardiac surgery and in the cardiac intervention laboratory.3
Follow-up question
ROSC comes back after 6 minutes, but the rhythm deteriorates into a wide-complex bradycardia with peaked T waves. The resident now tells you he has end-stage renal disease, missed his last dialysis, and received succinylcholine at induction.
What do you do?
Follow-up answer
HeadlineHyperkalemic arrest: succinylcholine on missed dialysis. I say so to the room.
Calcium chloride 1 g IV repeated as needed, insulin 10 units with 25 g dextrose, sodium bicarbonate 50–100 mEq, hyperventilation, and CPR again if the pulse goes. AHA 2025 rates calcium, bicarbonate and insulin in hyperkalemic arrest as of uncertain effectiveness and advises against inhaled beta-agonists during arrest,3 but they are my fastest tools. Potassium sent; nephrology for emergent dialysis, compressions continued: hyperkalemic arrests can survive prolonged resuscitation. Once stable, finish or abort with the surgeon; post-arrest temperature control at 32–37.5 °C for at least 36 hours if he is not following commands, MAP at least 65 mmHg;4 family disclosure.
Pitfalls that cost points
- Stopping compressions for a pulse check when the arterial trace already answers the question.
- Giving amiodarone for a hyperkalemic or toxic rhythm without treating the cause.
Rapid-fire
Q: Why epinephrine early in non-shockable rhythms? A: It raises aortic diastolic and coronary perfusion pressure; earlier administration in PEA and asystole improves ROSC.2
Q: When do you give lidocaine or amiodarone? A: For shock-refractory VF or pVT after the second or third shock; amiodarone 300 mg then 150 mg, or lidocaine 1–1.5 mg/kg then 0.5–0.75 mg/kg.5
Q: Why is vasopressin gone from the algorithm? A: Alone or with epinephrine it offers no advantage over epinephrine, so it was removed to simplify the algorithm.2
Q: What end-tidal CO2 makes you stop? A: Never end-tidal alone; below 10 mmHg after 20 minutes of good CPR predicts very low survival and is one part of a multimodal team decision.2
Numbers to know
| Item | Value |
|---|---|
| Compression rate / depth | 100–120/min, 5–6 cm1 |
| CPR quality target | ETCO2 ≥ 10 mmHg, ideally ≥ 20 mmHg2 |
| Epinephrine | 1 mg IV every 3–5 min5 |
| Amiodarone / lidocaine | 300 mg then 150 mg / 1–1.5 then 0.5–0.75 mg/kg5 |
| Biphasic defibrillation | Manufacturer dose (eg, 120–200 J); maximum if unknown5 |
| Lipid emulsion 20% | 1.5 mL/kg bolus, 0.25 mL/kg/min |
Links
- Intraoperative cardiac arrest: care after return of circulation, hyperkalemia, Local anesthetic systemic toxicity, anaphylaxis, Maternal cardiac arrest and resuscitative hysterotomy
- Atlas: Monitor atlas: perioperative cardiac events
- AHA Guidelines for CPR and Emergency Cardiovascular Care (2025); ASRA checklist for local anesthetic systemic toxicity
Sources
- 1.Part 7: Adult Basic Life Support (2025 AHA Guidelines for CPR and ECC) · AHA, 2025 · cpr.heart.orgCompression depth and rate; prone CPR (ILCOR review of 20 OR/ICU patients).
- 2.Part 9: Adult Advanced Life Support (2025 AHA Guidelines for CPR and ECC) · AHA, 2025 · cpr.heart.org
- 3.Part 10: Adult and Pediatric Special Circumstances of Resuscitation (2025 AHA Guidelines) · AHA, 2025 · cpr.heart.org
- 4.Highlights of the 2025 AHA Guidelines for CPR and ECC · AHA, 2025 · cpr.heart.org
- 5.Adult Cardiac Arrest Algorithm (text description) · AHA, 2025 · cpr.heart.org
Facts on this page were checked against these sources on Oct 14, 2026. Guidelines change; confirm doses against current institutional protocols.