Electroconvulsive therapy
Stem
A 68-year-old woman, 70 kg, with severe major depression that has not responded to three medication trials, is scheduled for her first ECT session in the post-anesthesia care unit. She has hypertension and coronary disease with a drug-eluting stent placed two years ago, takes metoprolol and aspirin, and has no angina. Blood pressure is 152/88 and heart rate 58. She fasted overnight.
Question
What is your anesthetic plan for her ECT, and what do you expect to happen when the stimulus is delivered?
Ideal answer
HeadlineA brief, deep-enough anesthetic that does not suppress the seizure, full relaxation so she does not injure herself, and control of the predictable surge.
- Metoprolol taken, no recent ischemic event, plan agreed with psychiatry, because the surge threatens her coronary supply.
- Preoxygenate, then methohexital 1 mg/kg, 70 mg, because it is the standard agent and does not shorten the seizure; then succinylcholine 1 mg/kg, 70 mg, titrated to response in later sessions.1
- Cuff on one arm before the relaxant, so the psychiatrist sees the motor seizure; mask ventilation, hyperventilating to lower the seizure threshold, and a bite block.2
- At the stimulus, parasympathetic then sympathetic: bradycardia and sometimes a pause, then tachycardia and hypertension during the clonic phase.1
- Esmolol or labetalol ready, glycopyrrolate and atropine drawn up, and I ventilate until she breathes and watch her ECG for ischemia in recovery.
Breaking down the answer
- Methohexital first — the gold-standard induction agent; propofol and ketamine are alternatives when it is unavailable or contraindicated, and barbiturates are contraindicated in acute intermittent porphyria.1 Propofol significantly shortens the seizure, which can make treatment ineffective.2
- Enough succinylcholine — doses below 1 mg/kg increase injury during the seizure, and larger doses prolong apnea.1 Changes if: succinylcholine is contraindicated; rocuronium with sugammadex.2
- Hyperventilate deliberately — hypocapnia reduces cerebral blood flow.2 This is one of the few times hyperventilation helps the procedure.
- The size of both phases — the post-stimulus pause usually resolves within 5–10 seconds; in the clonic phase systolic pressure rises on average about 45 mmHg and heart rate about 50 beats per minute.1 That surge threatens her coronary supply.
- Know who should not have it — pheochromocytoma and raised intracranial pressure with mass effect are absolute contraindications; recent infarction, aneurysm and tumor call for heightened precaution.1 2
- Adequate seizure — a generalized seizure should last at least 20 seconds; seizure duration tends to fall over the treatment course.2
Follow-up question
The psychiatrist delivers the stimulus. There is no visible seizure in the cuffed arm, the monitor shows asystole, and eight seconds later there is still no QRS.
What do you do?
Follow-up answer
HeadlinePost-stimulus asystole, most likely an unopposed vagal response to a subconvulsive stimulus; chronic beta-blockade raises her risk.1 I say "asystole" to the room.
I check the pulse and give atropine or glycopyrrolate while I keep ventilating with oxygen. If there is no rhythm within seconds, chest compressions and ACLS; most of these pauses recover quickly. Once she has a perfusing rhythm, I discuss with the psychiatrist whether restimulation is wise today. For later sessions, glycopyrrolate pretreatment, and if she needs antihypertensive prophylaxis, I avoid a beta-blocker in pretreatment and use hydralazine instead.1 A 12-lead ECG and troponin if the arrest was prolonged.
Pitfalls that cost points
- Treating the hypertensive surge without preparing for the bradycardic phase that comes first.
- Under-dosing succinylcholine to "be gentle" and risking fractures or dental injury.
Rapid-fire
Q: Which induction agent can lengthen the seizure compared with methohexital? A: Ketamine, which may also improve seizure quality.1
Q: How does etomidate affect the seizure? A: It prolongs seizure duration and has little hemodynamic effect.2
Q: What doses of labetalol or esmolol blunt the surge? A: Labetalol 0.1–0.5 mg/kg or esmolol 0.5–1 mg/kg.1
Q: Is ECT safe in pregnancy? A: Yes, for refractory or life-threatening depression; I give aspiration prophylaxis, intubate, avoid hyperventilation, use glycopyrrolate rather than atropine, and monitor the fetus continuously after 23 weeks.1
Q: Who needs cardiac input before ECT? A: Patients with a pacemaker, coronary disease, prior infarction or other known cardiac abnormality.1
Numbers to know
| Item | Value |
|---|---|
| Methohexital | 1 mg/kg (70 mg for her)1 |
| Succinylcholine | 1 mg/kg initial, titrate later1 |
| Post-stimulus pause | Usually resolves in 5–10 s1 |
| Clonic-phase surge | SBP +45 mmHg, HR +50 bpm on average1 |
| Adequate seizure | At least 20 s2 |
| Labetalol / esmolol | 0.1–0.5 / 0.5–1 mg/kg1 |
Links
- Choosing an induction agent, succinylcholine, Recent MI, coronary stents and antiplatelet therapy, Pacemakers and ICDs in the operating room, porphyria
- AANA Journal review of ECT anesthesia (2024)
Sources
- 1.Anesthesia Management for Electroconvulsive Therapy · AANA Journal, 2024 · onlinedigeditions.comCzerwonka, Johnston, Smith-Steinert; AANA Journal February 2024.
- 2.Review and Update of Anesthetic Management for Electroconvulsive Therapy: A Narrative Review · Neuropsychiatric Disease and Treatment, 2026 · dovepress.comSingh A, et al. Neuropsychiatr Dis Treat 2026;22.
Facts on this page were checked against these sources on Oct 15, 2026. Guidelines change; confirm doses against current institutional protocols.