Anesthesia and electroconvulsive therapy: A retrospective study comparing etomidate and propofol

Background: The choice of anesthetic can influence the efficacy of electroconvulsive therapy (ECT). In the UK, propofol is a popular induction agent for ECT, but is associated with higher stimulus charge, shorter seizures, and known to affect seizure threshold. Etomidate is an alternative induction agent but there are concerns over its adverse events and safety. Objectives: We examined the differences between propofol and etomidate in the real life situation of an ECT clinic by assessing their effect on (i) length of course of ECT (ie, number of treatments required to remission), (ii) adverse effects of each induction agent, (iii) the number of 'missed seizures,' and (iv) stimulus dose (charge in mC), which relates to seizure threshold. Method: Using a retrospective naturalistic study design, 94 patients were identified over a 36-month period in our ECT clinic, of which, 65 met the inclusion criteria. Of these, 36 had received etomidate and 29 had received propofol as induction agents throughout their course of ECT. Results: Patients who received propofol had a significantly longer course of ECT, higher seizure thresholds, and increased amounts of electrical charge (mC) over their course. There were no significant differences in adverse events with either of the induction agents. Conclusions: When used for acute courses of ECT, propofol and etomidate are equally well tolerated as induction agents. Patients who received propofol had longer acute courses of ECT and, consequently, longer and costlier inpatient stays. Etomidate could be a better alternative induction agent in ECT.