Effects of Propofol on Electroconvulsive Therapy Seizure Duration

Dear Editor: Propofol is an anesthetic agent alternative to methohexital. It is widely used because it is associated with smaller hemodynamic response during electroconvulsive therapy (ECT) (1). Studies have shown that propofol reduces seizure duration, and reports of reduced seizure duration with ECT under propofol anesthesia have led to concerns that propofol may diminish the efficacy of this treatment (2,3). However, although propofol has been associated with shorter seizures when given for ECT anesthesia, the reduced seizure duration has not been associated with smaller therapeutic effect when compared with methohexital anesthesia (4,5). We compared the effects of propofol on seizure duration with ECTs performed without anesthesia. We retrospectively studied 26 patients consecutively referred for ECT. All patients were hospitalized and treated in Trakya University Psychiatry Clinic, Edirne, Turkey, between January 1, 2001, and December 31, 2003. Until March 2002, ECT treatments in this clinic were performed without anesthesia. Of the 26 patients, 15 had ECT treatments under anesthesia, and 11 had treatments without anesthesia. Propofol was used as an anesthetic agent and succinylcholinc was used as a muscle relaxant in the 15 patients who received anesthesia. Patients in both groups were treated with the same ECT machine (Thymatron(TM) DGx, Somatics Inc, Lake Bluff, IL). Bilateral electrode placement was applied for all patients. Seizure duration measurements were based on the machine's automated seizure duration determinations. The groups were compared without taking into consideration the patients' diagnosis, the drugs that they used, or their psychiatric outcomes. Results The groups were similar in terms of sex and mean age. Major depression was the most frequent diagnosis in both groups. The number of ECT treatments in the propofol anesthesia group (mean 9.67, SD 2.99) did not differ significantly from the nonanesthesia group (mean 9.27, SD 2.05; t = 0.37; P = 0.71). When the seizure durations were compared, seizure duration was longer in the propofol anesthesia group (mean 44.38, SD 14.52) than in the nonanesthesia group (mean 39.45, SD 3.47). However, this difference was not significant (t = 1.26, P = 0.22). Mean (SD) propofol dosage was 98.68 (4.48) mg. We found no linear correlation between the propofol dosage and seizure duration (r = 0.24, P = 0.41). We assessed the effect of both the number of ECTs and having anesthesia on seizure duration; no effects for ECT number (F^sub 1,11^ = 1.80, P > 0.05) or patient group (F = 0.81, P Discussion Contrary to previous studies (6-8), we did not find that propofol had any considerable effect on seizure duration. Our study design was different from other studies in that they compared 2 different induction agents (9-11); in our study, seizure durations of patients who received propofol anesthesia were compared with seizure durations of patients who received ECT treatments without anesthesia. …