RESUMEN
OBJECTIVES: Recently, ketamine has attracted attention for induction of anesthesia during electroconvulsive therapy (ECT). This study compared the effects of thiopental and ketamine in patients undergoing this procedure. METHOD: This randomized, double-blind clinical trial included inpatients, with major depressive disorder, undergoing ECT. Subjects were randomly allocated to receive either ketamine or thiopental. Mini-Mental State Examination and Hamilton Depression Rating Scale were used to assess memory and depression, respectively, before the first and second ECT sessions as well as a few days and 1 month after the sixth session. The electrical charge, seizure duration, blood pressure, and heart rate were also recorded. RESULTS: Of the 31 patients, 17 met the criteria for the ketamine group but 2 dropped out of the study. Therefore, 15 patients received ketamine and 14 received thiopental. Each patient underwent 6 ECT sessions. At the end of the study, depression improved significantly in both groups. However, a significant difference in depression improvement was noted only before the second ECT with ketamine compared with thiopental. Despite a significant decline in Mini-Mental State Examination scores in both groups after the first ECT, cognitive function improved afterward but was only significant in ketamine group. Seizure duration was found to be significantly longer with ketamine. Stimulus intensity used for each ECT increased gradually and linearly with a greater increase observed in thiopental group. CONCLUSIONS: Ketamine administration during ECT is well tolerated and patients may experience earlier improvement in depressive symptoms, longer seizure duration, and better cognitive performance when compared with thiopental.