Comparison between the Effects of Propofol and Etomidate on Motor and Electroencephalogram Seizure Duration during Electroconvulsive Therapy

An ideal anaesthetic for electroconvulsive therapy (ECT) should have rapid onset and offset with no effect on seizure duration, and provide cardiovascular stability during the procedure. Propofol is commonly used, even though it has been shown to shorten seizure duration which might affect the efficacy of ECT. Etomidate has been advocated as an alternative. This prospective, randomised, single-blind, crossover study was conducted to compare the effects of etomidate (Etomidate-®Lipuro, B. Braun Ltd, Melsungen, Germany) and propofol (Diprivan®, AstraZeneca, UK) on seizure duration as well as haemodynamic parameters in patients undergoing ECT. Twenty patients aged between 18 and 70 years were recruited. Group I received etomidate 0.3 mg/kg for the first course of ECT (Group IA) and propofol 1.5 mg/kg for the second ECT (Group IB), while Group II received propofol for the first ECT (Group IIA) and etomidate for the second ECT (Group IIB). There was a washout period of two to three days in between procedures. Parameters recorded included motor seizure duration, electroencephalogram seizure duration, blood pressure and heart rate. Analysis demonstrated neither period effect nor treatment period interaction. Etomidate was associated with a significantly longer motor and electroencephalogram seizure duration compared with propofol (P <0.01). Neither drug demonstrated consistent effects in suppressing the rise in heart rate or blood pressure during ECT. Myoclonus and pain on injection were the most common adverse effects in etomidate group and propofol group respectively. Etomidate is a useful anaesthetic agent for ECT and should be considered in patients with inadequate seizure duration with propofol.