Comparison of Premedication with Low-Dose Midazolam Versus Etomidate for Reduction of Etomidate-Induced Myoclonus During General Anesthesia for Electroconvulsive Therapy: A Randomized Clinical Trial

Background:A variety of anesthetics including methohexital, thiopental sodium, propofol, ketamine, and etomidate are used for electroconvulsive therapy (ECT), each accompanied by adverse effects that can cause unpleasant experiences for patients. Etomidateinduced myoclonus is among the adverse effects. We attempted to assess the effect of premedication with lowdose midazolam compared to etomidate on the reduction of this complication.Objectives:This study was designed to compare the effectiveness of lowdose etomidate and low dose midazolam to suppress etomidateinduced myoclonus in ECT.Methods:This randomized doubleblinded clinical trial was conducted on 132 patients who were candidates for ECT. They were divided into three groups of 44 patients to receive 0.015 mg/kg midazolam, 0.03 mg/kg etomidate, or placebo. Independent ttest and chisquare test were used for comparison of variables.Results:The frequency of myoclonic movements during anesthesia was different between the three groups (P value 0.001). Myoclonic movements were significantly lower in the midazolam group than in the placebo (P value 0.001) and etomidate (P value = 0.002) groups. In addition, the intensity of myoclonic movements was significantly higher in the midazolam group than in the placebo and etomidate groups (P value 0.001).Conclusions:Lowdose midazolam (0.015 mg/kg) before anesthesia induction with etomidate was accompanied with significantly lower incidence and intensity of myoclonus than lowdose etomidate (0.03 mg/kg).