Effect of pretreatment with midazolam on etomidate-induced myoclonus: A meta-analysis

OBJECTIVE: To investigate the effect of pretreatment with midazolam on myoclonus induced by etomidate injection. METHODS: A meta-analysis was performed using Review Manager software, version 5.2. Two researchers independently searched PubMed, Cochrane Library, and Embase® databases for randomized controlled trials involving patients who underwent etomidate induced general anaesthesia with or without midazolam pretreatment, published between 1990 and 2016. Outcome measures comprised overall myoclonus incidence rate and incidence rate classified by degree of myoclonus following etomidate injection. Data were assessed using a fixed effects model. RESULTS: Five studies, comprising 302 patients, were included for analysis. Overall incidence rate of etomidate injection-induced myoclonus was significantly lower in the pooled midazolam group versus controls (relative risk [RR] 0.34, 95% confidence interval [CI] 0.26, 0.44); Results subgrouped by degree of myoclonus showed significantly lower incidence in midazolam groups versus control groups for mild myoclonus (RR 0.56, 95% CI 0.39, 0.80); moderate myoclonus (RR 0.20, 95% CI 0.10, 0.41); and severe myoclonus (RR 0.12, 95% CI 0.04, 0.39). CONCLUSION: Midazolam can effectively prevent etomidate-induced myoclonus, and alleviate the degree of etomidate-induced myoclonus.