Low-Dose Intravenous Midazolam Reduces Etomidate-Induced Myoclonus: A Prospective, Randomized Study in Patients Undergoing Elective Cardioversion

In Brief BACKGROUND: Myoclonic movements are a common problem in unpremedicated patients during induction of anesthesia with etomidate. METHODS: In a double-blind fashion, 40 patients (ASA physical status III–IV) scheduled for elective cardioversion were randomly assigned to receive either 0.015 mg/kg midazolam or placebo 90 s before the injection of 0.3 mg/kg etomidate. Myoclonic movements and sedation were recorded on a scale between 0 and 3. Pulse oximetry, noninvasive arterial blood pressure, and heart rate were recorded during the study period. RESULTS: Two patients (10%) in the midazolam group had myoclonic movements after the administration of etomidate, whereas 10 of the 20 patients (50%) receiving placebo experienced such movements (P = 0.006). No other differences were found between the groups; in particular, there was no difference in recovery 5 min after the administration of etomidate. CONCLUSIONS: IV midazolam 0.015 mg/kg administered 90 s before induction of anesthesia with etomidate is effective in reducing myoclonic movements and does not prolong recovery in unpremedicated patients after short procedures. IMPLICATIONS: Myoclonic movements are a common problem in unpremedicated patients during induction of anesthesia with etomidate. We have shown that IV midazolam 0.015 mg/kg administered 90 s before induction of anesthesia with etomidate is effective in reducing myoclonic movements and does not prolong recovery in unpremedicated patients after short procedures.