Background: During the induction of anesthesia with etomidate, myoclonic movements are a common problem.
Objective: To compare the effect of midazolam on the incidence and severity of myoclonic movement from etomidate induction.
Materials and methods: One hundred and tweleve patients, American Society of Anesthesiologists class I-II, were randomly assigned in a double-blind fashion into 4 groups: 0.03 mg/kg of midazolam with 0.3, 0.15 mg/kg of etomidate, and placebo with 0.3, 0.15 mg/kg of etomidate. The myoclonic movements were blindly observed on a scale of 0 to 3. The onset of hypnosis and hemodynamic changes were monitored during the operative period.
Results: The incidence of myoclonus was not significantly different between groups. Seventeen in 28 patients (60%) in the 0.03 mg/kg of midazolam with 0.15 mg/kg of etomidate group had myoclonic movement, whereas 22 patients (78%) in the 0.03 mg/kg of midazolam with 0.3 mg/kg of etomidate group, 25 patients (89%) and 21 patients (77%) in the 0.3 and 0.15 mg/kg etomidate group experienced such movement. The onset of induction in the low dose etomidate with mida-zolam co-induction group was not significantly different from the conventional dose of etomidate.
Conclusion: Pretreatment with midazolam lowered the incidence of myoclonic movement during induction with 0.15 mg/kg of etomidate but the reduction was not statistically significant.