Effect of midazolam and fentanyl on etomidate-induced myoclonus

Objective To investigate the effect of midazolam and fentanyl on etomidate-induced myoclonus.Methods A total of 128 patients scheduled for surgery under genaral anesthesia were randomly divided into 5 groups according to the different sequence and dose of anesthetics during anesthesia induction. Midazolam 0.05 mg/kg,etomidate 0.25 mg/kg and fentanyl 3 μg/kg was used in group Ⅰ,fentanyl 3 μg/kg,etomidate 0.25 mg/kg,midazolam 0.05 mg/kg in group Ⅱ,midazolam 0.05 mg/kg,fentanyl 3 μg/kg,etomidate 0.25 mg/kg in group Ⅲ,midazolam 0.08 mg/kg,etomidate 0.25 mg/kg,fentanyl 3 μg/kg in group Ⅳ,etomidate 0.25 mg/kg,midazolam 0.05 mg/kg,fentanyl 3 μg/kg in group Ⅴ as the control. After the injection of etomidate,the scales and positive incidences of myoclonus were observed within 2 minutes.Results The positive incidences of myoclonus were 68.18% in group Ⅰ,41.67% in group Ⅱ,21.88% in group Ⅲ,21.74% in group Ⅳ,and 59.26% in group Ⅴ,respectively. Compared with group Ⅴ,groups of Ⅲ and Ⅳ had lower positive incidences and scales (P0.05),whereas groups of Ⅰ and Ⅱ had no statistical changes in positive incidences and scales.Conclusion Using midazolam,fentanyl,and etomidate consequently may reduce the occurrence of etomidate-induced myoclonus during anesthesia induction.