To investigate the effect of sufentanil combined with butorphanol on etomidate-induced myoclonus during anesthesia induction and clinical appropriate dose.

One hundred and twenty patients (ASA-Ⅱ) undergoing general anesthesia admitted to Baoding NO.1 Central Hospital from November 2018 to June 2019 were randomly divided into group S, group BS1 and group BS2. According to the analgesic intensity and the peak time of efficacy of sufentanil and butorphanol, group S received sufentanil 0.4 μg/kg, group BS1 received butorphanol 10 μg/kg + sufentanil 0.3 μg/kg,and group BS2 received butorphanol 20 μg/kg + sufentanil 0.2 μg/kg. All patients were treated with etomidate 0.3 mg/kg 1 minute later (injection time 10-15 s). After two-minutes continuous observation, tracheal intubation was performed. The incidence of cough reaction and myoclonus were observed and the value of mean arterial pressure (MAP) and heart rate (HR) was recorded at the following time points: before administration, immediately before tracheal intubation and immediately after tracheal intubation. The incidence of sleepiness, nausea and vomiting within 6 hours after operation were recorded.

There was no significant difference in the incidence of myoclonus among the three groups. The incidence of cough reaction in group S was higher than that in groups BS1 and BS2 (χ²=10.350, P=0.006). The decrease of MAP and HR in group S before administration to intubation was more than that in groups BS1 and BS2 (F=25.910, 22.057, both P<0.001), while there was no difference between group BS1 and group BS2. The increase of HR and MAP was the smallest in group BS1 before and after tracheal intubation, followed by that in group S, and the increase in group BS2 was the largest (F=8.849, 16.101, both P<0.001). All patients successfully underwent the operation, and there were no serious anaesthesia related complications after operation.

The inhibitory effect of sufentanil combined with butorphanol is the same as sufentanil taken the same equivalent analgesic dose on etomidate-induced myoclonus, which has contributed to maintain hemodynamic stability of general anesthesia induction. Butorphanol significantly reduces the incidence of cough response induced by sufentanil.