Effect Of Prior Administration Of Butorphanol On The Sufentanil-induced Cough And Muscle Rigidity During General Anesthesia Induction:(a Randomized Placebo-controlled Trial)

Introduction: Opioid-induced cough and muscle rigidity may occur during general anesthesia induction and should be effectively managed.Objective: Our study was to evaluate the suppressive effects of intravenous butorphanol on sufentanil-induced cough（SIC）and muscle rigidity during the induction of general anesthesia.Methods: One hundred six patients aged between 18 and 75 years,with an American Society of Anesthesiology classification of I or II,scheduled to receive surgeries under general anesthesia were randomized in two groups.The patients with a history of asthma,chronic cough,chronic smoking,impaired liver or kidney disease,under bronchodilators or steroids therapy,with upper respiratory tract infection within the previous 2 weeks,taking angiotensin converting enzyme inhibitors,or allergic to butorphanol were excluded.Patients in the butorphanol group（study group）were treated with intravenous 1mg（1ml）butorphanol,whereas the control group were treated with the same volume of normal saline.Sufentanil 0.3mcg/kg and 0.4mcg/kg over 5sec was administrated 30 sec after injection of butorphanol or normal saline.The mean arterial pressure（MAP）,heart rate（HR）,and oxygen saturations via pulse oximetry（SpO₂）were monitored and compared before the administration of butorphanol or normal saline（T0）,starting during anesthesia（T1）,30 sec after sufentanil injection（T2）,1minute（T3）,3mintutes（T4）and 5minutes（T5）after intubations,the number and severity of coughs at 2 min after the sufentanil injection,and severity of muscle rigidity within induction time were also compared between the two groups..Result: Five patients were excluded according to the exclusion criteria.A total of 101 Chinese patients（54 women and 47 men）entered into final analysis with 51 in butorphanol group and50 in control group.The 2 groups were comparable in basic demographic features.During study period,the MAP,HR and SpO₂ were recorded.The incidence of SIC was 29.4% in control group,2% in butorphanol group（P<0.001）.Mild cough and moderate cough was 23.5%and 5.9% in control group,and 2% and 0% in butorphanol group,respectively（P<0.001）.In both groups,none of the patients developed severe cough.Compared to control,butorphanol decreased the incidence of muscle rigidity（9.8% vs2%）,but not reaching statistically significance（P=0.205）.Conclusion: Our study shows that prime administration of intravenous butorphanol suppresses the sufentanil-induced cough and decreases the incidence of muscle rigidity without worsening hemodynamics variation during general anesthesia induction procedure.