复合咪达唑仑-依托咪酯时阿芬太尼抑制气管插管心血管反应的量效关系

Dose-effect relationship of alfentanil inhibiting cardiovascular responses to endotracheal intubation when combined with midazolam and etomidate

目的:探讨复合咪达唑仑-依托咪酯时阿芬太尼抑制气管插管心血管反应的量效关系。方法:选择气管插管全身麻醉下行择期手术的患者,性别不限,年龄18~64岁,BMI<32 kg/m^(2),ASA分级Ⅰ或Ⅱ级。静脉注射咪达唑仑0.025 mg/kg充分镇静5 min后连续记录3次MAP和HR,间隔3 min,取平均值为基础值。静脉注射依托咪酯0.3 mg/kg,待BIS值<60后静脉注射阿芬太尼和罗库溴铵0.6 mg/kg,1.4 min后行气管插管术。采用Dixon序贯法进行试验,阿芬太尼初始剂量设定为20μg/kg,根据气管插管心血管反应发生情况确定下一例患者阿芬太尼的剂量,相邻剂量比值为1.0∶1.1。气管插管后2 min内MAP最大值或HR最大值较基础值升高≥20%为发生心血管反应。采用probit法确定阿芬太尼抑制气管插管心血管反应的ED_(50)、ED_(95)及其95%可信区间。结果:复合咪达唑仑-依托咪酯时,阿芬太尼抑制气管插管心血管反应的ED_(50)(95%可信区间)为21.343(19.105~24.516)μg/kg,ED_(95)(95%可信区间)为25.043(22.983~48.983)μg/kg。结论:复合咪达唑仑-依托咪酯时,阿芬太尼抑制气管插管心血管反应的ED_(50)为21.343μg/kg,ED_(95)为25.043μg/kg。

Objective To investigate the dose-effect relationship of alfentanil inhibiting cardiovascular responses to tracheal intubation when combined with midazolam and etomidate.Methods American Society of Anesthesiologists Physical Status classificationⅠorⅡpatients of either sex,aged 18-64 yr,with body mass index<32 kg/m2,undergoing elective operation under general anesthesia with endotracheal intubation,were enrolled in this study.Midazolam 0.025 mg/kg was intravenously injected for adequate sedation,and 5 min later mean arterial pressure and heart rate were recorded for 3 consecutive times at an interval of 3 min,and the mean value was calculated and served as the baseline value.Etomidate 0.3 mg/kg was intravenously injected,and alfentanil and rocuronium 0.6 mg/kg were intravenously injected when bispectral index value<60,and then 1.4 min later tracheal intubation was performed.The dose of alfentanil was determined by the Dixon′s up-and-down method.The initial dose of alfentanil was set at 20μg/kg.The dose of alfentanil in the next patient was determined according to the development of cardiovascular responses to tracheal intubation,and the ratio between the two successive doses was 1.0∶1.1.The cardiovascular response was defined as as positive when the maximum value of mean arterial pressure or heart rate increased by≥20%of the baseline value within 2 min after endotracheal intubation.Probit method was used to determine the ED50,ED_(95) and 95%confidence interval of alfentanil inhibiting cardiovascular responses to tracheal intubation.Results When combined with midazolam and etomidate,the ED50(95%confidence interval)of alfentanil inhibiting cardiovascular responses to tracheal intubation was 21.343(19.105-24.516)μg/kg,and the ED_(95)(95%confidence interval)was 25.043(22.983-48.983)μg/kg.Conclusions When combined with midazolam and etomidate,the ED_(50)and ED_(95) of alfentanil inhibiting cardiovascular responses to tracheal intubation are 21.343 and 25.043μg/kg,respectively.