目的:评价丙泊酚抑制双腔支气管插管心血管反应的有效浓度（effective concentration, EC）。方法:纳入拟行全身麻醉单侧肺部手术的患者100例，按年龄分为青年组和中年组。青年组患者给予丙泊酚靶控输注（target controlled infusion, TCI）血浆浓度3.0 mg/L，中年组患者给予丙泊酚2.5 mg/L。根据前一例置入双腔支气管时情况，决定下一例丙泊酚浓度。根据最终观察结果，分析计算丙泊酚的有效浓度。结果:青年组和中年组丙泊酚抑制双腔支气管插管心血管置入反应的半数效应浓度（median effective concentration, ECn 50）分别为3.594 mg/L（95%CI 1.992~3.594）和2.938 mg/L（95%CI 2.426~3.104），95%效应浓度（95% effective concentration, ECn 95）分别为4.031 mg/L（95%CI 3.810~4.917）和3.479 mg/L（95%CI 3.284~4.283）。n 结论:青年组和中年组抑制双腔支气管插管心血管反应的丙泊酚血浆靶控浓度ECn 95分别为4.031 mg/L和3.479 mg/L。n “,”Objective:To determine the effective concentration (EC) of propofol for inhibiting cardiovascular response during double-lumen endobronchial intubation.Methods:A total of 100 patients who were scheduled for single-lung surgery under general anesthesia were enrolled and divided into two groups according to their ages: a young group and a middle-aged group. Patients in the young and middle-aged group were given propofol through target controlled infusion (TCI) and achieved a plasma concentration of 3.5 mg/L and 2.5 mg/L, respectively. During double-lumen endobronchial intubation, the previous case determined the concentration of propofol in the next case. Then, the effective concentration of propofol was calculated on the basis of final observation.Results:During double-lumen endobronchial intubation, the median effective concentration (ECn 50) of propofol for inhibiting cardiovascular response was 3.594 mg/L [95% confidence interval (CI) 1.992-3.594] for the young group and 2.938 mg/L (95%CI 2.426-3.104) for the middle-aged group. Meanwhile, the 95% effective concentration (ECn 95) of propofol was 4.031 mg/L (95%CI 3.810-4.917) for the young group and 3.479 mg/L (95%CI 3.284-4.283) for the middle-aged group.n Conclusions:During double-lumen endobronchial intubation, the plasma target controlled concentration ECn 95 of propofol for inhibiting cardiovascular response was 4.031 mg/L for the young group and 3.479 mg/L for the middle-aged group.n