不同血浆靶浓度丙泊酚对老年患者心室复极的影响

Effects of different target plasma concentrations of propofol on ventricular repolarization in elderlypatients

目的评价不同血浆靶浓度丙泊酚对老年患者心室复极的影响。方法择期全麻手术老年患者45例，ASA分级Ⅰ或Ⅱ级，年龄65～80岁，体重43～85 kg。采用随机数字表法分为3组（n＝15）：丙泊酚血浆靶浓度2 μg/ml组（P1组）、丙泊酚血浆靶浓度3 μg/ml组（P2组）和丙泊酚血浆靶浓度4 μg/ml组（P3组）。麻醉诱导前（T1）和丙泊酚达靶浓度后5 min（T2）时采集12导联心电图，测量QT间期和Tp-e间期，计算心率校正的QT间期（QTc间期）和Tp-e/QT比值。结果3组T1，2时QTc间期、Tp-e间期、Tp-e/QT比值比较差异无统计学意义（P〉0.05）。与T1时比较，T2时P1组、P2组QTc间期、Tp-e间期缩短，Tp-e/QT比值降低，P3组Tp-e间期缩短，Tp-e/QT比值降低（P〈0.05），QTc间期差异无统计学意义（P〉0.05）。结论临床相关剂量丙泊酚可缩短老年患者心室复极。

ObjectiveTo evaluate the effects of different target plasma concentrations of propofol on ventricular repolarization in elderly patients.MethodsForty-five patients, aged 65-80 yr, weighing 43-85 kg, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, scheduled for elective surgery under general anesthesia, were divided into 3 groups（n=15 each）using a random number table： propofol at target plasma concentration of 2 μg/ml group（group P1）, propofol at target plasma concentration of 3 μg/ml group（group P2）and propofol at target plasma concentration of 4 μg/ml group（group P3）. Before induction of anesthesia（T1）and at 5 min after propofol reached the target plasma concentration（T2）, 12-lead electrocardiogram was recorded, the QT and Tp-e intervals were measured, and the corrected QT（QTc）interval and Tp-e/QT ratio were calculated.ResultsThere were no significant differences in QTc interval, Tp-e interval or Tp-e/QT ratio at T1, 2 between the three groups（P〉0.05）. Compared with those at T1, the QTc and Tp-e intervals were significantly shortened and the Tp-e/QT ratio was decreased at T2 in P1 and P2 groups, and the Tp-e interval was shorten and the Tp-e/QT ratio was decreased at T2（P〈0.05）, and no significant change was found in the QTc interval at T2 in group P3（P〉0.05）.ConclusionPropofol at clinically relevant concentrations can shorten the ventricular repolarization in elderly patients.