Effects of different target plasma concentrations of propofol on ventricular repolarization in elderly patients / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of different target plasma concentrations of propofol on ventricular repolarization in elderly patients.Methods Forty-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 tablepropofol 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.Results There 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).Conclusion Propofol at clinically relevant concentrations can shorten the ventricular repolarization in elderly patients.