Effects Of Sevoflurane And Propofol On Heart Rate Variability During Induction Of Anesthesia In Elderly Patients With Coronary Artery Disease

Objective:To investigate the effects of sevoflurane and propofol on cardiovascular response and heart rate variability(HRV) during induction of anesthesia in elderly patients with coronary artery disease. Methods:Forty ASAⅡ～Ⅲpatients with coronary artery disease aged 60-80yrs weighing 45-80kg, scheduled for elective surgery were randomly divided into sevoflurane group(S group,20 cases) and propofol group(P group,20 cases). ECG,invasive BP,HR and HRV were monitored before and during induction of anesthesia. Patients in group S inducted by inhaling sevoflurance with 4% concentration until falling into sleep and then fentanyl 3ug/kg and vecunium 0.1mg/kg intravenous injection. In group P, the target controlled induction concentration of propofol was 3 ug/ml until the patients went into sleep and then followed by administration of fentanyl 3ug/kg and vecunium O.lmg/kg. All these drugs were injected by vein. The changes of hemodynamics and HRV were observed at the time points of before induction(baesline), and 5min, 10min,15min,20min after induction. Side effects such as chest wall rigidity,hypotension and the uses of any vasoactive drugs were also recorded. Results:There were no statistical differences between the two groups with respect to sex,age,weigh,height,type of operation,preoperation blood pressure,HR and HRV,In S group the SBP,DBP,HR were significantly lower than the baselinet at the time points of 5min, 10min after induction(P<0.05),in P group the SBP,DBP were significantly lower than the baseline at the time points of 5min, 10min,15min after inductio(P＜0.05). The SBP,DBP in group P were significantly lower than those in group S, but the HR was significantly higher in group P. After the induction of anesthesia, the low frequency(LF) was mainly decreased in a time-depended manner in S group, significantly lower than the baseline at the time point of 5min,10min,15min(P<0.05), but not at the time point of 20min; while the high frequency(HF) was no significant difference between the time points and the baseline; LF/HF was significantly lower than the baseline only at the time point of 15min(P<0.05). In P group, LF was significantly lower than the baseline only at the time point of 5min(P <0.05); HF was mainly decreased in a time-depended manner, significantly lower than the baseline at all the time points(P<0.05); LF/HF was significantly higher than the baseline at the time point of 10min,15min,,20min(P<0.05).The incidences of side effects such as chest wall rigidity,hypotension and the uses of any vasoactive drugs were no significant difference between the two groups. Conclusion:Propofol mainly inhibits cardiac parasympathetic nerve system, while sevoflurane might reduce cardiac sympathetic tone more than parasympathetic tone and would maintain hemodynamics during the induction of anesthesia in elderly cornary heart disease patients, so, induction of anesthesia with sevoflurane is beneficial to elderly cornary heart disease patients. There is no remarkable difference in cardiovascular response induced by propofol and sevoflurane during tracheal intubation.