Effects Of Sevoflurane Or Propofol Maintained Anesthesia In Elderly Patients Undergoing Abdominal Surgery

Objective To compare the effects of sevofiurane and propofol on intraoperative haemodynamic state, recovery profile and perioperative cTnT change in elderly patients undergoing abdominal surgery.Methods Sixty patients aged 65-80 yr,with the history or at high risk of coronary heart disease. undergoing general anesthesia for elective intra- abdominal surgery of more than 2h,were assigned randomly to one of two groups(n=30 each):sevoflurane group(group S) and propofol group (group P).Anesthesia was induced with TCi of propofol and sufentanil in both groups.TCI of sufentanil was started at a target effect-site concentration of 0.25ng/ml with the pharmacokinetic set of Gepts et al.Synchronously the TCI of propofol was started at a target plasma concentration of 1.5μg/ml with the pharmacokinetic set of Marsh et al,followed by increments of target plasma concentration until the patient lost eye lash reflex.Then rocuromiun 0.6mg/kg was administered and assisted respiration with 100%O₂ 6L/min was instigated by face mask.The target plasma concentration of propofol was adjusted to keep BIS values 40-50.Endotracheal intnbation was performed when adequate muscle relaxation had been achieved and patients were mechanically ventilated with O₂.Group S received sevoflurane and Group P used TCI of propofol for maintenance of anesthesia.Both groups used infusion of rocuronium(0.15mg·kg^-1·h^-1) and TCI of sufentanil (C_e 0.15ng/ml) to supplement anesthesia intraoperatively.Sevoflurane and propofol were titrated to keep BIS values 40-60.Sufentanil and vasoactive drugs were adjusted according to haemodynamic responses to surgical stimuli.No rocuronium was given during the last 40 min of the procedure,and tropisetron hydrochloride 5mg was administered at the last 30 minutes of the surgery.BIS values were kept 60-70 for the last 20 minutes of the procedure.Immediately after sevoflurane or propofol infusion was terminated at the end of the procedure,0.04mg/kg neostigmine and 0.02mg/kg atropine sulphate were administered to all the patients.Assisted respiration with 100%O₂ 6L/min was instigated by lace mask after extubation.SBP,DBR HR,BIS were recorded prior to induction of anesthesia(baseline),and then again at predetermined times;pre-and post-intubation,pre-and post-incision,pre-and post-extubation,leaving the operating room.The dose of propofol and volume of sevoflurane were calculated.Time intervals were recorded including eye opening(end of surgery to eye opening on command),extubation(end of surgery to extubation),and orientation(end of surgery to until the patient state his or her name and birth date).All adverse effects associated with recovery and the intraoperative uses of any vasoactive drugs were noted.cTnT concentrations were measured preoperatively and on the first 2 postoperative days using Elecsys 2010 analyzer(Roche Diagnostics,Mannheim,Germany).New ECG changes were noted, including ST-segment depression or elevation and arrhythmia.Results There was a significant decrease in HR.MAP,SBP,DBP towards baseline values preintubation and preincision in both groups(P＜0.01).There was no significant difference between the two groups with respect to HR,MAP,SBP,DBP at each point(P＞0.05).The intraoperative lowest MAP and SBP were lower in group S than in group P(P＜0.05).The incidence of vasoactive drugs's use was lower in group P than in group S from induction to maintenance(P＜0.05).BIS values after incision and before leaving the operating room in group S were significantly higher than in group P (P＜0.05).Time intervals to eye opening,extubation and orientation with group S were significantly shorter than group P,but the incidence of PONV was higher than group P(P＜0.05).The incidence of elevated troponin T concentrations was 50%and the values were mainly "marginal" elevations.The peak concentrations were often found at 6h or 48h after the surgeries.The incidence of positive cTnT levels was higher in group P than in group S.Conclusion Intraoperative haemodynamic stability is good and comparable in both groups.TIVA of propofol leads to lower incidence of vasoactive drugs's use from induction to maintenance and lower incidence of PONV for its antiemetric properties which make patients comfortable,Less emergence time and lower incidence of abnormal cTnT are found in group S.Perioperative myocardiac damage is common in an elderly population and routine perioperative surveillance for cardiac troponins could be used in detecting patients with high cardiac risk.