Evaluation Of AAI And BIS To Titrating Sevoflurane Anesthesia

Objective To evaluate the impact of intraoperative monitoring with the electroencephalogram bispectral index(BIS) or auditory evoked potential(AEP) device on the usage of sevoflurane and the eye-opening time and extubation from the end of operation,OAA/S scale scores were recorded.Methods Forty-five ASAâ… andâ…¡adult patients undergoing laparoscopic cholecystectomy general surgery procedures using a standardized anesthetic technique were randomly assigned to one of three monitoring groups:standard clinical practice(control),BIS-guided,or AAI-guided.After a induction of midazolam 0.05 mg·kg^-1,propofol 1.5mg·kg^-1 and fentanyl 3ug·kg^-1,laryngoscopy and intubation were facilitated with intravenous vecuronium 0.1mg·kg^-1,and anesthesia was maintained with sevoflurane.In the control group,the anesthesiologists were not permitted to observe the BIS or AAI values during the intraoperative period.In the AAI-guided group,the volatile anesthetic was titrated to maintain a AAI value in the range of 15～20.In the BIS-guided group,the targeted BIS index range was 45～55.MAP,HR,SpO₂, the BIS indices and AAI indices,as well as end-tidal sevoflurane concentration,were recorded at 3～5 min intervals.Observer's assessment of alertness/sedation(OAA/S) scale score was assessed after surgery.Results The AAI- and BIS-guided groups were administered significantly smaller average end-tidal sevoflurane concentrations than the control group(P＜0.05).The emergence times to eye opening,tracheal extubation were consistently shorter in the AAI and BIS groups(P＜0.05).OAA/S scale scores were not significantly different in three groups.However,there were no significant outcome differences between the two cerebral monitored groups.Conclusions We concluded that cerebral monitoring with either the BIS or AAI devices reduced the maintenance anesthetic(sevoflurane) requirement,resulting in a shorter length of eye opening,tracheal extubation after surgery.