Feasibility Of Application Of Bispectral Index In Sevoflurane-remifentanil Anesthesia During Gynecological Laparoscopy Surgery

Objectives:Studies have shown that the application of the bispectral index can be a good assessment of the depth of anesthesia,reduce drμg consumption and shorten recovery times,even make the anesthesia more precise. This topic aims at investigating the impact of BIS monitoring on recovery times and sevoflurane consumption during sevoflurane-remifentanil anaesthesia.Methods:Altogether50patients, American Society of Anesthe-siologists physical status class Ⅰ or Ⅱ, aged18～60years, undergoing elective gynecological laparoscopic hysterectomy were randomly allocated into two groups:Control group and BIS group.In all the patients,anaesthesia was induced with propofol1-2mg/kg, midazolam0.05mg/kg,cis-atracurium0.15mg/kg,remifentanil1μg/kg and was continued with sevoflurane, remifentanil0.1μg/kg/min as well as atracurium0.3mg/kg/h.During the maintenance process,in BIS group,the anesthesiologist was instructed to adjust the sevoflurane concentration to keep BIS values at50±5,the same anesthesiologist was instructed to guide the titration of sevoflurane using routine clinical signs in the control group. All measured monitoring variables,especially heart rate,systolic blood pressure,diastolic blood pressure,average arterial pressure,pulse oximetry,BIS value,end-tidal carbon dioxide,end-tidal sevoflurane concentration were recorded at5-min intervals from intubation.The times of anaesthesia and surgery as well as the time of emergence from anaesthesia were recorded.Finally,all patients were observed the occurrence of nausea and vomiting and restlessness,visited on the first postoperative day and interviewed about intraoperative recall.Results:Compared with control group,patients with BIS monitoring needed less mean end-tidal sevoflurane concentrations(control group1.50±0.15%, BIS group1.23±0.13%),and had lower incidence of intraoperative hypotension, but had similar mean BIS value(48.74±3.50and52.57±3.40)as well as recovery times (spontaneous breathing recovery7.5±1.2min,7.6±1.5min; open eyes10.6±3.2min,10.8±2.8min;extubation14.8±2.9min,15.6±2.5min;out of PACU31.1±6.4min,32.5±5.9min). There is no difference between the two groups about the incidence of postoperative nausea and vomiting and restlessness. There is nobody had the intraoperative recall when visited on the first postoperative day.Conclusions:Compared with standard anaesthetic,the application of BIS monitoring is associated with a modest reduction in end-tital sevoflurane concentration as well as the incidence of intraoperative hypotension,but did not result in a reduction of recovery times during elective gynecological laparoscopic hysterectomy surgery with the use of sevoflurane and remifentanil.