Evaluation of cerebral state index(CSI) monitoring in elderly patients undergoing general anesthesia

Objective:To investigate the effect of cerebral state index(CSI) monitoring during propofol general anesthesia combined with remifentanil on anesthesia recovery profile and requirement in elderly patients undergoing elective intro-abdominal surgery.Methods:Forty ASA II or III patients aged over 65 years undergoing elective intro-abdominal surgery were randomly divided into two groups(n=20 each):group A(CSI group) and group B(control group) without the limitation of the types of operation.Both groups were induced with midazolam,remifentanil,propofol and rocuronium.Anesthesia were maintained with propofol in micro-pump.In group A protofol infusion rate were adjusted to keep CSI values between 50～60 during operation.The CSI values was increased to 60～70 at 20 min before the end of operation.In group B the depth of anesthesia was maintained based on the clinical experiences of anesthetist.Blood pressure(BP),heart rate(HR),saturation of blood oxygen(SpO2) and cerebral state index(CSI) were monitored.The awake time,emergence time,extubation time,anesthesia recovery time,and propofol consumption in two groups were recorded.The follow up study to make sure whether the patients had suffered from awareness and pain was performed.Results:There was no statistic meaning in the age,gender,weight and operation time between the two groups(P0.05).The total amount of protofol consumed was much lower in group A than in group B(P0.01).The average CSI values were higher in group A than in group B(P0.05),awake time,emergence time,extubation time and anesthesia recovery time were also significantly less than group B(P0.01).Conclusion:Propofol infusion combined with remifentanil using CSI monitoring can reduce the dose of propofol during operation and contribute to faster recovery from anesthesia in elderly patients undergoing elective intro-abdominal surgery.