Clinical Assessment of Bispectral Index on General Anesthesia

Objective To evaluate the accuracy and practicality of bispectral index(BIS)used in patients undergoing general anesthesia.Methods Forty patients of ASA classⅠorⅡ were randomly divided into group A and B,20patients in each group.Anesthetic depth was judged and anesthetics was administered by BIS monitoring(being kept in 50±5)in group A or based on the experience of anesthetist in group B.After anesthesia induction,target propofol and remifentanil concentrations were adjusted to maintain the MAP,HR within the range of±20%of preinduction values.Systolic pressure(SBP),distolic pressure(DBP),HR,SpO2and BIS were monitored.Awake time and anesthetic consumption were recorded.Results The changes of SBP,DBP,HR and BIS were less in group A than those in group B(P0.05).Awake time was shorter in group A than that in group B and restlessness drowsiness,nausea and vomitting after extubation were less in group A than those in group B.No awareness patient during operation was seen in group A,but one patient suffered from awareness in group B.Conclusion BIS monitoring can dynamicly reflect cerebral physilological function during general anesthesia and is helpful in judging anesthesia depth and directing the administration of anesthetics.