Significance of cerebral state index used in patients undergoing general anesthesia

Objective To evaluate the significance of cerebral state index(CSI)used in patients undergoing general anesthesia.Methods Forty patients,ASA class Ⅰ or Ⅱ,were randomly allocated into two groups with 20 cases each.Anesthetic depth was judged and anesthetics was administred by CSI monitoring(being kept in 50±5)in group A or based on the experience of anesthetist.Anesthesia was induced and maintained with midazolam,fentanyl,propofol and vecuronium.SBP,DBP,HR,ECG,SpO2 and CSI were monitored.Awake time and anesthetic consumption were recorded.The OAA/S was graded during induction and correlative coefficient between OAA/S and CSI was calculated.Results The changes of SBP,DBP,HR and CSI 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 case during operation was seen in group A,but one case suffered from awareness in group B.The rank correlation between CSI and OAA/S was significant.Conclusion CSI monitoring can dynamicly reflect cerebral physilological functions during general anesthesia and is helpful in judging anesthesia depth and directing the administration of anesthetics.