Relationship Between The Changes Of BIS And Short-term Postoperative Cerebral Impairment In Patients Undergoing Spinal-epidural Anesthesia

Objetive: To observe the changes of BIS and serum S100? protein in different age of patients undergoing Spinal-Epidural intravertabral anesthesia;to investigate the correlation between these changes and short-term postoperative cognitive dysfunction(POCD).Methods: ASA?or? patients undergoing lower extremity surgery with combined spinal-epidural anesthesia were divided into two groups: group ?(age?64years)and group ?(age?65years).One day before the operation,BP,HR,SpO2,BIS value and Observer's assessment of Alertness/sedation(OAA/S)scores were observed at the time time immediately after the patient arrived at OR(t0),10 min calm after arrival(t1),the end of intrathecal injection(t2),3 min after intrathecal injection(t3),10 min after intrathecal injection(t4),30 min after intrathecal injection(t5),5 min after skin incision(t6),30 min after skin incision(t7),the end of surgical procedures(t8);Arterial blood samples for pH,Hb and blood glucose measurement were taken before anesthesia and at the end of surgery.MMSE score and the Montreal cognitive assessment(MoCA)scores were performed at the day befor the surgery,24 hours after the end of surgery,72 hours after the end of surgery and 7 days post-surgery;the serum S100? protein were evaluated at 10 min before anesthesia,the end of surgery and 6 hours after the end of surgery.According to BIS value,all patients divided into group A(BIS<85)and group B(BIS?85).Results 1.BIS value: the patients in the two groups were the highest in t0 and lowest in T4 group,the T5 and T6 in group ?were significantly lower than those in group I(P < 0.05).2.There was no significantly difference in OAA/S scores betweening group ?and group ?,and the scores were lower at t4,t5,t7 compared to the other time points in each group.3.MMSE,MoCA score: Compared with preoperative,postoperative 24 h,postoperative 72 h scores of all patients decreased(P < 0.05).The patients in group?were lower than those in group?(P < 0.05).MMSE was correlated with MoCA score(P < 0.05).4.S100? protein : compared with preoperative,all patients with postoperative and postoperative 6h were elevated;the group ?after surgery and postoperative 6h was higher than group ?;group A after operation and postoperative 6h was higher than group B(P < 0.05).5.There was no correlation between S100? protein concentration and BIS value in group A during montitoring;S100? proteins in the patients with POCD were higher than those in the patients without POCD(P<0.05).6.The incidence of POCD in group A was higher than that in group B.7.Age is a risk factor of POCD,preoperative MoCA score is a protective factor of POCD.Conclusion 1.BIS were decreased in different age groups of patients undergoing intravertabral anesthesia,BIS value as a monitoring index has higher sensitivity than OAA/S score.2.BIS value of spinal anesthesia was lower than 85,which was correlated with the occurrence of POCD,and may be used as a predictive index of POCD.2.There was correlation between MMSE and MoCa,the lower of MoCa score before operation,the easier occurrence of POCD.