Effects Of Ultrasound-guided Stellate Ganglion Block On Postoperative Cognitive Function In Elderly Patients Undergoing Controlled Hypotension Lumbar Surgery

Objective:To investigate the effect of ultrasound-guided stellate ganglion block(SGB)on postoperative cognitive function in elderly patients undergoing controlled hypotension lumbar surgery.Method:A total of 80 patients,aged 65-80 years,who underwent lumbar spine surgery in the Second Affiliated Hospital of Nanchang University from June 2021 to January 2022 and underwent controlled hypotension during surgery were selected.Patients were randomly divided into 2 groups,including 40 patients in each group,who received preoperative ultrasound-guided stellate ganglion block group(SGB group,hereinafter referred to as group S)and blank control group(CON group,hereinafter referred to as group C).Group S received ultrasound-guided right stellate ganglion block(local anesthetic was 0.2% ropivacaine 4ml)before induction of general anesthesia,while group C received blank control and routine anesthesia without treatment before induction.Anesthesia induction and intraoperative maintenance were the same in group S and group C,and controlled hypotension and bilateral cerebral oxygen saturation were monitored during the operation.The changes of heart rate(HR),systolic blood pressure(SBP),diastolic blood pressure(DBP),mean arterial pressure(MAP)and r SO2 were recorded before nerve block(T1),before the beginning of controlled hypotension(T2),when the target level of controlled hypotension was reached(T3),when the blood pressure was stable after the end of hypotension(T4)and after operation(T5).Plasma Sβ-100 protein and neuron specific Enolase NSE values of 2groups were detected and compared before operation,after controlled hypotension and4 h after operation.Mini-mental State Examination(MMSE)was used to score the patients 1,3 and 7 days after operation.Postoperative Cognitive function was assessed.POCD was considered as Postoperative Cognitive Dysfunction if Postoperative MMSE score decreased by 2 points or more compared with preoperative baseline value.Result:A total of 80 patients were included,of which 2 were excluded.A total of 78patients(39 in group S and 39 in group C)completed the study.1.There was no difference in general conditions between the two groups beforeand during surgery,and no significant difference in SBP,DBP and MAPbetween the two groups at T1-T5 time point after SGB;however,HR in groupC was higher than that in group S at T2-T5 time point after SGB(P < 0.05).2.RSO2 in both groups was within the normal range before surgery(T1),andthere was no difference between the two groups.Cerebral oxygen satiationincreased gradually at T2-T5 in group S,while decreased significantly ingroup C and group S,with the average value of group S higher than that ofgroup C(P < 0.05).3.There was no significant difference in NSE and Sβ-100 protein betweenGROUP S and group C before surgery,while the indexes of group S aftercontrolled hypotension and 4h after surgery were lower than those of group C(P < 0.05).4.Compared with group C,MMSE scores of patients in group S showed nodifference before surgery,while MMSE scores of patients in group S werehigher and POCD incidence was lower 1,3 and 7 days after surgery(P < 0.05).Conclusion:Ultrasound-guided stellate ganglion block can be safely used in controlled hypressive lumbar spine surgery in the elderly,with more stable intraoperative circulation,improved cerebral oxygen supply,reduced brain injury,and reduced incidence of postoperative cognitive dysfunction.