Effect Of Stellate Ganglion Block On Postoperative Delirium In Elderly Patients Undergoing Lumbar Spine Surgery

Background and ObjectivePost-operative delirium(POD)is a common complication of central nervous system in elderly patients after anesthesia and surgery.Elderly patients undergoing lumbar spinal surgery are a group with high incidence rate of postoperative delirium.POD is related to many factors such as patients' preoperative condition,anesthesia and operation,postoperative monitoring and treatment,etc.Among them,the risk factors such as brain degeneration before operation,increased stress response,large fluctuation of hemodynamics during operation,imbalance of brain oxygen metabolism and sleep disorder after operation can all increase the risk degree of POD.Stellate ganglion block(SGB)is a common method for the treatment of painful diseases.With the deepening of research,some scholars have found that SGB can play significant roles in alleviating stress response during operation,stabilizing patients' hemodynamics or improving cerebral oxygen metabolism during operation,or improving patients' sleep quality after operation.Therefore,SGB should have good clinical effect in preventing POD from occurring in elderly patients undergoing spine surgery.But at present,there are few researches on this aspect at home and abroad.The purpose of this study was to observe whether SGB can reduce the incidence of POD in elderly patients undergoing lumbar spine surgery,and then to observe the effects of SGB on perioperative hemodynamic indexes,regional cerebral oxygen saturation(rSO2)and sleep time of the first night after surgery.Investigating the effect of SGB on POD in elderly patients undergoing lumbar spinal surgery and its possible mechanism was also the the purpose of this study.Subjects and MethodsFrom May 2019 to December 2019,90 elderly patients,aged 65-85 years old,undergoing lumbar surgery in prone position in the First Affiliated Hospital of Zhengzhou University were selected.The patients were divided into stellate ganglion block group(SGB group)and control group(CON group)by using random number table method,with 45 cases in each group.Ultrasound-guided right stellate ganglion block was performed 15 minutes before induction of general anesthesia,0.25%ropivacaine hydrochloride 4ml was injected in group SGB.CON group received no special treatment before induction of general anesthesia.Anesthesia induction and intraoperative management methods are the same in the two groups.BIS value was maintained at 40-60 during the operation,and the bilateral regional cerebral oxygen saturation(rSO2)was monitored continuously.But the anesthesia management was not carried out according to rSO2.The mean arterial pressure(MAP),heart rate(HR),BIS and rSO2 of the two groups were recorded before induction(T0),immediately before tracheal intubation(T1),immediately after tracheal intubation(T2),during skin incision(T3),1 hour after surgery(T4),at the end of surgery(T5),and immediately after extubation(T6).Intraoperative indicators such as the amount of fluid discharged and entered,operation time,anesthesia time and usage of vasoactive drugs were recorded.Besides,postoperative recovery indicators such as awakening time,extubation time,PACU residence time and the occurrence of nausea and vomiting were recorded as well.BIS monitor was used to record the sleep time of the first night after operation from 8:00 p.m.on the day of operation to 6:00 a.m.on the next day.The sleep time was the sum of durations with BIS value lower than 80.From the first day to the 7th day after operation,the POD occurrence of the two groups of patients was evaluated.Results79 patients(40 in SGB group and 39 in CON group)completed the study and 11 patients were excluded.There was no significant difference in preoperative general data,intraoperative situation and postoperative recovery situation between the two groups(P>0.05).MAP and HR increased at T2,T3 and T6 time points,while they decreased at T1,T4 and T5 time points compared with those at To time point in the two groups,and the above differences were statistically significant(P<0.05).Compared with SGB group,MAP and HR at T2,T3 and T6 time points in CON group were higher than those at T0 time point significantly,and the differences were statistically significant(P<0.05).rSO2 decreased at T4 and T5 time points but increased at other time points compared with that at To time point in the two groups,with statistically significant differences(P<0.05).But there was no significant difference in rSO2 between the two groups at each same time points from T0 to T6(P>0.05).Compared with CON group,the sleep time of the first night after operation in SGB group was prolonged by about 48 min,the difference was statistically significant(P<0.05).Compared with CON group,the total incidence rate of POD in SGB group was significantly lower,and the difference was statistically significant(P<0.05).Conclusion1.Stellate ganglion block can reduce elderly patients' stress response and stabilize circulation during lumbar spinal surgery.2.Stellate ganglion block can prolong elderly patients' sleep time of the first night after lumbar spinal surgery.3.Stellate ganglion block can reduce the incidence of POD in elderly patients underwent lumbar spinal surgery,and its mechanism may be related to the above factors.