Effects Of Dexmedetomidine On Delayed Neurocognitive Recovery In Elderly Patients Undergoing Spinal Surgery

Objective:To investigate the effect of dexmedetomidine on delayed neurocognitive recovery in elderly patients undergoing spinal surgery.Methods:86 patients underwent posterior lumbar interbody fusion at the Second Hospital of Shanxi Medical University,who aged at 65-75 years were included in this prospective study,and finally 60 patients completed the study.Randomly divided into two groups,that is,30 cases in the control group and the observation group.In the observation group,after induction of anesthesia,a loading dose of dexmedetomidine 0.5ug/kg was infused intravenously for 10 minutes,and then dexmedetomidine was infused at the rate of 0.3 ug/?kg·min?during the operation until 30 minutes before the end of operation.The control group was given the same amount of saline in the same manner.Record the regional cerebral oxygen saturation?rSO₂?before anesthesia induction?T0?,5min after anesthesia induction?T1?,prone position?T2?,spinal decompression?T3?,vertebral body fixation?T4?,and postoperative?T5?,and calculate the mean value of rSO₂?rSO₂mean??the minimum value of rSO₂?rSO₂min?and the maximum percentage decrease of rSO₂ from the basic value?rSO₂%max?.Venous blood was collected 5 minutes before anesthesia,immediately after surgery,and 1 day after surgery to determine IL-1?,IL-6,TNF-?,and S-100?protein concentrations.Record patient perioperative data.Neuropsychological tests were used to assess patients'cognitive function 1 day before surgery and 7 days after surgery.Patients were followed up using TICS-m at 30 days after surgery.Analyza the correlation between three inflammatory factors IL-1?,IL-6,TNF-?and postoperative DNR.Follow-up records were recorded at 4,12,24,and 48 h postoperatively at rest and activity with visual analogue pain scores.Results:There was no significant difference in gender,age,height,weight,ASA classification,operation time,bleeding volume,education level,hypertension,diabetes,and arrhythmia between the two groups?P>0.05?.Compared with the control group,the extubation time,PACU dwell time,intraoperative propofol,sufentanil,and remifentanil in the observation group were reduced?P<0.05?.Compared with 5 minutes before anesthesia,the S-100?protein level increased significantly immediately after surgery?P<0.05?;compared with the control group,the S-100?protein level decreased immediately after surgery and 1 day after surgery?P<0.05?.Compared with 5 minutes before anesthesia,IL-1?,IL-6,TNF-?increased significantly immediately after surgery and 1day after surgery?P<0.05?;compared with the control group,immediately after surgery and 1 day after surgery,the levels of IL-1?,IL-6 and TNF-?decreased in observation group?P<0.05?.There were no significant differences in rSO₂,HR,MAP,PaCO₂,and Hb at different time points between the two groups of patients?P>0.05?.There was no significant difference in rSO₂ basal value,rSO₂mean,rSO₂min,and rSO₂%max between the two groups of patients?P>0.05?.There was a significant difference in the number of DNR cases between the two groups at 7 days after surgery?P<0.05?.There were 8 cases of DNR in the control group,with an incidence of 26.7%,and 2 cases of observation group with DNR,the incidence was 6.7%.There was no significant difference in the number of DNR cases between the two groups at 30 days postoperatively?P>0.05?,DNR occurred in 2 cases in the control group,with an incidence rate of 6.7%,no DNR occurred in the observation group.There was a weak correlation between serum IL-6level at 1 day after operation and DNR at 7 days after operation.There was no significant difference in VAS scores between the two groups of patients at rest,at 4,12,24,and 48hours after surgery?P>0.05?.Conclusion:Dexmedetomidine can reduce the incidence of DNR at 7 days after surgery in elderly patients with spinal surgery,and has no effect on the occurrence of DNR at 30days after surgery.The serum IL-6 level at 1 day after surgery had a weak correlation with the DNR at 7 days after surgery,suggesting that there was a certain relationship between the increase in IL-6 and the decline in postoperative cognitive function.Intraoperative pumping of dexmedetomidine can reduce the levels of inflammatory factors IL-1?,IL-6,TNF-?and S-100?during the operation,reduce the amount of general anesthetic,shorten the extubation time and stay in PACU and speed up the recovery of the elderly in the wake period.