The Effect Of Intranasal Administration Of Insulin On Elderly Spinal Surgery Postoperative Cognitive Dysfunction

Objective: The purpose of this study was to investigate the effect of intranasal administration of insulin on cognitive dysfunction after elective spinal surgery in the elderly.Methods: This study was a prospective,randomized and controlled study.Sixty four elderly patients(ASA grade ? ~ ?,age ? 65 years)undergoing elective spinal surgery were randomly divided into two groups.In the insulin group(n =32)and the control group(n =32),40 units of insulin(1 ml,0.5ml per nostril)were injected into the nose 10 minutes before anesthesia induction in the insulin group.The patients in the control group were treated with the same amount of normal saline through the nose.The changes of cerebral oxygen saturation during operation and postoperative cognitive function were compared between the two groups.After entering the operating room,routine ECG monitoring,radial artery puncture and catheterization were performed to monitor arterial blood pressure,at the same time,2ml blood samples were taken for blood gas analysis.To maintain the hemodynamic stability of the patients during the operation,the pulse oxygen saturation(SpO2)was maintained greater than 97%,while maintaining the ETCO2 between 35 to 45 mmHg and the bispectral index(BIS)was between 40 to 60.Near infrared spectroscopy was used to continuously monitor the changes of cerebral oxygen saturation(rSO2)from preoperative wakefulness to tracheal extubation at the end of surgery.The regional cerebral oxygen saturation,the arterial blood CO2 partial pressure,the mean arterial pressure,and the bispectral index were recorded during 4 time periods: before anesthesia induction(T0),immediately after tracheal intubation(T1),immediately after operation(T2)and at the end of operation(T3).At the same time,blood was taken at the end of the non-dominant index finger in both groups.The blood glucose values were measured and recorded at T0,T1,T2 and T3 by blood glucose meter.The patients were evaluated with Mini-mental State Examination(MMSE)one day beforeoperation and compared with MoCA score on the 1st day before operation and the 7th day after operation,while the patients with cognitive impairment were excluded.At the same time,the incidence of postoperative cognitive dysfunction(POCD)was recorded.Results:1.All the patients in the two groups completed the study,and there was no significant difference in the general data between the two groups.2.There was no significant difference in MAP,HR,SPO2,PaCO2,BIS and Glu between the two groups at 10 minutes before anesthesia induction(T0),immediately after tracheal intubation(T1),immediately after operation(T2)and at the end of operation(T3).T0 was used as the baseline value in both groups,and both groups showed a slight decrease at T2 point,which was roughly the same as the baseline value at T1 and T3.3.There was no significant difference in preoperative MMSE and MoCA scores between the two groups.the postoperative MoCA scores in the insulin group were higher than those in the control group,and the incidence of POCD in the insulin group was lower than that in the control group(P < 0.05).4.There were no adverse events such as allergic reaction,nasal discomfort and hypoglycemia in both groups.Conclusion: Preoperative single administration of 40 units of insulin through the nose can reduce the incidence of postoperative cognitive dysfunction in elderly patients undergoing spinal surgery.