Relationship Between The Decrease Of Cerebral Oxygen Saturation And Postoperative Cognitive Dysfunction In Elderly Patients With Spinal Tuberculosis

Objective By monitoring the changes of cerebral oxygen saturation in elderly patients undergoing spinal tuberculosis surgery,investigate the correlation between the decrease of cerebral oxygen saturation and postoperative cognitive dysfunction（POCD）,help us to provide a basis for clinical application of cerebral oxygen saturation monitoring technology.Methods 64 patients,aged over 60,ASA Ⅱ-Ⅲ undergoing thoracolumbar spinal tuberculosis surgery under general anesthesia.After inhaling oxygen 6L/min 2 minutes when the patients enter the room（T0）,the rSO₂ value was taken as the preoperative rSO₂ value.Recording the rSO₂ value of five minutes after intubation（T1）,prone position for 30 minutes（T2）,prone position for 1 hour（T3）,prone position for 2 hour（T4）,debridement in lateral position（T5）,the operation is over（T6）.Record the general condition（age,gender,BMI,education level）,intraoperative vital signs,operation time,intraoperative infusion volume,blood loss,postoperative ICU time,hospital stay.MMSE was used to evaluate cognitive function on the 1^th day before and 3^rd and 7^th day after operation.Patients were divided into POCD group and non-POCD group according to the evaluation results.Results 64 elderly patients with spinal tuberculosis completed the test.There were 16 cases in POCD group and 48 cases in non-POCD group,the incidence of POCD was 25%.At T5,the MAP in POCD group was lower than that in non-POCD group（P<0.05）;The rSO₂ in POCD group was lower than that in non-POCD group（P<0.05）;The rate of reduction of rSO₂≥20%in POCD group was higher than that in non-POCD group（P<0.05）;The postoperative ICU time of POCD group was longer than that of non-POCD group（P<0.05）.Conclusions The occurrence of POCD in elderly patients with spinal tuberculosis is related to the decrease of rSO₂ during operation,Reducing the exposure time of rSO₂ less than 20%of the baseline may help to reduce the occurrence of POCD.