The Effect Of Dexmedetomidine On Postoperative Cognitive Function In Elderly Patients Undergoing Knee Replacement

Objective:To investigate the effects of Dexmedetomidine on postoperative cognitive function in elderly patients undergoing total knee replacement under epidural anesthesia.Methods:We choose to be affiliated hospital of Qiingdao University underwent bilateral total knee arthroplasty under epidural anesthesia,patients with ASA class I-II?over 60 years?,a total of 50 cases,including 24 cases of male,26 cases of female patients.On the day before operation,all the patients were tested by the mini mental state examination?MMSE?,and the patients'gender,age,BMI,basic diseases,education level,basal blood pressure and heart rate were recorded.All patients were divided into dexmedetomidine group?group D,?and propofol group?group P?,patients of two groups were both going through epidural anesthesia.After the epidural anesthesia effect meets the requirements of the operation,dexmedetomidine was intravenous pumped with loading dose 0.8ug/kg in15min,then pumped with maintenance dose 0.2-0.8ug·kg^-1·h^-1.In the Group P,propofol was intravenous with 1.0 mg/kg in 1min,and then pumped with maintenance dose1-4mg·kg^-1·h^-11 to maintain the Bispectral Index between 60-70.One day after the operation,the patients were asked to recall the events during the operation,and the patients were followed up for 1,3,and 5 days'MMSE scores.Results:D group and P group of surgery memories had no significant difference;compared with group P,the small fluctuation of blood pressure level of patients in the D group,the incidence of hypotension was significantly reduced,but the incidence of bradycardia was significantly increased;in the postoperative follow-up MMSE score in the two groups of patients on the first postoperative day score the lowest;compared with group P,the patients of the D group after a day,three days,five days MMSE scores were higher than that of group P?P<0.05?Conclusions:In elderly patients with epidural anesthesia,propofol and dexmedetomidine in patients with BIS values between the 60-70,can meet the depth of sedation required for the operation,no obvious intraoperative awareness;dexmedetomidine can improve patients with MMSE score,the incidence of cognitive impairment decreased early in the elderly patients after operation,with the protective effect of nerve function.