Effects Of Different Doses Of Dexmedetomidine On Early Cognitive Function After General Anesthesia In Chinese Population: Meta Analysis

Background With the increasing aging of China’s population,the proportion of middle-aged and elderly patients is increasing year by year,and the medical needs of these patients are also greatly increased.Therefore,the probability of postoperative cognitive impairment in middle-aged and elderly patients is also greatly increased.How to solve a series of surgical complications(postoperative cognitive dysfunction,cerebral infarction,deep venous thrombosis,etc.)caused by the aging population has increasingly become an urgent problem to be solved.Objective Meta-analysis was used to evaluate the effects of different doses of dexmedetomidine on(POCD)early postoperative cognitive function in Chinese population under general anesthesia.Methods The databases of Pub Med,EMbase,The Cochrane Library,CBM,CNKI,Wan Fang Data and VIP were searched by computer,and the(RCT),search time limit of randomized controlled trials about the effects of different doses of dexmedetomidine on POCD in elderly patients was established until December 2018.After two evaluators independently screened the literature,extracted the data and evaluated the bias risk included in the study,Meta analysis was carried out with Rev Man 5.3 software.Results A total of 1523 elderly patients were included in the 24 RCT,including dexmetomidine high dose group(0.5μg/kg/h≤ dose ≤ 1.0μg/kg/h)and low dose group(0.01≤dose<0.49ug/kg/h).The results of Meta-analysis by Rev Man 5.3software are as follows.Outcome indicator 1: The incidence of POCD on the 1st and 3rd day after operation in the high dose group was lower than that in the low dose group on the first day after operation [OR=0.24,95%CI(0.15 ~ 0.40),P<0.00001],and the incidence of POCD in the high dose group was lower than that in the low dose group on the 3rd day [OR=0.24,95%CI(0.15 ~ 0.40),P<0.00001].Outcome indicator 2: MMSE score on the 1st and 3rd day after operation(MMSE score on the first day after operation in the high dose group was higher than that in the low dose group [MD=2.06,95%CI(1.24,2.87),P<0.00001)];MMSE score on the third day in the high dose group was higher than that in the low dose group [MD=1.69,95%CI(1.01,2.37).P<0.00001].Conclusion Perioperative low-dose dexmedetomidine group and high-dose group can reduce the incidence of POCD and increase the postoperative MMSE score in middle-aged and elderly patients after general anesthesia,compared with low-dose dexmedetomidine(0.01μg/kg/h≤dose<0.49μg/kg/h),high-dosedexmedetomidine(0.5μg/kg/h≤dose≤1.0μg/kg/h)has a more significant effect on improving the early postoperative cognitive function of middle-aged and elderly patients.