Abstract: Objective To investigate the effects of sub-dose ketamine combined with total intravenous anesthesia on cognitive function and serum pro-inflammatory cytokine levels in elderly patients undergoing laparoscopic cholecystectomy（LC）. Methods 75 elderly with cholecystolithiasis were recruited in our hospital between June 2015 and June 2016,and all of them underwent LC. During the operation,the patients were randomly divided into observation group（n=40） receiving ketamine and intravenous anesthesia,and control group receiving intravenous anesthesia alone. The satisfaction of anesthesia was assessed by Ramsay’s score,and the cognition was assessed by mini mental state scale （MMSE） score. Serum tumor necrosis factor alpha （TNF-alpha）,interleukin-1 beta（IL-1 beta） and interleukin-6（IL-6） were detected by ELISA. Results At the end of anesthesia,10 min,30 min and 1 hour after the discontinuation of anesthesia,the Ramsay’s scores in the observation group were （4.3±0.3）,（3.1±0.5）,（2.5±0.3） and （2.3±0.3）,much lower than[（4.5±0.4）,（3.4±0.5）,（3.1±0.4） and （2.7±0.5）,P<0.05] in the control;1 h, 3 h,1 d and 3 d after extubation, the MMSE scores were （17.5±0.7）,（20.6±0.7）,（26.1±1.3） and（27.3±0.9）,much higher than [（14.6±0.7）（15.7±0.8）,（20.3±1.4） and（25.1±1.1）,P<0.05] in the control;at the end of the operation and 30 min after extubation,serum TNF-α,IL-1β and IL-6 levels were significantly higher than those in the control（P<0.05）;the awakening time,the time of extubation and orientation recovery were （13.5±1.8） min,（18.2±1.7） min and （20.4±1.8）min,much earlier than[（15.7±1.5） min,（20.6±2.1） min and（23.8±2.9）min,respectively,P<0.05] in the control. Conclusion The combination of total intravenous anesthesia and subdose ketamine can effectively improve the cognitive function in elderly patients undergoing LC operation. It has good anesthetic effect, and the mechanism might be related to the suppression of inflammatory reactions.

Key words: Cholecystolithiasis, Subdose ketamine, Total intravenous anesthesia, Cognitive function, Proinflammatory cytokines, Elderly