Effects of dexmedetomidine on postoperative cognitive function and serum S100B in elderly patients

Objective To investigate the effects of dexmedetomidine on postoperative cognitive dysfunction(POCD) in elderly patients.Methods Forty-six elderly patients undergoing total hip replacement surgery were randomly divided into dexmedetomidine group(n = 23) and control group(n = 23).The patients in dexmedetomidine group were infused 0.6 μg/kg dexmedetomidine at first 10 min,followed by 0.4 μg /(kg·h) infusion until the end of operation.The patients in control group received intravenous infusion of saline.All the patients underwent total intravenous anesthesia.Serum S100 B was measured before anesthesia,1 h during operation,12 h,24 h and 48 h after operation.MMSE scores were estimated at baseline,12 h,24 h and 48 h after operation.Results There was no difference in S100 B and MMSE scores at the baseline between two groups(P 0.05).Compared with control group,serum concentration of S100 B decreased in dexmedetomidine group at 1 h during operation,12 h,24 h and 48 h after operation(P 0.05).The MMSE score was higher in dexmedetomidine group than that in control group at 12 h,24 h and 48 h after operation(P 0.05).Conclusion Dexmedetomidine can reduce the incidence of POCD,which may be related to the decrease of S100 B.