The Influence Of Dexmedetomidine On Earlier Postoperative Cognitive Dysfunction

Objective To observe the influence of dexmedetomidine on earlier postoperative cognitive dysfunction after non-cardiac surgery in the elderly.Methods From September 2010 to March 2011, eighty-seven 61-82 years old patients (ASAⅡ) who undergone the elective operation of transurethral resection, prostate were randomly divided into group I (placebo group) and groupⅡ(control group). In groupⅡdexmedetomidine 1μg/kg was given i.v.10 minutes before induction of anesthesia. During surgery dexmedetomidine was given 0.4μg/kg·h-until the finish of operation. In total intravenous anesthesia propofol and remifentanil were given to maintain anesthesia. We detected the change of blood cortisol and glucose at 3 time points:before anesthesia(T1), after intubation(T2), finish of operation(T3). Operation time, fluid given, blood loss and the amount of anesthetic were recorded. We evaluated cognitive function by means of MMSE (Mini-Mental State Examination) 1 day before operation,1 day,2 days, and 3 days after operation.Results There were no significant differences between the two groups in relevant medical history, culture level, operation time, fluid given and blood loss. The amount of propofol was much lower in groupⅡthan groupⅠwhereas there were no differences between the two groups in the use of remifentanil, fentanyl, atracurium. The blood cortisol concentration in groupⅡafter intubation was inhibited stronger. The rate of cognitive decline on MMSE 1day after operation in groupⅠ(20%) was much higher than that in groupⅡ(9.5%). The rates of cognitive decline on MMSE 2 days after operation were 10%(groupⅠ) and 4.8%(groupⅡ), respectively.3 days after operation the rates were 2.5%(groupⅠ) and 2.4%(groupⅡ) respectively.Conclusion Intraoperative infusion of dexmedetomidine probably has a prevention effect on earlier postoperative cognitive decline after non-cardiac surgery in the elderly. However, whether it has the same effect on long-term postoperative cognitive dysfunction still needs to study.