Effects Of Dexmedetomidine In Elderly Patients With Laparascopic Hysterectomy On Postoperative Cognitive Dysfunction

Objective: to investigate the effects of dexmedetomidine in elderly patients undergoing total intravenous anesthesia with laparoscopic hysterectomy on postoperative cognitive dysfunction(POCD)and to explore the correction between S100β and POCD.Methods:American society of Anesthesilolgists(ASA)physical status Ⅰ-Ⅱ patients aging sixty-five to seventy scheduled undergoing laparascopic hysterectomy were randomly divided into dexmedetomidine group(D group)(n=30)and controlled group(C group)(n=30).The patients in dexmedetomidine group were continuously infused 0.5μg/kg dexmedetomidine at first 10 min before the anesthesia inducing,followed by 0.2μg/(kg·h)infusion until 30 minutes before the end of the operation.The patients in controlled group received intravenous infusion of sodium chloride injection with the same speed of the dexmedetomidine group.All patients were in total intravenous general anesthesia and laryngeal mask.The medcines anesthesia-inducing are midazolam 、 fentanyl 、 etomidate and Cis atracurium.Later insert laryngeal mask,connect the anesthesia machine,make ventilation,monitor the end-tidal carbon oxide gas tension(PETCO2),and adjust the PETCO2 between 40-45 mm Hg.Anesthesia-maintaining with propofol infused、 remifentayl infused and Cis atracurium injected intermittently.Serum S100β was measured before anesthesia,1d,2d after operation.MMSE scores were estimated at the day before the operation,1d,3d and 7d after operation.Results:The two groups were comparable with regard to the distributions of age,weight and showed non-significant differences on data comparison(P>0.05).The patients were in stable vital sign between the two groups during the anesthesia and the operation.There was no difference between the two groups in operation time and anesthesia time.Lower dosage of remifentanil,fentanyl,propofol and Cis atracurium was used in dexmedetomidine compared to the controlled group,with significant difference.There were no differences in S100β and MMSE scores at the baseline between two groups before operation(P>0.05).Compared with control group,serum concentration of S100β was lower in dexmeditomidine group during 1d and 2d after operation(P<0.05).The MMSE score was higher in dexmedetomidine group than that in controlled group at 1d,3d,7d after operation.(P<0.05)The MMSE scores before surgery shows no significant difference bewteen two groups.Of all patients,14 (23.3%)patients were diagnosed with POCD for their MMSE score being evaluated under27,with 5(16.7%)in dexmedetomidine group and 9(30%)in controlled group.The average MMSE scores in 1d,3d,7d after operation of dexmedetomidine group was higher than controlled group,with significant difference.Conclusion:dexmeditomidine can reduce the incidence of POCD,which may be relative to the decrease of serum S100β concentration,and can protect the central nervous system’s functions.