Efefcts Of Dexmedetomidine On Early Postoperative Cognitive Dysfunction And Inflammation In The Elderly Patients Undergoing Laparoscopic Rectal Cancer Radical

Objective: To investigate the effect of dexmedetomidine on earlypostoperative cognitive dysfunction (POCD) and inflammation in elderly patientsundergoing laparoscopic rectal cancer radical.Methods: Forty elderly patients scheduled for elective laparoscopic rectalcancer radical (＞65) were randomly divided into the two groups:Dexmedetomidine (DEX) group (D group, n=20) and Normal saline controlgroup(N group, n=20). All surgeries were completed by total intravenous anesthesia.The patients in group D were infused intravenously dexmedetomidine1ug/kg over15min before anesthesia induction, then infused at the speed of0.2~0.5ug/kg/hintraoperative and stop at30min before the end of the surgery. The patients in groupN infused intravenously the same volume of normal saline. Monitored ECG、BP、HR、SpO2and PetCO2. Respectively recorded average blood pressure and heart rateat5points: before induction (T0),5minutes after intubation (T1),20minutes afterof pneumoperitoneum (T2), the end of operation (T3),5minutes after extubation(T4). Recorded surgical time and blood loss、 fluid input、the total anesthetic dosageof the patients intraoperative. Respectively evaluated cognitive function of thepatients with the Mini Mental State Examination (MMSE) at three time points:1daybefore surgery,1day and7days after surgery and calculate the incidence of POCD.Collected venous blood at three time points: before anesthesia induction, at the endof operation and24h after operation and measure the concentration of tumor necrosisfactor-α (TNF-α).Results: There is no significant difference on the general situation between twogroups of patients. The total dosage of propofol and remifentanil of patients in D group are significantly smaller than group N (P<0.05). The fluctuation of bloodpressure and heart rate in the D group were also less marked than group N.1d and7dafter operation MMSE score in the D group obviously increased, the difference is ofsignificance statistically (P<0.05). The POCD incidence of1d and7d after operationin the D group were respectively15.0%and5.0%, the group N were respectively25.0%and15.0%. The difference is of no significance statistically (P>0.05). There’sno statistical difference in the comparison of serum TNF-α concentration of twogroups of patients before anesthesia. At the end of the operation the serum TNF-αconcentration in group N was significantly higher than group D,24h after surgerythe serum TNF-α concentration in group D was significantly lower than group N (P<0.05).Conclusion: The application of dexmedetomidine can increase MMSE score ofthe elderly patients undergoing laparoscopic rectal cancer radical during the earlypostoperative period, but not decrease the incidence of POCD. The mechanismshould be related to the decreasing cytokine. The dexmedetomidine can maintainintraoperative hemodynamic stable and decrease the anesthetic dosage of patients inoperation.