[Effects of dexmedetomidine on recovery period of anesthesia and postoperative cognitive function after robot-assisted laparoscopicradical prostatectomy in the elderly people].

OBJECTIVE: To evaluate the neuroprotective effect of dexmedetomidine on recovery period of anesthesia and postoperative cognitive function after robot assisted laparoscopicradical prostatectomy in the elderly people. METHODS: A total of 100 elderly patients who underwent robotic laparoscopic radical prostatectomy were divided into 2 groups: A dexmedetomidine group (n=50) and a control group (n=50). Patients in the dexmedetomidine group were given a loading dosage of dexmedetomidine [0.8 μg/(kg.h)] intravenously 10 min before the induction of general anesthesia followed by continuous infusion [0.3 μg/(kg.h)]. Patients in the control group were given 0.9% saline solution instead of dexmedetomidine. After pneumoperitoneum establishment, all patients adopted 40°trendelenberg position. MAP, HR, and BIS from each patient at the end of surgery immediately (T0), wake up (T1), extubation (T2), 10 min after extubation (T3) were monitored. Ramsay score, surgery comfort score, postoperative delirium score, and VAS scores were measured. At the time of preoperative 1 d, postoperative 1 d or 5 d, cognitive function was assessed and the concentration of neuron-specific enolase (NSE), tumor necrosis factor-α (TNF-α), superoxide dismutase (SOD) and interleukin-6 (IL-6) were detected. RESULTS: In the dexmedetomidine group, delirium rating scale was significantly smaller than that of the control group (P<0.05) while Ramsay sedation score was significantly greater than that of the control group (P<0.05). The levels of TNF-α, NSE, and IL-6 in the dexmedetomidine group were significantly reduced compared with those in the control group (P<0.05). The level of SOD in the dexmedetomidine group significantly elevated compared with that in the control group (P<0.05). Seventeen patients in the control group and 11 in the dexmedetomidine group displayed postoperative cognitive dysfunction (POCD) at the 1st day after surgery. Meanwhile, 12 patients in the control group and 9 in the dexmedetomidine group showed POCD at the 5th day after surgery (P<0.05). CONCLUSION: Dexmedetomidine could exert a neuroprotective effect on elderly patients in robotic-assisted laparoscopic radical prostatectomy in recovery period of anesthesia and postoperative recovery period, which might be related to the reduction of inflammatory reaction by dexmedetomidine.