目的 探讨右旋美托咪啶对老年患者经尿道前列腺电切除术后认知功能障碍的影响。方法 选择全身麻醉下择期行经尿道前列腺电切除术后ASAI～II级的老年患者80例，年龄65～85岁，采用随机数字表法，随机分为两组，右旋美托咪啶组（40例）和对照组（40例）。右旋美托咪啶组在全麻插管后给予右美托咪定负荷剂量0.5μg?kg－1，输注时间10 min，然后以维持剂量0.5μg?kg－1?h-1持续泵注，手术结束前40 min停止输注；对照组以相同方法静脉给予等容量0.9%氯化钠注射液。两组患者于麻醉前和术后第4d和7d应用简易智力状态量表（MMSE）评估术后认知功能。结果 两组患者术前MMSE评分组间差异无统计学意义（P＞0.05）。右旋美托咪啶MMSE评分在术后第4d和7d时均明显高于对照组，差异有统计学意义（P＜0.05）。结论 应用右旋美托咪啶能够提高老年患者经尿道前列腺电切除术后认知功能。

Objective To evaluate the effects of dexmedetomidine on postoperative cognitive dysfunction in elderly patients undergoing Transurethral Resection of Prostate.Methods eighty ASA I～II elderly patients scheduled for selective Transurethral Resection of Prostate under general anesthesia,aged 65～85 years,were randomized equally into 2 groups(n=40 each): dexmedetomidine group and control group.In the dexmedetomidine group，a loading dexmedetomidine dose of 0.5μg?kg－1 was infused about 30 min after endotracheal intubation of anesthesia，respectively，followed by infusion a maintenance dose of 0.5μg?kg－1?h-1, respectively,until 40 min before the end of surgery，while the equal volume of normal saline was given in the control group．All patients were tested with mini-mental state examination(MMSE),preoperatively and postoperatively on day 4 and day 7.Results There was no significant difference in the score of MMSE and WMS between dexmedetomidine group and control group preoperatively(P＞0.05).Compared with control group, the score of MMSE in dexmedetomidine group was obviously higher on day 4 and day 7 postoperatively,which was significantly different(P＜0.05). Conclusion dexmedetomidine can reduce the incidence of postoperative cognitive dysfunction in elderly patients undergoing Transurethral Resection of Prostate.