不同剂量右美托咪定对妇科手术患者异丙酚顺行性遗忘作用的影响

Effects of different doses of dexmedetomidine on anterograde amnesia of propofol in patients undergoing gynecological surgery

目的 评价不同剂量右美托咪定对妇科手术患者异丙酚顺行性遗忘作用的影响.方法 择期行腹腔镜下全子宫切除术患者60例,年龄20～50岁,体重指数18 ～ 25 kg/m2,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将其分为3组（n=20）：异丙酚组（C组）、低剂量右美托咪定复合异丙酚组（D1组）和高剂量右美托咪定复合异丙酚组（D2组）.D1组和D2组分别经15 min静脉输注右美托咪定0.2、0.4 μg/kg.随后3组靶控输注异丙酚,初始血浆靶浓度（Cp）为0.5 μg/ml,依次递增至0.9、1.3、1.7、2.1 μg/ml,每一浓度维持3 min.分别于入室后（基础水平）、右美托咪定输注完毕、异丙酚Cp达0.5、0.9、1.3、1.7、2.1 μg/ml维持3 min时进行遗忘测试和警觉/镇静评分（OAA/S评分）,计算遗忘率达95％时异丙酚Cp和BIS值,并记录该期间低血压、心动过缓、呼吸抑制和上呼吸道梗阻的发生情况.结果 与C组比较,D1组和D2组遗忘率升高,遗忘率达95％时异丙酚Cp和呼吸抑制发生率降低,BIS值升高（P＜0.05）,其他不良事件发生率差异无统计学意义（P＞0.05）;与D1组比较,D2组遗忘率升高,遗忘率达95％时异丙酚Cp降低,BIS值升高（P＜0.05）,D1组和D2组不良事件发生率差异无统计学意义（P＞0.05）.结论 右美托咪定增强妇科手术患者异丙酚顺行性遗忘作用的适宜剂量为0.4 μg/kg.

Objective To evaluate the effects of different doses of dexmedetomidine on the anterograde amnesia of propofol in the patients undergoing gynecological surgery.Methods Sixty patients,aged 20-50 yr,with body mass index of 18-25 kg/m2,of ASA physical status Ⅰ or Ⅱ,scheduled for elective laparoscopic total hysterectomy,were randomly divided into 3 groups （n =20 each） using a random number table：propofol group （group C）,low-dose dexmedetomidine combined with propofol group （group D1） and high-dose dexmedetomidine combined with propofol group （group D2）.Dexmedetomidine 0.2 and 0.4 mg/kg were infused intravenously over 15 min in D1 and D2 groups,respectively.Target-controlled infusion of propofol was then started at an initial target plasma concentration （Cp） of 0.5 μg/ml.The Cp increased to 0.9,1.3,1.7 and 2.1 μg/ml in turn and maintained at each level for 3 min.After entering the operating room （baseline）,at the end of dexmedetomidine infusion,and when Cp was maintained at each level for 3 min after being increased to 0.9,1.3,1.7 and 2.μg/ml in turn,and amnestic test and OAA/S score were performed.The Cp of propofol and BIS value were calculated when the amnestic rate reached 95 %.The development of hypotension,bradycardia,respiratory depression,and upper airway obstruction was also recorded.Results Compared with group C,the amnestic rate was increased,the Cp of propofol and incidence of respiratory depression were decreased when the amnestic rate reached 95%,BIS value was increased （P 〈 0.05）,and no significant change was found in the incidence of the other adverse events in D1 and D2 groups （P 〉 0.05）.Compared with group D1,the amnesia rate was increased,the Cp of propofol was decreased and the BIS value was increased when the amnestic rate reached 95 % in group D2 （P 〈 0.05）,and no significant change was found in the incidence of the other adverse events in D1 and D2 groups （P 〉 0.05）.Conclusion The optimum dose of dexmedetomidine enhancing the anterograde amnesia of propofol is 0.4 μg/kg in the patients undergoing gynecological surgery.