妇科术后病人硬膜外注射不同剂量咪达唑仑对舒芬太尼镇痛效果的影响

目的 评价妇科术后病人硬膜外注射不同剂量咪达唑仑对舒芬太尼镇痛效果的影响.方法 妇科术后病人120例,年龄30～50岁,ASA Ⅰ或Ⅱ级,体重指数<30 kg/m2,随机分为4组,每组30例,S组经硬膜外注射负荷剂量舒芬太尼10 ml,M.组、M1组和M3组分别经硬膜外注射咪达唑仑0.025、0.050、0.075 mg/kg+舒芬太尼10 ml作为负荷剂量,各组均以2 ml/h速率持续输注.按序贯法进行试验,各相邻浓度之间的比值为1.2.采用视觉模拟评分法(VAS评分)评价疼痛程度,VAS评分≤3分为镇痛有效,计算各组舒芬太尼的半数有效镇痛浓度(EC50)及其95%可信区间;采用Rammsay评分法评价镇静水平;观察不良反应的发生情况.结果 S组、M1组、M2组和M3组舒芬太尼的EC50及其95%可信区间分别为0.87(0.79～0.96)、0.82(0.74～0.90)、0.67(0.61～0.74)、0.63(0.56～0.71)μg/ml;与S组比较,M2组、M3组舒芬太尼的EC50降低(P<0.05);Rammsay评分M3组M2组M1组及S组(P<0.05);M3组镇静过度及呼吸抑制发生率较其余3组高(P<0.05).结论 妇科术后病人硬膜外注射舒芬太尼复合咪达唑仑镇痛时,推荐咪达唑仑剂量为0.050～0.075 mg/kg.

Effect of epidural midazolam on the epidural analgesia with sufentanil after gynecological operation

Objective To evaluate the effect of different doses of midazolam administered epidurally on the epidural analgesia with sufentanil after gynecologic operation. Methods One hundred and twenty ASA patients aged 30-50 yr with body weight index<30 kg/m2 undergoing abdominal gynecological operation under epidnral anesthesia received continuous epidnral infusion of sufentanil for 48 h (a loading dose of 10 ml of sufentanil+continuous infiusion at 2 ml/h) after operation. The patients were randomly allocated to one of 4 groups (n=30each):group Ⅰcontrol (C) received epidural sufentanil only; group Ⅱ, Ⅲ , Ⅳ received epidural sufentanil +epidural midazolam 0.025 mg/kg (M1), 0.050 mg/kg (M2) and 0.075 mg/kg (M3) respectively. Epidural catheter was placed at L1.2 or L2.3 interspace. The severity of postoperative pain was assessed with an 100 cm VAS score. Adequate analgesia was defined as VAS score of ≤ 30 cm. Echo of epidural sufentanil was determined by up-and-down sequential technique. The initial sufentanil concentration was 1 μg/ml. Each time the concentration of epidural sufentanil increased/decreased by 20% of the previous concentration. The level of sedation was evaluated with Ramsay sedation score (1=fully awake, 6=asleep, unresponsive to verbal stimulus). The side effects were also recorded. Results The EC50 of sufentanil and 95% confidence interval were 0.87 ('0.79-0.96),0.82(0.74-60.90), 0.67 (0.61-0.74) and 0.63 (0.56-0.71) μg/ml respectively in group C, group M1, M2 and M3. EC50 was significantly lower in group M2 and M3 than in group C. The Ramsay sedation score was in the order of group M3 group M2 group M1 and group C (P<0.05). The incidences of over-sedation and respiratory depression were significantly higher in group M3 than in other 3 groups. Conclusion Epidural midazolam 0.050-0.075 mg/kg can enhance the analgesic effect of epidural sufentanil after gynecological operation.