鞘内注射吗啡用于胸腔镜肺叶切除术患者术后镇痛的半数有效剂量

Median effective dose of intrathecal morphine for postoperative analgesia with thoracoscopic lobectomy

目的探讨鞘内注射吗啡(ITM)用于胸腔镜肺叶切除术患者术后镇痛的半数有效剂量(ED 50)。方法选择拟行全麻下胸腔镜肺叶切除术患者22例,年龄35~64岁,BMI 18~30 kg/m^(2),ASAⅠ或Ⅱ级。所有患者于术前在L_(2-3)间隙行蛛网膜下腔穿刺。患者鞘内吗啡的初始给药剂量为5μg/kg,相邻药物剂量比值为1∶1.1,剂量梯度依次为5.00、4.55、4.14、3.76、3.42、3.11μg/kg。根据上一例患者术后镇痛效果,下一例患者上升或下降一个剂量梯度。术后镇痛有效标准:若术后6、12、24、48 h活动时VAS疼痛评分均≤3分,则认为术后镇痛有效;若任一时刻活动时VAS疼痛评分>3分,则认为镇痛无效。采用Probit法计算ED_(50)、ED_(95)及其95%可信区间(CI)。记录呼吸抑制、恶心呕吐、皮肤瘙痒、尿潴留等不良反应的发生情况。结果ITM用于胸腔镜肺叶切除术的ED_(50)为3.468μg/kg(95%CI 2.926~3.782μg/kg),ED_(95)为4.037μg/kg(95%CI 3.746~7.127μg/kg)。有2例(9%)出现皮肤轻微瘙痒,3例(14%)出现恶心呕吐,未观察到其他不良反应发生。结论鞘内注射吗啡用于胸腔镜肺叶切除术的ED_(50)为3.468μg/kg(95%CI 2.926~3.782μg/kg)。

Objective To explore the median effective dose(ED 50)of intrathecal morphine(ITM)for postoperative analgesia with thoracoscopic lobectomy.Methods Twenty-two patients scheduled for elective thoracoscopic lobectomy,aged 35-64 years,BMI 18-30 kg/m^(2),ASA physical statusⅠorⅡ,were enrolled in this study.All patients underwent subarachnoid puncture at the L_(2-3)space before surgery.The initial dose of ITM in patients was 5μg/kg,and the ratio of adjacent drug doses was 1∶1.1.The dose gradients of morphine were:5.00,4.55,4.14,3.76,3.42,and 3.11μg/kg.Depending on the postoperative analgesic effect of the previous patient,the next patient rase or droped by a dose gradient.Effective criteria for postoperative analgesia:if the exercise VAS pain score 6,12,24 and 48 hours after operation was all≤3 points,the postoperative analgesia was considered effective;if the exercise VAS score at any time was>3 points,the analgesia was considered ineffective.The ED_(50),95%effective dose(ED_(95))and 95%confidence intervals(CIs)were calculated using the Probit method.The occurrence of adverse reactions such as respiratory depression,nausea and vomiting,skin itching,and urine retention were recorded.Results The ED_(50)of ITM for postoperative analgesia with thoracoscopic lobectomy was 3.468μg/kg(95%CI 2.926-3.782μg/kg),and the ED_(95)was 4.037μg/kg(95%CI 3.746-7.127μg/kg).Two patients(9%)had mild skin itching,three patients(14%)had nausea and vomiting,and other adverse reactions were not observed.Conclusion The ED_(50)of ITM for postoperative analgesia with thoracoscopic lobectomy was 3.468μg/kg(95%CI 2.926-3.782μg/kg).