ANALGESIC EFFICACY OF EPIDURAL MORPHINE AND CLONIDINEIN PATIENTS UNDERGOING DECOMPRESSION OF THE LUMBAR CANAL: A PROSPECTIVE RANDOMIZED TRIAL

ABSTRACT Objective: To evaluate the postoperative analgesic efficacy in patients undergoing lumbar canal decompression using epidural morphine and clonidine at the Hospital Santa Casa de Vitória - ES, Brazil. Methods: Prospective, randomized study of 60 patients with stenosis of the lumbar canal up to two levels with surgical indication, in which decompression of the canal was performed in association with lumbar arthrodesis. In group 1 we performed conventional postoperative analgesia and in group 2, in addition to conventional analgesia, we associated epidural morphine and clonidine. We used VAS as a means of analyzing pain intensity at 1, 12, and 36 hours after surgery. The statistical analysis was performed using Microsoft Office/Excel and the software GraphPad Prism (San Diego, CA, USA). Results: The mean age of patients was 47 years, and 52% were female. The mean VAS in the first hour, 12th, and 36th hours after surgery in the control group was 5.44, 2.13, and 0.55 respectively. In the morphine-clonidine group it was 6.96; 2.21 and 0.60. Comparing one group with another in its absolute values through the Mann-Whitney test, as well as comparing the pain variations between the 1st and 12th hour (1h X 12h) and between the 12th hour and 36th hour (12h x 36h ) through Student’s t test it became clear that there was no statistical difference between groups (p > 0.05). Conclusions: The addition of epidural morphine and clonidine to conventional analgesia is not beneficial to reduce postoperative pain in patients undergoing lumbar canal decompression.

摘要
目的：在巴西圣埃斯皮里图州维多利亚市圣卡萨医院（Hospital Santa Casa de Vitória - ES），评估硬膜外吗啡（epidural morphine）联合可乐定（clonidine）用于腰椎管减压术（lumbar canal decompression）患者的术后镇痛效果。
方法：本研究为前瞻性随机对照研究，纳入60例存在1~2个节段腰椎管狭窄症（stenosis of the lumbar canal）且具备手术指征的患者，所有患者均接受椎管减压联合腰椎融合术（lumbar arthrodesis）。将患者分为两组：对照组采用常规术后镇痛方案，试验组在常规镇痛基础上联用硬膜外吗啡与可乐定。分别于术后1、12、36小时采用视觉模拟评分法（Visual Analogue Scale，VAS）评估疼痛强度。统计学分析采用Microsoft Office/Excel软件及GraphPad Prism软件（美国加利福尼亚州圣地亚哥市）。
结果：纳入患者的平均年龄为47岁，女性占比52%。对照组术后第1、12、36小时的平均VAS评分分别为5.44、2.13、0.55；试验组对应时间点的平均VAS评分分别为6.96、2.21、0.60。通过曼-惠特尼U检验（Mann-Whitney test）比较两组间的绝对评分值，同时通过学生t检验（Student’s t test）比较两组术后1~12小时、12~36小时的疼痛变化幅度，结果显示两组间均无统计学差异（p > 0.05）。
结论：在常规术后镇痛方案基础上加用硬膜外吗啡与可乐定，无法为接受腰椎管减压术的患者带来术后疼痛缓解的获益。