Background: 

Epidural opioids provide effective postoperative analgesia after lumbar spine surgery. Ketamine has been shown to reduce opioid-induced central sensitization and hyperalgesia. We hypothesized that adding ketamine to epidural opioids would prolong the duration of analgesia and enhance analgesic efficacy after lumbar spine surgery.

Methods: 

American Society of Anesthesiologists physical status class I to II patients aged between 18 and 70 years with normal renal function undergoing lumbar laminectomy were recruited into this single-center randomized trial. Patients were randomized to receive either single-dose epidural morphine (group A) or epidural morphine and ketamine (group B) for postoperative analgesia. The primary objective was to compare the duration of analgesia as measured by time to the first postoperative analgesic request. Secondary objectives were the comparison of pain scores at rest and movement, systemic hemodynamics, and the incidence of side effects during the first 24 hours after surgery.

Results: 

Fifty patients were recruited (25 in each group), of which data from 48 were available for analysis. The mean±SD duration of analgesia was 20±6 and 23±3 hours in group A and group B, respectively (P=0.07). There were 12/24 (50%) patients in group A and 17/24 (71%) patients in group B who did not receive rescue analgesia during the first 24-hour postoperative period (P=0.07). Pain scores at rest and movement, systemic hemodynamics, and postoperative complications were comparable between the groups.

Conclusions: 

The addition of ketamine to epidural morphine did not prolong the duration of analgesia after lumbar laminectomy.

中文翻译：

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在硬膜外吗啡中加入氯胺酮不会延长腰椎椎板切除术或椎间盘切除术后的术后镇痛

背景： 

硬膜外阿片类药物可在腰椎手术后提供有效的术后 镇痛。氯胺酮已被证明可以减少阿片样物质引起的中枢敏化和痛觉过敏。我们假设在硬膜外阿片类药物中加入氯胺酮会延长镇痛时间并增强腰椎手术后的镇痛效果。

方法： 

美国麻醉师协会身体状况等级为 I 至 II 级且年龄在 18 至 70 岁之间且肾功能正常并接受腰椎椎板切除术的患者被招募到这项单中心随机试验中。患者被随机分配接受单剂量硬膜外吗啡（A 组）或硬膜外吗啡和氯胺酮（B 组）进行术后 镇痛。主要目的是比较按时间测量的镇痛持续时间与首次术后镇痛要求。次要目标是比较疼痛休息和运动评分、全身血流动力学以及手术后最初 24 小时内副作用的发生率。

结果： 

招募了 50 名患者（每组 25 名），其中 48 名的数据可用于分析。A 组和 B 组的平均镇痛持续时间分别为 20±6 和 23±3 小时（P =0.07）。A 组和 B 组分别有 12/24 (50%) 和 17/24 (71%) 患者在术后第一个 24 小时内未接受抢救镇痛（P =0.07）。休息和运动时的疼痛评分、全身血流动力学和术后并发症在两组之间具有可比性。

结论： 

腰椎椎板切除术后在硬膜外吗啡中加入氯胺酮并没有延长镇痛时间。