Aida S, Yamakura T, Baba H, Taga K, Fukuda S, Shimoji K
Departments of Anesthesiology, Teikyo University School of Medicine, Tokyo, Japan.
Anesthesiology. 2000 Jun;92(6):1624-30. doi: 10.1097/00000542-200006000-00020.
Morphine and ketamine may prevent central sensitization during surgery and result in preemptive analgesia. The reliability of preemptive analgesia, however, is controversial.
Gastrectomy patients were given preemptive analgesia consisting of epidural morphine, intravenous low-dose ketamine, and combinations of these in a randomized, double-blind manner. Postsurgical pain intensity was rated by a visual analog scale, a categoric pain evaluation, and cumulative morphine consumption.
Preemptive analgesia by epidural morphine and by intravenous low-dose ketamine were significantly effective but not definitive. With epidural morphine, a significant reduction in visual analog scale scores at rest was observed at 24 and 48 h, and morphine consumption was significantly lower at 6 and 12 h, compared with control values. With intravenous ketamine, visual analog scale scores at rest and morphine consumption were significantly lower at 6, 12, 24, and 48 h than those in control subjects. The combination of epidural morphine and intravenous ketamine provided definitive preemptive analgesia: Visual analog scale scores at rest and morphine consumption were significantly the lowest at 6, 12, 24, and 48 h, and the visual analog scale score during movement and the categoric pain score also were significantly the lowest among the groups.
The results suggest that for definitive preemptive analgesia, blockade of opioid and N-methyl-d-aspartate receptors is necessary for upper abdominal surgery such as gastrectomy; singly, either treatment provided significant, but not definitive, postsurgical pain relief. Epidural morphine may affect the spinal cord segmentally, whereas intravenous ketamine may block brain stem sensitization via the vagus nerve during upper abdominal surgery.
吗啡和氯胺酮可能在手术期间预防中枢敏化并产生超前镇痛作用。然而，超前镇痛的可靠性存在争议。
对接受胃切除术的患者以随机、双盲方式给予由硬膜外吗啡、静脉低剂量氯胺酮及其组合组成的超前镇痛。术后疼痛强度通过视觉模拟评分、分类疼痛评估和吗啡累积消耗量进行评定。
硬膜外吗啡和静脉低剂量氯胺酮进行超前镇痛均有显著效果，但并不确切。使用硬膜外吗啡时，与对照值相比，在24小时和48小时时静息视觉模拟评分显著降低，且在6小时和12小时时吗啡消耗量显著更低。使用静脉氯胺酮时，在6小时、12小时、24小时和48小时时静息视觉模拟评分和吗啡消耗量均显著低于对照组。硬膜外吗啡和静脉氯胺酮联合使用可提供确切的超前镇痛：在6小时、12小时、24小时和48小时时静息视觉模拟评分和吗啡消耗量均显著最低，且运动时视觉模拟评分和分类疼痛评分在各组中也显著最低。
结果表明，对于确切的超前镇痛，在诸如胃切除术的上腹部手术中，阻断阿片类和N-甲基-D-天冬氨酸受体是必要的；单独使用任何一种治疗方法均可提供显著但不确切的术后疼痛缓解。硬膜外吗啡可能对脊髓产生节段性影响，而静脉氯胺酮可能在上腹部手术期间通过迷走神经阻断脑干敏化。
