Department of Anesthesiology, Hospital General Universitario de Ciudad Real, Ciudad Real, Spain.
Minerva Anestesiol. 2013 Jun;79(6):667-78.
The efficacy and safety of intrathecal magnesium as analgesic adjuvant has been tested by several clinical trials in recent years. We performed a meta-analysis of the available literature.
Randomized clinical trials comparing a 50 to 100 mg dose of intrathecal magnesium sulfate versus placebo in addition to an intrathecal local anesthetic and/or opiate for a below-umbilicus procedure were included. Medline, LILACS, Cochrane Library and Google Scholar databases were searched. A random analysis was performed and heterogeneity was tested for. The size of the effect for quantitative outcomes was calculated as standard mean difference (SMD, neutral=0); and as odds ratio (OR, neutral=1) for dichotomous outcomes.
Twelve studies totaling 817 patients were included. The "time to first analgesia request" was at least 35 minutes longer when intrathecal magnesium was included in the intervention (SDM 0.94, 95%CI 0.51 to 1.37, P<0.001). The "onset time to sensory block" (SDM 0.64, 95%CI 0.15 to 1.12, P=0.01) and the "time to maximal motor block" (SDM 0.97, 95%CI 0.28 to 1.67, P=0.006) were 2.4 minutes slower with intrathecal magnesium. There was no difference in "time to full motor recovery, incidence of pruritus, postoperative nausea and vomiting, bradicardia, low blood pressure and urinary retention". No cases of respiratory depression or neurotoxicity were recorded in these studies.
The inclusion of 50 to 100 mg of intrathecal magnesium in a spinal anesthetic prolongs opiate analgesia duration; no safety concerns have been identified by the included clinical studies but additional evidence is advised.
近年来，已有几项临床试验测试了鞘内注射镁作为镇痛佐剂的疗效和安全性。我们对现有文献进行了荟萃分析。
纳入比较鞘内给予 50 至 100mg 硫酸镁与鞘内给予局部麻醉药和/或阿片类药物联合鞘内注射镁治疗下腹部以下手术的随机临床试验。检索了 Medline、LILACS、Cochrane 图书馆和 Google Scholar 数据库。进行了随机分析并测试了异质性。定量结果的效应大小计算为标准均数差（SMD，中性=0）；二分类结果为比值比（OR，中性=1）。
共纳入 12 项研究，总计 817 例患者。鞘内注射镁时，“首次镇痛请求时间”至少延长 35 分钟（SMD 0.94，95%CI 0.51 至 1.37，P<0.001）。“感觉阻滞起效时间”（SMD 0.64，95%CI 0.15 至 1.12，P=0.01）和“最大运动阻滞起效时间”（SMD 0.97，95%CI 0.28 至 1.67，P=0.006）分别慢 2.4 分钟。“完全运动恢复时间、瘙痒发生率、术后恶心呕吐、心动过缓、低血压和尿潴留”无差异。这些研究中未记录到呼吸抑制或神经毒性病例。
椎管内麻醉中加入 50 至 100mg 鞘内镁可延长阿片类药物镇痛持续时间；纳入的临床研究未发现安全性问题，但建议进一步提供证据。
