BACKGROUND The comparative efficacy of epidural bupivacaine alone and bupivacaine combined with magnesium sulfate in providing postoperative analgesia remains controversial. METHODS We searched Mediline (OvidSP), EMBASE (OvidSP) and Cochrane Central Register of Controlled Trials (CENTRAL) to identify trials that compared epidural bupivacaine and magnesium sulfate combination (intervention) with bupivacaine alone (control). Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework was used to assess the quality of evidence. RESULTS Eleven studies fulfilled our inclusion criteria after screening. We found that epidural bupivacaine combined with magnesium sulfate could prolong the time for first rescue analgesics (SMD 4.96; 95% CI [2.75, 7.17], P < 0.00001, I2 = 98%), reduce the number of patients who need rescue analgesics (RR 0.38; 95% CI [0.20, 0.74], P = 0.004, I2 = 75%) and requirement for rescue analgesics (SMD -2.65; 95% CI [- 4.23, - 1.06], P = 0.001, I2 = 96%). CONCLUSIONS Magnesium suifate as an adjuvant of epidural bupivacaine improved postoperative analgesia. However, we rated the quality of evidence to be very low because of high heterogeneity, imprecise of results and small sample sizes. Furthermore, further large high-quality trials are still needed to confirm the effects of magnesium sulfate on postoperative analgesia.

中文翻译：

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硬膜外布比卡因单独和布比卡因联合硫酸镁在提供术后镇痛方面的比较评估：一项随机对照试验的荟萃分析。

背景硬膜外布比卡因单独使用和布比卡因联合硫酸镁在提供术后镇痛方面的比较疗效仍存在争议。方法我们搜索了Mediline（OvidSP），EMBASE（OvidSP）和Cochrane对照试验中央登记册（CENTRAL），以鉴定将硬膜外布比卡因和硫酸镁联合使用（干预）与单独使用布比卡因（对照）进行比较的试验。建议，评估，发展和评估（GRADE）框架的分级被用来评估证据的质量。结果筛选后，有11项研究符合我们的纳入标准。我们发现硬膜外布比卡因联合硫酸镁可以延长首次抢救镇痛的时间（SMD 4.96； 95％CI [2.75，7.17]，P <0.00001，I2 = 98％），减少需要急救镇痛药的患者数量（RR 0.38; 95％CI [0.20，0.74]，P = 0.004，I2 = 75％）和急救镇痛药的需求量（SMD -2.65; 95％CI [-4.23，-1.06 ]，P = 0.001，I2 = 96％。结论硫酸镁作为硬膜外布比卡因的佐剂可改善术后镇痛效果。但是，由于异质性高，结果不精确和样本量小，我们认为证据质量很差。此外，仍需要进一步的大型高质量试验来证实硫酸镁对术后镇痛的作用。由于异质性高，结果不精确且样本量小，我们认为证据质量很差。此外，仍需要进一步的大型高质量试验来证实硫酸镁对术后镇痛的作用。由于异质性高，结果不精确且样本量小，我们认为证据质量很差。此外，仍需要进一步的大型高质量试验来确认硫酸镁对术后镇痛的作用。