Magnesium sulfate reduces postoperative pain in women with cesarean section: a meta-analysis of randomized controlled trials

Pain Pract. 2021 Apr 25. doi: 10.1111/papr.13022. Online ahead of print.

ABSTRACT

OBJECTIVES: The use of magnesium sulfate (MgSO₄ ) as an adjunct in different anesthetic regimens for cesarean section (CS) delivery often reports conflicting results. This study aimed to review the effectiveness of magnesium sulfate on improving postoperative analgesia after CS systematically.

METHODS: PubMed, Embase, and the Cochrane library were searched for randomized controlled trials (RCTs) published from inception to February 2020.

RESULTS: A total of 880 women were included (440 in each group). MgSO₄ had a statistically significant effect compared to the control group on the highest VAS (WMD=-0.74, 95%CI: -1.03, -0.46, P<0.001; I² =91.7%, P_{heterogeneity} <0.001) and the last VAS (WMD=-0.47, 95%CI: -0.71, -0.23, P<0.001; I² =95.0%, P_{heterogeneity} <0.001). MgSO₄ prolonged the time to the first use of analgesia compared to the control group (SMD=-3.03 min, 95%CI: -4.32, -1.74, P<0.001; I² =96.3%, P_{heterogeneity} <0.001). MgSO₄ decreased the consumption of analgesia compared to the control group (SMD=-3.20 mg of IV morphine equivalent, 95%CI: -5.45, -0.95, P=0.005; I² =97.6%, P_{heterogeneity} <0.001).

DISCUSSION: MgSO₄ decreases the highest VAS in women who underwent general anesthesia, spinal anesthesia, or epidural for CS (all P<0.05). Additional MgSO₄ significantly reduces postoperative pain in women undergoing CS.

PMID:33896098 | DOI:10.1111/papr.13022