The effect of intravenous magnesium on postoperative morphine consumption in noncardiac surgery: A systematic review and meta-analysis with trial sequential analysis.

Study answer

What this study found

Adjunctive intravenous magnesium reduced postoperative morphine consumption in the first 24 hours, with a pooled mean difference of -5.6 mg (95% CI -7.54 to -3.66; P < 0.001; I2 = 92%) across 18 trials and 899 active-arm participants, and it delayed time to first analgesia by 143 minutes (95% CI 103 to 183; P < 0.001) in 11 trials with 824 active-arm participants. It did not meaningfully improve postoperative pain scores (MD -0.30 on a 0 to 10 scale, 95% CI -0.69 to 0.09; P = 0.13) or postoperative nausea and vomiting (OR 1.01, 95% CI 0.75 to 1.37; P = 0.93). Magnesium lowered shivering…

Study & population

Systematic review and meta-analysis with trial sequential analysis of randomized trials in adults undergoing noncardiac surgery.

Intervention

Prophylactic intravenous magnesium was administered perioperatively as a bolus, an infusion, or a bolus followed by infusion, with regimens varying widely across trials.

Key limitation

The evidence was limited by substantial heterogeneity for several outcomes, including morphine consumption and serum magnesium concentration, and by risk of bias, indirectness, and imprecision.

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Original abstract