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Evidence-Based Supplement Research
Evidence-Based Supplement Research

Efficacy and safety of perioperative magnesium on postoperative pain in adult patients undergoing cardiothoracic surgeries- a systematic review and meta-analysis.

  • 2026-05-07
  • Journal of cardiothoracic surgery 21(1)
    • R K Swetha
    • Balasubramaniam Gayathri
    • Madhumitha Haridoss
    • Deepakraj Kuppuraman
    • Sananthya Karthikeyan

Study Design

Type
Meta-Analysis
Sample size
n = 140
Population
adult patients undergoing cardiothoracic surgery
Methods
Systematic review and meta-analysis of 10 RCTs, searching PubMed, EMBASE, Scopus, and CENTRAL up to 14 May 2025, comparing perioperative magnesium with placebo or other analgesics, with random-effects meta-analyses
Funding
Unclear

Background

Cardiothoracic surgeries such as CABG, valve replacement, and thoracotomy are associated with significant postoperative pain, for which opioids remain the primary treatment despite notable adverse effects and tolerance. Magnesium, an NMDA receptor antagonist with analgesic and cardioprotective properties, has been suggested as a perioperative adjuvant to improve pain control. This systematic review and meta-analysis examined the efficacy and safety of perioperative magnesium for postoperative pain relief in adult cardiothoracic surgery patients.

Methods

The review followed PRISMA guidelines and was registered with PROSPERO (CRD420251049449). A search was conducted in PubMed, EMBASE, Scopus, and CENTRAL up to 14 May 2025 for randomized controlled trials comparing perioperative magnesium with placebo or other analgesics in adult patients undergoing cardiothoracic surgery. Pain scores, opioid consumption (MME), time to rescue analgesia, length of hospital stay, and adverse events were analyzed. Random-effects meta-analyses were performed using R Studio (v4.3.2) with mean difference (MD) or risk ratio (RR) and 95% confidence intervals (CI).

Results

Ten RCTs involving 1,140 participants were included. Magnesium significantly reduced pain intensity compared with placebo at 24 h postoperatively (MD - 0.85, 95% CI: -1.53 to - 0.16), although the effect did not reach the minimal clinically important difference. No significant differences were observed when magnesium was compared with active analgesics. For all other outcomes, including opioid consumption (MME), time to first rescue analgesia, and length of hospital stay, no significant differences were found in pooled analyses versus either placebo or other analgesics. Heterogeneity was substantial across most outcomes (I² > 75%), and no major adverse events were reported.

Conclusion

Perioperative magnesium shows small and safe analgesic effects after cardiothoracic surgery, but the clinical relevance remains uncertain due to substantial heterogeneity and variable dosing. Further robust trials are needed to define its efficacy and optimal use.

Research Insights

  • For all other outcomes, including opioid consumption (MME), time to first rescue analgesia, and length of hospital stay, no significant differences were found in pooled analyses versus either placebo or other analgesics.

    Effect
    Neutral
    Effect size
    Small
  • For all other outcomes, including opioid consumption (MME), time to first rescue analgesia, and length of hospital stay, no significant differences were found in pooled analyses versus either placebo or other analgesics.

    Effect
    Neutral
    Effect size
    Small
  • For all other outcomes, including opioid consumption (MME), time to first rescue analgesia, and length of hospital stay, no significant differences were found in pooled analyses versus either placebo or other analgesics.

    Effect
    Neutral
    Effect size
    Small
  • No significant differences were observed when magnesium was compared with active analgesics.

    Effect
    Neutral
    Effect size
    Small

Adverse Events Reported

  • MagnesiumOverall tolerability

    no major adverse events were reported

    Finding
    Reported
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