Intraoperative magnesium helps control postoperative pain and vomiting in spine surgery: Lancet

China: A team of researchers led by Lei Yue discovered that intraoperative intravenous magnesium (IIM) as adjuvant analgesics exhibited overall advantages in terms of lowering analgesic demand and postoperative nausea and vomiting in spine surgery. The findings of this were published in the journal of E Clinical Medicine by Lancet on 04th January 2022.

Recent randomized controlled trials (RCTs) have shown contradictory results about the usefulness and safety of IIM in spine surgery. As a result, the researchers undertook this study with the goal of determining the influence of IIM on spine surgery.

On July 12th, 2021, a literature search was conducted using numerous electronic databases, including ClinicalTrial.gov and Google Scholar, and reference lists were inspected. The researchers chose RCTs that compared the impact of IIM vs placebo therapy on spine surgery. They used a random-effect model to generate pooled standard mean difference (SMD) or risk ratio (RR) with a 95 percent confidence interval (CI). The Cochrane risk-of-bias tool was used to assess the risk of bias, and the Jadad score was used to assess the quality of each included study. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method was used to calculate the level of certainty in effect estimations. Sensitivity analysis was performed by removing each included study from the pooled analysis one at a time.

The results of this work stated as follow:

1. There were 14 trials with a total of 781 participants. IIM lowers postoperative morphine consumption at 24 h (SMD: -161 mg) and intraoperative remifentanil demand (SMD: -209 ug/h).

2. High-quality data suggests that IIM when compared to placebo, lowers the incidence of postoperative nausea and vomiting (RR: 043).

3. Furthermore, moderate-quality data revealed that the IIM group's recovery orientation time was greater than the control group's (SMD: 113 min).

4. The current systematic review and meta-analysis found low- to moderate-quality evidence that IIM lowers intraoperative remifentanil needs and morphine consumption at 24 hours.

Finally, given the available evidence, IIM as adjuvant analgesics had overall positive benefits on spine surgery in terms of analgesics and PONV reduction. Despite these benefits, doctors should be aware that IIM may result in prolonged anesthesia recovery. To verify our findings, future research should include a large sample size, well-defined subgroups, and a longer follow-up period.

Reference:

Lei Yue, Zeng-Mao Lin, Guan-Zhang Mu, Hao-Lin Sun, Impact of intraoperative intravenous magnesium on spine surgery: A systematic review and meta-analysis of randomized controlled trials, eClinicalMedicine, https://doi.org/10.1016/j.eclinm.2021.101246.