The effect of magnesium sulfate on emergence agitation in surgical adult patients undergoing general anesthesia: A systematic review and meta-analysis of randomized controlled trials

Study objective: Investigating the effect of magnesium sulfate (MS) on emergence agitation (EA) in adult surgical patients following general anesthesia (GA). Design: Systematic literature review and meta-analysis (PROSPERO number: CRD42023461988). Setting: Review of published literature. Patients: Adults undergoing GA. Interventions: Intravenous administration of MS. Measurements: We searched PubMed/MEDLINE, EMBASE, the Cochrane Library, Scopus, and Web of Science for publications until September 14, 2023. The primary outcome was the incidence of EA, while the secondary outcomes included the impact of MS on postoperative agitation score (PAS), emergence variables and adverse events. Relative risk (RR) with 95% confidence interval (CI) measured dichotomous outcome, while standardized mean difference (SMD) or mean difference (MD) with 95% CI measured continuous outcomes. Main results: Meta-analysis of five randomized controlled trials (RCTs) indicated that MS was associated with a lower incidence of EA at various time points (0 min: RR = 0.62, 95% CI [0.41, 0.95]; p = 0.183, I-2 = 43.6%; 5 min: RR = 0.29, 95% CI [0.16, 0.52]; p = 0.211, I-2 = 36%; 10 min: RR = 0.14, 95% CI [0.06, 0.32]; p = 0.449, I-2 = 0%; 15 min: RR = 0.11, 95% CI [0.02, 0.55]; p = 0.265, I-2 = 19.5%; 30 min: RR = 0.05, 95% CI [0.00, 0.91]; the postoperative period: RR = 0.21, 95% CI [0.09, 0.49]; p = 0.724, I-2 = 0%;). Additionally, MS was associated with a reduced PAS at various time points except for 0 min. However, no significant differences were observed in extubation time, the length of stay in the post-anesthesia care unit, postoperative nausea and vomiting or total complications. Conclusions: Limited available evidence suggests that MS was associated with a lower incidence of EA. Nevertheless, further high-quality studies are warranted to strengthen and validate the effect of MS in preventing EA in adult surgical patients.