Effectiveness of Intravenous and Nebulized MgSO4 in Children with Asthma Exacerbation: A Systematic Review and Meta-Analysis of Clinical Trials

Abstract

Background/Objectives: Moderate or severe asthma exacerbations may require pharmacological interventions in addition to standard treatment. In this context, magnesium sulfate has been proposed as a second-line therapeutic option, owing to its physiological effects on bronchial smooth muscle. Therefore, the objective of this meta-analysis is to determine the effectiveness of intravenous or nebulized magnesium sulfate in patients with a moderate-to-severe asthmatic crisis. Methods: This systematic review and meta-analysis included randomized controlled trials published between 1990 and 2024, using the PubMed, Scopus, Science Direct, Web of Science, LILACS, Cochrane Library, Springer, and Scielo databases. The risk of bias was assessed using the RoB 2 tool, the quality of evidence with the Jadad scale, and the certainty of the evidence per outcome was evaluated following the GRADE guidelines. The meta-analysis was developed using the statistical software Jamovi 2.3.28^® and RevMan 5.4^®. Results: Fourteen studies with a total of 2242 patients with a moderate-to-severe asthmatic crisis were included. Of these, ten studies evaluated the severity score, eight evaluated hospitalization, five evaluated the length of the hospital stay, and three evaluated intensive care unit admission. The meta-analysis demonstrates that the use of magnesium sulfate is associated with a statistically significant reduction in the risk of hospitalization (RR: 0.79, 95% CI: from 0.67 to 0.94, p = 0.02). However, no effects were observed on the severity score (SMD: -0.37, 95% CI: from -0.92 to 0.17, p = 0.16), the length of the hospital stay (SMD: -0.75, 95% CI: from -1.90 to 0.40, p = 0.14), or admission to intensive care units (RR: 0.62, 95% CI: from 0.28 to 1.36, p = 0.23). Subgroup and sensitivity analyses did not yield significant findings or produce any modification of the effect. Conclusions: Magnesium sulfate reduces hospitalizations in moderate-to-severe pediatric asthma, although it does not improve other relevant clinical outcomes.

Keywords: asthma; child; hospitalization; intensive care units; length of stay; magnesium sulfate.

Figure 1

PRISMA flow diagram with the search and study selection.

Figure 2

Risk-of-bias assessment for the studies included in this review. (a) The symbols used indicate the level of bias risk: “+” corresponds to low risk, “?” denotes unclear risk, and “–“ indicates high risk. These are color-coded as green (low risk), yellow (unclear), and red (high risk). (b) The second panel summarizes the distribution of risk of the bias across all the studies, presenting the percentage of evaluations for each bias domain [28,29,30,31,32,33,34,35,36,37,38,39,40,41].

Figure 3

Forest plot of the effect of magnesium sulfate on the severity score of patients with an asthmatic crisis [27,28,29,30,31,32,33,34,36,38].

Figure 4

Subgroup analysis by route of administration of magnesium sulfate on the severity score in patients with an asthmatic crisis [28,29,30,31,32,33,34,35,37,39].

Figure 5

Forest plot of the effect of magnesium sulfate on hospitalization in patients with an asthmatic crisis [29,31,32,33,34,35,38,41].

Figure 6

Forest plot of the effect of magnesium sulfate on the length of hospital stay in patients with an asthmatic crisis [28,30,35,36,40].

Figure 7

Subgroup analysis by route of administration for the effect of magnesium sulfate on the length of hospital stay in patients with an asthmatic crisis [28,30,35,36,40].

Figure 8

Forest plot of the effect of magnesium sulfate on the risk of admission to the intensive care unit for patients with an asthmatic crisis [31,34,35].

Figure 9

Risk of publication bias. Part (a) hospitalization. Part (b) severity score of the asthmatic crisis.