Children Receiving IV Magnesium for Acute Asthma More Likely to Be Hospitalized

Nearly 9 in 10 children given intravenous (IV) magnesium for refractory asthma ended up being admitted to the hospital, but new research suggests that may be partly due to a lack of clarity about the therapy’s safety profile.

A new report finds that children who receive intravenous (IV) magnesium sulfate to treat refractory asthma are much more likely to be hospitalized than children who did not receive the treatment.

The study, published in JAMA Network Open, suggests further clarification of the benefits of magnesium therapy is needed.

When a child is brought to the emergency department with acute asthma exacerbation, the primary treatment is typically systemic corticosteroids, inhaled β2 agonists, or anticholinergics. However, some patients will not respond to those therapies, and in such cases, IV magnesium sulfate is a common second-line therapy.

The problem, according to the authors, is that “the evidence of IV magnesium benefit is…limited to disparate results from 3 small randomized controlled trials” representing a total of 115 patients.

In an effort to better understand the impact, or lack thereof, of magnesium in patients with asthma, the investigators conducted a secondary analysis of a trial that compared the use of albuterol and magnesium with that of albuterol alone. The initial study concluded that magnesium did not appear to have a benefit for patients with moderate to severe asthma. That study was based on the experiences of children who received care at 1 of 7 Canadian emergency departments between 2011 and 2019.

A total of 816 patients were included in the secondary analysis, of whom 63% were male. The patients had a median age of 5 years, and less than half (44.6%) ended up being hospitalized. The investigators found that 26.3% of the 215 participants who were given IV magnesium and almost all of those patients (88.4%) were eventually hospitalized. At the same time, just 29.0% of the 601 children who did not receive magnesium were hospitalized.

The rate of hospitalization among patients given magnesium was particularly high during the first 5 years of the study, from 2011 to 2016. Pediatric Respiratory Assessment scores of 3 or lower at emergency department disposition were also associated with hospitalization among patients receiving magnesium. Finally, patients given albuterol after the experimental treatment were more likely to be hospitalized.

The authors noted that their findings conflict with those of earlier systematic reviews that suggested that magnesium reduces the risk of hospitalization. They cited a number of possible reasons for the contradiction.

“First, IV magnesium therapy is a second-line intervention typically reserved for patients with more severe illness and therefore may be associated with a low threshold for hospitalization,” they wrote. Other potential reasons include the lack of clarity with regard to the safety of discharging patients after administration of IV magnesium, which the authors suggested may prompt physicians to err on the side of hospitalization.

However, the investigators noted that such precautionary hospital admittance may not always be warranted. None of the children in the study who were discharged following magnesium therapy required a return visit to the hospital, suggesting that the therapy is safe.

“Of interest, almost all children in this study who were discharged home after IV magnesium therapy were managed at 1 center, which had the highest rate of IV magnesium use and therefore possibly greater confidence in its use,” they wrote.

The investigators concluded that further research is needed to better understand the potential benefits of the therapy and also to clarify its safety profile.

Reference

Schuh S, Freedman SB, Zemek R, et al. Association between intravenous magnesium therapy in the emergency department and subsequent hospitalization among pediatric patients with refractory acute asthma: secondary analysis of a randomized clinical trial. JAMA Netw Open. 2021;4(7):e2117542. doi:10.1001/jamanetworkopen.2021.17542