Children With Status Asthmaticus Do Not Benefit From Magnesium Sulfate

Administration of magnesium sulfate to children with status asthmaticus outside of an intensive care setting is safe but confers no benefit, according to the results of a retrospective cohort study published in Pediatric Pulmonology.

Children with status asthmaticus whose asthma does not improve on the standard therapy of inhaled bronchodilator therapy administered in combination with systemic corticosteroids receive a number of different therapies, many of which do not have robust evidence to support their use. Magnesium sulfate is an adjunctive therapy recommended by the National Heart, Lung, and Blood Institute for the treatment of severe asthma exacerbations that do not improve with standard therapy.

Ryan L. DeSanti, DO, from the Department of Pediatric Critical Care at the University of Wisconsin in Madison, and colleagues conducted a retrospective cohort analysis of children between the ages of 2 and 18 years who were being treated with continuous albuterol and were admitted to the pediatric unit (general medical floor or intermediate care unit) of a tertiary care children’s hospital between January 2014 and December 2015. Patients receiving magnesium therapy were matched with patients who had the same respiratory assessment score (RAS) and similar duration of albuterol therapy but did not receive magnesium.

The investigators identified 33 patients who received magnesium and found that in comparison with matched controls, those who received magnesium therapy had longer duration on continuous albuterol (34 vs 18 hours; 95% CI, 4-20 hours; P =.001; effect size, 0.41) and longer length of hospital stay (72 vs 49 hours; 95% CI, 1-33 hours; P =.037; effect size, 0.26). No adverse events attributed to magnesium occurred in any of the 33 patients receiving this therapy. However, 27% of patients in the magnesium sulfate group had to be transferred to the pediatric intensive care unit compared with only 6% of the group that did not receive magnesium therapy.

A number of reasons were listed that could account for the lack of benefit seen with this therapy. For example, magnesium levels were not measured routinely for the study and dosing was not standardized. Therefore, the patients could have received suboptimal doses of magnesium sulfate. Patients who received magnesium may have been sicker than reflected by their RAS, or magnesium sulfate may not have a positive effect on status asthmaticus outside the emergency department or intensive care setting. Failure to adhere to hospital protocol when weaning patients from albuterol for a RAS ≤4 or discharging a patient after 2 doses of albuterol treatment every 4 hours may have also affected efficacy.

The study is further limited by its retrospective design, the small patient population, potential bias in patient selection, and lack of standardized criteria for magnesium administration.

However, the authors noted the high safety profile of and strong evidence for magnesium sulfate administration in the emergency department and called for a well-designed randomized double-blind control trial to better determine the efficacy of magnesium therapy for children on continuous albuterol therapy in the nonintensive care setting.

Reference

DeSanti RL, Agasthya N, Hunter K, Hussain MJ. The effectiveness of magnesium sulfate for status asthmaticus outside the intensive care setting [published online April 16, 2018]. Pediatr Pulmon. doi:10.1002/ppul.24013