Intravenous Magnesium: Prompt use for Asthma in Children Treated in the Emergency Department (IMPACT-ED), a pilot randomized trial.

BACKGROUND

Asthma is the most common chronic illness of childhood and a leading cause of hospitalization and health care costs for children. Intravenous magnesium sulfate (IVMg) may help severely ill children avoid hospitalization when added to standard treatment in an emergency department (ED), but this has not been adequately evaluated in a large trial. We conducted a pilot trial to test procedures and gather information to plan a large multicenter trial.

METHODS

Children 2-17 years old with severe acute asthma were randomized in a multicenter, double-blind, controlled trial of placebo (saline, 1 mL/kg, max 40 mL), low-dose IVMg (50 mg/kg, max 2 g), or high-dose IVMg (75 mg/kg, max 3 g) in addition to standard asthma therapy at the EDs of three tertiary pediatric hospitals between September 2022 and May 2023. We assessed the feasibility of delivering study drug within 90 min of treatment (defined as the start of the first inhaled albuterol) and monitoring for hypotension and obtained blood samples for pharmacologic analysis. Our target enrollment was one participant per site per week (90 total).

RESULTS

A total of 52 patients were randomized, and 49 received study drug. Median (Q1, Q3) participant age was 6.3 (4.6, 9.6) years and 35 (67.3%) were male. Among 52 randomized participants, study drug was delivered within 90 min to 34 (65.4%), 486/542 (89.7%) anticipated blood pressure measurements were within time frames, 138/156 (88.5%) anticipated blood samples were obtained, and 38 (73.1%) were hospitalized. Hypotension was measured within 2 h of study drug administration in 2/18 (11.1%) who received placebo and 2/31 (6.5%) who received IVMg.

CONCLUSIONS

Most anticipated blood pressure measurements and blood samples were obtained. Hypotension occurred at rates similar to previous reports. Lower-than-expected enrollment (related to low patient volumes) and timely delivery of study drug will require consideration for a larger trial.