236 - Prompt use of Intravenous Magnesium for Asthma in Children Treated in the Emergency Department: A pilot randomized trial

Poster Number: 236
Publication Number: 236.2953

Background: Asthma is the most common chronic illness of childhood and a leading cause of hospitalization and healthcare costs for children. Intravenous magnesium sulfate (IVMg) may help severely ill children avoid hospitalization when given in addition to standard treatment in an emergency department (ED) but has not been adequately evaluated in a large trial.

Objective: We conducted a pilot clinical trial to test procedures and gather necessary information to plan the large trial.

Design/Methods: Children 2-17 years old with severe acute asthma were randomized in a multicenter, randomized, double-blind, controlled trial of placebo (saline, 20 ml/kg), low-dose IVMg (50 mg/kg, max 2 gm), or high-dose IVMg (75 mg/kg, max 3 gm) 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 the first 90 minutes of treatment (defined as the start of the first inhaled albuterol), measuring blood pressure frequently, and obtaining three blood samples for pharmacologic analysis. Our target enrollment was one per site per week (90 patients total).

Results: A total of 52 children were randomized, and 49 received study drug. Mean age of participants was 7.3 years (standard deviation [SD] 3.6 years) and 35 (67.3%) were male. Mean time from start of treatment to start of study drug (truncated at 180 minutes) was 95.6 minutes (SD 41.2 min) and study drug was delivered within 90 minutes to 29 (55.8%) children. Of 572 anticipated blood pressure measurements, 521 were obtained, with 496 (86.7%) obtained within expected time windows. Hypotension was measured in 4 (8.2%) patients within 2 hours after study drug infusion. Of 156 anticipated blood samples, 138 (88.5%) were obtained. Hospitalization was the outcome for 38 (73.1%) children.

Conclusion(s): A multi-center randomized trial of early IVMg in children with severe acute asthma is feasible. A very high number of planned blood samples and blood pressure measurements were obtained. Hypotension was measured at rates similar to previous reports. A lower-than-expected enrollment rate and delivery of study drug within 90 minutes to just more than half of participants will require consideration for a larger trial.