North American Practice Patterns of Intravenous Magnesium Therapy in Severe Acute Asthma in Children

Objectives: Although intravenous (IV) magnesium (Mg) can decrease hospitalizations in children with severe acute asthma, its use is often limited to resistant disease, and disposition may be determined prior to its use. Since knowledge about practice patterns of IV Mg would enhance knowledge translation and guide future research, we surveyed pediatric emergency physicians with interest in clinical research to determine the frequency, indications, adverse events, and barriers to use of IV Mg in children with severe acute asthma. Methods: A cross-sectional online survey of two national pediatric emergency physician associations in Canada and the United States was conducted using a modified Dillman technique. Results: Response rates were 124 of 180 (69%) in Canada and 75 of 108 (69%) in the United States. Although 88% of participants report knowing that Mg is effective, only 14 of 199 (7%) give it to prevent hospitalizations and 142 of 199 (71%) give it to prevent admissions to the intensive care unit (ICU). Thirty-eight percent of respondents use Mg in < 5% of stable children with severe acute asthma, while 79% use it in 50% or more of the ICU candidates with concern about impending respiratory failure. Seventy-nine percent of the participants report that < 5% of their patients given Mg are discharged home from the ED. Twenty-four percent of respondents who administer Mg have encountered associated severe hypotension requiring therapy, and 2% have witnessed-related apnea. Factors affecting Mg use include concern about side effects expressed by 24% of physicians and a belief that IV therapy is not necessary, expressed by 31%. Conclusions: Intravenous Mg appears to be uncommonly used in stable children with severe acute asthma and does not frequently play a role in reducing hospitalizations. Further research to justify its enhanced use and to better establish its true adverse effect profile is indicated.