Outpatient epinephrine administration reduces ICU admission rates in anaphylactic reactions: A propensity score–matched cohort

ImplicationsWe confirm that outpatient epinephrine use reduces significantly intensive care unit admissions for anaphylactic reactions.There is an urgent need for enhanced education and training among both caregivers and health care professionals to ensure that epinephrine is administered promptly.Anaphylaxis is an acute life-threatening reaction that is a common reason for presenting to the emergency room. 1 Despite the well-recognized benefits of epinephrine in potentially treating anaphylaxis, its independent impact on patient outcomes remains uncertain owing to confounding factors.To address this knowledge gap, we utilized propensity score matching (PSM), a statistical method that mitigates confounders, to determine whether prehospital epinephrine, referred to as outpatient epinephrine, truly influences hospital outcomes when these confounders are accounted for.From April 2011 to November 2023, children (0e18 y old) presenting to the emergency department (ED) of the Montreal Children's Hospital (MCH) were recruited into the anaphylaxis registry.Anaphylaxis was defined as a reaction involving at least 2 organ systems and/or hypotension according to the Food Allergy & Anaphylaxis Network/National Institute Allergy and Infectious Disease (FAAN/NIAID) criteria. 2We collected data prospectively and retrospectively through a standardized data entry form.For prospectively recruited patients, the treating ED physician along with a trained member of the research team identified cases of anaphylaxis and, after obtaining informed written consent, completed the data entry form.The remaining cases were identified retrospectively by searching the electronic medical record system for the International Classification of Diseases, 10th Revision codes related to anaphylaxis.Data were collected regarding demographics (age and sex), the severity of symptoms (mild, moderate, and severe), presence of comorbidities (asthma, exercise, environment, and food allergy) and locations where reaction occurred (at home, restaurant, and school).The severity of anaphylaxis was classified as mild, moderate, or severe, using a modified Muraro et al 3 grading system.Descriptive statistics were used to present demographics and reaction characteristics.All statistical data were analyzed using R 4.2.3 binary for macOs 10.3 (R Foundation for Statistical Computing, Vienna, Austria).The c 2 tests were used to compare baseline categorical variables, whereas an unpaired 2-sided t-test was used to compare baseline medians of continuous variables.