11 Is emergency department transfer always required following anaphylaxis and epinephrine use?
Authors: Perlman Lauren , Gabrielli Sofianne , Clarke Ann E , Colli Luca Delli , Colli Marina Delli , Morris Judy , Gravel Jocelyn , Lim Rodrick , Chan Edmond S , Goldman Ran D , O’Keefe Andrew , Gerdts Jennifer , Chu Derek K , Upton Julia , Hochstadter Elana , Moisan Jocelyn , Bretholz Adam , McCusker Christine , Zhang Xun , Protudjer Jennifer L P , Abrams Elissa M , Simons Elinor , Ben-Shoshan Moshe 
Published: October 2024

Abstract

Background
Patients known for anaphylaxis are advised to always carry 2 epinephrine auto-injectors (EAI) with them. With epinephrine being the first-line treatment for anaphylaxis, current guidelines recommend prompt EAI administration, followed by observation in the emergency department (ED) for 4 hours. Data supporting transfer to the ED in all cases after epinephrine are sparse. Recent North American allergy guidelines no longer suggest that ED presentation after EAI use is required for all cases of anaphylaxis.

Objectives
We aimed to describe the need for additional ED treatment in children known for food-triggered anaphylaxis who received at least 1 EAI pre-hospital.

Design/Methods
Data on children under 18 years with food-induced anaphylaxis who received at least one dose of pre-hospital epinephrine was collected from the Cross-Canada Anaphylaxis REgistry (C-CARE) from seven hospitals. A standardized questionnaire obtained information on symptoms, allergens, comorbidities, and pre-hospital and in-hospital management. Multivariable logistic regression was performed to identify factors associated with ED management, among children who received 1, 2 or 3 or more doses of epinephrine pre-hospital.

Results
From 2011 to 2023, 1054 children with known food-triggered anaphylaxis and who used one or more EAIs pre-hospital were enrolled in C-CARE. The mean age at reaction was 8.2 (standard deviation [SD] 5.3) years, 648 (60.8%) were male and 82 (7.8%) of reactions were severe (defined as loss of bowel control, cyanosis, respiratory arrest, hypotension and/or circulatory collapse, dysrhythmia, severe bradycardia and/or cardiac arrest, confusion, and loss of consciousness). Primary triggers included peanuts (n=280; 26.6%) followed by tree nuts (n=173; 16.4%). 193 patients (18.3%) had known asthma and 201 received additional dose(s) of epinephrine in the ED, the majority of whom (177, 88.1%) received one dose. Only 2.9% of patients required admission. Among all patients, reactions to egg were less likely to require additional epinephrine (aOR 0.90; 95% CI 0.83, 0.99), and more likely with severe reactions (aOR 1.24; 95% CI 1.14-1.35). Among patients who received only one EAI pre-hospital, severe reactions (adjusted odds ratio [aOR] 1.19; 95% confidence interval [CI] 1.08-1.31) and reactions to tree nuts (aOR 1.12; 95% CI 1.04-1.20) were associated with increased odds of an additional dose of epinephrine in hospital.

Conclusion
One-fifth of anaphylaxis cases that used EAI require an additional dose of epinephrine in ED. Children with severe reactions and reactions to tree nuts are more likely to require additional doses; these cases should be considered for ED transfer and treatment following pre-hospital EAI use.