Barriers to Timely Intramuscular Epinephrine Administration for Anaphylaxis in Emergency Departments: A Systematic Review

Background: Anaphylaxis is a life-threatening emergency which requires prompt intramuscular epinephrine administration and its use in emergency care still below guideline recommendations. Methods: PubMed, Web of Science, and Scopus were systematically searched for original studies examining barriers to timely intramuscular epinephrine administration in emergency departments and acute care settings. Two reviewers independently screened records, extracted data, and assessed risk of bias using tools appropriate to each study design: the JBI Checklist, NOS, RoB 2, MMAT, and ROBINS-I. Results were synthesized narratively. Results: Twenty-three studies were included: 11 physician knowledge surveys, 11 patient cohort studies, and one simulation study. Clinician barriers included difficulty recognizing anaphylaxis, errors in dose and route selection, and concerns about adverse effects. Older age and the absence of cutaneous symptoms were associated with lower rates of epinephrine administration. Reported organizational barriers included inadequate training, prolonged observation protocols, and deficiencies in discharge practices. Clinicians often reserved epinephrine for severe reactions, contrary to recommendations for its use in all cases of anaphylaxis. Intramuscular administration rates ranged from 16.9% to 60.8%, with treatment omitted in more than 40% of patients in most cohorts. Conclusion: Barriers to timely intramuscular epinephrine administration involve clinical recognition, treatment decisions, patient characteristics, and care procedures. Strategies to reduce delays and omissions should combine targeted education, clinical pathways, and changes to emergency care systems.