Prehospital epinephrine administration for treating anaphylaxis among those with comorbid asthma: A scoping review

Prompt and correct use of epinephrine for treating anaphylaxis is considered essential in reducing the risk of fatal outcomes from anaphylaxis. Nevertheless, prehospital use of epinephrine remains low. Although asthma is a common comorbidity in individuals experiencing severe allergic reactions, little attention has been given to whether asthma functions as a predictor of prehospital epinephrine administration.

To perform a scoping review of the extant literature on using epinephrine to manage anaphylaxis in patients with comorbid asthma before presenting to the emergency department.

Per Preferred Reporting Items for Systematic Reviews and Meta-Analyses Scoping Review guidelines, peer-reviewed articles published in English or French were searched for within the Medline, Cumulative Index to Nursing and Allied Health Literature, and Embase databases between June 11 and June 18, 2021. We excluded studies that did not contain primary data.

The literature search yielded 1022 articles that were screened at the title and abstract level by 2 independent reviewers. Of these, 90 (8.8%) advanced to full-text review, and ultimately, 8 studies (0.8% of all articles; 8.9% of full-text articles) were included in the analysis. Overall, the association between comorbid asthma and epinephrine use in the prehospital setting for managing anaphylaxis was inconsistently reported in the literature. Three studies reported a positive association, whereas 2 others suggested a link, but their results were no longer significant when controlling for other study variables. Three studies described no significant association.

Although asthma is frequently comorbid in individuals experiencing anaphylaxis, the association between comorbid asthma and prehospital epinephrine treatment rates remains an understudied area of patient care.