Does an Epinephrine MDI (Primatene Mist) Work for Croup?

March 10, 2023

Written by Rebecca White

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Epinephrine administration via metered-dose inhaler (MDI) for the treatment of croup in children may be a safe and effective alternative to nebulization.

Why does this matter?
Croup is a common presentation in pediatric patients, especially during respiratory virus season. During the COVID-19 era, concern was raised over nebulization as an aerosol-generating procedure – can we effectively deliver epinephrine via MDI for children with croup?

‘Sealing’ the deal
A quality assurance network of nine pediatric emergency departments (PEDs) in Canada developed algorithms for assessment and dosing of epinephrine MDI (i.e. over-the-counter Primatene Mist), with valved spacer device, for croup. Initially, five puffs of epinephrine MDI (125μg/puff) were administered. Patients were reassessed 10 minutes later using the Westley Croup Score (WCS), and adverse effects were recorded. Additional administration was recommended, up to 15 total puffs, if there was minimal change in WCS (<2 points) and no adverse effects.

Data were collected from seven PEDs from August 2020 to October 2021, including 210 children. The mean age was 36.4 (±29.27) months. Pre-treatment WCS was mild (0-2) in 27 children (12.9%), moderate (3-4) in 118 (56.2%), severe (5-7) in 60 (28.6%), and near respiratory failure (≥8) in five (2.4%). The median croup scores of pre- versus post-treatment were 4 and 1, with a median change of 2 (IQR 1-3) within 60 minutes of treatment (p < 0.001). There were two reports of agitation (0.7%), and two children had continued pre-existing tachycardia. No other adverse events were reported.

This study is limited by lack of a control group, though previous studies of nebulized racemic epinephrine show similar improvements in WCS.

Source
Epinephrine metered-dose inhaler for pediatric croup. Acad Emerg Med. 2023 Feb;30(2):144-146. doi: 10.1111/acem.14616. Epub 2022 Dec 7.