Can epinephrine help reduce the severity of BOAS?

26 April 2021 – News

Brachycephalic obstructive airway syndrome (BOAS) includes various components that can be alleviated with surgical treatment. Nevertheless, there are secondary complications, like inflammation and edema that can lead to the need for further proceedings.
Nebulized epinephrine has been used in human medicine to improve respiratory function as it seems to cause vasoconstriction of vessels within the mucosa of the upper airways. Nebulized epinephrine has been used postoperatively in dogs submitted to BOAS surgery, in order to reduce mucosal edema. However, there are no objective reports on the efficacy of this procedure.
This study included 26 brachycephalic dogs (Pugs and French and English bulldogs) that tolerated both whole-body barometric plethysmography and nebulization and were classified as having functional grade II (moderate) or III (severe). Thirteen of these dogs, underwent bilateral tonsillectomy, folding flap palatoplasty, vestibuloplasty and rhinotomy.
Nebulizations were performed pre and postoperatively. Patients monitoring was done during and until 60 minutes after the procedure and included arrythmias assessment, via ECG, in the dogs that tolerated that. Adverse effects were rare, being nausea the most reported.
In dogs where the baseline BOAS index was above 70%, a clinically significant reduction in BOAS index due to nebulized epinephrine was noticed. Additionally, this procedure seems to be more effective in Pugs than in French bulldogs.
BOAS indices improvements after nebulization where more consistent within the postoperative cohort, which can be explained by the higher probability of mucosal swelling secondary to the surgery.
Despite this study´s encouraging results regarding the use of nebulized epinephrine, it is important to highlight that there are limitations that can be consulted in the original article. Furthermore, it should be borne in mind that this procedure should not be performed in cases where it induces stress as it is known to exacerbate upper respiratory tract obstruction in BOAS-affected dogs.

Franklin, P. H., Liu, N. C., & Ladlow, J. F. (2021). Nebulization of epinephrine to reduce the severity of brachycephalic obstructive airway syndrome in dogs. Veterinary surgery: VS, 50(1), 62–70. https://doi.org/10.1111/vsu.13523