Did a steroid and two antibiotics prevent airway narrowing after prolonged intubation in puppies?

Details

Researchers used a previously developed canine animal model to evaluate whether a combination of systemic antibiotics and a steroid could prevent acquired subglottic stenosis (ASGS), or acquired narrowing below the vocal cords. This was a controlled animal experiment.

Thirty-five healthy, postweanling mongrel puppies aged 5 weeks were each intubated for 14 days with an uncuffed polyvinyl endotracheal tube.

Twenty puppies received intramuscular dexamethasone (1 mg) daily, plus procaine penicillin (100,000 IU) and dihydrostreptomycin (0.125 g) in two divided doses on the day of intubation and every day thereafter until the study ended. The remaining 15 puppies were controls and received no medical therapy.

Animals from both groups were killed at 5, 7, 12, 15, 20, 30, and 56 days following intubation.

Comparative examination of the treated and control dogs’ larynx-and-trachea specimens found no significant difference between groups in the eventual degree of ASGS, measured by intraluminal cross-sectional area analysis. There was also no significant difference in the extent of the lesion, assessed by gross and microscopic histology.

The investigators concluded that this specific systemic combination of two antibiotics and a steroid was not effective in preventing ASGS in the canine model. On that basis, they questioned the benefit of analogous drug regimens used to prevent ASGS in infants and children requiring long-term endotracheal intubation.