A Randomized Controlled Trial of Dexamethasone as a Prophylactic Treatment for Subglottic Stenosis in a Rabbit Model

Abstract

Objective: Iatrogenic injury is a common cause of subglottic stenosis (SGS). We investigated the role of pre-injury dexamethasone as a preventive treatment for iatrogenic subglottic stenosis. Methods: 16 New Zealand White rabbits were used in an IACUC approved study. Subjects were divided into two groups: intramuscular dexamethasone (DEX) at a dose of 2 mg/kg 15 minutes prior to an endoscopic injury to create SGS, and the same injury creation with a preoperative intramuscular saline (SAL) injection. Three independent, blinded raters evaluated endoscopic images to obtain cross sectional area (CSA) airway measurements. Rabbit airways were measured just prior to injury and at one week post-injury. All subjects were provided as-needed postoperative steroids and buprenorphine for symptoms of respiratory distress. Data analysis was performed using Student t-test. Intraclass correlation coefficients were used to assess inter-rater agreement. Results: All subjects survived to the one-week post-injury airway evaluation. There was no difference in airway size between groups prior to injury ( P = .28). Subjects in the DEX group demonstrated an average stenosis of 20.3% (95% CI 10.2-30.5) at one week compared to 60.6% (95% CI 40.3-80.9) in the SAL group ( P = .01). Subjects in the control group required significantly more doses of postoperative dexamethasone ( P = .02). Inter-rater agreement for between raters was excellent (ICC = .88). Conclusion: This is the first study to examine the role of pre-injury glucocorticoids in preventing iatrogenic subglottic stenosis. In our model, a single dose of intramuscular dexamethasone given prior to a subglottic injury resulted in a statistically significant reduction in airway stenosis. This research suggests that administering systemic dexamethasone should be considered prior to any procedure that may injure the subglottis, including traumatic intubation, to prevent iatrogenic subglottic stenosis.