Risk factors for the development of aspiration pneumonia after unilateral arytenoid lateralization in dogs with laryngeal paralysis: 232 cases (1987–2012)

Abstract

OBJECTIVE To identify risk factors for the development of aspiration pneumonia after unilateral arytenoid lateralization in dogs with laryngeal paralysis. DESIGN Retrospective case series. ANIMALS 232 client-owned dogs with a diagnosis of laryngeal paralysis treated with leftsided unilateral arytenoid lateralization. PROCEDURES Medical records were reviewed. Signalment, medical history, surgical complications, and outcome data were collected. Follow-up was performed via review of medical records and by telephone interview with the owner, referring veterinarian, or both. RESULTS At the 1-, 3-, and 4-year follow-up periods, aspiration pneumonia occurred in 18.6%, 31.8%, and 31.8% of dogs, respectively. The 1-, 3-, and 4-year survival rates for dogs with postoperative aspiration pneumonia were 83.1%, 51.5%, and 25.8%, respectively. None of the dogs with aspiration pneumonia before surgery developed clinical signs of aspiration pneumonia after surgery. Postoperative megaesophagus (hazard ratio [HR], 2.58; 95% confidence interval [CI], 1.56 to 3.93) and postoperative administration of opioid analgesics prior to discharge (HR, 1.69; 95% CI, 1.12 to 2.80) were significant risk factors for the long-term development of aspiration pneumonia in this study. Perioperative metoclopramide administration did not significantly decrease the risk for development of aspiration pneumonia (HR, 0.94; 95% CI, 0.67 to 1.37). CONCLUSIONS AND CLINICAL RELEVANCE In the present study, aspiration pneumonia was the most commonly reported postoperative complication of unilateral lateralization in dogs treated for laryngeal paralysis; however, preexisting aspiration pneumonia was not associated with an increased risk for development of aspiration pneumonia after surgery. Megaesophagus was identified as an important risk factor for eventual development of aspiration pneumonia. Administration of an opioid analgesic may increase the risk of aspiration pneumonia in dogs treated surgically for laryngeal paralysis.