Review of 23 cases of postintubation tracheal obstructions in birds.

Although recognized as a potential complication after endotracheal intubation in birds, the complication rate of postintubation tracheal obstruction in this taxon is unknown. Twenty-three cases of postintubation obstruction in birds from two institutions are reported. Clinical signs were noted an average of 16.6 days postintubation and consisted primarily of indications of acute respiratory distress. Diagnosis was confirmed via tracheoscopy or radiology. Five birds died before treatment could be initiated. Medical treatment alone was successful in three birds that had mild changes consisting primarily of a luminal mucoid plug that could be manually removed without tracheal surgery but was unsuccessful in an additional six birds. Tracheal resection and anastamosis was successful in four birds and unsuccessful in five birds. Overall mortality was 70%. Postintubation tracheal obstruction in birds appears to be more common in zoo practice than is suggested by the literature, as a total of 1.8% (1.2-2.7%, 95% confidence interval) of intubations or 3.5% (2.3-5.3%, 95% confidence interval) of individual animals intubated in these institutions resulted in this complication. Multiple cases were found in Ciconiiformes (n = 4), Columbiformes (n = 4), Gruiformes (n = 4), Anseriformes (n = 3), Galliformes (n = 3), and Passeriformes (n = 2). No cases were found in Coraciiforms, Falconiforms, or Psittaciformes despite many (>40) recorded intubations. The specific cause of these lesions is unclear, but some type of tracheal mucosa trauma or irritation is suggested by histologic findings. Prevention may include selective intubation, use of a laryngeal mask airway in place of intubation, careful placement of an endotracheal tube, minimal movement of the head and neck after placement, humidification of anesthetic gases, and gentle positive-pressure ventilation.