Tracheal rupture in cats: 16 cases (1983-1998)

Objective-To determine causes of tracheal rupture in cats and the mechanism of injury. Design-A retrospective study was conducted to identify cats with tracheal r upture. A second study was conducted to establish mechanism of injury, and a third study was conducted to determine volume of air needed to obtain an airtight seal when inflating the cuff of an endotracheal tube in a cat. Animals-16 cats with clinical signs of tracheal rupture, 10 cat cadavers, a nd 20 clinically normal cats that were undergoing anesthesia. Procedures-Details were extracted from medical records of 16 cats with trac heal rupture (9 treated surgically and 7 treated conservatively). For the c adaver study, the trachea of each cat cadaver was intubated and observed du ring overinflation of the endotracheal tube cuff. For clinically normal cat s, volume of air needed to obt Results-Most ruptures were associated with cats anesthetized for dental pro cedures. Clinical signs associated with tracheal rupture included subcutane ous emphysema, coughing, gagging, dyspnea, anorexia, and fever. Tracheoscop y was the method of choice for documenting tracheal rupture. Surgical and c onservative management were successfully used, unless the injury extended t o the carina. In the cadaver study, overinflation of the endotracheal tube cuff with > 6 ml of air resulted in tracheal rupture in 7 of 10 cadavers. f or clinically normal cats, the volume of air (mean +/- SD) needed to obtain an airtight seal was 1.6 +/- 0.7 ml. Clinical Implications-Overinflation of an endotracheal tube cuff may result in tracheal rupture in cats.