Clarifying the link between sleep disordered breathing and tracheal collapse: a retrospective analysis

Background Symptoms of acquired tracheobronchomalacia (TBM) include wheezing, shortness of breath, and chronic cough, and can negatively affect quality of life. Successful treatment of TBM requires identification of the disorder and of contributing factors. Acquired TBM is generally associated with a number of conditions, including asthma, chronic obstructive pulmonary disease (COPD), and gastroesophageal reflux. Although a possible relationship with obstructive sleep apnea (OSA) has been observed, data illuminating such an interaction are sparse. Methods In the present study, we analyzed the percent tracheal collapse (as measured on dynamic chest CT) and detailed sleep reports of 200 patients that had been seen at National Jewish Health, half of which had been diagnosed with OSA and half which did not have OSA. Results Tracheal collapse ranged from 0 to 99% closure in the population examined, with most subjects experiencing at least 75% collapse. OSA did not relate significantly to the presence or severity of tracheobronchomalacia in this population. Sleep disordered breathing (SDB) did show a strong association with TBM ( p < 0.03). Conclusions Tracheobronchomalacia may develop as a result of increased negative intrathoracic pressure created during attempts at inhalation against a closed or partially closed supraglottic area in patients experiencing apneic or hypopneic events, which contributes to excessive dilation of the trachea. Over time, increased airway compliance develops, manifesting as tracheal collapse during exhalation. Examining TBM in the context of SDB may provide a reasonable point at which to begin treatment, especially as treatment of sleep apnea and SDB (surgical or continuous positive airway pressure) has been shown to improve associated TBM.