Is the level of expiratory positive airway pressure (EPAP) needed for tracheal stenting correlated to improvement in exercise capacity in patients with tracheobronchomalacia (TBM)

Introduction: TBM can be treated by noninvasive positive airway stenting with the use of portable continuous positive airway pressure (CPAP) devices. CPAP improves exercise tolerance. However, the level of EPAP can be challenging to determine. Our aim was to determine if the level of EPAP required to stent the trachea was correlated to the improvement in exercise capacity. Methods: We retrospectively reviewed the recordings of bronchoscopy performed for the clinical management of patients with TBM referred for CPAP initiation. During the bronchoscopy, the EPAP level was titrated by 5cmH2O increments from 5cmH2O to 20cmH2O. We measured: the decrease in lumen area (DLA) from inspiration to expiration, the angulation α between the posterior and the lateral wall during expiration as well as the anteroposterior distance (apD). These measurements were made during tidal breathing. They were compared to the improvement in the 6-minute walking distance (6MWD) achieved with CPAP. Results: Our cohort consisted of 16 patients. The use of portable CPAP improved by 33m [11 – 53] when compared to self-ventilation (p=0.01). At 5cmH2O, the EPAP did not change the DLA nor the α angle or the apD. At 10cmH2O and above a significant improvement was seen in all these parameters (p Conclusion: Our results suggest that a significant level of EPAP is required to improve the exercise capacity of patients with TBM.