Portable CPAP benefits on exercise capacity in patients with excessive dynamic airway collapse (EDAC)

Introduction: EDAC is a rare condition for which treatment options are sparse. Pneumatic airway stenting using CPAP is a non invasive treatment approach. Using portable CPAP devices with built-in battery during exercise may help to improve breathlessness in patients with EDAC. The aim of our study was to assess the improvement in exercise capacity in patients with EDAC. Methods: Retrospective monocentric study including patients referred for suspicion of EDAC between 01/2017 and 02/2019 that underwent bronchoscopy that confirmed EDAC. Results: Out of the 30 patients referred, 27 had EDAC. Patients had a mean age of 65±11 with a BMI of 28±6kg/m2. EDAC was idiopathic in 4 patients and secondary to COPD (n:10), obesity (n:8), asthma (n:4) and lung transplantation (n:1). At rest, mMRC dyspnea scale was 3.2±1.0. Health-related quality of life assessed by the severe respiratory insufficiency questionnaire was low: 46±17. Daytime arterial blood gases were: pH: 7.42±0.06, PaCO2: 5.4±1.4kPa, PaO2: 11.0±4.0kPa. Lung function tests results were: FEV1:1.5±0.7L (63±34%), FVC: 2.3±0.7L (77±27%), FEV1/FVC:69±23%. Tracheal lumen reduction was estimated at 36±23% at rest. Level of positive expiratory pressure requires to counterbalance expiratory collapse was 13±4cmH2O. Distance achieved on the 6 minute-walking test (6MWT) on room air was 280m [158 – 346] (52±27%). Distance improved significantly with CPAP: +32m [8 – 53] (p:0.003). Dyspnea (Borg scale) at the end of 6MWT did not improve significantly: -1.5 [-2 – 3] (p:0.405). Conclusion: Portable CPAP improves exercise capacity in patients with EDAC and may enhance benefits of pulmonary rehabilitation in those patients.