RT Journal Article SR Electronic T1 A pilot study of CPAP therapy for excessive dynamic airway collapse during acute exacerbation of COPD JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 3401 VO 44 IS Suppl 58 A1 Yee Tung (Eric) Kuo A1 Kenneth Lau A1 Garun Hamilton A1 Eunice Dai A1 Paul Leong A1 Philip Bardin YR 2014 UL http://erj.ersjournals.com/content/44/Suppl_58/3401.abstract AB Background: Excessive dynamic airway collapse (EDAC) occurs in expiration when the posterior wall of the trachea bulges forward causing ≥ 50% cross sectional area reduction. EDAC can be diagnosed with four-dimensional dynamic volume 320-slice multi-detector computed tomography (4D-CT) and has been reported to occur in 20% of patients with COPD. Whether EDAC persists in stable COPD or occurs predominantly during exacerbations is unknown. Overall effectiveness of CPAP in EDAC has also not been assessed.Aims: To determine whether CPAP therapy reduced EDAC in patients with acute exacerbation of COPD (AECOPD) and if EDAC persisted after recovery from AECOPD.Methods: Patients with AECOPD requiring hospitalization (n = 11) were recruited. 4D-CT of the larynx and trachea (2-4 mSv) was performed within 48 hours of admission and repeated immediately after with 10-12cmH2O CPAP. CT was repeated at 6-8 weeks post discharge (without CPAP). EDAC was diagnosed if expiratory tracheal area was reduced by ≥ 50%.Results: Of the 11 patients recruited, four had EDAC detected. EDAC severity ranged from 60-64% (median = 63.5%). EDAC resolved with CPAP in all four patients (median narrowing = 39.5% [29%-49%]). EDAC was not evident in the three patients who completed follow-up CT (one CT not done).Conclusions: EDAC in AECOPD can be improved by CPAP. Larger studies are warranted to further evaluate the functional significance of EDAC and clinical benefits of CPAP treatment.