• Ricardo Gass, Pietro Merola, Mariane B Monteiro, Dannuey M Cardoso, Dulciane N Paiva, Paulo Jz Teixeira, Marli M Knorst, and Danilo C Berton.
• Programa de Pós-Graduação em Ciências Pneumológicas, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS), Serviço de Pneumologia Hospital de Clínicas de Porto Alegre, Brazil.
• Respir Care. 2017 Oct 1; 62 (10): 1298-1306.

IntroductionThe application of expiratory positive airway pressure (EPAP) in patients with COPD during exercise may reduce dynamic hyperinflation, while, on the other hand, it can increase the resistive work of breathing. Therefore, we evaluated the effects of 2 intensities of EPAP during exercise on tolerance, dynamic hyperinflation, and dyspnea in subjects with moderate to very severe COPD.MethodsWe performed a cross-sectional, experimental, 4-visit study. In visit 1, subjects performed symptom-limited cycling incremental cardiopulmonary exercise test (CPET). In visits 2-4, at least 48 h apart, in a randomized order, subjects performed constant CPET without EPAP, EPAP with 5 cm H2O (EPAP5), or EPAP with 10 cm H2O (EPAP10).ResultsThe study included 15 non-hypoxemic subjects ranging from moderate to very severe COPD (mean FEV1 = 35 ± 11% predicted). Increasing intensities of EPAP during constant CPET tended to cause progressive reduction in exercise tolerance (P = .11). Of note, 10 of 15 subjects demonstrated significantly shorter average exercise duration with EPAP10 compared to the test without EPAP (-151 ± 105 s, P = .03 or -41 ± 26%). Minute ventilation increment was constrained by EPAP, secondary to a limited increase in tidal volume (P = .01). Finally, dyspnea sensation and serial measurements of inspiratory capacity during exercise were similar when comparing the three interventions at isotime and at end-constant CPETs.ConclusionsThe application of EPAP5 or EPAP10 during exercise tended to cause a progressive reduction in exercise tolerance in subjects with COPD without improvement in dyspnea or dynamic hyperinflation at equivalent exercise duration.Copyright © 2017 by Daedalus Enterprises.

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