RT Journal Article
SR Electronic
T1 Effects of Expiratory Positive Airway Pressure on Exercise Tolerance, Dynamic Hyperinflation, and Dyspnea in COPD
JF Respiratory Care
FD American Association for Respiratory Care
SP respcare.05556
DO 10.4187/respcare.05556
A1 Ricardo Gass
A1 Pietro Merola
A1 Mariane B Monteiro
A1 Dannuey M Cardoso
A1 Dulciane N Paiva
A1 Paulo JZ Teixeira
A1 Marli M Knorst
A1 Danilo C Berton
YR 2017
UL http://rc.rcjournal.com/content/early/2017/08/01/respcare.05556.abstract
AB INTRODUCTION: The 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.METHODS: We 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).RESULTS: The 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 = 0.03 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.CONCLUSIONS: The 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.