RT Journal Article SR Electronic T1 Effects of Nasal Positive Expiratory Pressure on Dynamic Hyperinflation and Six Minute Walk Test in Patients with COPD JF Respiratory Care FD American Association for Respiratory Care SP respcare.02668 DO 10.4187/respcare.02668 A1 Thomas Wibmer A1 Stefan Rüdiger A1 Claudia Heitner A1 Cornelia Kropf-Sanchen A1 Ioanna Blanta A1 Kathrin M. Stoiber A1 Wolfgang Rottbauer A1 Christian Schumann YR 2013 UL http://rc.rcjournal.com/content/early/2013/10/29/respcare.02668.abstract AB Introduction: Dynamic hyperinflation is an important target in the treatment of COPD. There is increasing evidence that positive expiratory pressure (PEP) could reduce dynamic hyperinflation during exercise. PEP application through a nasal mask and a flow resistance device might have the potential to be used during daily physical activities as an auxiliary strategy of ventilatory assistance. The aim of this study was to determine the effects of nasal PEP on lung volumes during physical exercise in patients with COPD. Methods: 20 subjects (mean age 69.4 ± 6.4 years) with stable, mild-to-severe COPD were randomized to undergo physical exercise with nasal PEP breathing, followed by physical exercise with habitual breathing, or vice versa. Physical exercise was induced by a standard six-minute walk test (6MWT) protocol. PEP was applied by means of a silicone nasal mask loaded with a fixed-orifice flow resistor. Body plethysmography was performed immediately pre- and post-exercise. Results: Differences in mean pre- to post-exercise changes in TLC (-0.63 ± 0.80 L; p = 0.002), FRC (-0.48 ± 0.86 L; p = 0.021), RV (-0.56 ± 0.75 L; p = 0.004), SpO2(-1.7 ± 3.4 %; p = 0.041) and 6MWT distance (-30.8 ± 30.0 m; p = 0.001) were statistically significant between the experimental and the control interventions. Conclusions: The use of flow-dependent expiratory pressure, applied with a nasal mask and a PEP device, might promote significant reduction of dynamic hyperinflation during walking exercise. Further studies are warranted addressing improvements in endurance performance under regular application of nasal PEP during physical activities.