Abstract Rationale COPD patients frequently experience dyspnea and impaired exercise tolerance, leading to inactivity and worse outcomes. Nasal high flow (NHF) therapy can enhance gas exchange, reduce respiratory effort and dyspnea, and improve exercise capacity. At high flow rates, NHF may further benefit exercise tolerance and perceived exertion. This study examined the effects of NHF at higher flows on exercise performance in COPD patients. Methods Twenty-two participants with COPD, able to ambulate without assistance, underwent two 6-minute walk tests (6MWT) one hour apart of each other, one with and one without NHF at 70L/min, in randomized order. The fraction of inspired oxygen (FiO2), which ranged from 0.21 to 0.36, was maintained at each participant’s baseline for both conditions. Each participant rested for 10 minutes before each 6MWT, using NHF if assigned to that condition. The 6MWT distance was recorded, as well as the heart rate (HR), peripheral oxygen saturation (SpO2), and Modified Borg scores for fatigue and dyspnea before and after each test. Results All participants completed both 6MWT under the two conditions. The mean age was 66.4 ± 7.0 years, 43.48% were males, mean FEV1 was 1.42 ± 0.7 L, and mean 6MWT distance without NHF was 406 m. There was no significant difference in walking distance with NHF compared to no NHF (mean difference -4.2 ± 46.9 m, p = 0.68). HR, SpO2, and Modified Borg score for dyspnea at the end of each test also did not differ significantly (p = 0.53, 0.54, and 0.15, respectively). However, the Modified Borg score for fatigue was significantly lower with NHF use (mean difference -0.66 points, 95% CI -1.281 to -0.374, p = 0.038), indicating reduced perceived exertional fatigue. Conclusion In COPD patients, NHF therapy at 70 L/min during ambulation significantly reduced perceived exertional fatigue compared with standard breathing conditions, even though walking distance, oxygen saturation, heart rate, and perceived dyspnea remained unchanged. These findings suggest that NHF may improve subjective exercise tolerance and comfort in COPD patients. Larger studies are warranted to confirm these effects and explore their clinical implications. This abstract is funded by: ATS/Fisher & Paykel Healthcare Research Grant in Nasal High Flow
Castiblanco et al. (Fri,) studied this question.