Effect of high-flow nasal cannula oxygen therapy on exercise tolerance in patients with idiopathic pulmonary...

Exercise capacity in idiopathic pulmonary fibrosis (IPF) is limited by exercise-induced hypoxaemia. This study aimed to examine the effect of high-flow nasal cannula oxygen therapy (HFNC) on exercise tolerance in patients with IPF.

We conducted a single-centre, open-label, randomized crossover trial to compare HFNC and Venturi mask (VM) therapy in terms of exercise tolerance. Patients underwent constant-load symptom-limited exercise testing at 80% peak work rate with HFNC or a VM in a randomized order. The settings were 60 L/min and a 50% fraction of inspired oxygen (FiO₂ ) for HFNC and 12 L/min and 50% FiO₂ for VM. The primary outcome was endurance time, and the secondary outcomes were heart rate (HR), percutaneous oxygen saturation (SpO₂ ), dyspnoea and leg fatigue, as determined by the modified Borg Scale at the isotime and endpoint, and the level of comfort while using the devices.

Twenty-four participants (75.0% men; age, median [interquartile range]: 77.5 [68.8-83.0] years) were enrolled. Compared with VM, HFNC significantly improved the endurance time (647.5 s [454.0-1014.8] vs. 577.5 s [338.0-861.5]), minimum SpO₂ (96.0% [95.0-98.0] vs. 94.0% [92.8-96.0]) and leg fatigue at the isotime (3.0 [1.6-4.0] vs. 5.0 [3.0-6.3]) and endpoint (4.0 [2.8-5.0] vs. 5.0 [3.8-6.3]). Differences in maximum HR, dyspnoea at the isotime and endpoint and comfort were non-significant between HFNC and VM therapy.

HFNC increased exercise tolerance in patients with stable IPF experiencing exercise-induced hypoxaemia.