Benefits of supplemental oxygen on exercise capacity in IPF patients with exercise-induced hypoxemia

Background and objective: Although efficacy of supplemental oxygen during exercise training is recognized in COPD patients, its efficacy remains unclear for IPF patients, in which exertional hypoxia is more frequent and profound. The purpose of this study was to assess the effect of supplemental oxygen on exercise capacity in idiopathic pulmonary fibrosis (IPF) patients with exercise-induced hypoxemia. Methods: This randomized crossover trial comparing the effect of supplemental oxygen versus supplemental air during exercise. A hundred-six consecutive patients with IPF were assessed for eligibility using room-air 6-min walk test. Subjects showing desaturation with SpO2 of 89% or less were eligible. Patients underwent constant load ergometry tests under each supplemental gas, and endurance time and SpO2 were evaluated. Oxygen and air were provided at 4 L/min intranasally during the test. Results: Seventy-two patients (Age: 66.5 ± 8.6 years, %FVC: 81.8 ± 19.1 %, %DLco: 53.2 ±15.4 %) were included in this study. Supplemental oxygen increased endurance time than supplemental air (oxygen: 546.5 ± 326.8 sec vs air: 427.8 ± 242.4 sec, p<0.05), and improved minimum SpO2 (oxygen: 92.7 ± 4.1 % vs air: 87.6 ± 5.6 %, p<0.05), respectively. Conclusions: These findings suggest that supplemental oxygen benefits exercise capacity in IPF patients with exercise-induced hypoxemia.