Oxygen therapy boosts exercise capacity in IPF patients with exertional desaturation
Supplemental oxygen while exercising leads to improved endurance time, desaturation, and subjective symptoms in mild-to-moderate idiopathic pulmonary fibrosis (IPF) with exercise-induced hypoxaemia even without resting hypoxaemia, a study has shown.
In addition, patients with shorter endurance time with placebo air demonstrated better improvement with supplemental oxygen.
Recent prospective studies with small sample sizes have shown conflicting results as regards the efficacy of supplemental oxygen during exercise for patients with IPF. To address this, the authors conducted a prospective, single-blind, randomized, crossover trial, which assessed the efficacy of supplemental oxygen compared with placebo air during exercise in consecutive IPF patients without resting hypoxaemia at initial evaluation.
Patients with <90 percent oxygen saturation (SpO2) in a 6-minute walk test using room air were randomized to a constant work-rate endurance test at 80 percent of peak work rate with oxygen or placebo air gas via nasal cannula at 4 L/min. The effect of supplemental oxygen on endurance time was the primary endpoint.
Seventy-two consecutive patients with IPF (median age, 66.5 years; forced vital capacity, 84.6 percent; diffusion capacity for carbon monoxide, 61.4 percent) were included in the trial. Those who received supplemental oxygen during exercise had significantly increased endurance time (340–424 s; p<0.001) and minimum SpO2 (88.0–94.0 percent; p<0.001) compared to those on placebo air. Supplemental oxygen also significantly improved dyspnoea and leg fatigue.
Multivariate linear regression analysis revealed that endurance time on air was an independent explanatory variable of the improvement rate of endurance time (p=0.02).