Fibrotic interstitial lung disease (fILD) is characterised primarily by impaired lung function and quality of life. The present study investigated whether oxygen therapy could improve exercise capacity among patients with fILD.

Previously published randomised controlled trials (RCTs) were surveyed. A systematic review and meta-analysis was conducted to evaluate the effectiveness of oxygen therapy in improving the exertional capacity of patients with fILD. The primary outcome was peripheral oxygen saturation (SpO₂) during exercise. The effects of oxygen therapy on fatigue, dyspnoea, heart rate, and exercise duration or distance were also analysed.

Fourteen RCTs involving 370 patients were included. Oxygen therapy improved SpO₂ during exercise (mean difference, MD = 6.26 %), exercise duration (MD = 122.15 s), fatigue (standard mean difference, SMD = −0.30), and dyspnoea (MD = −0.75 Borg score units). High-flow oxygen systems tended to be more effective than low-flow systems in improving exercising SpO₂, duration, fatigue, dyspnoea, and heart rate. High-flow nasal cannulas (HFNCs) yielded better outcomes regarding SpO₂ and fatigue than did high-flow Venturi masks (MD = 1.60 % and MD = −1.19 Borg score units, respectively). No major adverse events were reported.

The evidence from RCTs supports the short-term use of oxygen supplementation to improve SpO₂, exercise capacity, fatigue, and dyspnoea among patients with fILD. Further analyses demonstrates that HFNCs yield more favourable outcomes, yet not reaching statistical significance except for improving SpO₂ and fatigue. However, the long-term effects of oxygen therapy on quality of life and mortality remain unclear.