HFNC oxygen therapy improves exercise tolerance in ILD

Oxygen supplementation in patients with interstitial lung disease (ILD) who are undergoing high-flow nasal cannula (HFNC) therapy results in better exercise tolerance and percutaneous oxygen saturation (SpO₂), a study has shown.

“We found that gas flow alone did not improve exercise tolerance but improved SpO₂ during exercise,” the authors said.

Twenty-five ILD patients (mean age 71.2 years, 10 men) participated in this three-treatment crossover study. Participants did the exercises on room air (room air setting: flow, 0 L/min; fraction of inspired oxygen [FiO₂], 0.21), HFNC (flow setting: flow, 40 L/min; FiO₂, 0.21), and HFNC with oxygen supplementation (flow plus oxygen setting: flow, 40 L/min; FiO₂, 0.6).

Endurance time, measured using constant-load cycle ergometry exercise testing at a peak work rate of 80 percent, was the primary endpoint.

Exercise duration increased by 46.3 s (95 percent confidence interval [CI], ‒6.1 to 98.7; p=0.083) between the room air and flow settings and by 91.5 s (95 percent CI, 39.1‒143.9; p<0.001) between the flow and flow plus oxygen settings.

The flow plus oxygen setting showed a higher SpO₂ at rest than the room air and flow settings. This difference persisted during exercise. Moreover, the SpO₂ with the flow setting was significantly higher than with the room air setting at equivalent time points during exercise.

“ILD is characterized by dyspnoea on exertion and exercise-induced hypoxaemia,” the authors said. “HFNC therapy reduces the respiratory workload through higher gas flow and oxygen supplementation, which may affect exercise tolerance.”