Effects of Automated Oxygen Titration Alone or With High Flow Nasal Therapy on Dyspnea and Exercise Tolerance

Inclusion Criteria

• •One of them
• •Moderate to severe COPD (forced expiratory volume in 1 second (FEV1) \< 80% predicted and FEV1/forced vital capacity (FVC) ratio \< 0.7)
• •Chronic interstitial lung disease such as usual interstitial pneumonitis (UIP), non-specific interstitial pneumonitis (NSIP) or hypersensitivity pneumonitis on high-resolution computed tomography
• •Pulmonary arterial hypertension type 1 or 4, excluding involvement secondary to collagenosis as well as secondary to congenital heart disease, as diagnosed with mean pulmonary artery pressure \> 25 mm Hg at right heart catheterization
• •Cystic fibrosis, as diagnosed by a positive sweat test (\>60 mmol/L) or having 2 genetic mutations known to cause cystic fibrosis.
• •AND having a 6-minute walking test with significant desaturation defined as a decrease in O2 saturation greater or equal to 5% with O2 saturation at the end of the walking test \< 88%