Exercise Performance on Ambient Air vs. Low-Flow Liquid Oxygen Therapy in Chronic Lung Diseases

Exercise Performance on Ambient Air vs. Commonly Prescribed Nasal Low Flow Oxygen Therapy in Patients With Exercise Induced Desaturation Due to Pulmonary Disease

The investigators aim to study the effect of liquid oxygen therapy (4l/min, nasal) )in Swiss residents with pulmonary vascular diseases (PVD) defined as pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH).

Participants with PVD diagnosed with precapillary PH with right heart catheterization and classified to groups 1 and 4 (PAH or CTEPH) who live in Switzerland will have 6-minute walk distance (6MWD) test with and without nasal liquid oxygen therapy (LOX) approximately 4l/min via nasal cannula according to a randomized cross-over design.

The trial aims to test that the 6MWD with LOX is inferior to a 6MWD in the same participant under ambient air.

Inclusion Criteria:

• Minimum 18 years of age
• Written informed consent
• Patients with diagnosed pulmonary arterial hypertension (PAH), distal chronic thromboembolic pulmonary hypertension (CTEPH), chronic obstructive pulmonary disease (COPD) with emphysema, COPD without emphysema, or interstitial lung disease
• Former desaturation under exercise defined as SpO2-decrease >3%
• Treated with a stable drug therapy (with no changes for at least 14 days prior to screening)

Exclusion Criteria:

• Severe hypoxemia needing supplemental oxygen therapy defined as PaO2 < 6.9 kPa
• Inability or contraindications to undergo the investigated intervention
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, walk disability etc.