Exploration of the VOLATOLOM in the Stable Severe COPD (Chronic Obstructive Pulmonary Disease)

Inclusion Criteria: 1. Severe COPD (FEV ≤ 50% of theoretical values) * stable for at least two months, * treated for at least one year with one (or more successively) combination of at least two inhaled drugs: either a Long-Acting Beta2-Adrenergic bronchodilator (LABA) combined with a corticosteroid (CSI), or a LABA combined with a long-acting anti-cholinergic bronchodilator (LAMA), or a triple combination LABA/LAMA/CSI; 2. History of at least one severe COPD exacerbation (treated with antibiotics and / or oral corticosteroid therapy) in the two years preceding the study; 3. Ex-smokers (at least 6 months of withdrawal) or active daily smokers of more than 10 pack-years 4. Severe dyspnea at baseline (mMRC stage ≥ 2) 5. Aged 40-85 years inclusive 6. Fluency in French 7. A signed and dated written informed consent is obtained prior to participation 8. Affiliated to a health insurance plan Exclusion Criteria: 1. Severe exacerbation in the 4 months preceding the study 2. Chronic inflammatory disease (rheumatic, etc.) treated with long-term systemic corticosteroid therapy, 3. Long-term oxygen therapy (exclusive ambulatory oxygen therapy is not a non-inclusion criterion) 4. Unstable cardiovascular pathology (right or left heart failure, coronary artery disease); 5. Cancer 6. Pregnant women; 7. Deprived of liberty or under guardianship.