Respiratory Support in Chronic Obstructive Pulmonary Disease (COPD) Patients

Inclusion Criteria:

1. Patients with COPD, GOLD C or D and Forced expiratory volume in one second (FEV1)<65%;

2. AHRF (pH<7,35 and PaCO2≥45mm Hg (≥6kPa) treated more than 24h with Ventilation (non-invasive or invasive);

3. 48h to 2 weeks with pH>7.35, and PaCO2>45 (>6kPa) after NIV withdrawal, duringdaytime at rest without oxygen or ventilatory support (or with O2 if patientsare not able to avoid O2 with immediate desaturation below 80%).

Exclusion Criteria:

1. Patient treated with chronic NIV or continuous positive airway pressure (CPAP)device, with ongoing treatment;

2. Primary diagnosis of restrictive lung disease causing hypercapnia i.e. obesityhypoventilation and chest wall disease, however these patients will be included ifthe "FEV1/Forced vital capacity (FVC)" ratio is <60% and the FEV1 <50% if thepredominant defect is considered to be obstructive by the center clinician;

3. BMI > 35 kg/m2;

4. Sedative medication causing hypercapnia (> 3 drugs or more than 20mg ofmorphine/day);

5. Polygraphic diagnosis of Obstructive Sleep Apnoea Syndrome (AHI>30/h (Frenchcriteria);

6. Cognitive impairment that would prevent informed consent into the trial

7. Pregnancy;

8. Tobacco use < 10 pack-year;

9. Psychiatric disease necessitating anti-psychotic medication, ongoing treatment fordrug or alcohol addiction, persons of no fixed abode post-discharge;

10. Unstable coronary artery syndrome;

11. Age <18 years;

12. Inability to comply with the protocol;

13. Expected survival<12 months due to any situation other than COPD disease;

14. Duration of ICU stay>10 days;

15. No affiliated to national health insurance;

16. Measure of legal protection (guardianship, wardship or judicial protection) forpatients over the age of majority.