Design studies of nebulization in COPD does not respond adequately to the clinically relevant question: the intervention of administering nebulized bronchodilators at home it is likely to make a profit, compared to the standard optimized treatment as defined by the recommendations of the SPLF, patients with severe COPD (stage III, FEV between 30% and 50% of the theoretical value) and very severe (stage IV, less than 30% of the theoretical value FEV)? The concept of profit in this context is based on criteria of dyspnea, quality of life, use of health system (exacerbations, hospitalizations, prescription of antibiotics and steroids ...).

Inclusion Criteria:

• Adult
• COPD Patients stage 3 et 4
• Has not submitted an exacerbation in the 3 months preceding the pre-inclusion visit
• Weaned from tobacco for at least 6 months
• vaccinated against pneumococcal
• Have not been included in a pulmonary rehabilitation program during the 6 months preceding the screening visit inclusion
• Patient pre-included not showing exacerbation since the pre-inclusion visit

Exclusion Criteria:

• Patient under nebulizer or has been treated with nebulized bronchodilators at home over the last 6 months
• Patient with an indication of oxygen is expected in the coming year
• Progressive malignant disease known
• Patient under non-invasive ventilation (NIV) for less than 6 months or NIV provided in the following year
• Patient known to be colonized by Pseudomonas aeruginosa, A. xylosoxidans, Burkholderia cepacia or Stenotrophomonas maltophilia
• Patients with severe cardiovascular disease
• Pregnancy