Clinical Research Directory

Inclusion Criteria: For patients with stable COPD: * Men or women aged 18 to 85 * FEV1/FVC \< 70% or proven BPCO * Patients who have given their free and informed consent in writing For patients with decompensated COPD: * Men or women aged 18 to 85 * FEV1/FVC \< 70% or proven BPCO * At the time of acute respiratory failure (ARF), when admitted to hospital: * Respiratory rate \> 25 cycles per minute * PaCO2 \> 45 mmHg * blood pH \< 7.35 * When included in the study: * pH \> 7.33 at the end of ARF, 2 days in a row, or 3 to 7 days post-D1 decompensation (admission to the hospital) * Fever \< 38.5°C * Patients who have given their free and informed consent in writing Exclusion Criteria: * Obvious evolving infection or CRP \> 100 mg/L * Cardiac decompensation considered the main cause of decompensation or chronic heart failure with LVEF \< 45% * Evolving neoplasia * On antioxidants: N-acetyl-cysteine, selenium, vit. C, vit. E * Pregnant or nursing women * Patients under tutorship or curatorship * Patients participating in a drug clinical research study * Patients not affiliated to the French social security system (or equivalent) * Patients deprived of liberty or hospitalized without consent.