Monitoring of the End-tidal Carbon Dioxide (EtCO2) as a Severity Criterion in COPD Exacerbations

Inclusion Criteria: * All patient presenting to the emergency department with acute dyspnea and with a history of COPD documented or reported by the patient and/or family * Male or female≥18 years old who did not oppose to participating in the study Exclusion Criteria: * Hypotension (SBP \< 90 mmHg or MBP \< 65 mmHg) * Patient already included in the study during a previous visit to the emergency department * Patient already ventilated with invasive or NIV during admission to the emergency department * COPD exacerbation rejected after medical and additional examinations * Non-communicative or non-French speaking patients, or with impaired comprehension, or with impaired consciousness * Protected persons referred to in articles L1121-6 and L1121-8 of French public health code (deprived of liberty, tutorship or curatorship)