Obstructive respiratory diseases such as asthma or COPD are a common reason for emergency room visits. Currently, nasal gill capnography and oxygen saturation measurement (SpO2) are the only two non-invasive means of continuously monitoring a respiratory pathology. To date, Respiratory Functional Explorations (CFE) and more particularly spirometry, are considered as the reference examinations for the diagnosis or monitoring of asthma or COPD. However, physical and physical constraints make their use almost impossible in the context of the emergency with patients presenting to emergencies in respiratory distress, often require oxygen therapy or even non-invasive ventilation. Only pulmonary auscultation can make the diagnosis of acute decompensation of obstructive pathology. This technique is qualitative and imprecise, sometimes leading to a diagnostic uncertainty resulting in delay in taking charge and inappropriate therapy.

Studies have shown a change in the capnography curve in obstructive airway disorder and a strong correlation between some capnography parameters and spirometry parameters such as the Tiffeneau ratio (FEV1 / FVC), suggesting capnography as a simple and effective technique for the diagnosis of obstructive syndrome of patients in emergencies.

Inclusion Criteria:

• Major patient male or female
• Patient with respiratory disease with and without obstructive syndrome or patient without respiratory pathology
• Patient requiring spirometry breathing functional exploration
• Subject affiliated to a social health insurance scheme
• Subject able to understand the objectives and the risks related to the research and to give its non opposition

Exclusion Criteria:

• Pregnant and lactating woman
• Patient not affiliated to a social protection scheme
• Subject in exclusion period (determined by previous or current study),
• Impossibility of giving the subject information enlightened (subject in emergency situation, difficulties of understanding the subject, ...)
• Subject under the protection of justice Subject under guardianship or curatorship

Major patient requiring spirometry breathing functional exploration