Automatic Administration of Oxygen During Respiratory Distress

Inclusion Criteria: * Admission to the emergency for respiratory disease (or cardiac - acute pulmonary edema)justifying an oxygen administration to over 3 L / min to maintain a SpO2 ≥ 92%. * Inclusion within a time less than two hours after the start of the oxygen at the emergency. * Patient consent,or a close. Exclusion Criteria: * Necessity of an oxygen flow exceeds 15 L / min to maintain a SpO2 higher than 92%. * Criteria of gravity justifying immediately a different technique of ventilatory support: * Disturbance of consciousness with a Glasgow Coma Score ≤ 12 * Serious ventricular rhythm disorders * Hemodynamic instability (SBP \<80mmHg or recourse to vasopressors) * Cardiac or respiratory arrest * pH \< 7.35 and PaCO2 \> 55 mm Hg * Necessity of a urgent surgery, or coronary revascularization * Age \<18 years * Pregnant women, lactating * Patient not relevant * Unavailability of the prototype FreeO2