Mechanical ventilation of the patient with acute respiratory distress syndrome is one of the first therapies.

The application of positive end expiratory pressure is recommended but the question remains "How to set the best positive end-expiratory pressure (PEEP) level for each patient? ". Different titration techniques have been studied on oxygenation and respiratory mechanics parameters without reaching a consensus. Currently we have a module that is connected to the ventilator to collect the patient's lung volume. It will therefore allow us to optimize the settings of the ventilator and to set the best level of positive end-expiratory pressure "best peep" in order to individualize our treatment for each patient.

Inclusion Criteria:

• Patients admitted to intensive care with a diagnosis of moderate to severe ARDS in accordance with the Berlin criteria, i.e. a PAFI <200 and PEEP >5cm H20 ratio
• Diagnosis of ARDS made within 72 hours
• Age over 18 years
• Informed consent of the patient and/or trusted person where applicable

Exclusion Criteria:

• Start of mechanical ventilation more than 72 hours prior to inclusion.
• SDRA evolving for more than 72 hours
• Presence of major hemodynamic instability with mean blood pressure <60mmhg, and/or heart rate <45 bpm or >150bpm with an increase in vasopressor amine dosage of more than 20% over the last 6 hours.
• Intracranial hypertension with CPP<60mmhg
• Massive hemoptysis requiring immediate surgical or interventional radiology procedure
• Tracheal surgery (except intensive care tracheotomy) or sternotomy within the previous 15 days
• Trauma or surgery of the face in the previous 15 days.
• Deep vein thrombosis treated for less than 2 days
• Pacemaker implantation in the last 2 days
• Unstable fracture (spine, femur or pelvis)
• Respiratory reasons
• use of extracorporeal oxygenation
• nitric oxide
• pleural drainage system with bronchopleural gap
• pulmonary transplantation
• Poor respiratory tolerance per procedure with desaturation Spo2<85%.
• Poor hemodynamic tolerability per procedure combining hypotension with MAP<65mmhg and a 20% increase in norepinephrine dosage.
• Lack of patient consent to proceed
• minor patient
• lack of consent