No more Covid patients in the service and number of patients included sufficient for stastistical analysis.

Use of veno-venous extracorporeal oxygenation membrane is a therapeutic option for the management of the most severe patients with acute respiratory distress syndrome (ARDS).

Given the prolonged duration of this strategy, the question of its impact on the occurrence on diaphragm dysfunction has been raised. The present study endeavors to evaluate and follow up the prevalence, risk factors and prognosis of diaphragm dysfunction in patients with VV-ECMO.

Use of veno-venous extracorporeal oxygenation membrane is a therapeutic option for the management of the most severe patients with acute respiratory distress syndrome (ARDS). It allows to provide a protective lung ventilation by reducing the level of airway pressures generated by the ventilator. The objective is to minimize the harmful effects of mechanical ventilation in the lungs and to provide adequate gases exchanges. This strategy requires a deep sedation to allow a perfect synchrony between the patient and the ventilator. Such a synchrony puts the respiratory muscles - in particular the diaphragm - completely at rest.

Given the prolonged duration of this strategy, the question of its impact on the occurrence on diaphragm dysfunction has been raised. Such a dysfunction has been associated with prolonged duration of mechanical ventilation and poor outcomes but its effect in patients with veno-venous extracorporeal oxygenation membrane has never been evaluated so far.

Inclusion Criteria:

• age > 18 years
• ARDS according to the Berlin definition
• V-V ECMO
• patient or next of kin agrees to participate
• patient with health insurance

Exclusion Criteria:

• pregnancy
• Opposition to participate
• Contra indications to the phrenic nerves stimulation technique (pace maker, pneumothorax)"