Phrenic Nerve Stimulation-Induced Lung ReAeration Trial

Inclusion Criteria: * Are 18 years or older * Have been mechanically ventilated due to moderate ARDS for 48-120h * Have a PaO2/FiO2 ratio \< 200 and \> 100 at the time of screening with PEEP ≥ 5 cmH2O * Are expected to remain on mechanical ventilation ≥ 48 hours * Are under continuous sedation with Richmond Agitation Sedation Scale (RASS) ≤ -3 Exclusion Criteria: * Septic shock with hemodynamic instability (norepinephrine or epinephrine \< 0.5 gamma/kg/min) * Catheter access to left subclavian vein deemed impossible * Use of neuromuscular blocking agents within last 12 hours * Bacteremia within the last 48 hours or uncontrolled source of infection * Currently on ECMO * Enrolled in any other study of an investigational drug or device, which may affect the outcomes of the current study * Pre-existing neurological, neuromuscular or muscular disorder that could affect the respiratory muscles * BMI \>45 kg/m2 * Known or suspected phrenic nerve paralysis * Any electrical device (implanted or external) that may be prone to interaction with or interference from the Lungpacer PROTECT DPTS, including neurological pacing/stimulator devices and cardiac pacemakers and defibrillators * No affiliation to the French health insurance system * Under curatorship * Imprisoned * Known or suspected to be pregnant or lactating