Low-Flow CO2 Removal for Mild to Moderate ARDS With PRISMALUNG

Inclusion Criteria: * Mechanical ventilation with expected duration of \>24 hours * Mild to moderate Acute Respiratory Distress Syndrome (ARDS) according to the Berlin definition: 100 mmHg \<PaO2/FiO2 \<300 mmHg, with PEEP \> 5 cmH2O Exclusion Criteria: * Age \<18 years * Pregnancy * Severe hypoxemia with PaO2/FiO2 \<100 mmHg * Body mass index \> 40 kg/m2 * Decompensated heart insufficiency or acute coronary syndrome * Severe Chronic obstructive pulmonary disease (COPD) * Major respiratory acidosis with PaCO2 \>60 mmHg * Acute brain injury * Severe liver insufficiency (Child-Pugh scores \>7) or fulminant hepatic failure * Heparin-induced thrombocytopenia * Contraindication for systemic anticoagulation * Patient moribund, decision to limit therapeutic interventions * Catheter access to femoral vein or jugular vein impossible * Pneumothorax * Platelet \<50 G/L * Lacking consent