Extracorporeal Membrane Oxygenation (ECMO) in Non-intubated Patients With Acute Respiratory Distress Syndrome (ARDS)

Inclusion Criteria: * Patients aged 18-75 yrs with acute respiratory failure due to ARDS or pneumonia fulfilling standard criteria for endotracheal intubation * Severe and progressive hypoxemia, i.e. PaO2 \< 60 mmHg or SaO2 \< 90% on O2 \> 10 l/min not tolerating noninvasive ventilation, or * PaO2/FiO2 \< 200 not improving or deteriorating on noninvasive ventilation, or * Respiratory distress and hypoxemia not fulfilling the criteria above with clinical impression of the ICU attending that intubation and mechanical ventilation are mandated * Patient considered eligible by at least two investigators of this study Exclusion Criteria: * Patient does not fulfill the inclusion criteria * Uncontrolled malignancy * Severe and untreatable coagulation or bleeding disorders (INR \> 2,0; aPTT \> 60s, Platelet count \< 50.000/µl, all after substitution) * Stroke within the past 3 months * Uncontrolled sepsis or septic shock * Multiorgan failure involving \> 2 organ systems * Norepinephrine dose \> 1 mg/h * Hyperdynamic circulation, indicated by cardiac index \> 4.0 l/min/m2 (measured by PiCCO or Swan-Ganz catheter), or SvO2 \> 80% * Cardiac pump failure, indicated by echocardiography (EF \< 40%), PiCCO or Swan Ganz catheter (CI \< 2,5 l/min/m2 despite adequate volume management), or SvO2 \< 50% (provided Hb \> 9,0 g/dl and SaO2 \> 90%), or the need for inotropes (dobutamine, epinephrine, levosimendan) * Clinical or echocardiographic signs of pulmonary hypertension with right ventricular dysfunction * APACHE-II score15 \< 25 * Other conditions suggesting that the patient would benefit from intubation and mechanical ventilation * Severe neurological disorders * Estimated mortality due to severity of acute and/or underlying illness \> 50%