Lung Open Ventilation to Decrease Mortality in the Acute Respiratory Distress Syndrome

Inclusion Criteria: * Invasive mechanical ventilation * Acute respiratory insufficiency (within past 28 days) * Bilateral infiltrates on frontal chest radiograph * Hypoxemia, defined as PaO2/FiO2\<=250 Exclusion Criteria: * Primary cause of respiratory failure is cardiac * Anticipated duration of mechanical ventilation \< 48 hours * Inability to wean other experimental ventilation strategies * Severe chronic respiratory disease * Neuromuscular disease that will prolong mechanical ventilation * Conditions where hypercapnia-induced intracranial hypertension should be avoided * Morbid obesity (\> 1Kg per cm body weight) * Pregnancy * Very unlikely to survive and lack of commitment to life support Underlying irreversible condition with 6 month mortality \>= 50% * Greater than 48 hours elapsed since first eligible * Current participation in competing trial * Lack of physician, patient or proxy consent