Although much has evolved in our understanding of its pathogenesis and factors affecting patient outcome, still there is no specific pharmacologic treatment for ARDS. Despite advances in supportive measures and antibiotics, ARDS has a mortality rate of about 40-50% in most series and it is associated with significant health care costs. Patients with ARDS invariably require endotracheal intubation and mechanical ventilation (MV) to decrease the work of breathing and to improve oxygen transport. To date the only proven, widely accepted method of MV for ARDS is what is called "lung protective ventilation" using a low tidal volume strategy plus positive end-expiratory pressure (PEEP).