Abstract
The acute respiratory distress syndrome is characterized by the acute onset of hypoxemia and bilateral pulmonary infiltrates in absence of clinical signs of left heart failure. The coexistence of excess lung fluid, ventilation-perfusion mismatch (shunting), increased dead space and pulmonary hypertension leads to severe hypoxemia and impaired carbon dioxide excretion. To avoid ventilator induced lung injury, lung protective ventilation strategies, such as the use of low tidal volumes and modest levels of positive end-expiratory pressure are recommended. However, when positive-pressure ventilation alone cannot maintain adequate oxygenation (refractory hypoxemia) a clinical decision for rescue therapy needs to be implemented. Beside many existing nonventilatory interventions (inhaled vasodilatator therapy, prone positioning), the use of extracorporal membrane oxygenation (ECMO) facilitates most effectively the use of lung protective ventilation. Nevertheless, the use of rescue therapies still remains controversial requiring further investigations in large heterogeneous populations of patients with ARDS.
