The therapeutic protocol of venovenous extracorporeal life support in patients with posttraumatic acute respiratory distress syndrome. ACT: Active clotting time. aPTT: Activated partial thromboplastin time. PEEP: Positive end-expiratory pressure. SpO2: Pulse oximetry-detected oxyhemoglobin saturation. PaO2: Arterial oxygen tension. PaCO2: Arterial carbon dioxide tension. MAP: Mean arterial pressure. Hb: Hemoglobin. FiO2: The fraction of inspired oxygen. TV3: Tidal volume. Pplt: Inspiratory plateau pressure.