Table 2 Endpoints

Primary

All-cause mortality

Early respiratory failure (PaO2/FiO2 ratio <200 in the first hour after transfer to ICU after surgery)

Late respiratory failure (heavy oxygenation support (non-invasive ventilation, high-flow oxygen or mechanical ventilation) 2 days after surgery)

Ventilator-acquired pneumonia

Early pneumonia (early or ventilator-acquired)

Secondary

All-cause in-hospital mortality

Early respiratory failure

Heavy oxygenation support

Pneumonia

Length of stay in the ICU (days) after the initial cardiac surgery)

Length of stay in the hospital (days) after the initial cardiac surgery

Cost of hospitalization (euros)

Other

Revision surgery (requirement for any revision cardiac surgery after the initial surgery)

Pneumothorax (diagnosed on chest x-ray or  CT-scan occurring after the initial surgery)

Postoperative bleeding (mL)

Cardiopulmonary bypass duration (minutes)

Red blood cells transfusion (units)