We measured respiratory parameters (FiO 2 , tidal volume, mean airway pressure, peak inspiratory pressure, respiratory rate, and Edi max) directly from data exported from the respirator. Nurses recorded vital signs and SpO2. The oxygenation saturation index, OSI = (FiO 2 × mean airway pressure)/SpO 2 , was used to provide a non-invasive method of oxygenation assessment. This index can be used for the diagnosis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in children when SpO 2 values are ≤ 97% [5] . Diagnosis of ALI and ARDS required an acute onset of the process, bilateral infiltrates on a chest radiograph, no evidence of left atrial hypertension, and OSI > 6.5 (ALI) or > 7.8 (ARDS). Blood samples were also analyzed to provide blood pH and PCO 2 values.