Blood gases and hemodynamic parameters over time. Partial pressure of arterial oxygen (PaO2)/fraction of inspired oxygen (FiO2), partial pressure of arterial carbon dioxide (PaCO2), mean arterial pressure (MAP), and mean pulmonary arterial pressure (MPAP) for forced oscillation technique (FOT) group (closed symbols) and for acute respiratory distress syndrome (ARDS)Net group (open symbols). Data are presented as mean ± standard deviation. Significance of differences between the two groups at any protocol step are also reported. *, P < 0.01; +, P < 0.05.