Gas exchange data.

Data are shown as mean values ± standard deviation. ALI: acute lung injury, FIo2: arterial oxygen saturation, Pao2: arterial partial pressure of oxygen, Paco2: arterial partial pressure of carbon dioxide, P: pressure, V: volume. At the time point ‘PV maneuver’, data was obtained immediately after the low-flow inflation maneuver during ventilation with high VT and with PEEP set 2 cmH2O above the lower inflection point. *: vs. time point 1 (P<0.05). **: vs. time point 1 (P<0.001). †: vs. PV maneuver (P<0.0001).