Pulmonary outcomes. There were no differences between Injury, Dexamethasone (Dex), and Cortisol groups. (A) PaCO2 decreased similarly in all groups at 15 min after the initial high VT stretch injury, then increased with continued ventilation. PaCO2 was lower after 120 min in the betamethasone group (Beta) relative to the injury group. (B) Ventilation efficiency index (VEI) decreased with time of ventilation, indicating progressive injury, with less decrease in the Beta group. (C) Dynamic compliance decreased following the stretch injury, with less decrease at 60 min for the Beta group. (D) Oxygenation index increased (indicating deterioration in oxygenation) with ventilation in all groups except the Beta group. t p < 0.05 vs Injury group.