Fig. 2. (  A ) Microvascular leakage (bronchoalveolar lavage Evans blue absorbance) was significantly less in the groups ventilated with 70% or 100% O²  versus 21% O²(*  P < 0.05, one-way analysis of variance,  post hoc Student-Neumann-Keuls tests). (  B ) Increasing the percentage of inspired oxygen resulted in a dose-dependent increase in arterial oxygen tension (Pao ²;  P < 0.05). (  C ) Increased inspired oxygen was associated with an increased delta alveolar–arterial oxygenation gradient (AaDO²) (final − baseline AaO²;  P < 0.05). Data are expressed as mean ± SD (  A ) or as actual data points (  B and  C ).