Figure 6.
Effects of PEEP at baseline conditions (black triangles), after saline lavage (grey circles), and following surfactant administration (gray squares) on the distribution of aeration density ranges (% of total slice area). Density ranges were defined as: non-aerated (≥ −100 HU), poorly aerated (−500 to −101 HU), normally aerated (−900 to −501 HU), and hyperinflated (< −900 HU). †: P<0.01 and ‡: P<0.001 for the effect of PEEP; ¶: P<0.01 and §: P<0.001 vs. saline lavage at PEEP 0 or 9 cmH2O.