Fig. 2.
Lung morphometry in mechanically ventilated animals. Bars represent mean ± SD of eight animals in each group. Asterisks show alveolar collapse. Arrows indicate alveolar overdistension. Alveolar collapse indicates the fractional area of lung occupied by collapsed alveoli. Box plots represent the median and interquartile range of eight animals in each group. Mann–Whitney U test with Bonferroni correction for multiple comparisons (P < 0.0167, PCV_VTvs. PSV, PCV_ΔPLvs. PSV, and PCV_ΔPL_Tivs. PSV). AD, alveolar duct; β, heterogeneity index; D2/Lm, central moment of the mean linear intercept (D2 of mean linear intercept between alveolar walls); PCV_ΔPL, pressure-controlled ventilation with dynamic ΔPL similar to that achieved by pressure-support ventilation; PCV_ΔPL_Ti, pressure-controlled ventilation with dynamic ΔPL and inspiratory time (Ti) similar to that achieved by pressure-support ventilation; PCV_VT, pressure-controlled ventilation with the same VT of pressure-support ventilation; PSV, pressure-support ventilation adjusted to VT = 6 ml/kg; VT, tidal volume.