Parameters of lung histopathology.

§ depicts p < 0.05 vs. the corresponding Non-CS group, $ depicts p < 0.05 vs. the corresponding air group (K-W ANOVA Kruskall-Wallis analysis of variance on ranks with post-hoc Dunn’s test for multiple comparisons). Parameters of lung histopathology at the end of the four-hours observation period (n = 8 in each group) obtained from mice without (Non-CS) and with (CS) cigarette smoke exposure over 3–4 weeks prior to blunt chest trauma and mechanical ventilation with air (FiO2 0.21) or 100% O2 (FiO2 1.0) (n = 8 in each group). Parameters were scored as 0 (normal lung histology without pathological findings), 0.5 (minor histological injury), 1 (moderate and patchy histological injury), 1.5 (major histological injury < 25% of the lung involved), and 2 (major histological injury 25–50% of the lung involved). All data are median (quartiles).