Table 3.

Injury scores based on histological evaluations.

Condition	Alveolar wall thickening	Alveolar wall breakage	Blood cell infiltration	Interstitial edema	Vascular bed injury	Alveolar wall flooding
CV	7–9	7–8	7	6–7	6–7	7
VV1	2–6	2–6	2–5	1–3	1–4	1–3
VV2	1–2	1–2	1	1	1	0

Histological scoring criteria: Alveolar wall thickening: structural changes in the alveolar extracellular matrix (ECM) due to swollen and/or loose ECM and hyaline membrane formation covering the epithelial layer. Alveolar wall rupture: thinner or broken alveolar walls with tissue retraction. Blood cell infiltration: increase in inflammatory cell numbers in the alveolar wall. Interstitial edema: protein containing free fluid and swelling of the extracellular matrix of alveolar wall space. Vascular bed injury: degeneration of vessels (swollen, vacuole rich vascular walls with cell necrosis). Alveolar wall flooding: platelet invasion including infarcts like hemorrhagic changes of alveolar walls after vascular rupture. Left upper lobes of the lungs (n + 5 in each group) and 20 sections/lamb were chosen randomly for analysis.