The Study Of Histopathologic Changes In Experimental Lung Injury With Partial Liquid Ventilation

Objective:To investigate the histopathologic effect of partial liquid ventilation (PLV) with perfluorocarbons (PFC) in piglets of acute lung injury (ALI) . Mothods:16 healthy piglets weighting 23+ 2kg were randomly divided into control group (n=8) and PLV group (n=8). The animals were tracheotomized and mechanically ventilated with oxygen (FiO₂=1.0). At that time point the parameters of gas exchange and hemodynamics were measured as Baseline. Acute lung injury (ALI) were induced by lung lavage according to Lachmann,. All piglets were surfactant-depleted by lung lavage using 37℃, 40 ml/kg of 9 g/L NaCl until PaO₂<100mmHg for one hour. Conventional mechanical ventilation was administered in control group; PLV group received doses of 30 ml/kg FC-77 and were administered the same respiratory parameters as the control group for four hours. FC-77 was continued dropping via tracheal tube to surport the evaporation of FC-77 during therapy.All piglets were killed by injecting 10 milliliter 10% potassium chloride after the experiment, the lungs were taken out after clamping the endotracheal catheter at the end of expiration. 8 hematoxylin-and-eosin-stained sections from each piglet (ventral and dorsal specimens from the upper and lower parts of the right and left lungs ) were examined by the same experimenter for 6 different histologic features under light microscope : (1) interstitial edema; (2) perivascular edema; (3) intra-alveolar edema; (4) interstitial hyperemia; (5) intra-alveolar hemorrhage; (6) neutrophil accumulation. These characteristics were subjectively scored on a scale from 0 to 3: 0 = normal, 1 = slight effect, 2 = moderate presenceof that feature, 3 = severe effect. Then 2 uranil acetee and plumbum medicinal . citronate -stained sections from each piglet ( central specimens of the right and left lungs ) were observed under electron microscope. Result:The score was reduced in the partial liquid ventilation-treated animals, compared with the gas-ventilated animals ; the scores of all histologic features and the scores of all regions were reduced in the partial liquid ventilation group, compared with the gas-ventilated group; Regional analysis demonstrated a higher score for gas-ventilated group in the dorsal regions of the lungs than that in the ventral regions of the lungs and a higher score for gas-ventilated group in the left regions than that in the right regions ; Comparison of upper and lower scores revealed notably decreased scores for upper regions in the partial liquid ventilationanimals. Conclusion:PLV with PFC is associated with a reduction in the histopathologicalchanges observed in piglets lungs of ALL...