The Treatment Efficacy Of Lavage Administration Of Pulmonary Surfactant On Pulmonary Gas Exchange At Different Time Interval After Acute Lung Injury Induced By Hydrochloric Acid In Rabbits

Objective To investigate the effect of lavage administration of pulmonary surfactant on pulmonary gas exchange at different time interval after acute lung injury(ALI) induced by hydrochloric acid in rabbits.Methods After the rabbit was anesthetized and mechanically ventilated via tracheotomy, lung injury was then induced by endotracheal instillation of 0.0225N hydrochloric acid (12 ml/kg). The rabbits with PaO₂ less than 150 mmHg lhour after the hydrochloric acid instillation were randomly divided into five groups, with 5 animals each. Lung lavage was then performed with surfactant solution (12mg/ml, lOml/kg) 1 hour after the hydrochloric acid instillation in the Group T₁, 2 hours in the Group T₂ and 3 hours in the Group T₃. Normal saline was used to substitute the pulmonary surfactant 1 hour after the hydrochloric acid instillation in the Group C₁ and 2 hours in the Group C₂.Results PaO₂ after the lung lavage dramatically improved in the Group T₁ and the Group T₂ (p<0.01), improved little in the Group T₃ and showed no improvement in the Group C₁ and the Group C₂. The histological changes in the Group T₁ and the Group T₂ manifested that the alveoli were expanded well, with a few neutrophils infiltration and red cells leakage. Compared with the Group T₁ and the Group T₂, there were more neutrophils infiltration andred cells leakage .in the Group T₃. The alveoli in the Group C₁ and the Group C₂ collapsed with a great number of neutrophils infiltration and red cells leakage .Conclusion Early lavage administration of pulmonary surfactant may improve PaO₂ in acute lung injury rabbit induced by hydrochloric acid.