The effects of intratracheal dexamethasone on acute lung injury in rabbits--experimental study.

Background And Objective: The aim of our study was to investigate, in rabbits with hydrochloric (HCl) acid-induced Acute Lung Injury (ALI), the effects of intra-tracheal (i.t.) dexamethasone administration on neutrophil and platelet counts, plasma malonyl dialdehyde (MDA) level, histopathology, and arterial blood gases.

Methods: Twenty-eight New Zealand rabbits were randomly divided into a control (n = 14) and dexamethasone groups (n = 14). Anesthesia was applied with ketamine (50 mg kg(-1) h(-1), i.m.) and tracheostomy was performed. Both groups received 2 ml kg(-1) HCl (hydrochloric acid) i.t.. Five minutes later, 0.9% saline was given to the controls while the other group received i.t. dexamethasone. MDA levels of the plasma, neutrophil and platelet counts, and arterial blood gases were recorded at the beginning of the study and then at two and five hours. The rabbits were ventilated in pressure control mode for 5 hours. At the end of the study, the lungs were examined by light microscopy and the changes evaluated on a scale of 0 to 4.

Results: Neutrophil and platelets counts (p < 0.01) and PaO2 (p < 0.05) were greater in the dexamethasone group than the controls at five hours. Plasma MDA level (p < 0.01) and PaCO2 (p < 0.01) were greater in the control group. Histopathological changes were less severe in the dexamethasone group.

Conclusion: Giving dexamethasone i.t. may have beneficial effects on the development of ALI.