Development of an experimental model of an acute respiratory failure by intratracheal sea water infusion: a comparison with a conventional oleic acid induction.

An experimental model of acute respiratory failure (ARF) was successfully developed in dogs by endotracheal sea water infusion. Serial changes in blood gases and hemodynamics, and histological changes in the lungs after use of this method were compared with those of the conventional model induced by oleic acid, and the following results were observed. Blood gases deteriorated more rapidly after sea water than after oleic acid, while the changes caused by oleic acid progressed with time, and those caused by sea water did not. Not only systemic but also pulmonary hemodynamics were adversely influenced by oleic acid, but not by sea water. Extravascular lung water was observed to increase significantly in both groups. The increase was linear after oleic acid treatment, however, while with the sea water method it leveled off to a plateau. There was no significant difference between the histological changes in lungs of the two models. Our model will provide many advantages over the conventional one using oleic acid, and will be useful for studying the pathophysiology of ARF and its therapeutic strategies, such as extracorporeal membrane oxygenation and/or carbon dioxide removal.