Surfactant replacement therapy in surfactant-deficient rabbits: early effects on lung function and biochemical...

Lung-surfactant-deficient rabbits (n = 6) requiring artificial ventilation were subjected to a weaning-off regimen following surfactant replacement therapy. Surfactant-deficient rabbits (n = 6) that did not receive surfactant but underwent the same procedure served as controls. All surfactant-treated rabbits survived (i.e., reestablished spontaneous air breathing) whereas all the control animals died. In the surfactant-treated animals lung function improved in such a way that during the weaning period PaCO2 did not increase and the level of PaO2 remained significantly higher than in the control animals. The static lung compliance and the stability and expansion indices in vitro were significantly higher in the surfactant-treated rabbits. The lamellar body fraction of the lungs of surfactant-treated animals contained a significantly higher amount of surfactant phospholipids than those of the control animals. It is concluded that the animal model used in this study is an excellent tool for testing early effects of different surfactant preparations.