Pulmonary fat embolism in rabbits induced by forced immobilization

In the study reported here, rabbits were used to develop an experimental model for inducing pulmonary fat embolism by forced immobilization. The emboli were quantitated by a computerized system. The activity of lipoprotein lipase in post-heparin plasma (PHP-LPL) and concentrations of free fatty acids (FFA) were measured. Also, blood gases were analyzed and pulmonary morphology and ultrastructure were observed. Forced immobilization for 5 hours was found to induce pulmonary embolism. This was accompanied by elevation of PHP-LPL and FFA levels in the blood, hypocapnia, and a tendency for insufficiency of pulmonary surfactant. The results suggest that the disorder of homeostasis caused by immobilization is strong enough to bring about pulmonary embolism without bone fracture.