Pulmonary responses of unilateral positive end expiratory pressure (PEEP) on experimental fat embolism.

The role of positive end expiratory pressure (PEEP) was evaluated in preventing the deleterious mechanical respiratory effects of fatty acid pulmonary embolism. One group of animals had ventilation without PEEP, while the second group had PEEP of 10 cm H2O applied only to the right lung. In the right lung, PEEP slightly reduced the blood flow, increased the vascular resistance, but reduced intersititial edema and reduced the degree of shunting to almost normal. Hypoxemia was prevented in the right pulmonary venous system, but was prominent in the left. The hypoxemia and shunting in the left lung were comparable to the Group I animals without PEEP to either lung. These studies confirm the value of PEEP in the therapy of the pulmonary manifestations of fat embolism which are the lethal factors in the fatty embolism syndrome.