Pulmonary injury caused by free fatty acid: Evaluation of steroid and albumin therapy

Intrapulmonary free fatty acid (FFA) release has been suggested as a pathogenetic mechanism in respiratory failure caused by acute pancreatitis and fat embolism. Utilizing the isolated perfused ventilated canine pulmonary lobe, we evaluated the effects of FFA infusion and its subsequent modification by albumin and steroid therapy. In control lobes perfused for a 4-hour period, there was minimal weight gain (11 gm), intrapulmonary shunting did not occur, and compliance remained within normal limits. When 1 ml of oleic acid was infused into the pulmonary artery lobe weight tripled (188 gm), intrapulmonary shunting (20%) developed, and compliance was significantly decreased compared to controls. When 30 gm of human salt-poor albumin was added to the perfusate immediately after FFA infusion, the lobe response was similar to that of untreated oleic acid lobes. In contrast, when 400 mg of methylprednisolone succinate was added to the perfusate immediately after FFA infusion, lobe weight gain was significantly reduced (94 gm) compared to oleic acid lobes, intrapulmonary shunting did not occur, and compliance was within normal limits. This study suggests that steroids may be of benefit in the treatment of respiratory insufficiency secondary to acute pancreatitis and fat embolism.