Respiratory failure in acute pancreatitis. A possible role for triglycerides

Respiratory failure is a frequent complication of acute pancreatitis. Two clinical studies of this association have demonstrated a high incidence of concomitant hypertriglyceridemia. Experimental studies were carried out using an ex vivo, isolated, perfused, ventilated, canine pulmonary lobe to evaluate the effects of triglyceride elevations on pulmonary mechanics and gas exchange. Control lobes perfused for a four hour period remained stable. When 5 g and 10 g of triglyceride were added to the perfusate, the lobes became grossly edematous and hemorrhagic. Intrapulmonary shunting developed (23 and 46%), weight gain occurred (130 and 189 g), effective compliance decreased, and the pressure-volume deflation curves became abnormal. Free fatty acid (FFA) levels increased markedly during the perfusion periods. When small quantities of FFA were infused directly into the pulmonary artery, similar changes, but less severe, occurred. These studies demonstrate that triglyceride elevations are capable of adversely affecting pulmonary gas exchange and mechanics. Such changes probably occur secondary to FFA release. These data thus add support to the concept that the respiratory insufficiency that is seen in acute pancreatitis could be mediated through triglyceride elevations.