Impairment of pulmonary function in acute pancreatitis

Arterial blood gas levels, lung volumes, and diffusing properties for carbon monoxide were measured in 22 patients with uncomplicated acute pancreatitis who had no clinical or radiographic evidence of pulmonary involvement. Mild arterial hypoxemia (less than 75 mm Hg) was present in four patients. The mean values of inspiratory lung volumes were clearly reduced, and the diffusing properties were sharply altered; the mean value for the diffusing capacity of carbon monoxide per unit of lung volume (Krogh's constant [KCO]) was 78 percent of predicted. Four patients with a low KCO in the first four days after an acute episode had normal values when reevaluated one week later. These findings suggest the occurrence, even in mild acute pancreatitis, of transient pulmonary injury mainly localized at the level of the capillaries, leading to decreased gas transfer.