Intrapulmonary Gas Distribution in Cystic Fibrosis

Cystic fibrosis of the pancreas, or mucoviscidosis, is one of the diseases which produce a physiological dysfunction pattern of airway obstruction, intrapulmonary gas distribution* defects, and increase in the residual volume of the lung. To this picture is added loss of lung elasticity due to fibrosis and perhaps changes in lung diffusion. We have studied the intrapulmonary gas distribution in patients with cystic fibrosis to ascertain its role in the pulmonary dysfunction, especially early in the disease, and its relationship to the patient's clinical state. We have found abnormal gas distribution in patients before the development of signs and symptoms of lung involvement. Cook and others¹ have defined the changes in lung volumes and factors in mechanics in wellestablished cases. West and others² studied 6 patients, in whom they measured intrapulmonary gas mixing by the nitrogen clearance test, in addition to other tests. In our laboratory, we have