Therapy for chronic obstructive lung disease.

CAO is a chronic, degenerative disease of the lung that produces a number of serious physiologic abnormalities in respiratory function. It is progressive and, in general, responds poorly to medical therapy. Cigarette smoking is almost universally the cause of the disease, and stopping smoking clearly slows the progress of the disorder. Therapy is of marginal value at best in a substantial number of patients with this problem, and even in those who respond well, improvement in function is not great. A conservative approach to therapy is advised, but only when its value can be documented. As the illness progresses, chronic oxygen therapy in hypoxic patients may be of value in preventing or treating cor pulmonale.