Studies of Total Pulmonary Capacity and Its Subdivisions Ix. Relationship to the Oxygen Saturation and Carbon Dioxide Content of the Arterial Blood.

The interpretation of the roentgenograph of pulmonary fibrosis in terms of functional respiratory disability is one of the most difficult problems which confronts the physician in industrial medicine. While the anatomical lesions of pulmonary fibrosis and their roentgenographic detection have been studied extensively, the mechanisms responsible for the respiratory disability are inadequately understood. The functional aspect of the fibroses acquires special importance in cases of pneumoconiosis. Measurements of the total pulmonary capacity and its subdivisions and their relation to anatomical findings in patients with chronic pulmonary diseases have been presented in previous communications (1) (2). The limits of variation in normal subjects, both male and female, and the method for the prediction of the normal capacity of a given subject have been described (1) (2) (3). The purpose of the present communication is to correlate the anatomical findings with measurements of the total pulmonary capacity and its subdivisions in 58 cases of pulmonary fibrosis.