CHRONIC OBSTRUCTIVE LUNG DISEASE .3. INTERRELATIONSHIPS OF PULMONARY FUNCTION DATA

Abstract
The intercorrelation of pulmonary function data in 175 cases of chronic obstructive lung disease has been reviewed. With the exception of the total lung capacity, all parameters studied showed a statistically significant correlation with expiratory slowing. This relationship was quite striking in the case of vital capacity, RV/ TLC ratio, PCO2, and abnormal nitrogen washout; but the correlation with expiratory slowing was relatively poor for residual volume, single-breath diffusing capacity, and arterial O2 saturation. Some ralationship was noted between hypercapnea and hypoxemia, but arterial unsaturation was not correlated with pulmonary diffusing capacity as measured by the single-breath method. Regression formulas have been reported for some of the closely related variables in the study.