[Gas exchange and acid-base equilibrium in chronic bronchitis and in emphysema]

Blood gas data for HbO2% and PaCO2 and determination of acid-base balance enable the biochemical features of bronchial obstruction to be related to primarily "intrinsic" or "extrinsic" factors. Long-term gas studies and ventilation mechanics data (lung elastic recoil pressure, maximum expiratory flow at different volumes and the corresponding recoil pressures) are also of assistance in this respect. Each type of bronchial obstruction thus has its own peculiarities, and these are also reflected in the level of metabolic compensation for respiratory acidosis.