Abstract
In order to know which is more dominant factor for the elevation of pulmonary arterial pressure, anoxia or hypercapnia, hemodynamic studies were performed on 14 cases of pulmonary emphysema and 17 cases of pulmonary tuberculosis, special attentions being paid on the correlation between the pressure and resistance in the pulmonary circuit with those determinants including blood gases, pulmonary blood flow and pulmonary blood volume.
1) The pulmonary hypertension in pulmonary emphysema is the result of either anoxemia or hypercapnemia.
2) A highly significant correlation was found between the pulmonary vascular resistance and degree of hypercapnemia, but not with anoxemia in patients of pulmonary emphysema. These results are in fair accordance with our observations on animals breathed low O2 or high CO2, or both together. Such findings suggest that hypercapnia may be more dominant than anoxia in the genesis of pulmonary hypertension in patients with pulmonary emphysema.
3) The genesis of pulmonary hypertension in patients with pulmonary tuberculosis may chiefly be based upon the pathological change of pulmonary blood vessels viz. the pressure elevation in pulmonary capillary areas.
4) There seems to be a decreasing tendency of the pulmonary blood volume, resulting probably from pathlogical changes of pulmonary vessels or pulmonary arterial constriction in cases of chronic pulmonary disease, though this requires further investigation.
