Sites of Pulmonary Vasoconstriction: Indirect and Direct Measurements

Abstract

Because pulmonary capillary pressure is an important factor in the fluid balance of the lungs, there has been considerable interest in methods for determining it and the arteriovenous sites of pulmonary vasoconstriction. Since pulmonary arterial and venous pressures but not capillary pressure can be measured directly, the methods have, in general, been indirect (Dawson, 1984; Dawson et al., 1989). In our laboratory, we have used two complementary indirect methods; the vascular occlusion method (Linehan et al., 1982) and the low viscosity bolus method (Dawson et al., 1988).