Determination of Pulmonary Blood Volume by Single Intravenous Injection of One Indicator in Patients with Normal and High Pulmonary Vascular Pressures

MOST of the methods for estimation of blood volume in the pulmonary circuit are based on the Stewart-Hamilton principle. Different types of indicators (dyes and radio-isotopes) are used, and their varying concen-trations are determined either from arterial sampled blood 1, 2 or by precordial scan-ning.3-9 Combined right and left heart cathe-terization provides a more direct measure-ment of pulmonary blood volume in man, by the indicator-dilution technic. In methods already described,1 2 the pulmonary artery and the left atrium are used as sites of injec-tion of the indicators, sampling being made in a peripheral artery. Milnor, Jose, an