THE HEPATIC BLOOD FLOW AND SPLANCHNIC OXYGEN CONSUMPTION OF MAN—THEIR ESTIMATION FROM UREA PRODUCTION OR BROMSULPHALEIN EXCRETION DURING CATHETERIZATION OF THE HEPATIC VEINS 1

Abstract

The hepatic blood flow was first estimated in normal man by Bradley, Ingelfinger, Bradley and Curry (1). Before applying this bromsulphalein procedure to clinical problems, it seemed advisable not only to confirm their measurements but to esti- mate hepatic blood flow by a fundamentally differ- ent method. The urea method for hepatic blood flow, worked out in the dog by Lipscomb and Crandall (2), has been adapted to normal un- anesthetized human subjects. The hepatic venous- arterial oxygen difference, total oxygen consump- tion, and cardiac output have been measured in the same subjects. By multiplying the hepatic vein flow by the hepatic venous-arterial oxygen difference, one obtains an estimate of the splanch- nic oxygen consumption.2 The oxygen consumption and blood flow of the brain and kidney have been estimated by other investigators. Thus, the measurement of oxygen consumption and blood flow of the splanchnic area allows one to construct a fairly complete picture of the degree of oxygen utilization by and the blood flow through the most important areas of the body. Urea, among the various metabolites involving the liver, has several attributes which adapt it as a test substance for the estimation of liver blood flow. As far as is known, urea is produced in the human organism only by the liver (3, 4) and, once formed, is not converted to other compounds. Urea is very diffusible not only through the vari-