Comparison of the Bromsulphalein Method with Simultaneous Direct Hepatic Blood

A method has been devised for directly measuring hepatic outflow in dogs so as to permit simul-taneous comparison with the indirect method, employing the hepatic removal of Bromsulphalein (BSP). The results show that the indirect method averages 7.3 per cent higher than the direct. This difference is attributed to a small degree of extrahepatic removal of the dye. THE Bromsulphalein extraction methoddeveloped by Bradley, Ingelfinger, Brad-ley, and Curry1 is being applied with increasing frequency to problems of hepatic hemodynamics. However, estimates of the validity of the method have been controver-sial.2"9 A method for measuring hepatic venous outflow directly has been developed and has been employed in the present investigation to evaluate critically the Bromsulphalein (BSP) extraction method for measuring effective hepatic blood flow (EHBF). METHOD Dogs were anesthetized with pentobarbital so-dium (30 mg. per kilogram, intravenously) to permit the necessary surgical procedures. Approach to the vena cava inferior to the hepatic veins was made through a right flank incision, beginning at the rib margin. Loose ligatures were placed around the vena cava between the right adrenal vein and the light renal vein. All cannulas, manometers, and parts of the external circuit were filled with saline before in-sertion and connection. The animals were heparin-ized (4 mg. per kilogram) before any vessels were cannulated. Supplementary heparin was adminis-tered in a dose of 10 mg. every half hour. In three experiments in which the rotameter was used, an additional dose of 250 mg. of the heparinoid man