Sampling of Hepatic Venous Blood in the Dog

¹ From the Clinical Research Unit, Royal Prince Alfred Hospital, Sydney, Australia

When hepatic blood flow is estimated in the dog by Bromsulphalein (BSP) technique, the results suggest that there is a variable error in the method and that this may be related to the technique of sampling hepatic venous blood. The well-known possibility of inclusion of inferior vena caval blood in the samples has been shown to be less likely than previously believed, and it has been demonstrated that, if the hepatic vein is blocked by the catheter tip, falsely low values for hepatic venous BSP can result from dilution of samples by saline infused through the catheter. Simultaneous sampling from right and left hepatic veins showed consistently higher BSP extraction by the left lateral lobe in two dogs. Elimination of major sampling error in the dog is possible by using a large animal and a small catheter, by carefully placing the catheter tip in a large hepatic vein and by discarding infusion through the catheter in favor of an alternative method of keeping the lumen patent.