Catheter Induced Error in Hepatic Venous Sampling

That the composition of hepatic venous blood sampled by catheter is not representative of the mixed hepatic venous blood has been shown by demonstrating that the concentrations of mesenterically infused para-aminohippuric acid and systemically infused Rose Bengal are exceedingly variable in blood sampled by a catheter placed at various positions within the hepatic venous system. These results suggest that a large and previously unsuspected error may confound the estimation of hepatic blood flow by dye infusion technics employing catheterization of the hepatic veins.