Determination of hepatic clearance by derivations of the indocyanine green retention test in cirrhosis

Abstract

Background and Aim:The study was undertaken in order to compare single injection indocyanine green (ICG)-clearances with the steady-state ICG-clearance (ICG Cl ) in patients with cirrhosis in order to assess the most accurate estimate for ICG-clearance and to relate the ICG-clearances to established indicators of liver dysfunction. Methods: Thirty-eight patients (male 29) with cirrhosis (Child-Turcotte class A 8, class B 21, and class C 9) were studied during a hemodynamic investigation. A single injection of ICG was followed by blood samples for 5, 10, 15, and 20 min. The dose/plasma area clearance (Cl A ) and plasma volume • initial slope clearance (Cl PV ) were determined and compared with the steady-state infusion/plasma concentration ratio clearance (ICG Cl ). Results: The Cl A (310; 214; 502 mL/min) and Cl PV (294; 164; 481 mL/min) correlated closely with ICG Cl (243; 120; 383 mL/min [median; interquartile range], R = 0.95-0.98, P < 0.000), but were significantly higher than ICG Cl (P < 0.001). All three clearance measures correlated significantly with biochemical and hemodynamic variables of liver dysfunction (P < 0.05-0.000). All three ICG-clearances showed significantly lower values in patients with ascites compared to those without, and lower ICG-clearance values were present in patients with esophageal varices compared to those without (P < 0.05-0.002). Conclusion: Single injection markers (Cl A and Cl PV ) of the steady-state ICG-clearance as derived from the ICG-retention curve and the plasma volume correlate with ICG Cl and established variables of portal hypertension and liver cell bile excretory dysfunction. Therefore, these markers can safely replace the more costly ICG Cl .