Indocyanine green R15 ratio depends directly on liver perfusion flow rate

Abstract

ICG R15 is reliable within one group at defined perfusion rates. Doubled perfusion rates contribute to higher ICG clearance. For clinical application we would like to suggest considering cardiac output of the patient for interpretation of ICG ratios.

Effect of intra‐abdominal pressure on hepatic microcirculation: Implications of the endothelin‐1 receptor

“…Although the PDR of ICG is a complex measurement of both sinusoidal perfusion and hepatic function, such a rapid change (within 3 h) and the low values can be explained almost exclusively by changes in sinusoidal blood flow. 23,24 These results reinforce the concept that the sinusoidal microcirculation suffered an important impairment, to which pretreatment with tezosentan at high IAP gave moderate protection.…”

Green light for liver function monitoring using indocyanine green? An overview of current clinical applications

“…In the case of ICG, hepatic clearance of ICG is highly dependent on hepatic blood flow because the ICG hepatic extraction rate is very high. Therefore, dynamic liver function monitoring with ICG is regarded as a surrogate of both intrinsic liver function and hepatic blood flow, and so can only adequately assess liver function if measured under steady‐state haemodynamic circumstances .…”

Indocyanine green plasma disappearance rate as dynamic liver function test in critically ill patients

“…They conclude that ICG R15 ratio in hyperdynamic states may conceal the true excretory graft function. 19 In patients with steatosis and hepatitis (global hepatocellular dysfunction), some of the transport polypeptides can be downregulated, thus affecting the uptake of indocyanine green, making all of the measurements lower. 3,17 Hyperbilirubinaemia (> 51 μmol/l) can reduce ICG-PDR probably because ICG and bilirubin use the same transport carrier and a competitive inhibition of the two is seen in patients with obstructive jaundice.…”