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

Abstract

SummaryThe dye indocyanine green is familiar to anaesthetists, and has been studied for more than half a century for cardiovascular and hepatic function monitoring. It is still, however, not yet in routine clinical use in anaesthesia and critical care, at least in Europe. This review is intended to provide a critical analysis of the available evidence concerning the indications for clinical measurement of indocyanine green elimination as a diagnostic and prognostic tool in two areas: its role in peri-operative liver function monitoring during major hepatic resection and liver transplantation; and its role in critically ill patients on the intensive care unit, where it is used for prediction of mortality, and for assessment of the severity of acute liver failure or that of intra-abdominal hypertension. Although numerous studies have demonstrated that indocyanine green elimination measurements in these patient populations can provide diagnostic or prognostic information to the clinician, 'hard' evidence -i.e. high-quality prospective randomised controlled trials -is lacking, and therefore it is not yet time to give a green light for use of indocyanine green in routine clinical practice.

Indocyanine green kinetics to assess liver function: Ready for a clinical dynamic assessment in major liver surgery?

“…Worldwide, ICG clearance is the most common and easy -to -use test for the perioperative dynamic assessment of liver function in case of major liver surgery (resective surgery and liver transplantation) and in the intensive care unit (ICU) [2,[6][7][8] . ICG is an inert, water-soluble, fluorescent tricarbocyanine, with a protein binding close to 95% (mainly, alpha1-and beta-lipoproteins and albumin).…”

“…Toxicity is very low, and very rare are the adverse effects, reported in 1/40000 cases. The presence of Iodine in the ICG molecule constitutes a contraindication to its use in case of thyrotoxicosis and iodine allergy (a reaction due to non-immunological histamine release) [6][7][8] . Since the early sixties, ICG elimination kinetics were used to measure blood volume and cardiac output, while in recent years an increased interest exists in using ICG clearance parameters for a dynamic assessment of liver function both in medical and surgical settings [6,[9][10][11] .…”

“…The presence of Iodine in the ICG molecule constitutes a contraindication to its use in case of thyrotoxicosis and iodine allergy (a reaction due to non-immunological histamine release) [6][7][8] . Since the early sixties, ICG elimination kinetics were used to measure blood volume and cardiac output, while in recent years an increased interest exists in using ICG clearance parameters for a dynamic assessment of liver function both in medical and surgical settings [6,[9][10][11] . The "standard" determination of ICG clearance (ICGCl) relies upon a rather complex ex vivo photometric analysis of multiple arterial blood samples obtained in a short time frame (15 min) after the intravenous administration: In spite of being so far the gold standard, it is now used for research purposes only.…”

“…The "standard" determination of ICG clearance (ICGCl) relies upon a rather complex ex vivo photometric analysis of multiple arterial blood samples obtained in a short time frame (15 min) after the intravenous administration: In spite of being so far the gold standard, it is now used for research purposes only. New bedside, easy to use transcutaneous -non-invasive pulse dye densitometry (PDD) devices able to measure ICG concentrations are on the rise for the use in clinical practice [1,6,7] . Among them are LiMon, (Pulsion Medical System, Germany) and DDG 2001 (Nihon Kohden, Japan): ICG elimination is expressed as ICG plasma disappearance rate (ICGPDR) or retention rate at fifteen minutes (ICGR15), assessing relative ICG concentration changes ( Figure 2).…”

“…ln modern critical care medicine, extensive and accurate liver function assessment has a relevant place while caring for high risk medical patients or candidates to major liver surgery: At the moment, static and dynamic tests are available [1][2][3][4][5][6][7] . Static tests, since long included in scores able to quantify acute and chronic (CHILD PUGH, MELD) hepatic dysfunction, assess separately the different functions of the liver and describe the size of the hepatic injury [1][2][3][4] .…”