Plasma Disappearance Rate of Indocyanine Green for Determination of Liver Function in Three Different Models of Shock

Alexander Mathes; Christopher Plata; Hauke Rensing; Sascha Kreuer; Tobias Fink; Alexander Raddatz

doi:10.3390/diagnostics9030108

Plasma Disappearance Rate of Indocyanine Green for Determination of Liver Function in Three Different Models of Shock

Diagnostics (Basel). 2019 Aug 31;9(3):108. doi: 10.3390/diagnostics9030108.

Authors

Alexander Mathes¹, Christopher Plata², Hauke Rensing³, Sascha Kreuer⁴, Tobias Fink⁴, Alexander Raddatz⁴

Affiliations

¹ Department of Anesthesiology and Intensive Care Medicine, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. alexander.mathes@uk-koeln.de.
² Department of Anesthesiology and Intensive Care Medicine, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
³ Department of Anesthesiology and Intensive Care Medicine, Leopoldina Hospital Schweinfurt, Gustav-Adolf-Str. 8, 97422 Schweinfurt, Germany.
⁴ Department of Anesthesiology, Critical Care and Pain Medicine, Saarland University Hospital, 66424 Homburg (Saar), Germany.

Abstract

The measurement of the liver function via the plasma disappearance rate of indocyanine green (PDR_ICG) is a sensitive bed-side tool in critical care. Yet, recent evidence has questioned the value of this method for hyperdynamic conditions. To evaluate this technique in different hemodynamic settings, we analyzed the PDR_ICG and corresponding pharmacokinetic models after endotoxemia or hemorrhagic shock in rats. Male anesthetized Sprague-Dawley rats underwent hemorrhage (mean arterial pressure 35 ± 5 mmHg, 90 min) and 2 h of reperfusion, or lipopolysaccharide (LPS) induced moderate or severe (1.0 vs. 10 mg/kg) endotoxemia for 6 h (each n = 6). Afterwards, PDR_ICG was measured, and pharmacokinetic models were analyzed using nonlinear mixed effects modeling (NONMEM^®). Hemorrhagic shock resulted in a significant decrease of PDR_ICG, compared with sham controls, and a corresponding attenuation of the calculated ICG clearance in 1- and 2-compartment models, with the same log-likelihood. The induction of severe, but not moderate endotoxemia, led to a significant reduction of PDR_ICG. The calculated ICG blood clearance was reduced in 1-compartment models for both septic conditions. 2-compartment models performed with a significantly better log likelihood, and the calculated clearance of ICG did not correspond well with PDR_ICG in both LPS groups. 3-compartment models did not improve the log likelihood in any experiment. These results demonstrate that PDR_ICG correlates well with ICG clearance in 1- and 2-compartment models after hemorrhage. In endotoxemia, best described by a 2-compartment model, PDR_ICG may not truly reflect the ICG clearance.

Keywords: PDRICG; endotoxemia; hemorrhagic shock; liver function.