Plasma disappearance of indocyanine green: a marker for excretory liver function?
OBJECTIVE
To investigate whether the plasma disappearance rate of indocyanine green (ICG) assessed using a commercially available bedside monitor provides an accurate estimation of cumulative biliary ICG excretion in a clinically relevant model of long-term, hyperdynamic porcine endotoxemia.


METHODS
Prospective experimental study in the animal laboratory in a university hospital.


METHODS
Fifteen domestic pigs.


METHODS
Pigs were anesthetized, mechanically ventilated, and instrumented. Intravenous endotoxin was continuously infused over 12 h concomitant with fluid resuscitation. Measurements were performed before and 12 h after the start of endotoxin infusion.


RESULTS
All animals developed hyperdynamic circulation characterized by a sustained increase in cardiac output. Despite well maintained portal venous and consequently total liver blood flow endotoxemia decreased hepatic lactate uptake, which was accompanied by a significant fall in portal and hepatic venous pH. Both the cumulative bile flow and biliary ICG and bicarbonate excretion measured during 1 h after intravenous bolus of 25 mg ICG fell significantly. By contrast, neither the plasma disappearance rate of ICG nor the rate corrected for liver blood flow exhibited any changes over time.


CONCLUSIONS
In hyperdynamic porcine endotoxemia the plasma disappearance rate of ICG failed to accurately substitute for direct short-term measures of biliary ICG excretion. Hence normal values of plasma disappearance rate of ICG should be interpreted with caution in early, acute inflammatory conditions.
Stehr
Alexander
A
Klinik und Poliklinik für Chirurgie, Universitätsklinikum, Regensburg, Germany.
Ploner
Franz
F
Traeger
Karl
K
Theisen
Marc
M
Zuelke
Carl
C
Radermacher
Peter
P
Matejovic
Martin
M
D000818:Animals; D001646:Bile / Q000378:metabolism*; D004396:Coloring Agents / Q000493:pharmacokinetics; D019446:Endotoxemia; D006439:Hemodynamics; D007208:Indocyanine Green / Q000493:pharmacokinetics; D008099:Liver / Q000098:blood supply / Q000378:metabolism; D008111:Liver Function Tests / Q000379:methods*; D008657:Metabolic Clearance Rate; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D018805:Sepsis / Q000175:diagnosis*; D013552:Swine
D004396:Coloring Agents; D007208:Indocyanine Green