Prognostic impact of ICG-PDR in patients with hypoxic hepatitis

BACKGROUND Hepatic impairment is found in up to 20 % in critically ill patients. Hypoxic/ischemic hepatitis (HH) is a diffuse hepatic damage associated with high morbidity and mortality. Indocyanine green plasma disappearance rate (ICG-PDR) is an effective tool assessing liver function in acute and chronic hepatic diseases. Aim of this study was to evaluate the prognostic impact of ICG-PDR in comparison to established parameters for risk stratification. METHODS Patients with HH were included in this prospective observational study and compared to cirrhosis, acute liver failure (ALF) and patients without underlying liver disease. ICG-PDR, measured non-invasively by finger pulse densitometry, was assessed on admission and in patients with HH serially and results were compared between groups. Diagnostic test accuracy of ICG-PDR predicting 28-day mortality was analyzed by receiver operating characteristics (ROC). RESULTS ICG-PDR on admission was significantly lower in patients with liver diseases than in patients without hepatic impairment (median 5.7 %/min, IQR 3.8-7.9 vs. 20.7 %/min, IQR 14.1-25.4 %/min; p < 0.001). ICG-PDR predicted 28-day mortality independently of SOFA score and serum lactate in patients with underlying liver disease (HR 1.27, 95 % CI 1.10-1.45, p < 0.001). In patients with HH, ICG-PDR was identified as best predictor of 28-day mortality which performed significantly better than SOFA, lactate, INR and AST over course of time (p < 0.05). Best cut-off for identification of 28-day survivors was ICG-PDR ≥9.0 %/min 48 h after admission. CONCLUSIONS ICG-PDR is an independent predictor of mortality in patients with liver disease. Diagnostic test accuracy of ICG-PDR was superior to standard liver function parameters and established scoring systems in patients with HH.