Sensitivity and specificity of plasma disappearance rate of indocyanine green as a prognostic indicator in acute liver failure

BACKGROUND: In patients presenting with acute liver failure (ALF) prediction of prognosis is vital to determine the need of transplantation. Based on the evidence that plasma disappearance rate of indocyanine green (ICG-PDR) correlates with liver cell function, we evaluated the ability of ICG-PDR measured by pulse dye densitometry to predict outcome in patients with acute liver failure. METHODS: Prospectively markers of hepatocellular injury, synthesis and excretion, including ICG-PDR were measured daily until liver transplantation, death, discharge from intensive care unit, or up to 7 days in 25 patients with acute liver failure. Receiver operating curve (ROC) analysis was performed to assess the value of ICG-PDR to predict outcome in ALF. RESULTS: The 25 patients analyzed included 18 that recovered spontaneously and 7 that underwent liver transplantation (n = 6) or died (n = 1). Causes of ALF included viral hepatitis (n = 4), toxic liver injury (n = 15), ischemic liver injury (n = 2), and cryptogenic liver failure (n = 4). King's college criteria were fulfilled in 85.7% of patients not recovering spontaneously and in 16.7% of patients recovering spontaneously. The mean ICG-PDR measured on day 1 in patients recovering spontaneously was 12.0 ± 7.8%/min and in patients not recovering spontaneously 4.3 ± 2.0%/min (P = 0.002). By ROC analysis the sensitivity and specificity of an ICG-PDR value ≤ 6.3%/min on study day 1 were 85.7% and 88.9%, respectively, for predicting a non spontaneous outcome in ALF. CONCLUSION: ICG-PDR allows early and sensitive bedside assessment of liver dysfunction in ALF. Measurement of ICG-PDR might be helpful in predicting the outcome in acute liver failure. TRIAL REGISTRATION: Clinicaltrials.gov, NCT 00245310