Rapid measurement of indocyanine green clearance by pulse spectrophotometry: a validation study in 70 patients with Child-pugh A liver function

Abstract

BACKGROUND: Inadequate liver functional reserve is the greatest barrier for major hepatectomy in patients with hepatocellular carcinoma and liver cirrhosis. The development of pulse spectrophotometry provides a faster alternative for ICG measurement but its accuracy in for preoperative assessment is not well documented as most of the previous studies consisted of a heterogenous group of patients in the critically ill patients. This study compared the result of non-invasive liver function monitoring using the LiMON (Pulsion Medical System, Munich, Germany) and traditional spectrophotometry by serial blood sampling in patient with Pugh Child A score before major hepatic resection. STUDY DESIGN: From September 2008 to Jan 2009, 70 patients with Pugh Child A score were enrolled for investigations. Their ICG clearance at 15 min were measured by traditional spectrophotometry with serial blood sampling and the LiMON. The results were compared. RESULTS: The median ICG retention at 15 min by spectrophotometry was 14.748%. The median ICGR15 measured by LiMON was 10.38. The mean difference between the LiMON and spectrophotometry was -4.3606. There was a strong correlation between the 2 measurement methods (correlation coefficient 0.844, 95% CI = 0.762, 0.899). The ICGR15 measured by LiMON, the ICG15 measured by traditional method can be calculated using the following formula. ICG15 = 1.16 * ICGR15 + 2.73 Conclusions: The LiMON is a portable unit which provides a fast and repeatable method to evaluate the ICG clearance at 15 min for patient with Pugh Child A Score. Adjustment of result is necessary in order to achieve a comparable result obtained by spectrophotometry.