Use of finger-piece method for indocyanine green clearance test.

Abstract

The indocyanine green (ICG) finger-piece method (FPM), which allows measurement of the ICG concentration by mounting a light sensor onto a finger, is used to assess liver function. We compared the ICG FPM with the conventional ICG blood sampling method (BSM) in patients with liver disorders. Ninety consecutive patients simultaneously underwent the ICG BSM and ICG FPM. After ICG administration, blood samples were collected at 5, 10, and 15min for the ICG BSM. The ICG concentration was measured through the finger piece by an ICG clearance meter. Seventy-one patients (78.9%) had Child-Pugh class A liver disease, and 19 (21.1%) had class B or C. The FPM-measured ICG plasma disappearance rate was positively correlated with the BSM-measured values (r = 0.886, P <0.001). Bland-Altman analysis showed good agreement between the two methods (mean difference, 0.012 ± 0.018). The FPM-measured ICG plasma disappearance rate was positively correlated with the BSM-measured values both in patients with Child-Pugh class A liver disease (r = 0.821, P <0.001) and class B or C liver disease (r = 0.859, P <0.001). The ICG FPM may be an alternative to the ICG BSM for liver function assessment.