Indocyanine green clearance test in non-cirrhotic hepatitis patients: A comparison and analysis between convention blood sampling method and finger piece monitoring method

Background: The indocyanine green (ICG) Finger Piece Monitor system is a non-invasive method for measuring blood ICG concentrations for the evaluation of hepatic function. This study was conducted to determine its clinical usefulness in non-cirrhotic patients. Methods: Traditional liver function tests, alpha-fetoprotein, prothrombin time, and ICG clearance tests, by both blood sampling method and Finger Piece Monitoring method were performed simultaneously on 56 non-cirrhotic hepatitis patients. The plasma clearance rate (K) and 15-minute retention ration (R15) of ICG were analyzed and compared with traditional liver function test results. Results: The clearance rate using the Finger Piece Monitoring method was slightly lower than that of the blood sampling method (9.16±5.00%/min vs. 11.24±3.56%/min) with good correlation (r=0.721, p=0.0003). The 15-minute retention ratio using the Finger Piece Monitoring method showed better correlation with blood sampling method (32.83±23.99% vs.28.49±23.74%, r=0.944, p=0.0002). Analysis between traditional laboratory tests and fR15 revealed a higher fR15 value in patients with bilirubin-total-T ≥ 3mg/dl (49.71±26.22% vs. 22.23±13.48%), alpha-fetoprotein ≥ 100ng/ml (61.96±15.84% vs. 28.52±21.74%), and PT prolongation ≥ 3 sec (71.46±16.80% vs. 29.03±21.06%). Conclusion: There is a good correlation between the conventional blood sampling method and the ICG Finger Piece Monitoring system method. The ICG Finger Monitoring system provides an alternative for traditional laboratory tests for the evaluation of hepatic dysfunction in hepatitis patients.