Quantitative evaluation of human's hepatic functional reserve by indicator pharmacokinetics method

After liver surgery, the most common cause of death is hepatic failure; therefore, the preoperative evaluation of hepatic functional reserves is of great significance. Thus, a method has been applied to an optical measurement from the artery in a patient's finger. The indicator indocyanine green (ICG) was intravenously injected. Afterwards, the optical signals which were picked up from the sensor were measured with the signal conditioning module, and then collected to the PC by Lab-VIEW acquisition system. The ICG spectral signal is analyzed by the methods of delta absorption model, so the dilution and excretion curve of ICG concentration can be attained. The parameters reflecting the hepatic functional reserves can be calculated, including the mean transit time, the ICG 15 min retention rate, the EHBF (effective hepatic blood flow). Compared with the clinical “gold standard” methods of blood sampling to measure these two parameters by clinical controlled trials, 30 sets of data were obtained. About the 15 min retention rate of ICG, the two groups of data have fine linear relationship (coefficient of determination R2 = 0.9738, P < 0.001); and the EHBF, the coefficient of determination R2, P < 0.001. Through the analysis of the test data by Bland–Altman method, the two group results are consistent. Therefore, a simple and minimal invasive method for liver functional reserves was realized more practicability in clinic and relatively precision.