Calculation of ICG kinetics by two simultaneous differential equations and non-linear least square method.

概要

論文の詳細を見る
A computer program that calculate plasma ICG distribution volume (VP), maximal hepatic extraction rate (Rmax), Michaelis constant (Km), plasma-liver (a), liver-plasma (b) and liver-bile (h) transfer rates from plasma ICG levels measured after loading ICG was tested to 38 patients with liver diseases. Two simultaneous differential equations were introduced from a two compartment model, in which Rmax/(Km+CP) was substituted for "a". The equations are solved by Runge-Kutta-Gill method after giving initial values to the parameters. The parameters are changed repeatedly by damping Gauss-Newton method, compareing calculated plasma levels of ICG with measured ones by least square method, until final values for parameters were obtained. A single load of 3-4mg/kg was enough to get reliable values of the parameters, although it was more reliable when data of both 0.5-1 mg/kg and 3-4mg/kg loads were used. VP, a, b, h were very close to the values obtaine by simple two compartment analysis for 0.5mg/kg load. Rmax and Km correlated significantly to those measured by Paumgartner's method, although the values of the former were lower than the values of the latter.
社団法人日本肝臓学会の論文