Analysis of Urea Nitrogen and Creatinine Kinetics in Hemodialysis: Comparison of a Variable-Volume Two-Compartment Model with a Regional Blood Flow Model and Investigation of an Appropriate Solute Kinetics Model for Clinical Application

2000 ◽  
Vol 18 (1) ◽  
pp. 18-29 ◽  
Author(s):  
Toshio Yamada ◽  
Seigo Hiraga ◽  
Takashi Akiba ◽  
Fumiaki Marumo
Keyword(s):  
Blood Flow ◽  
Clinical Application ◽  
Flow Model ◽  
Regional Blood Flow ◽  
Compartment Model ◽  
Kinetics Model ◽  
Urea Nitrogen ◽  
Variable Volume ◽  
Two Compartment Model ◽  
Creatinine Kinetics

scholarly journals Analytical Solution of Multicompartment Solute Kinetics for Hemodialysis

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Przemysław Korohoda ◽  
Daniel Schneditz
Keyword(s):  
Blood Flow ◽  
Flow Model ◽  
Linear Models ◽  
Regional Blood Flow ◽  
Compartment Model ◽  
Practical Applications ◽  
Novel Approach ◽  
The Matrix ◽  
Creatinine Kinetics ◽  
Blood Flow Model

Objective.To provide an exact solution for variable-volume multicompartment kinetic models with linear volume change, and to apply this solution to a 4-compartment diffusion-adjusted regional blood flow model for both urea and creatinine kinetics in hemodialysis.Methods.A matrix-based approach applicable to linear models encompassing any number of compartments is presented. The procedure requires the inversion of a square matrix and the computation of its eigenvaluesλ, assuming they are all distinct. This novel approach bypasses the evaluation of the definite integral to solve the inhomogeneous ordinary differential equation.Results.For urea two out of four eigenvalues describing the changes of concentrations in time are about 105times larger than the other eigenvalues indicating that the 4-compartment model essentially reduces to the 2-compartment regional blood flow model. In case of creatinine, however, the distribution of eigenvalues is more balanced (a factor of 102between the largest and the smallest eigenvalue) indicating that all four compartments contribute to creatinine kinetics in hemodialysis.Interpretation.Apart from providing an exact analytic solution for practical applications such as the identification of relevant model and treatment parameters, the matrix-based approach reveals characteristic details on model symmetry and complexity for different solutes.

Direct and indirect measurement of the hepatic extraction ratio of Indocyanine Green in the rat

1989 ◽  
Vol 76 (5) ◽  
pp. 503-508 ◽  
Author(s):  
E. Burns ◽  
C. E. Ball ◽  
J. P. Christie ◽  
G. D. Broadhead ◽  
G. T. Tucker ◽  
...  
Keyword(s):  
Blood Flow ◽  
Indocyanine Green ◽  
Liver Blood Flow ◽  
Compartment Model ◽  
Indirect Measurement ◽  
Extraction Ratio ◽  
Isolated Perfused Rat Liver ◽  
Time Data ◽  
Two Compartment Model ◽  
Liver Preparation

1. In order to estimate liver blood flow in the rat, the extraction ratio of Indocyanine Green was determined using a two-compartment model fitted to the plasma concentration time data after a single intravenous bolus dose and compared with values obtained directly by transhepatic sampling, both in the intact rat and in an isolated perfused rat liver preparation. 2. There was no agreement between estimates of the extraction ratio obtained by using the kinetic model and the directly measured values. 3. Elimination curves for Indocyanine Green were simulated to yield varied clearance values. Despite a 250% variation in clearance, extraction ratios derived using the two-compartment model were all greater than 0.9 and varied by less than 6%. 4. Estimates of liver blood flow obtained by deriving a value of the extraction ratio of Indocyanine Green using the two-compartment model are inaccurate.

scholarly journals A diffusion-adjusted regional blood flow model to predict solute kinetics during haemodialysis

2009 ◽  
Vol 24 (7) ◽  
pp. 2218-2224 ◽  
Author(s):  
Daniel Schneditz ◽  
Dieter Platzer ◽  
John T. Daugirdas
Keyword(s):  
Blood Flow ◽  
Flow Model ◽  
Regional Blood Flow ◽  
Blood Flow Model

scholarly journals Two‐compartment model of rat renal inner medullary vasculature: relevance to countercurrent exchange and medullary blood flow

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Thomas L. Pannabecker ◽  
Julie Kim ◽  
Justin Yuan ◽  
Brandi Hoopes ◽  
Collin Laufenberg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Compartment Model ◽  
Medullary Blood Flow ◽  
Two Compartment Model ◽  
Countercurrent Exchange

A Regional Blood Flow Model for Glucose and Insulin Kinetics During Hemodialysis

ASAIO Journal ◽  
2013 ◽  
Vol 59 (6) ◽  
pp. 627-635 ◽  
Author(s):  
Daniel Schneditz ◽  
Magda Galach ◽  
Karl Thomaseth ◽  
Jacek Waniewski
Keyword(s):  
Blood Flow ◽  
Flow Model ◽  
Regional Blood Flow ◽  
Insulin Kinetics ◽  
Blood Flow Model
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