Urea volume distribution in hemodialysis patients: differences between the kinetic and anthropometric models. Usefulness of on-line determinations

Abstract

Introduction: The urea distribution volume (V) is used to estimate dialysis dose. There are several measurement methods, including anthropometric (aV) and kinetics (kV), according to DOQI guidelines. Objective: The aim of this study was to compare the differences between aV and kV methods. Methods: One hundred and five measurements were performed employing kV methodology in the same number of hemodialyzed patients with OCM FME (on line clearance monitor) software. In addition, Va was determined simultaneously, using Watson, Hume, Chertow and weight percent formulas. Descriptive statistics were performed with SPSS software and Bland and Altman test was used to assess clinical measurements (concordance analysis for numerical variables). Mean V values +/- SD obtained by different methods were as follows: kV: 32.7 +/- 7.96 L ; V weight %: 41.2 +/- 9.5 L; Watson: 33.2 +/- 4.6 L; Hume: 35.0 +/- 5.7 L and Chertow: 40.1 +/- 8.0 L ( p = 3.7 Annova). Conclussion: Significant statistical differences were found between groups with exception of V weight % compared with V by Chertow (p= 0.31). It could be observed that aV measurements are higher than kV one (V overestimation) and these differences are relevant taking into account concordance levels. It was observed a lack of homogeneity between different methods. OCM clearance monitor software simplifies kV calculation.

How to cite this article:

Mengarelli C, Ferricher G, Claudepierre R, Molina C, Carreras R, Carrillo JP, Najún Zarazaga C. Urea volume distribution in hemodialysis patients: differences between the kinetic and anthropometric models. Usefulness of on-line determinations. Rev Nefrol Dial Traspl. 2009;29(4):163-8.