ESTIMATION OF DIALYSIS DOSE USING KT/V INDEX, WHERE V IS ESTIMATED BY MULTIFREQUENCY BIOIMPEDANCE SPECTROSCOPY (BIS) VERSUS DIFFERENT FORMULAS FOR DETERMINING OF KT/V

Abstract

The most extended index for quantification of dialysis dose is Kt/V calculated by urea kinetic modeling (UKM). Based on principle, that volume of urea distribution (V) is equal to post dialysis total body water (TBW) in human objects, we meaured regulalry TBW using whole body bioimpedance (BIS) technique. BIS analysis has been validated using multifrequency BIS approach (4200 Hydra, Analyzer, Xitron, San Diego, CA, U.S.A.). The purpose of our study was to evaluate of Kt/V index in 321 hemodialysis (HD) patients where V is measured by BIS technique (Kt/VBIS), versus different formulas based on UKM calculation: single pool spKt/V, 2nd generation Daugirdas formula (Kt/VDaug) = -LnBUNpost/BUNpre-(0.008*Td)-UF/WPost, and equilibrated Daugirdas-Schneditz formula (eKt/V) = spKt/V-0.6 x K/V + 0.03; where BUNpost and BUNpre= pre, and post HD blood urea nitrogen concentration, UF=ultrafiltration rate. Td=dialysis time, and Wpost=post HD weight.TableBIS technique can be reccomended for accurate and non invasive measurement of TBW=V,- but Kt/VBIS highly overestimated of eKt/V as “gold standard”, because of incorrect manufacture prescription of dialyzer clereance.