KT/Vand Protein Catabolic Rate Determination from Serial Urea Measurement in the Dialysate Effluent Stream

Publisher Website
Google Scholar
Abstract
A bloodless technique of evaluating protein catabolic rate (PCR) and KT/V (K, clearance; T, dialysis time; V, urea distribution volume) in hemodialysis patients is presented based on serial measurement of urea in the dialysate effluent stream. PCR follows from equating urea generation and urea removal over a 7 day cycle, changes in body stores being comparatively negligible: PCR = 0.026 [U1+ U2+ U3]/BWdry+ 0.17, where Ui is the amount of urea in mmol appearing in the dialysate for each session in the 7 day period. KT/V is obtained from the slope of the natural logarithm of spent dialysate urea concentration‐time plot: KT/V = [‐ slope. T+ 3. ΔBW/ BWdry]/[1–0.01786 *T(hr)], where ΔBW = amount ultrafiltered in liters. The dialysate‐based approach was validated and compared with conventional urea kinetic modeling (UKM) for 17 patients studied for three consecutive dialyses. The dialysate‐based and UKM values of PCR agreed well when in vivo clearance values based on total dialysate collection were used for UKM. KT/V values agreed poorly on a session‐by‐session basis but were nearly equivalent when averaged for the three dialyses of the week. These findings lay the foundation for UKM automation with a urea sensor in the effluent dialysate stream.

This publication has 2 references indexed in Scilit: