WHOLE-BODY KT V FROM DIALYSATE UREA MEASUREMENTS DURING HEMODIALYSIS/

A new method fur the calculation of dialysis dose from continuous meas urements of dialysate urea concentrations has been developed. It is ba sed on urea mass in the patient instead of plasma concentrations, and results in a measure of dialysis dose that has been named whole body K t/V. The measured urea mass removal rate and the slope of the dialysat e urea concentration curve are the key parameters needed for the calcu lations. No assumptions have to be made about urea distribution in the body (single or double pool, etc.). Blood sampling is not needed. Thi s simplifies the logistics and eliminates the problems with rebound an d timing in taking samples. The total urea mass present in the body be fore treatment is also obtained. It can be used directly, or in relati on to body weight or water volume, as a measure of the level of urea i n the body. This may serve as an alternative to pretreatment plasma co ncentration. If a pretreatment plasma urea concentration is available, the urea distribution volume can be calculated, which may be of separ ate clinical interest.