Significance of distribution volume in dialysis quantification

The urea distribution volume is in several ways an important parameter in the treatment of end-stage renal disease (ESRD) patients. It has a major impact on the relative dose of dialysis treatment as measured by Kt/V. It is also important in the assessment of fluid status, which has a direct influence on blood pressure. Nevertheless, urea distribution volume is usually not measured on a regular basis, probably because it has been perceived as a relatively complicated measurement. With the arrival of on-line monitors for dialysate urea this situation has improved radically. In this article a number of volume determination methods are discussed, including some new methods based on on-line dialysate urea monitoring, which are shown to perform well in comparison to reference methods.