Kt/V a measure for quality control of haemodialysis therapy: how valid is it?

Since the beginning of maintenance haemodialysis many attempts have been made to quantify this kind of renal replacement therapy. The most widely used methods are urea kinetic models and simple approximation formulae based on measured data of the individual patients. The most common term of dialysis dose is Kt/V. The errors of data put into the calculations are transferred to the result. Analysis of the error of the calculated result depending on the errors of the primary data using Gauss' law of progression of errors reveals errors of the calculated Kt/V between 7.7% and 18%. It is concluded that comparison of different groups of dialysis patients by means of Kt/V should only be done using one method with the least error.