Ionic dialysance and conductivity modeling

In the 1993 two papers showed that instantaneous ionic dialysance can be measured without the need for blood or dialysate sampling and at no extra cost, simply by using two conductivity probes placed at the dialyzer inlet and outlet or a single probe alternately activated at the inlet and outlet. Given the very close correlation between the conductivity of dialysate and its sodium content it has been suggested that ionic dialysance can be considered equivalent to effective sodium dialysance. When ionic dialysance value is known it is possible to indirectly derive the plasma water conductivity value and thus the sodium concentration. The possibility to estimate sodium dialysance and plasma water sodium concentration without the need for blood samples and laboratory determination makes it very easy to apply the sodium kinetic model changing it in a conductivity kinetic model. Moreover, because of the similar molecular weight of sodium chloride and urea it has been suggested that ionic dialysance can also be considered equivalent to effective urea clearance. Thus, it should be possible to use ionic dialysance instead of urea clearance for the routine monitoring of delivered dialysis dose. Therefore, ionic dialysance seems a very promising and easy tool to improve dialytic treatment. © 2013 Springer-Verlag Berlin Heidelberg.