OPTIMIZING SODIUM-BALANCE IN HEMODIALYSIS

This paper develops and tests a mathematical model for Na+ kinetics ap plied to standard hemodialysis. The volume of distribution of exchange able Na+, dialyzer surface area, blood and dialysis fluid flow rate, t arget weight loss, treatment duration and the Na+ diffusibility consta nt are taken into account. The model is used to compute the optimal ho ur by hour dialysis fluid Na+ concentration required to achieve the pr escribed end-dialysis natremia and maintain a constant end-dialysis bo dy Na+ pool, while providing a nearly uniform removal of Na+ over dial ysis. The model was preliminarily tested on 10 consecutive dialyses in a single patient using a special dialyzer which generates a part of u ltrafiltrate uncontaminated by dialysate.