Sorbents in treatment of uremia: a short history and a great future

To regenerate dialysate in hemodialysis for kidney failure, it is necessary to remove all uremic toxins, avoid excessive removal of various electrolytes, and supply beneficial components such as bicarbonate. Surprisingly, a simple collection of components can accomplish this task very well: charcoal, urease, cation exchanger, and anion exchanger. From the early days of use of the Redy system and the Sorb cartridge, improvements have been made both in machine design and column chemical function. This article describes the chemical function of the Sorb cartridge, recent improvements, and the methods to predict the chemical function of the column. It also describes a number of improvements made in dialysis machines using sorbent regeneration of the dialysate. Some ongoing improvements in sorbent chemistry are also described.