Role of dialysis technology in the removal of uremic toxins

Traditionally, the amount of hemodialysis prescribed for a patient has been based on urea clearance, as urea is not only retained in patients with chronic kidney disease, but also readily measurable, by reliable and inexpensive assays. More recently, other retained solutes, phosphate, beta(2) microglobulin, and latterly p-cresol have been reported to be associated with increased risk of mortality in hemodialysis patients. As such, developments in dialysis practice that would result in greater clearance of water-soluble middle-sized toxins and also protein-bound and/or organic solutes are being studied. Although session time is a key factor, switching from low flux to dialyzers with larger pores, the addition of convective transport with hemodiafiltration can help increase phosphate and beta(2) microglobulin clearances. Adsorption techniques can increase the clearance of organic and protein bound toxins either directly or indirectly by regenerating dialysate and ultrafiltrates.