Optimizing the treatment of the dialysis patient: a painful lesson

Our current understanding of how dialysis should be measured and optimized evolved from several painful lessons. The pain was felt by patients who were passive recipients of treatments that were often limited by the toxic effects of acetate, attempts to shorten treatment time, and adverse effects of the membranes. Pain was also felt by caregivers who were burdened by the complications of inadequate dialysis that required their efforts and vigilance. Early efforts to quantify dialysis by controlling the serum urea concentration were replaced by methods to control the dialyzer urea clearance expressed per dialysis and factored for the patient's size (Kt/V). This understanding resulted largely from data collected during US National Cooperative Dialysis Study in the late 1970s, but it took several years for the lesson to become a standard of practice. We continue to struggle with our understanding of uremic toxins and how best to remove them. The future promises to resolve the age-old question of toxicity and to give us a better perspective on the effects of protein catabolism, residual renal clearance, and both dialysis duration and frequency. Other factors yet to be explored may ultimately impact on the requirement for dialysis and allow better tailoring of treatment to individual needs.