The importance of residual renal function for patients on dialysis

Division of Nephrology, 1University Health Network, University of Toronto, Canada and 2Vanderbilt University Medical Center, Nashville, TN, USA It is the goal of every practitioner involved in the care of dialysis patients to maximize survival and quality of life. The last two decades have seen a plethora of investigations that have sought to determine how this goal can be achieved. The bulk of the studies have, unfortunately, concentrated on small solute clearance and outcome (measured principally as mortality). The HEMO [1] and ADEMEX [2] studies suggested that this is not a fruitful avenue of investigation. However, the residual kidney function in patients on dialysis, particularly in those on peritoneal dialysis (PD), has proven to be a consistent and powerful predictor of mortality. We will review the evidence supporting the importance of residual renal function (RRF) on outcome, propose some explanations as to why this relationship exists, and suggest ways to prolong the renal function in dialysis patients.