Peritoneal Dialysis Adequacy in Asia—Is Higher Better?

Sufficient data are available to support the contention that renal and peritoneal clearances are not equivalent, and that loss of residual renal function (RRF) cannot be completely compensated by an increase in the exchange volume or frequency of peritoneal dialysis. When RRF is minimal (for example, renal Kt/V is 0.1 - 0.3), increasing the peritoneal Kt/V beyond the "conventional" value recommended by the Dialysis Outcomes Quality Initiative yields little additional clinical benefit. The cut-off peritoneal (not total) Kt/V is possibly 1.6 - 1.7. However, delivery of peritoneal small-solute clearance below that cut-off level has a major detrimental effect on clinical outcome in CAPD patients with little RRF. Measures to preserve RRF therefore become an important goal in the treatment of CAPD patients. In short, with regard to RRF (renal Kt/V), higher is always better, and we should always try to preserve it. For peritoneal Kt/V, higher is better only up to a certain limit. The importance of aspects of adequate dialysis other than small-solute removal--especially fluid removal, blood pressure control, nutrition, acid-base balance, mineral metabolism, and anemia and lipid control--cannot be sufficiently emphasized.