Are Adequacy Targets for Peritoneal Dialysis Meaningful?

p eritoneal dialysis has undergone considerable change since it was first used in managing end stage renal disease (ESRD) patients in the early 1960s. Its use then was predominantly as a holding procedure for hemodialysis, and as such, it was used in a very limited number of patients. With the introduction of continuous ambulatory peritoneal dialysis (CAPD) in 1976, the use ofPD has increased dramatically, with a corresponding improvement in survival rates as well retention on therapy (1,2). However, comparison of populations on PD and hemodialysis (HD) show that technique survival on PD is not as good as that on HD (3), and one of the major reasons is inadequate dialysis in up to 25 % of patients. Adequacy of dialysis should refer to providing enough replacement renal function to alleviate ure mic symptoms and to improve a patient's overall wellbeing and survival. Hitherto, adequacy ofPD has come to be equated solely to solute removal, for which various groups have laid down guidelines and targets (4-6). Still, the best way to assess overall adequacy in peritoneal dialysis remains ill defined. Other aspects that need to be considered, in addition to solute removal, are adequate fluid removal, blood-pressure control, normal mineral metabolism [β2-microglobulin, parathyroid hormone (PTH), phosphate], and adequate nutritional status without acidosis, anemia, or lipid abnormalities. DEFINING ADEQUATE SOLUTE REMOVAL The measurement of dialytic dose in PD has tradi-tionally been assessed in terms of weekly Kt/V urea and creatinine clearance normalized to body surface area. Solute clearance is an important predictor of good clinical outcome, but it should not be the only criteria used to assess adequacy of PD.