Evaluation of CAPD prescription.

Adequacy of CAPD has not been established. The recommendation is a Kt/V (K, total urea clearance in ml/min; t. time in minutes on dialysis; and V, total body water which is the volume of distribution of urea) greater than 1.5/week and/or a creatinine clearance (residual + dialysis) greater than 40 l/week/1.73 m2. We followed 20 CAPD patients for 38.6 +/- 28 mo. We measured blood urea nitrogen, serum creatinine, body weight, residual renal function (Kr), normalized protein catabolic rate (NPCR), Kt/V/week and creatinine clearance (CC) l/w/1.73 m2. We obtained the following values: B Wt 72 +/- 16 kg, BUN 56 +/- 13 mg/dl, s. Cr. 12.6 +/- 5 mg/dl, Kr 0.6 +/- 1 ml/min, NPCR 0.84 +/- 0.3 g/kg/day, Kt/V/week 1.8 +/- 0.3 and CC 50.4 +/- 10 l/w/1.73 m2. Patients dialyzed with a wide range of prescription. There was a good correlation between Kt/V and CC. There was no correlation between the dialysis prescription changes in weight and biochemical determinations. There was a direct correlation between Kt/V and NPCR: patients who were dialyzed more eat more. Of the 20 patients, 10 had 24 hospitalizations, and of these were 12 due to peritonitis. Dialysis prescription and biochemical findings of these patients did not differ significantly from nonhospitalized patients. Larger prospective studies are necessary to determine the adequate range of CAPD prescription and its relationship to morbidity and mortality.