CAPD prescription in current clinical practice

A total of 132 patients from 15 dialysis centers were studied. Analyses were made of each drained dialysate exchange over 24 hours to determine total peritoneal urea clearance (KpT, liters/day), and a 24-hour urine was collected to determine total renal urea clearance (KrT, liters/day) and the sum of KpT+KrT or KprT, liters/day. Body water volume (V, L) was estimated from gender and surface area, and daily fractional urea clearance (KprT/V) was calculated. Normalized protein catabolic rate (PCRN, grams/kilogram/day) was also calculated from the urea data. Major results were the following: KrT comprised 25% of KprT; the mean KprT/V was 0.28, but ranged from 0.10-0.50; an equivalent thrice-weekly hemodialysis KT/V was calculated from the KprT/V values and showed mean KT/V = 1.07, but 67% of values were less than 1.0. In contrast, the Health Care Finance Administration (HCFA) consensus criteria indicated 91% of prescriptions were adequate. These data indicate the need for clinical outcome studies with KprT/V randomized over the range 0.20-0.30 to better define the domain of adequate CAPD.