Urea kinetic modeling (UKM) is an established method for quantitating hemodialysis, with target values clearly defined. Precise methods for measuring continuous ambulatory peritoneal dialysis (CAPD) prescriptions are less well-defined, and 24-hour collections of dialysate effluent are logistically impractical. UKM parameters derived from an abbreviated (4-hour) collection period were compared with simultaneously obtained 24-hour collections of urine and dialysate effluent in 22 CAPD patients. Daily Kt/V was calculated from total (residual renal and peritoneal) urea clearance and an anthropometric-derived total body water volume. Results yielded from the 24-hour collection included a mean Kt/V of 0.29 +/- 0.09, and mean protein catabolic rate (PCR) of 0.84 +/- 0.24 g/kg/day. Daily Kt/V values were calculated from each individual dialysate cycle. The first morning cycle after an overnight dwell correlated best with results obtained using 24-hour collections (r = 0.921; p < 0.0001) with no significant differences in Kt/V found (p = 0.454) between the short and 24-hour methods. Daily Kt/V values converted by exponential transformation to a thrice-weekly hemodialysis value yielded a Kt/V equivalent of 1.02 +/- 0.40. UKM using an abbreviated collection period is an accurate and practical tool for quantitating CAPD adequacy in a routine clinical setting.

Copyright © 1993 by Multimed Inc.