Comparing a urea kinetic monitor with Daugirdas formula and dietary records in children.
The use of the online urea monitor has not been validated in children on hemodialysis. We compared online measured Kt/V(urea) and protein catabolic rate (PCR) with single- and double-pool Daugirdas formula (DF and eDF) based Kt/V(urea) and with protein intake derived from dietary records (DPI). In 8 children aged 8-18 years, 26 measurements were performed with the online urea monitor (UM 1000) with double-needle access. In 7 children, aged 4-14 years, 12 additional measurements were performed using single-needle dialysis. Pre-dialysis serum urea was determined by the monitor in equilibrated ultrafiltrate, obtained with ultrafiltration rates (UF) of 0.5 or 1.0 l/h, in 10 and 23 experiments respectively, and compared with the laboratory results. Urea determination in ultrafiltrate correlated well with blood sample urea: r=0.945 and 0.88 for UF rates of 0.5 l/h and 1.0 l/h, respectively. The correlation of online Kt/V with DF and eDF was 0.79 for double-needle and 0.21 for single-needle access. Bland-Altmann analysis showed a mean bias of 0.02 and 0.001, but levels of agreement of +0.3 and -0.3 for double-needle and +0.77 and -0.77 for single-needle dialysis respectively with DF. Maximum percentage error for double-needle access was 18% and 59% for single-needle access. The correlation of DPI with PCR was 0.5. A Bland-Altmann plot showed a mean bias of =0.22 with upper and lower limits of agreement of +0.55 and -0.1, respectively. Online urea kinetic modelling is feasible in children with double-needle hemodialysis only. Even with small dialyzers, an accurate serum urea measurement is obtained. PCR underestimates dietary protein intake.
Van Hoeck
K J
KJ
Department of Pediatric Nephrology, University Hospital Antwerp, UIA Belgium.
Lilien
M R
MR
Brinkman
D C
DC
Schroeder
C H
CH
D000293:Adolescent; D002408:Catheters, Indwelling; D002648:Child; D002675:Child, Preschool; D015930:Diet Records; D004044:Dietary Proteins / Q000008:administration & dosage / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008962:Models, Theoretical; D006435:Renal Dialysis; D013813:Therapy, Computer-Assisted; D014508:Urea / Q000097:blood*
D004044:Dietary Proteins; D014508:Urea