title: Comparing a urea kinetic monitor with Daugirdas formula and dietary records in children.
abstract: 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.
authors.affiliation: Department of Pediatric Nephrology, University Hospital Antwerp, UIA Belgium.
authors.forename: K J
authors.initials: KJ
authors.lastname: Van Hoeck
authors.forename: M R
authors.initials: MR
authors.lastname: Lilien
authors.forename: D C
authors.initials: DC
authors.lastname: Brinkman
authors.forename: C H
authors.initials: CH
authors.lastname: Schroeder
mesh_terms: 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*
chemical_list: D004044:Dietary Proteins; D014508:Urea