RELIABILITY OF HEMODIALYSIS UREA KINETIC MODELING IN CHILDREN

The reliability of urea kinetic modelling (UKM) in paediatric haemodia lysis was tested by comparing results of the classic variable volume m odel (UKM(3)), a recently introduced two-sample modification of this ( UKM(2)) and direct quantification by a partial dialysate collection me thod (PDC). Urea generation rate (G) was also found from a 1-week coll ection of dialysate and urine (OWC). Nine children aged 2-18 years and weighing 10.6-39.9 kg were examined over 1 week (25 treatments). UKM( 3) and UKM(2) gave almost identical results, but deviated from PDC and OWC. The two indirect methods overestimated G by 24% and 18%. However , the correlations between the results were very high for all variable s and all methods (r greater than or equal to 0.96). Repeating UKM(3) and UKM(2) mid-week for 5 consecutive weeks, the following coefficient s of variation were found: for the normalised whole body urea clearanc e (Kt/V) 10% and 11%, respectively; for normalised protein catabolic r ate 17% and 14%. It is concluded that all tested methods can be used, but each method requires its own reference interval. Results of UKM se em to vary somewhat more than in adults. This should be considered whe n assessing children by such methods.