Glomerular filtration rate by single-injection inulin clearance: definition of a workable protocol for children.
The total serum clearance of inulin after a single intravenous injection is an established method for the determination of the glomerular filtration rate (GFR). To optimize this procedure in children, we analyzed 117 serum inulin time-decay curves in 59 children (age range 1.3-15.2 years)with renal disease. It was found that the two-compartment model fitted statistically better to the disappearance curves of serum inulin than the one-compartment model. The sampling frequency could be reduced from 12 to a minimum of seven data points (t=0, 10, 20, 30, 65, 120 and 240 min) in 4 h without a relevant change in the fit of the two-compartment model to the date or in the calculated clearance of serum inulin. We conclude that, by using a standardized 'seven-sample schedule', followed by a two-compartment analysis, the single-injection serum clearance of inulin is a suitable compromise between practical convenience and clinical accuracy for the determination of the GFR in children.
Swinkels
D W
DW
Department of Clinical Chemistry, University Hospital Nijmegen, The Netherlands. D.Swinkels@ckcl.azn.nl
Hendriks
J C
JC
Nauta
J
J
de Jong
M C
MC
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques / Q000592:standards; D005919:Glomerular Filtration Rate; D006801:Humans; D007223:Infant; D007444:Inulin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007755:Laboratories, Hospital / Q000592:standards; D011237:Predictive Value of Tests
D007444:Inulin