Limitations concerning the Use in Children of the Relationship between Plasma Creatinine and Body Height to Derive Glomerular Filtration Rate

Abstract

The value of the formula,

$\text{glomerular filtration rate}=\frac{\text{factor}\times \text{body height}}{\text{plasma creatinine concentration}}$

was assessed over a two-year period in 314 children aged 1 month to 17 years by comparing simultaneously determined ⁵¹Cr EDTA slope clearance and plasma creatinine measurements, and in 225 children aged 1 month to 16 years comparing with duplicate short-term creatinine clearance determinations. The relationship with ⁵¹Cr EDTA slope clearance is best in patients over the age of 3 years with clearance rates below 60 ml. min⁻¹/l · 73m² but even so is subject to doubt over a wide range. The relationship with creatinine clearance shows less scatter at higher levels of clearance but the same doubt exists when it is used as an estimate of glomerular filtration rate.