In this section
For most clinical purposes an estimate of the GFR can be
obtained from the serum creatinine and the height of the
GFR (ml/min/m2) = 40 x height (cm) /serum creatinine
This formula is valid for children over 3 years old.
This is used to measure GFR but has generally been replaced by
the EDTA or DTPA clearance tests or the estimated creatinine
clearance (see above).
Normal values are 80-150 ml/min/m2 (1.3 - 2.5 ml/sec/m2)
This is used for precise determination of GFR. It does not
involve urine collection and is therefore more accurate than the
The child receives an intravenous injection of 51Cr EDTA and the
blood radioactivity is measured at 2 hours and at 4 hours
afterwards. About 4 ml blood is taken at these times for
estimation of the T1/2 of the radioactivity from which is
calculated the clearance.