Estimation of glomerular filtration rate in infants and in children using a single-plasma sample method.

This work was undertaken to look for distribution volume-plasma clearance converting equations(s) that can be used to estimate glomerular filtration rate (GFR) in children. GFR calculated using the two-blood sample slope-intercept method was used for comparison. It was shown that the 2-hr distribution volume and the two-blood sample clearance were closely related. For all the age groups, the coefficient of correlation between these two parameters was high (range: 0.95 to 0.99) and the s.e.e. was low (range 0.76-3.86 ml/min). It was also shown that a linear equation (GFR = 2,602 V120-0,273) could be used to convert the two hour distribution volume into an accurate estimate of two-blood sample GFR whatever the age of the patient. The use of the single-sample technique for measuring GFR in children is therefore recommendable.