Height x Weight x 0.007184Creatinine clearance is a simpler way to determine the GFR compared to inulin
clearance but it is subjected to variations in both the daily production of creatinine
and the ability of the diseased kidney to secrete creatinine.
Two formulas are generally applied to estimate the GFR:
Cockcroft-Gault formula, used mainly in adults
(140 – age)(body weight in kg)/72 x PCrPCr=plasma creatinine
Schwartz formula, used in children with renal failure
K x height (cm)/PCr (mg/dL)K factor (lean body mass)= 0.55 for children 2-12, 0.55 for girls 13-21, 0.70 for
boys 13- 21
In one study evaluating almost 200 children, the Schwartz formula overestimated
the GRF by 25 to 30% in children. The Cockcroft-Gault formula was acceptable
for children older than 12 years. No formula was accurate for infants and
prepubertal children.
Urine output
Urine output (UO) is a clinical indicator of adequate renal function in children with
normal circulatory volumes. UO of 1-2 mL/kg/h in infants and 0.5-1 mL/kg/h in
children older than 1 year are considered within normal range.
Definition of acute renal failure
Acute renal failure (ARF) is defined as the inability of the kidney to maintain fluid,