Uric acid clearance and fractional excretion of uric acid are important in identifying a patient's ability to excrete uric acid.
Parameters:
(1) urine volume in mL per 24 hours
(2) urine uric acid concentration in mg/day
(3) serum uric acid in mg/dL
(4) creatinine clearance in mL per min
clearance of uric acid in mL per min =
= (urine volume) * (urine uric acid concentration) / (serum uric acid) / 1440
glomerular load of uric acid in mg per minute =
= (creatinine clearance) * (serum uric acid concentration) /100
where:
• 1440 is the number of minutes in 24 hours.
• The division by 100 is based on conversion of urate from mg/dL to mg/mL.
clearance of uric acid in mL per min per 1.73 square meter =
= (clearance in mL/min) * 1.73/(BSA)
glomerular load of uric acid in mg per min per 1.73 square meter =
= (glomerular load) * 1.73/(BSA)