UREA - (U)
Test Code: UU
Urea is the major end product of protein and amino acid metabolism. It is synthesized by the urea cycle in the liver from ammonia which is produced by amino acid deamination. It is excreted primarily by the kidneys.
Determination of urea is widely used as a screening test for renal function. When used in conjunction with creatinine it can aid in the differential diagnosis of pre-renal, renal and post-renal hyperuremia.
To calculate the total amount of nitrogen excreted per day in mg, multiply the 24 h urea excretion in mmols by a factor of 28.
Collect 24 h urine without preservative. Must be collected and stored refrigerated. Collection & storage at room temperature is not acceptable.
Random urine specimens must be stored refrigerated.
Similar lab approved leak-proof containers acceptable.
Urine: 3.0 mL
Stability 7 days refrigerated, 1 month frozen
430 - 710 mmol/d
(mmol/d x 28 = mg of nitrogen/d) (mmol/d x 60 = mg urea/d)
If random urine, specify. Random urine specimens must be stored refrigerated.
If 24h urine, measure and record volume. Must be collected and stored refrigerated. Collection & storage at room temperature is not acceptable.