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Test ID CRTFR Creatinine, Random, Urine


Specimen Required


Only orderable as part of a profile. For more information see RLTE4 / Leukotriene E4, Random, Urine.

 

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Container/Tube: Plastic, 5-mL tube

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.


Secondary ID

618560

Useful For

Normalizing urinary analytes to account for the variation in urinary concentrations between individuals when using random urine collections

Method Name

Only orderable as part of a profile. For more information see RLTE4 / Leukotriene E4, Random, Urine.

 

Enzymatic Colorimetric Assay

Reporting Name

Creatinine, Random, U

Specimen Type

Urine

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Frozen (preferred) 30 days
  Refrigerated  30 days
  Ambient  14 days

Clinical Information

Creatinine is formed from the metabolism of creatine and phosphocreatine, both of which are principally found in muscle. Thus, the amount of creatinine produced is, in large part, dependent upon the individual's muscle mass and tends not to fluctuate much from day-to-day.

 

Creatinine is not protein bound and is freely filtered by glomeruli. All filtered creatinine is excreted in the urine. Renal tubular secretion of creatinine contributes a small proportion of excreted creatinine. Although most excreted creatinine is derived from an individual's muscle mass, dietary protein intake, particularly of cooked meat, can contribute to urinary creatinine levels.

 

The renal clearance of creatinine provides an estimate of glomerular filtration rate. Since  creatinine in the urine only comes mainly from filtration, the concentration of creatinine reflects overall urinary concentration. Therefore, creatinine can be used to normalize other analytes in a random urine specimen.

Reference Values

Only orderable as part of a profile. For more information see RLTE4 / Leukotriene E4, Random, Urine.

 

≥18 years old: 16-326 mg/dL

Reference values have not been established for patients who are younger than 18 years of age.

Cautions

Intraindividual variability in creatinine excretion may be due to differences in muscle mass or amount of ingested meat.

 

Acute changes in glomerular filtration rate, before a steady state has developed, will alter the amount of urinary creatinine excreted.

Day(s) Performed

Monday through Sunday

Report Available

1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

82570

NY State Approved

Yes