Laboratory Services

Creatinine Clearance

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Updated Test Information:

Test Description
Creatinine Clearance
Test ID
CC
General Information
Renal function test; estimate glomerular filtration rate (GFR); evaluate renal function in small or wasted subjects; follow possible progression of renal disease; adjust dosages of medications in which renal excretion is pivotal (eg, aminoglycosides, methotrexate, cisplatin)
Specimen Type
Serum
Urine
Specimen Requirements
SST
Urine, 24 hour collection
Specimen Collection / Processing Instructions
Urine, 24 hour collection - The test request must include date and time collection started and date and time collection finished. The 24-hour urine volume is also needed for calculation of eGFR. Collect urine without using additives. If urine must be collected with a preservative for other analytes, only hydrochloric acid (14 to 47 mmol/L urine, e.g. 5 mL 10 % HCl or 5 mL 30 % HCl per liter urine) or boric acid (81 mmol/L, e.g. 5 g per liter urine) may be used.
Minimum Sample Volume
1 mL serum (Red, Li heparin, KEDTA plasma) AND 10 mL aliquot of entire urine collection
Pediatric Min. Volume (if applicable)
500 uL serum AND 500 uL aliquot of entire urine collection
Additional Processing Details
Separate serum from cells within 45 minutes of collection.
For 24 hour urine, instruct the patient to void at 8 AM and discard the specimen. Then collect all urine including the final specimen voided at the end of the 24-hour collection period (ie, 8 AM the next morning). Screw the lid on securely. Collection container must be labeled with patient's full name, date, and start/stop times for a 24-hour collection. Submit both urine and serum simultaneously. It is preferable to collect the serum at the time the urine collection is completed or when the serum is brought to the draw station. The serum should be collected within 24 hours of the start or finish of the urine collection.
Stability
Serum:
7 days at 15-25˚C
7 days at 2-8˚C
3 months at -15 to -25˚C

Urine without preservative:
2 days at 15-25˚C
6 days at 2-8˚C
6 months at -15 to -25˚C

Urine - with preservative:
3 days at 15-25˚C
8 days at 2-8˚C
3 weeks at -15 to -25˚C
Limitations
Exercise may cause increased creatinine clearance. The glomerular filtration rate is substantially increased in pregnancy. Ascorbic acid, ketone bodies (acetoacetate), hydantoin, numerous cephalosporins, and glucose may influence creatinine determinations. Trimethoprim, cimetidine, quinine, quinidine, procainamide reduce creatinine excretion. Icteric samples, lipemia, and hemolysis may interfere with determination of creatinine. Since tubular secretion of creatinine is fractionally more important in progressing renal failure, the creatinine clearance overestimates GFR with high serum creatinine levels. 
Methodology
Colorimetric
Estimated TAT
0-2 days
Testing Schedule
Monday-Saturday
CPT Code(s)
82575
Reference Range
Age Reference Range
< 1 month No established reference range
1 - 5.9 months 41 - 103
6 - 12 months 49 - 157
1 - 2 years 63 - 175
3 - 12 years 89 - 165
Females 13 - 60 years 75 - 115
Males 13 - 60 years 85 - 125
> 60 years No established reference range
Performing Lab
Incyte Diagnostics
LOINC Code(s)
2164-2