24-Hour Creatinine Clearance

Test Code
CC24

CPT Codes
82575

Includes
Total Volume, Hours, Flow Rate, Urine Creatinine, Serum Creatinine, Creatinine Clearance, Body Surface (if Flow Rate < 0.50), Corrected Creatinine Clearance (if Flow Rate < 0.50)

Preferred Specimen

Timed urine specimen



Minimum Volume
Urine - 1 mL; Serum or Plasma - 0.5 mL

Instructions

Collect serum or plasma specimen right before the start of or during urine collection.

Record time of collection and have patient start and stop at the same time on the hour for the number of hours urine is to be collected.  Collection is typically for 24 hours, but can also be any number of hours, for example, 4 hours or 12 hours.  Record start and stop time or number of hours on collection bottle.  If transferring an aliquot to another container, measure volume before transfer and record on transfer container, along with time.

This test is for creatinine clearance.  For timed or random creatinine measurement without clearance, order URCRN, which does not require blood draw.  For Creatinine measurement on Plasma or Serum with an Estimated Glomerular Filtration Rate, order CRNGFR.  For creatinine measurement on body fluids, order MISCRN.



Transport Container

Blood:  Serum (gold top) or Lithium Heparin Plasma (green top) tube
Urine:   24-hour urine container or sterile urine cup



Transport Temperature
Refrigeration

Specimen Stability
3 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Quantity Not Sufficient for blood specimen, EDTA (purple top tube) contamination of blood specimen

Methodology
Colorimetric

Setup Schedule

Monday - Sunday, 8:00 am - 3:00 pm upon receipt



Report Available
Upon completion of analysis

Limitations
Do not use serum or plasma specimens obtained through catheters used to infuse hyperalimentation fluid. Serum specimens contaminated with dobutamine from intravenous fluid have been reported to show a significant negative bias. Patients on long-term lidocaine therapy may show an increase of up to 1.0 mg/dL (88 umol/L) due to a metabolite of lidocaine, N-ethyl glycine (NEG).

Reference Range
Total Volume: 800 - 1800 mL/24 hours
Serum Creatinine:  
Birth - 1 month: 0.6 - 1.2 mg/dL
1 Month - Adult (Female): 0.52 - 1.04 mg/dL
1 Month - Adult (Male): 0.66 - 1.25 mg/dL
Creatinine Clearance: 66 - 166 mL/min


Clinical Significance

Creatinine Clearance measures the amount of creatinine cleared from the plasma by the kidneys in one minute.

Serum creatinine and urinary creatinine excretion is a function of lean body mass in normal persons and shows little or no response to dietary changes.  The serum creatinine concentration is higher in men than in women.  Since urinary creatinine is excreted mainly by glomerular filtration, with only small amounts due to tubular secretion, serum creatinine and a 24-hour urine creatinine excretion can be used to estimate the glomerular filtration rate.  Serum creatinine is increased in acute or chronic renal failure, urinary tract obstruction, reduced renal blood flow, shock, dehydration, and rhabdomyolysis.  Causes of low serum creatinine concentration include debilitation and decreased muscle mass.  Exercise may cause an increased creatinine clearance. The creatinine clearance rate is unreliable if the urine flow is low.

This test is for creatinine clearance.  For timed or random creatinine measurement without clearance, order URCRN, which does not require blood draw.  For Creatinine measurement on Plasma or Serum with an Estimated Glomerular Filtration Rate, order CRNGFR.  For creatinine measurement on body fluids, order MISCRN.





The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.