Sign in →

Test Code Billings Clinic: 4120 Creatinine Clearance

Performing Laboratory

Billings Clinic Laboratory: Chemistry

Useful For

Estimation of glomerular filtration rate

Methodology

Modified Jaffe method

Specimen Requirements

Plasma or serum and urine are required for this test. The plasma or serum specimen should be drawn sometime during the 24-hour period of urine collection.

 

Serum or Plasma should be physically separated from cells as soon as possible with a maximum limit of two hours from the time of collection.

  • Indicate plasma, serum or urine on request form.
  • Label specimen appropriately (plasma/serum/urine).
  • 24-Hour volume is required on request form for processing.
  • Follow instructions in “Urine Collection” under "Resources"

 

Plasma

  • Draw blood in a green-top (lithium heparin) tube(s).
  • Spin down and send 1 mL of heparinized plasma, or include plasma creatinine level measured in your laboratory for a specimen drawn during the 24-hour urine collection.
  • Send specimen refrigerated.

Serum

  • Draw blood in a plain, red-top tube(s) or a serum gel tube(s).
  • Spin down and send 1 mL of serum, or include serum creatinine level measured in your laboratory for a specimen drawn during the 24-hour urine collection.
  • Send specimen refrigerated.

Urine

  • 2 mL from a 24-hour urine collection in a urine container.
  • Refrigerate specimen during collection, and send specimen refrigerated.

Storage/Stability

Specimen Type Temperature Time
Plasma, Serum Refrigerated (preferred) 7 days
  Ambient 24 hours
  Frozen 3 months
Urine Refrigerated (preferred) 4 days
  Frozen 1 month

Reject Due To

  • Gross Hemolysis

Reference Values

80-120 mL/minute

Day(s) Test Set Up

Daily

Test Classification and CPT Coding

82575 - Creatinine; clearance

LOINC Code Information

Reporting Name LOINC Code
Creatinine, Serum 2160-0
Creatinine, Urine 24 hr 2162-6
Creatinine Clearance 2164-2
Volume, Urine 28009-9

Interferences

  • Unconjugated bilirubin at 15 mg/dL decreases the creatinine result in serum/plasma at 1.62 mg/dL by -13.4%.
  • Unconjugated bilirubin at 20 mg/dL decreases the creatinine result in serum/plasma at 5.32 mg/dL by -16.1%.
  • Glucose at 332 mg/dL increases the creatinine result in serum/plasma at 1.61 mg/dL by 10.6%.
  • Cefoxitin at 5.0 mg/dL increases the creatinine result in serum/plasma at 1.53 mg/dL by 17.0%.
  • Pyruvate at 10.0 mg/dL increases the creatinine result in serum/plasma at 1.53 mg/dL by 17.6%. Dopamine at 100 mg/dL increases the creatinine result in serum/plasma at 1.53 mg/dL by 13.7%.
  • Total Protein at 12.0 mg/dL increases the creatinine result in serum/plasma at 1.71 mg/dL by 10.5%.