Test Code Billings Clinic: 4496 Creatinine, Dialysis, Plasma or Serum
Performing Laboratory
Billings Clinic Laboratory: Chemistry
Useful For
Creatinine:
- Diagnosing and monitoring treatment of acute and chronic renal diseases
- Adjusting dosage of renally excreted medications
- Monitoring renal transplant recipients
Glomerular Filtration Rate (GFR):
- Serum creatinine measurement is used in estimating GFR for people with chronic kidney disease (CKD) and those with risk factors for CKD (diabetes, hypertension, cardiovascular disease, and family history of kidney disease).
Methodology
Modified Jaffe Method
Specimen Requirements
Submit only 1 of the following specimens:
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.
Plasma
- Draw blood in a green-top (lithium heparin) tube(s).
- Spin down and send 1.0 mL of heparinized plasma frozen.
Serum
- Draw blood in a plain, red-top tube(s) or a serum gel tube(s).
- Spin down and send 1.0 mL of serum frozen
Storage/Stability
Specimen Type | Temperature | Time |
Plasma, Serum | Refrigerated | 7 days |
Frozen (preferred) | 3 months | |
Ambient | 24 hours |
Reject Due To
- Gross hemolysis
- Gross icterus
- Gross lipemia
Reference Values
Males: 0.7 - 1.3 mg/dL
Females: 0.6 - 1.0 mg/dL
Test Classification and CPT Coding
82565 - Creatinine; blood
LOINC Code Information
Reporting Name | LOINC Code |
Creatinine, Blood | 2160-0 |
GFR, Non-African American | 48642-3 |
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%.