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Test Code CREA or LAB66 Creatinine w/ GFR, Serum or Plasma

Important Note

Calculated values: Estimated glomerular filtration rate (eGFR) is calculated with all creatinine requests on patients over the age of 18 years.    For all patients <16 years of age an AKI Alert is also calculated and reported if value is generated.  See November 2024 Critical Range Update. 

Effective 1/5/22, the CKD-EPI 2021 formula is used. This formula does not utilize race-based coefficients. See the December 2021 edition of LabWire for details. 

Specimen Requirements

Container Type:

Optimal: Gold or Mint*

*For STAT requests

Acceptable: Red or Green
Optimal Collection Volume: 

4.5mL; full tube
Minimum Volume:
  • Adults: 1 mL whole blood
  • Neonates: 1 microtainer (400-600 uL)
Collection Instructions:

Gently invert the sample 5-6 times after collection.
Specimen Transport:

Refrigerate
Processing Instructions: 

1. If serum, allow the specimen to clot for 30 minutes.

2. Centrifuge specimen within 2 hours of collection.

3. After centrifugation, specimen tubes without a gel barrier should have the serum or plasma aliquoted to a false bottom container.

4. Keep the serum or plasma refrigerated until testing can be performed.

Specimen Stability

Specimen Type Temperature Time
Serum* Refrigerated 7 days
Room Temperature 7 days
Frozen 3 months

*Note: Heparinized plasma in gel separator tubes is less stable than serum and is only suitable for add-on testing up to 2 days following sample collection.

Specimen Rejection Criteria

Hemolysis Mild OK; Moderate OK; Gross Reject
Lipemia Mild OK; Moderate OK; Gross Reject
Icterus Mild OK; Moderate OK; Gross Reject
Other Quantity not sufficient

Useful For

This assay is useful for diagnosing and treatment of acute and chronic renal diseases, and for monitoring renal dialysis.

Methodology

Roche Cobas - Enzymatic colorimetric

Reference Ranges

Age

Reference Range and Reporting Units
Newborns (1-4 days) 0.30-1.00 mg/dL
Infants (5 days to 11 years) 0.20-0.70 mg/dL
Adolescents (12-16 years) 0.50-1.00 mg/dL
Males ≥ 17 years 0.70-1.30 mg/dL
Females ≥ 17 years 0.60-1.10 mg/dL

 

Critical Values

  •   < 2 years:   ≥ 2.00 mg/dl
  •  2-11 years:  ≥ 2.50 mg/dl
  • 12-16 years: ≥ 3.00 mg/dl
  •    >16 years: ≥ 7.50  mg/dl 

AKI  Alert (pediatric only) :   Level 3   

 

Estimated GFR:

National Kidney Foundation Guidelines:

  • Chronic kidney disease: eGFR < 60 mL/min
  • Kidney failure: eGFR < 15 mL/min

Day(s) Performed

24/7

Expected TAT

Same day

Performing Laboratory

Bronson Laboratory, Chemistry - Kalamazoo, Battle Creek, Paw Paw, South Haven

Sample Retention Time

7 days

CPT Code

82565

LOINC Code

45066-8