Test Code CREA Creatinine with Glomerular Filtration Rate (GFR), Plasma or Serum
Methodology
Colorimetric, Jaffe Reaction
Performing Laboratory
Aspen Valley Hospital
Specimen Requirements
Submit only 1 of the following specimens:
Preferred:
Plasma
Container/Tube: Light green-top (lithium heparin gel) tube(s)
Specimen: 2 mL (minimum
volume: 1 mL) of lithium heparin plasma
Transport Temperature: Ambient
Collection Instructions: Spin down
immediately and send entire tube to laboratory. If there is a delay
in transport of >8 hours, send specimen refrigerated.
Note: 1. Indicate plasma on request
form.
2. Label specimen appropriately (plasma).
Alternate:
Serum
Container/Tube: Gold-top serum gel
tube(s) or Plain, red-top tube is also acceptable.
Specimen: 2 mL (minimum
volume: 1 mL) of serum
Transport Temperature: Ambient
Collection Instructions: Allow specimen to clot for approximately 10 minutes and spin down. If drawing gold-top serum gel tube, send entire tube to laboratory. If red-top tube, remove serum and place in separate plastic vial. If there is a delay in transport of >8 hours, send specimen refrigerated.
Note: 1. Indicate serum on request
form.
2. Label specimen appropriately (serum).
Reference Values
Creatinine: 0.6-1.3 mg/dL
GFR: ≥60
INTERPRETATION
Normal GFR: ≥60
Moderate reduction in GFR: 30-59
Severe reduction in GFR: 15-29
Kidney failure: <15
Critical Value: ≥ 5.0 mg/dL
Day(s) Test Set Up
Monday through Sunday
Test Classification and CPT Coding
82565