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Test Code CA Calcium, Plasma or Serum

Additional Codes

  • Expanse Test Name:Calcium, S
  • Medinet Ref Code:CA
  • OV Code:CHEM*CA

Performing Laboratory

St. Lukes Hospital Laboratory

Methodology

Calcium O-Cresolphthalein Complexone

Specimen Requirements

  • Separated specimens may be stored for up to 8 hours at room temperature or for up to 2 days at   2 - 8°C.
  • Freeze samples for up to 6 months at -20°C
  • Serum or plasma should be separated 2 hours from time of collection

Submit only 1 of the following specimens:
 
PlasmaDraw blood in a green-top (lithium heparin) plasma gel tube(s). Spin down and send 1 mL of lithium heparin plasma refrigerated.
Note:  1. Plasma should be separated from blood cells as soon as possible. Prolonged contact with the clot may cause lower calcium values.

2. Indicate plasma on request form.

3. Label specimen appropriately (plasma).
 
Serum
Draw blood in a serum gel tube(s). Spin down and send 1 mL of serum refrigerated.
Note:  1. Serum should be separated from blood cells as soon as possible. Prolonged contact with the clot may cause lower calcium values.

2. Indicate serum on request form.
3. Label specimen appropriately (serum).

Reference Values

4-21 years:  9.2-11.0 mg/dL

>21 years:  8.5-10.5 mg/dL

Critical values (automatic call-back):  <6.5 mg/dL or >12.5 mg/dL

Interfering Substances:

OMNISCANTM MRI contrast media may falsely lower measured calcium values by up to 70%.

EDTA when present at 200 mg/dL (2 g/L)d and potassium oxalate when present at 500 mg/dL (5 g/L) depresses the calcium result to less than the assay range of the method.

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

CPT: 82310

LOINC: 17861-6