Calcium, Ionized : 306

Test Code

CAIONQ or 306

CPT Codes
82330

Instructions

Serum separator tube.

Transport Container

Let clot and centrifuge immediately with the cap on. DO NOT OPEN the tube. Transport the unopened gel barrier tube. If submitting with any other assay, submit a separate tube for this test.

Transport Temperature

Ambient.

Specimen Stability

Ambient: 7 days; Refrigerated: 7 days; Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Frozen, Gross hemolysis, grossly lipemic, Red-top (no gel) tube

Methodology
Ion Specific Electrode (ISE)

Setup Schedule

Tuesday - Saturday

Report Available

1-2 days (From receipt at performing laboratory)

Reference Range

<8 Months 5.3-6.3 mg/dL
8-11 Months 5.2-6.1 mg/dL
1 Year 5.1-6.0 mg/dL
2 Years 4.9-5.8 mg/dL
3 Years 4.9-5.7 mgdL
4-6 Years 4.8-5.7 mg/dL
7-12 Years 4.8-5.6 mg/dL
13-17 Years 4.8-5.5 mg/dL
18-89 Years 4.7-5.5 mg/dL
> or = 90 Years 4.5-5.5 mg/dL

Clinical Significance

The ionized calcium is determined by an ion selective electrode methodology. The result that is generated is pH adjusted. The result is empirically based on a measured pH and ionized calcium concentration normalized to a pH of 7.40. This calculation compensates for in vitro changes in pH due to loss of CO2 through specimen handling. Ionized calcium represents the true "bioavailable" calcium in the circulation. In situations where the total calcium is normal but does not fit the clinical picture, e.g., hyperparathyroidism, a determination of the ionized calcium will, many times, show an elevation in the "bioavailable" calcium component. This may be due to alterations in protein concentrations, especially albumin, that binds most of the calcium in the circulation.

Performing Laboratory
Quest Diagnostics

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.