Calcium, Ionized, Serum
Also known as: IONCA-S
Use
This test is used to assess calcium status by measuring ionized calcium levels in the serum. Ionized calcium is the physiologically active form of calcium, and its measurement is critical in evaluating calcium metabolism in various clinical conditions such as kidney stone disease, thyroid nodules, and hypercalcemia. It aids in diagnosing and monitoring conditions that affect calcium levels, including parathyroid disorders and malignancies.
Special Instructions
The test requires collection in a serum separator tube. It is crucial not to open or split the specimen, freeze the separator tube, or expose the specimen to air during collection or transport. The specimen should be centrifuged with the stopper in place within one hour of collection and transported in the original tube. It is recommended to interpret the ionized calcium normalized to pH 7.4 with caution, considering the patient's acid/base status.
Limitations
The test's accuracy may be affected by exposure to air, which can artificially increase specimen pH or by delayed processing, which can decrease it. Accurate determination of in vivo pH is best performed by arterial blood gas testing. The ionized calcium normalized to pH 7.4 should be interpreted cautiously as it may not reflect the accurate physiologic state unless the patient's acid/base status is known.
FDA ApprovedNew York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 12180-6
- 19072-8
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
5 mL
Minimum Volume
0.5 mL
Container
Original serum separator tube
Collection Instructions
Collect specimen in a serum separator tube. Do not open or split the specimen, and do not freeze the separator tube. Avoid exposure to air during collection and transport. Centrifuge with stopper in place within one hour of collection.
Storage Instructions
Refrigerated. Ship upright in original serum separator collection tube and transport in the ARUP shipping rack. Do not ship on dry ice.
Causes for Rejection
Plasma; samples exposed to air in aliquot tubes; frozen specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 1 week |
| Frozen | Unacceptable |