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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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CALCIUM, IONIZED

Item Value
Approval req'd? no
Available Stat? Yes
Test code ICA
Performed by? Hematology
Sendout? no
Price range $$$
In House Availability Routine: 7 days.
STAT: 24 hours/7 days.
Principle Ion Selective Electrode.
Interpretation Ionized Calcium determinations are clinically useful in the differential diagnosis of calcium disorders of endocrine and metabolic origin.

Hypocalcemia: Hypoparathyroidism, tetany, hypotension, cardiac anomalies, GI disturbance, citrate toxicity in massive transfusion.

Hypercalcemia: Hyperparathyroidism, neoplastic disease, acid-base disturbances, granulomatous disease, post transplantation.
Container type green top lithium heparin tube (non gel) or heparinized syringe.
Amount to Collect 1 mL
Collection Instructions Send to lab immediately. If delay is anticipated, submit speciment syringe in ice.
Sample type Heparinized Whole blood
Special instructions Calcium chelating anticoagulants such as EDTA and citrate bind calcium and can lead to spuriously low results.
Normal range
0 -12 months: 0.95 – 1.5 mmol/L
> 12 months: 1.12 - 1.32 mmol/L


All values less than 0.8 mmol/L and greater than 1.50 mmol/L are considered Critical Values and are called to the physician or patient care unit immediately.
Stability 30 min (room temperature)

4 hours (sealed sample in ice bath)
References 1. Ionized Calcium Determinations: Precollection Variables, Specimen Choice, Collection, and Handling; Approved Guideline – Second edition. NCCLS Document C31-A2, Vol 21, No 10, Jun 2001.

2. Kost, GJ. The significance of ionized calcium in cardiac and critical care: Availability and critical limits at US Medical Centers and Children's Hospitals. Arch Pathol Lab Med, 117:890-896, 1993

3. Pediatric Reference Intervals. 5th ed. Soldin et al. (eds). AACC Press 2005.

4. Tietz, NW. Textbook of Clinical Chemistry and Molecular Diagnosis, 4th ed. St. Louis, MO: Elsevier Saunders, 2006.
CPT coding 82330
Last Updated 11/13/2010 10:03:35 AM
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