Specimen Collection Manual and Test Catalog
CALCIUM, IONIZED, WHOLE BLOOD
Geisinger Epic Procedure Code: LAB1925 Geisinger Epic ID: 14323Whole blood
1 mL whole blood; minimum 0.4 mL.
Due to sample instability, this test may only be collected and analyzed at a performing laboratory site (see below). Expel excess air from syringe. Mix well immediately after collection.
Room temperature (preferred). Transport immediately. If delay in transport is anticipated, place specimen in an ice slurry.
Stable 3 hours at room temperature or refrigerated.
Stability limits exceeded or clotted specimen.
0-17 years: 1.22-1.37 mmol/L
18 years and older: 1.13-1.32 mmol/L
None.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.
Ionized calcium in whole blood.
Unbound calcium, CAIWB, Free calcium
Ionized calcium represents the true "bioavailable" calcium in the circulation. It is measured with an ion-selective electrode (ISE) and corrected to a pH of 7.0. Ionized calcium is frequently measured with parathyroid hormone (PTH) to assess hyperparathyroidism.
Sheng-Ying (Margaret) Lo, PhD, DABCC
Benjamin Andress, PhD, DABCC