Lab Test

Calcium

Ca

Test Codes

Antrim #15619, EPIC: LAB5025, SOFT: CA

Instructions

Note: Blood should be obtained with as little venous stasis (i.e. tourniquet time) as possible. Prolonged use of a tourniquet may result in false elevation of calcium.

Specimen Collection Criteria

FOR EC AND INPATIENT SAMPLE COLLECTION ONLY:

Preferred Sample:  One Light Green Top Plasma Separator Tube (PST)(Minimum Whole Blood: 4.0 mL)

Acceptable Sample:  One Gold Top SST (Minimum Whole Blood:  4.0 mL)

FOR PHYSICIAN OFFICE/OUTREACH SAMPLE COLLECTION:

COLLECT:  One Gold Top SST (Minimum Whole Blood:  4.0 mL) 

Contact Laboratory for acceptability of other tube types. 
See Minimum Pediatric Specimen Requirements for Microtainer® collection.

Physician Office/Draw Specimen Preparation

Let SST specimens clot 30–60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2–8°C or 36–46°F) the centrifuged SST tube within two hours of collection. (Minimum: 0.5 mL)

Preparation for Courier Transport

Transport: Centrifuged SST tube, refrigerated (2–8°C or 36–46°F). (Minimum: 0.5 mL)

Rejection Criteria

Moderate to grossly hemolyzed specimens.

Red-top tubes with serum not separated from cells within two hours of collection.

In-Lab Processing

Let SST specimens clot 30-60 minutes. Centrifuge SST tubes and Microtainers® to separate serum from cells. Deliver immediately to the appropriate testing station.

Storage

Specimen Stability for Testing:

Centrifuged SST Tubes and Microtainers® with Separator Gel
Room Temperature (20–26°C or 68-78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Red-top Tubes and Microtainers® without Separator Gel
Room Temperature (20–26°C or 68–78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20–26°C or 68–78.8°F): 2–4 hours
Refrigerated (2–8°C or 36–46°F): 7 days
Frozen (-20°C/-4°F or below): 7 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2–8°C or 36–46°F): 7 days

Laboratory

Farmington Hills Chemistry Laboratory
Grosse Pointe Chemistry Laboratory
Royal Oak Automated Chemistry Laboratory
Troy Chemistry Laboratory

Performed

Sunday – Saturday, 24 hours a day.
STAT results available within 1 hour of receipt in the Laboratory.
Routine results available within 24 hours.

Reference Range

 Age Range (mg/dL) 
0 – < 1 Year 8.5 – 11.0
1 – 18 Years 9.2 – 10.5
19 Years – Adult 8.4 – 10.2

Royal Oak
Breast Milk: (15 days to 15 months post partum): 20.8–48 mg/dL.

Test Methodology

Spectrophotometry or Indirect Potentiometry.

Interpretation

  • High calcium levels can occur in a variety of conditions including primary hyperparathyroidism, malignancy, granulomatous disorders (e.g. sarcoidosis), milk-alkali syndrome, excess intake of vitamin D or A, hyperthyroidism, with thiazide treatment, and in familial hypocalciuric hypercalcemia.
  • Low calcium levels can occur with chronic renal failure, vitamin D deficiency, malabsorption, hypomagnesemia, pancreatitis and hypoparathyroidism.

Clinical Utility

The quantitative determination of calcium aids in the diagnosis and management of a variety of diseases including those involving the parathyroid glands, bone and kidneys.

CPT Codes

82310

Contacts

Last Updated

11/3/2020

Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.

 

This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.