Calcium
Use
Work-up for coma, pancreatitis and other gastrointestinal problems, nephrolithiasis, polydipsia, polyuria, azotemia, multiple endocrine adenomatosis.
Special Instructions
For the differential diagnosis of hypercalcemia, serum calcium should be measured on at least three occasions. A morning, fasting sample is desirable due to diurnal variation. Gross hemolysis and the use of EDTA, oxalate, or citrate anticoagulants are causes for rejection. Improperly labeled specimens will also be rejected.
Limitations
Interference may occur with specimens containing sodium citrate, EDTA, and NaF potassium oxalate. The routine method measures total calcium, half of which is bound to plasma proteins. Metabolically active calcium is ionized, and its interpretation should consider the serum protein level for accurate assessment.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 17861-6
- 17861-6
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL
Container
Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube
Collection Instructions
Separate serum or plasma from cells within 45 minutes of collection.
Patient Preparation
Morning, fasting sample is desirable due to diurnal variation.
Storage Instructions
Room temperature for 14 days, refrigerated for 14 days, or frozen for 14 days. Stable through three freeze/thaw cycles.
Causes for Rejection
Gross hemolysis; EDTA, oxalate, or citrate anticoagulant; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |