Sodium, Serum
Use
Sodium is the primary extracellular cation and plays a central role in maintaining normal distribution of water and osmotic pressure in the extracellular fluid compartment. This test is useful for assessing acid-base balance, water balance, water intoxication, and dehydration. It helps in identifying conditions such as hyponatremia, associated with symptoms from weakness to seizures, and hypernatremia, often attributable to excessive loss of sodium-poor body fluids, with symptoms ranging from thirst to coma.
Special Instructions
Patient's age and sex are required for testing. If not ordering electronically, complete and send either the Kidney Transplant Test Request or Cardiovascular Test Request Form with the specimen. For serum gel tubes, centrifuge within 2 hours of collection. For red-top tubes, centrifuge and aliquot serum into a plastic vial within 2 hours.
Limitations
No significant cautionary statements are provided. The test is classified as cleared, approved, or exempt by the FDA and used per manufacturer's instructions, with performance characteristics verified by Mayo Clinic under CLIA requirements.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 2951-2
- 2951-2
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.25 mL
Container
Plastic vial
Collection Instructions
For serum gel tubes, centrifuge within 2 hours of collection. For red-top tubes, centrifuge and aliquot serum into a plastic vial within 2 hours.
Causes for Rejection
Gross hemolysis: Reject; Gross lipemia: OK
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |