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Test Code NAS Sodium, Serum

Reporting Name

Sodium, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Assessing acid-base balance, water balance, water intoxication, and dehydration

Method Name

Potentiometric, Indirect Ion-Selective Electrode


Necessary Information


Patient's age and sex are required.



Specimen Required


Collection Container/Tube: 

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.


Specimen Type

Serum

Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Ambient  14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK

Reference Values

<1 year: not established

≥1 year: 135-145 mmol/L

Interpretation

Symptoms of hyponatremia depend primarily upon the rate of change in sodium concentration, rather than the absolute level. Typically, sodium values less than 120 mEq/L result in weakness; values less than 100 mEq/L result in bulbar or pseudobulbar palsy; and values between 90 and 105 mEq/L result in severe signs and symptoms of neurological impairment.

 

Symptoms associated with hypernatremia depend upon the degree of hyperosmolality present.

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 to 2 days

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

84295

LOINC Code Information

Test ID Test Order Name Order LOINC Value
NAS Sodium, S 2951-2

 

Result ID Test Result Name Result LOINC Value
NAS Sodium, S 2951-2

Forms

If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.