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Test Code NA Sodium Level

Clinical System Name

Sodium Level


Sodium is the major cation of extracellular fluids. The kidneys regulate sodium content of the body.  Low sodium levels may be caused by excessive urine loss, diarrhea, Addison’s disease, and renal tubular disease.  High sodium levels may occur in severe dehydration, some types of brain injury, diabetic coma, and excessive intake of sodium salts. 

Sample Requirements

Specimen: Whole Blood

Container(s):  Gold SST, Dark Green/Sodium Heparin, Red, Gold Microtainer, Lt. Green/Li Heparin Microtainer, or Heparinized Syringe

Preferred Vol:  1.0 mL

Minimum Vol:  0.5 mL


Notes: Method is affected by moderate to marked lipemia, line dilution or contamination.



Processing Instructions

Reject due to:  Insufficient Quantity

Spin: Y

Aliquot: Y

Temp:  2-8oC

Storage location:  Core 5 Chemistry Refrigerator


Off-site collection: Spin blood, separate serum/plasma from cells. Send refrigerated (2-8oC).



Specimen Type Temperature Time
Serum or Plasma RT

4 D

Serum or Plasma 2-8oC

 7 D

Serum or Plasma -20oC or -70oC

180 D



STAT Performed TAT
Y 24/7 1 H


Performing Laboratory

Seattle Children's Laboratory    


Department:  Core Chemistry

Phone Number: 206-987-2617



Reference Range


  mEq/L Critical Levels
0 - 1 Week 132 - 142

≤124 or ≥ 160

1 Week - Adult 135 - 145

≤ 124 or ≥ 160



Method:  Potentiometric method by Vitros 4600

Analytical Volume:  0.04 mL serum or plasma

CPT Codes


Critical Values

≤ 124 mmol/L

≥ 160 mmol/L