Potassium

Test Code

Alias/See Also

Epic: LAB114

Preferred Specimen

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 3 mL

Minimum Volume

0.5 mL

Other Acceptable Specimens

Specimen Type: Plasma
Collection Container: Green top (Lithium heparin)

Instructions

Centrifuge and separate cells after clot formation and within 4 hours of collection.

Transport Container

Plastic vial

Specimen Stability

Room temperature: 7 days
Refrigerated: 7 days
Frozen: 1 year

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Unlabeled, mislabeled, wrong tube type, QNS, Hemolysis index >400, gross lipemia.

Methodology

Indirect Ion-Selective Electrode (diluted)
(ICT = Integrated Chip Technology)

Setup Schedule

Daily

Report Available

Same day

Reference Range

0 - 1 month: 3.7 - 5.9 mEg/L
1 month - 1 year: 4.1 - 5.3 mEg/L
1 year - 12 year: 3.4 - 4.7 mEg/L
12 year - 150 year: 3.5 - 5.1 mEg/L

Clinical Significance

Potassium is the major intracellular cation. The concentration of K+ in the RBC’s is approximately 23 times the concentration in plasma. For this reason, only non-hemolyzed samples must be used. Decreased levels of extracellular potassium are characterized by weakness in the muscles, irritability, paralysis, accelerated heartbeat, and eventually cardiac arrest, and may be caused by a poor intake of K+ in the diet, by a redistribution of extracellular K+, and by an increased loss of body fluids rich in K+. Abnormally elevated levels of extracellular K+ produce mental confusion, general weakness, numbness, flaccid paralysis in the extremities, a slowed heart rate, and eventually collapse of the peripheral vascular system and cardiac arrest. Causes of increased K+ levels may be linked to inappropriate intravenous therapy, dehydration, shock, diabetic ketoacidosis, and severe burns.

Performing Laboratory

Inova Laboratories

2832 Juniper Street

Fairfax, VA 22031

Last Updated: March 27, 2023
Last Review: N. Wolford, March 27, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.