Potassium, Plasma

Test Code

38461

CPT Codes
84132<br>Limited Access Code

Preferred Specimen

1 mL plasma collected in lithium heparin (green-top) tube

Minimum Volume

0.5 mL

Other Acceptable Specimens

Plasma collected in sodium heparin (green-top) tube, or plasma separator tube (PST)

Instructions

Separate plasma from cells promptly.

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days

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

Hemolysis • Serum • Any anticoagulant other than lithium or sodium heparin

Methodology
Ion-Specific Electrode

Setup Schedule

Set up: Daily; Report available: Next day

Reference Range

3.4-4.8 mmol/L for all ages

Clinical Significance

False elevations of potassium may be due to hemolysis or rupture of platelets during coagulation process. The use of plasma potassium levels should be limited to those patients with spuriously elevated or depressed potassium levels, due to blood samples left at room temperature in patients with chronic lymphocytic leukemia with very high WBC counts (false decline), and those with thrombocytosis (increased platelets) with counts in excess of one million (false elevation).

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.