Potassium, Plasma
Use
Potassium measurement in plasma is used to assess electrolyte and acid–base balance, evaluate cardiac arrhythmias, renal function, and monitor diuretic therapy. False elevations may result from hemolysis or platelet rupture, and plasma measurement is preferred in scenarios with spuriously altered potassium levels—such as sample left at room temperature, very high WBC counts (chronic lymphocytic leukemia), or thrombocytosis with platelet counts exceeding one million.
Special Instructions
Not provided.
Limitations
Potassium levels can be falsely elevated due to hemolysis or platelet rupture. Plasma testing should be used when spurious elevations or depressions are suspected, such as in samples left at room temperature, in patients with very high white blood cell counts, or with thrombocytosis.
Methodology
Other
Biomarkers
Potassium
Analyte
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
Lithium heparin (green-top) tube
Collection Instructions
Separate plasma from cells promptly.
Causes for Rejection
Hemolysis; serum; any anticoagulant other than lithium or sodium heparin
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 28 days |
Other tests from different labs that may be relevant