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.