Description
Potassium, a metallic inorganic ion with atomic weight of 39, is the most abundant cation in the body. The vast majority of potassium is in the intracellular compartment with a small amount in the extracellular space. Normal serum potassium is 3.5 to 5.5 mEq/L; however, plasma potassium is 0.5 mEq/L lower. Potassium, Plasma test is False elevations of potassium may be due to hemolysis or rupture of platelets during coagulation process.
Abnormality of serum potassium concentration may thus be attributable to kidney disease, although there are other, less common, possible causes. If sufficiently severe, increase in serum potassium (hyperkalemia) causes abnormal cardiac rhythms that can result in cardiac arrest. The condition is thus a life-threatening emergency that demands urgent medical intervention.
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).
