Useful For

Potassium is the major cation of the intracellular fluid. Measurement of serum potassium is used for evaluation of electrolyte imbalance, cardiac arrhythmias, muscular weakness, hepatic encephalopathy, and renal failure and for the monitoring of ketoacidosis in diabetes mellitus and intravenous fluid replacement therapy.  More than 90% of hypertensive patients with aldosteronism have a low K⁺; a low K⁺ is also common in vomiting, diarrhea, alcoholism, and folic acid deficiency. High K⁺ values occur in rapid K⁺ infusion, end stage renal failure, hemolysis, trauma, Addison’s disease, metabolic acidosis, acute starvation, dehydration, and acute medical emergency.  Normally, K⁺ is freely filtered by the glomerulus but tends to be conserved if the serum K⁺ is low. Urinary potassium may be elevated with dietary increase, hyperaldosteronism, renal tubular acidosis, and at the onset of alkalosis.