Evaluate electrolyte balance; followed patients on diuretic therapy and with renal diseases, particularly salt-losing nephropathy; evaluate patients being treated for acidosis; prevent cardiac arrhythmias; evaluate alcoholism with delirium tremens; evaluate and treat ketoacidosis in diabetes mellitus; evaluate acid-base balance, water balance; manage intravenous therapy; evaluate anion gap; evaluate muscular weakness, leukemia, diseases of the gastrointestinal tract including laxative abuse, large villous adenomas, emesis, fistulas and tube drainage; detect, diagnose, and manage mineral corticoid excess (primary aldosteronism, Cushing syndrome, tumor with ectopic ACTH production, some cases of congenital adrenal hyperplasia); licorice ingestion. Potassium is increased in oliguria, anuria, urinary obstruction, renal failure due to shock (decreased removal of potassium), and renal tubular acidosis. Potassium is decreased in three ways:
• Inadequate intake
• Excessive loss due to diarrhea or vomiting or decreased reabsorption due to increased secretion of mineralocorticosteroids.