Potassium

Normal Range: 3.5-5.0 meq/L

Potassium is predominantly an intracellular cation whose plasma level is regulated by renal excretion. Plasma concentration determines neuromuscular and muscular irritability. Elevated or depressed potassium concentrations interfere with muscle contraction. 

 

increased in: Massive hemolysis, severe tissue damage, rhabdomyolysis, acidosis, dehydration, acute or chronic renal failure, Addison's disease, renal tubular acidosis type IV (hyporeninemic hypoaldosteronism), hyperkalemic familial periodic paralysis. Drugs: potassium salts, potassium-sparing diuretics (spironolactone, triamterene), non-steroidal anti-inflammatory drugs, beta-blockers, ACE inhibitors.

 

Decreased in: Low potassium intake, prolonged vomiting or diarrhea, renal tubular acidosis (types I, II), hyperaldosteronism, Cushing's syndrome, osmotic diuresis (eg, of hyperglycemia), alkalosis, familial periodic paralysis, diuretic therapy. 

 

Additional: Spurious K+ can occur with hemolysis of sample, delayed separation of plama from erythrocytes, prolonged fist clenching during blood drawing, tourniquet placed for prolonged periods, and very high white cell or platelet counts