Hyperkalemia causes


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]

Overview
Hyperkalemia (AE) or Hyperkalaemia (BE) is an elevated blood level (above 5.0 mmol/L) of the electrolyte potassium. The prefix hyper- means high (contrast with hypo-, meaning low). The middle kal refers to kalium, which is Latin for potassium. The end portion of the word, -emia, means "in the blood". Extreme degrees of hyperkalemia are considered a medical emergency due to the risk of potentially fatal arrhythmias.

Ineffective elimination from the body

 * Renal insufficiency
 * Medication that interferes with urinary excretion:
 * ACE inhibitors and angiotensin receptor blockers
 * Potassium-sparing diuretics (e.g. amiloride and spironolactone)
 * NSAIDs such as ibuprofen, naproxen, or celecoxib
 * The calcineurin inhibitor immunosuppressants ciclosporin and tacrolimus
 * The antibiotic trimethoprim
 * The antiparasitic drug pentamidine
 * Mineralocorticoid deficiency or resistance, such as:
 * Addison's disease
 * Aldosterone deficiency, including reduced levels due to the blood thinner, heparin
 * Some forms of congenital adrenal hyperplasia
 * Type IV renal tubular acidosis (resistance of renal tubules to aldosterone)
 * Gordon's syndrome (“familial hypertension with hyperkalemia”), a rare genetic disorder caused by defective modulators of salt transporters, including the thiazide-sensitive Na-Cl cotransporter.

Excessive release from cells

 * Rhabdomyolysis, burns or any cause of rapid tissue necrosis, including tumor lysis syndrome
 * Massive blood transfusion or massive hemolysis
 * Shifts/transport out of cells caused by acidosis, low insulin levels, beta-blocker therapy, digoxin overdose, or the paralyzing anesthetic succinylcholine

Excessive intake

 * Intoxication with salt-substitute, potassium-containing dietary supplements, or potassium-chloride (KCl) infusion. Note that for a person with normal kidney function and nothing interfering with normal elimination (see above), hyperkalemia by potassium intoxication would be seen only with large infusions of KCl or massive doses of oral KCl supplements.

Lethal injection
Hyperkalemia is intentionally brought about in an execution by lethal injection, potassium chloride being the third and last of the three drugs generally administered to cause death, after sodium thiopental has rendered the subject unconscious, then pancuronium bromide has been added to cause respiratory collapse.

Pseudohyperkalemia
Pseudohyperkalemia is a rise in the amount of potassium that occurs due to excessive leakage of potassium from cells, during or after blood is drawn. It is a laboratory artifact rather than a biological abnormality and can be misleading to doctors. Pseudohyperkalemia is typically caused by hemolysis during venipuncture (by either excessive vacuum of the blood draw or by a syringe needle that is of too fine a gauge); excessive tournequet time or fist clenching during phlebotomy (which presumably leads to efflux of potassium from the muscle cells into the bloodstream). ; or by a delay in the processing of the blood specimen. It can also occur in specimens from patients with abnormally high numbers of platelets (>1,000,000/mm³), leukocytes (> 100 000/mm³), or erythrocytes (hematocrit > 55%). People with "leakier" cell membranes have been found, whose blood must be separated immediately to avoid pseudohyperkalemia.