Hyperkalemia - causes

Pseudohyperkalemia:

• • Hemolysis during blood drawing

  • Excessive clenching of fist with tourniquet on during blood drawing

  • Platelet >1,000,000

  • WBC >200,000

  • Mononucleosis

  • Familial pseudohyperkalemia (potassium efflux from cells)

Redistribution (potassium shifts out of cells)

• • Acidosis (metabolic and respiratory)

  • Hypertonic states

  • Massive digitalis overdose

  • Autosomal dominant hyperkalemic periodic paralysis

  • Tumor lysis syndrome

Aldosterone deficiency/unresponsiveness

• • Primary adrenal failure (autoimmune, TB, hemorrhage, tumor infiltration)

  • Syndrome of hyporeninemic hypoaldosteronism

    • Accounts for many cases of unexplained hyperkalemia

    • GFR is generally >20%

    • May have associated NAGMA

    • Caused by a variety of interstitial renal diseases

    • Diabetes is the most common cause

    • RTA-4

  • Tubular unresponsiveness to aldosterone

    • Caused by a variety of interstitial renal diseases

    • Very similar to SHH but does not respond to fludrocortisone

Renal failure

• • GFR is typically reduced to <10 - 20% of normal.

  • Hyperkalemia may develop rapidly from exogenous potassium in patients with renal failure.

  • RTA - type 4

Drugs that can cause or aggravate hyperkalemia (multiple mechanism)

• Potassium soruces

  • • IV potassium solutions

    • Penicillin VK

    • Potassium citrate

    • Salt substitutes

    • Foods: dried fruits, nuts, bananas, oranges, potatoes, spinach.

• Redistribution hyperkalemia

  • • Arginine and lysine HCl (rarely used)

    • Beta2-adrenergic blockers

    • Succinylcholine

    • Digitalis (massive overdose)

    • Hypertonic mannitol (osmotic effect)

• Aldosterone deficiency/unresponsiveness

  • • NSAIDs

    • ACE-I

    • A2RB

    • Heparin

    • Cyclosporine (also causes hypetriglyceridemia and hypercholesterolemia)

    • FK 506

    • Aminoglutethimide

    • Potassium-sparing diuretics

    • TMP

    • Pentamidine

    • Nefamostat mesilate