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