There are 2 broad categories for hyperkalemia:
Renal cause: most commonly due to renal failure.
Non-renal cause: ABCDE
Acidosis – from transcellular shift of potassium in exchange of extracellular H+
- Beta-2 receptors causes uptake of potassium intracellularly via Na-K ATPase which is activated through a chain of events through formation of cAMP.
- Inhibition of beta-2 receptors decreases the ATPase function and therefore reduces potassium intake.
Cellular destruction eg rhabdomyolysis, tumour lysis syndrome
Drugs which block RAAS (ACEi, spironolactone)
Endocrine eg hypoaldosteronism, pseudo-hypoaldosteronism (type I, type II – Gordon’s syndrome)
- Type I: mutation in ENaC channel causes its loss of function.
- Type II: mutation in Na-Cl channel causes its gain of function (opposite to Gitelman’s syndrome).