Hypokalaemia is common but often unrecognised and can have serious metabolic and functional effects in many organ systems. Characteristic changes appear on the ECG as hypokalaemia becomes severe.
- Hypokalaemia is common in clinical practice and can lead to cardiac, neuromuscular and gastrointestinal abnormalities.
- Hypokalaemia is usually associated with total body potassium depletion caused by inadequate intake and/or excess gastrointestinal or renal loss.
- Occasionally, significant hypokalaemia is caused by a compartmental shift of potassium from the extracellular to the intracellular fluid caused by alkalosis, insulin or aldosterone excess.
- Severe potassium depletion (below 2.5 mmol/L) can cause ECG abnormalities, arrhythmias, weakness, rhabdomyolysis and renal tubular dysfunction.
- Hypokalaemia is often associated with other electrolyte abnormalities including alkalosis, hypomagnesaemia and hypophosphataemia, which can have other adverse effects.