Abnormal elevation of potassium in the blood is called hyperkalemia. The normal potassium level is between 3.5 to 4.5 meq/liter. A level greater than 4.5meq/L is called hyperkalemia.
Major Causes of Hyperkalemia
- It can result from decreased excretion from the kidneys as in renal failure.
- Drugs such as potassium sparing diuretics (e.g. spironolactone).
- Transcellular shifts i.e. the potassium tends to move out of the cells. Seen in a condition called acidosis (low pH of blood).
- Limb weakness.
- Abnormal heart rhythms which can be fatal if the level is very high. The ECG usually shows tall T waves.
- In emergency conditions, calcium is given intravenously to protect the heart from high potassium.
- Insulin and glucose is given intravenously. The insulin drives the potassium into the cell.
- Cationic exchange resins such as polystyrene sulfonate (kayexalate) can be given orally or rectally.
- Haemodialysis is used in renal failure patients.
When the serum potassium level goes below 3.5 meq/L it is called hypokalemia.
Causes of Hypokalemia
- Inadequate intake.
- Excessive loss of potassium from the kidney can occur with diuretics, antibiotics harmful to the kidney such as amphotericin and gentamicin.
- Gastrointestinal loss from vomiting, diarrhea.
- Excess loss from skin as in burns.