Hyperkalemia refers to the condition in which the concentration of the electrolyte potassium gets higher than normal. Potassium has several important functions in the body. It is essential for the normal functioning of the muscles, heart, and nerves. Potassium helps the body regulate activity of muscle, including the smooth muscle (involuntary muscles, such as the muscles found in the digestive tract), skeletal muscle (voluntary muscles, such as muscles of the extremities and torso), and the muscle of the heart. It is also important for maintaining normal heart electrical rhythm and for normal electrical signals in the nervous system.
Causes
Potassium is needed for cells to function properly. You get potassium through food. The kidneys remove excess potassium in the urine to keep a proper balance of this mineral in the body.
If your kidneys are not working well, they may not be able to remove the proper amount of potassium. As a result, potassium can build up in the blood. This buildup can be due to:
- Addison’s disease
- Burns over large areas of the body
- Certain medicines such as water pills (diuretics) or blood pressure drugs
- Damage to muscle and other cells from certain street drugs, alcohol abuse, untreated seizures, surgery, crush injuries and falls, certain hemotherapy, or certain infections
- Disorders that cause blood cells to burst (hemolytic anemia)
- Severe bleeding from the stomach or intestines
- Taking extra potassium, such as salt substitutes or supplements
- Tumors
Symptoms
Symptoms are fairly nonspecific and generally include malaise, palpitations and muscle weakness mild hyperventilation may indicate a compensatory response to metabolic acidosis, which is one of the possible causes of hyperkalemia. Often, however, the problem is detected during screening blood tests for a medical disorder, or after hospitalization for complications such as cardiac arrhythmia or sudden cardiac death.
During the medical-history intake, physicians focus on kidney disease and medication use (see below), as these are the main causes. The combination of abdominal pain, hypoglycemia, and hyperpigmentation, often in the context of other autoimmune disorders, may be signs of Addison’s disease,which is a medical emergency.
Exams and Tests
The doctor will perform a physical exam and ask about your symptoms.
Tests that may be ordered includes Electrocardiogram (ECG) Potassium level.
Your doctor will likely check your blood potassium level and do kidney blood tests on a regular basis if you:
- Have been prescribed extra potassium
- Have chronic kidney disease
- Take medications to treat heart disease or high blood pressure
- Uses salt substitutes
Treatment
Treatment of hyperkalemia must be individualized based upon the underlying cause of the hyperkalemia, the severity of symptoms or appearance of ECG changes, and the overall health status of the patient. Mild hyperkalemia is usually treated without hospitalization especially if the patient is otherwise healthy, the ECG is normal, and there are no other associated conditions such as acidosis and worsening kidney function. Emergency treatment is necessary if hyperkalemia is severe and has caused changes in the ECG. Severe hyperkalemia is best treated in the hospital, oftentimes in the intensive care unit, under continuous heart rhythm monitoring.
Treatment of hyperkalemia may include any of the following measures, either singly or in combination:
- A diet low in potassium (for mild cases).
- Discontinue medications that increase blood potassium levels.
- Intravenous administration of glucose and insulin, which promotes movement of potassium from the extracellular space back into the cells.
- Intravenous calcium to temporarily protect the heart and muscles from the effects of hyperkalemia.
- Sodium bicarbonate administration to counteract acidosis and to promote movement of potassium from the extracellular space back into the cells.
- Diuretic administration to decrease the total potassium stores through increasing potassium excretion in the urine. It is important to note that most diuretics increase kidney excretion of potassium. Only the potassium-sparing diuretics mentioned above decrease kidney excretion of potassium.
- Medications that stimulate beta-2 adrenergic receptors, such as albuterol and epinephrine, have also been used to drive potassium back into cells.
- Medications known as cation-exchange resins, which bind potassium and lead to its excretion via the gastrointestinal tract.
- Dialysis, particularly if other measures have failed or if renal failure is present.
Treatment of hyperkalemia naturally also includes treatment of any underlying causes, for example: kidney disease, adrenal disease, tissue destruction of hyperkalemia.
