The balance of nutrients and minerals in the body is vital to maintaining a properly functioning body. Although the body does a good job of keeping these substances within a narrow, healthy range, many disorders and conditions can lead to disruptions in this internal equilibrium (homeostasis) leading to conditions such as hyperkalemia, which is higher than normal levels of potassium in the bloodstream.
Potassium
In the body, potassium acts as a mineral and electrolyte, a substance that conducts electricity in the body. Potassium is vital to proper heart function and plays a role in the contraction of smooth and skeletal muscles. It helps the body maintain homeostasis as well as plays a part in digestion and metabolism. The majority of potassium is found inside cells and organs of the body with a small amount circulating in the bloodstream.
Causes
The majority of hyperkalemia cases are due to problems with the kidneys, which normally remove excess circulating potassium from the bloodstream. Acute or chronic kidney failure, glomerulonephritis, obstructive uropathy and kidney transplant rejection are all conditions and disorders that can lead to hyperkalemia. Aldosterone is a hormone in the body that increases excretion of potassium by the kidneys, among other functions, and deficiencies in aldosterone, such as in Addison's disease, can lead to high potassium levels. Because the majority of potassium is found in cells, tissue injury can lead to the release of potassium into the bloodstream. Medications or potassium supplements can also lead to hyperkalemia.
Symptoms
Often, there are no symptoms as a result of hyperkalemia; however, the condition can be life threatening if not treated properly, especially in individuals with renal failure. If symptoms are present, they most often include an irregular heartbeat, nausea and vomiting, and a slow and weak heartbeat. Complications of hyperkalemia include cardiac arrhythmia or arrest and impaired nerve functioning.
Diagnosis
Blood tests to detect the levels of potassium in the blood are the first step in diagnosing hyperkalemia. If hyperkalemia is suspected, generally a medical professional will administer an electrocardiography (ECG), a test that measures the electrical activity of the heart, to look for heart rhythm changes associated with hyperkalemia and to detect arrhythmias, according to the University of Maryland.
Treatment
During treatment of hyperkalemia, cardiac arrest may occur and close monitoring is required at all times. For acute treatment of hyperkalemia, the goal is to protect the body from the harmful effects of the condition. To lower potassium, many techniques and medications exist, such as cation-exchange resin medications, diuretics and dialysis. Cation-exchange resin medications bind potassium for removal from the body while diuretics lower potassium levels in the blood by promoting potassium excretion by the kidneys. Dialysis is generally reserved as a last resort or if renal failure is present. Often, calcium is administered intravenously (IV) to protect the heart and muscles from the effects of hyperkalemia. Long-term treatment of hyperkalemia includes a diet low in potassium and treating the underlying cause of hyperkalemia such as kidney disease.
