Potassium is one of the main blood minerals along with sodium, chloride and bicarbonate. These minerals are also called electrolytes because they carry a small electrical charge (or electric potential). Potassium plays a very important role in metabolism and other bodily functions. However, an excessive amount of potassium can be dangerous.
What is Hyperkalemia?
Hyperkalemia is a condition where there is an abnormally high level of potassium in the blood. The normal level is 3.5 to 5.0 milliequivalents per liter (mEq/L).
5.1 ~ 6.0 mEq/L of potassium levels indicate mild hyperkalemia.
6.1 ~ 7.0 mEq/L of potassium levels indicate moderate hyperkalemia.
7.0 mEq/L and higher potassium levels indicate severe hyperkalemia.
What are the Symptoms of Hyperkalemia?
Hyperkalemia has no obvious symptoms. However, some patients have complained feeling fatigued and nauseated. Other symptoms include muscle weakness, tingling sensation, and in serious cases weak pulse and slow heartbeat.
What are the Causes?
The most common causes of hyperkalemia are:
- potassium sifting
- kidney dysfunction
- diseases of the adrenal glands
The adrenal glands are responsible for secreting the hormone aldosterone, which allows the kidneys to maintain proper levels of fluid, sodium and potassium. Addison's disease and other disorders affecting the adrenal gland often cause a decreased secretion of aldosterone. This results in the kidneys' weakened ability to excrete potassium, which leads to hyperkalemia.
Salt substitutes, potassium supplements, and other similar medications that contain potassium can cause hyperkalemia.
Because the kidneys discharge potassium, hyperkalemia can result when kidney disorders occur. These disorders include:
- lupus nephritis
- acute or chronic renal failure
- urolithiasis or stones in the urinary tract
Unfortunately, the medications for these disorders may cause sensitive reactions to the patients since some of these treatments contain potassium, which can increase the potassium levels in the blood.
Normally, 98% of the total potassium in the body is found in the cells while the other 2% is found in the blood or extracellular tissues. Hyperkalemia results when the potassium found in the cells is released into the blood circulation. One of the causes for this condition is diabetes where acidosis and elevated levels of glucose in the blood cause fluid and potassium to move out of the cells. Other causes include the destruction of tissue such as surgery, trauma, burns, and conditions involving the destruction of the red blood and muscle cells.
What are the Effects?
The body needs a sufficient amount of potassium in order for the heart and nerves to function normally. It is vital in controlling the activities of the smooth muscles, skeletal muscles, and cardiac muscles. Hyperkalemia is thought to be the cause of a rare condition called hyperkalemic periodic paralysis where hyperkalemia hinders the electrical activity of the muscle.
Potassium also plays an important role in the proper transmission of electrical impulses in the heart. Lowered and elevated levels of potassium can interfere with the normal electrical impulses. This leads to arrhythmias or irregular heart rhythms.
While mild hyperkalemia has a limited effect on the heart, moderate hyperkalemia can result in EKG (electrocardiogram) changes. Severe hyperkalemia can inhibit the electrical activity of the heart and cause it to stop beating.
What are the Treatments?
An analysis of the following factors should be considered before a patient is treated for hyperkalemia:
• Changes in EKG
• Seriousness of the symptoms
• Root cause of the hyperkalemia
• Overall health condition of the patient
Common treatments for hyperkalemia include a low-potassium diet, which is usually prescribed to patients suffering from mild symptoms.
Medications that bind potassium to allow for its excretion through the gastrointestinal tract may also be prescribed as well as those, which promote the beta-2 adrenergic receptor that propels the potassium back to the cells.
Diuretics help decrease the potassium supply by increasing the excretion of potassium in the urine.
Intravenous administration of glucose and insulin is a way to help move the potassium back to the cells. Calcium, also administered intravenously, help protect the heart and muscles from the effects of hyperkalemia although temporarily.