Hyperkalemia
The definition of hyperkalemia
Hyperkalemia is common: it is diagnosed in up to 8% of patients hospitalized in the United States. Fortunately, most patients have mild hyperkalemia (which is usually well tolerated). However, all conditions that cause even a mild hyperkalemia should be treated to prevent progression into more severe hyperkalemia. Potassium levels are high is very extreme in the blood (severe hyperkalemia) can lead to cardiac arrest (cardiac arrest) and death. If not recognized and treated properly, severe hyperkalemia results in the death rate approximately 67%.
Technically, hyperkalemia mean levels of potassium in the blood rise abnormally. Levels of potassium in the blood of normal is 3.5-5.0 milliequivalents per liter (mEq / L). Potassium levels between 5.1 mEq / L to 6.0 mEq / L reflects a mild hyperkalemia. Potassium levels of 6.1 mEq / L to 7.0 mEq / L is being hyperkalemia, and potassium levels above 7 mEq / L is hyperkalemia severe / severe.
How hyperkalemia Affect the Body?
Potassium is critical for normal functioning of the muscles, heart, and nerves. It plays an important role in controlling the activity of smooth muscle (a muscle that is found in the digestive tract) and skeletal muscles (the muscles of the limbs and torso), and heart muscles. He also is important for transmission (delivery) the electrical signals throughout the nervous system in the body.
Blood levels of potassium is normal critical to maintain a normal heart's electrical rhythm. Both levels of low potassium (hypokalemia) and levels of high blood potassium (hyperkalemia) can lead to heart rhythms are abnormal.
The most important clinical effects of hyperkalemia associated with the heart's electrical rhythm. While mild hyperkalemia likely have a limited effect on the heart, hyperkalemia who are able to produce ECG changes (ECG is the electrical readings of the heart muscles), and hyperkalemia severe / severe can lead to compression of the heart's electrical activity and can lead to heart to stop beating.
Another important effect of hyperkalemia is impaired functioning of skeletal muscles. Hyperkalemia periodic paralysis is a hereditary disease (inherited) are rare in which patients can develop sudden onset of hyperkalemia which in turn causes muscle paralysis. Cause for muscle paralysis is not clearly understood but are likely to be caused by hyperkalemia which suppresses the electrical activity of muscles.
Symptoms of hyperkalemia
Hyperkalemia can be asymptomatic, meaning that it does not cause symptoms. Occasionally, patients with hyperkalemia reported symptoms are vague, including:
* Nausea,
* Tired,
* Muscle weakness, or
* Tingling feelings.
The symptoms are more serious hyperkalemia include slow heartbeat and weak pulse. Severe hyperkalemia can result in a fatal cardiac arrest. Generally, potassium levels rise slowly (as with chronic renal failure) is better tolerated than level-potassium levels rise suddenly. Except for potassium is very rapid rise, the symptoms of hyperkalemia is usually not clear until potassium levels are very high (typically 7.0 mEq / l or higher).
Symptoms may also be present That Reflect the underlying medical conditions are Causing That the hyperkalemia.
Causes of hyperkalemia
The main causes of hyperkalemia is kidney dysfunction, diseases of the adrenal glands, filtering out potassium from cells into the blood circulation, and drugs.
Kidney dysfunction
Potassium normal secreted (released) by the kidneys, so the diseases that reduce the function of the kidneys can result in hyperkalemia. These include:
* Acute and chronic renal failure,
* Glomerulonephritis,
* Lupus nephritis,
* Transplant rejection, and
* Diseases that block the urinary tract (urine), such as urolithiasis (stones in the urinary tract).
Furthermore, patients with renal dysfunctions are particularly sensitive to drugs that can increase blood potassium levels. For example, patients with renal dysfunctions may develop worsening of hyperkalemia if given salt substitutes that contain potassium, when given potassium supplements (orally or intravenously), or drugs that can increase blood potassium levels. Examples of drugs that can increase blood potassium levels include:
* ACE inhibitors,
* Nonsteroidal anti-inflammatory drugs (NSAIDs),
* Angiotensin II Receptor Blockers (ARBs), and
* Potassium-sparing diuretics (see below).
Adrenal Gland Diseases
The adrenal glands are small glands located adjacent to the kidneys, and is important in secreting hormones such as cortisol and aldosterone. Aldosterone causes the kidneys to hold liquid sodium and excrete potassium in the urine while. Therefore diseases of the adrenal glands, such as Addison's disease, which leads to reduced secretion of aldosterone which can reduce the excretion of potassium from the kidneys, resulting in the detention of potassium in the body, and hence hyperkalemia.
Potassium-Displacement Movement
Potassium can move out of and into the cells. Supplies, supplies total body potassium is approximately 50 mEq / kg of body weight. At any time, approximately 98% of the total potassium in the body located inside the cells (intracellular), with only 2% are located outside of the cells (in the blood circulation and in tissues "extracellular"). Blood tests to measure potassium levels measured just outside of potassium from the cells. Therefore, conditions that can cause potassium to move out of the cells into the blood circulation can increase blood potassium levels although the total amount of potassium in the body unchanged.
One example of the displacement of potassium causing hyperkalemia is diabetic ketoacidosis. Insulin is vital in patients with type 1 diabetes. Without insulin, patients with type 1 diabetes can develop blood sugar levels that increase is severe. Lack of insulin also causes the breakdown of fat cells, with the release of ketones into the blood, changing the blood becomes acidic or acidic (hence the term ketoacidosis). Acidosis and glucose levels in the blood work together cause fluid and potassium to move out of the cells into the blood circulation. Patients with diabetes often also have a reduced capacity of the kidneys to excrete (issued) of potassium into the urine. The combination of the displacement of potassium out of cells and reduced urinary excretion of potassium causing hyperkalemia.
Another cause of hyperkalemia is tissue damage, the dying cells release potassium into the blood circulation. Examples of tissue damage that causes hyperkalemia include:
* Trauma,
* Burns,
* Operation,
* Hemolysis (disintegration or destruction of red blood cells),
* Massive lysis of tumor cells, and
* Rhabdomyolysis (a condition that involves destruction of muscle cells that is sometimes associated with muscle injury, alcoholism, or drug abuse).
Medicines
Potassium supplements, salt substitutes containing potassium and other medications can cause hyperkalemia.
In individuals with normal, healthy kidneys are able to adapt to excessive oral intake of potassium by increasing urinary excretion of potassium, so preventing the development of hyperkalemia. However, inclusion of too much potassium (through foods, supplements, or salt substitutes containing potassium) can cause hyperkalemia if renal dysfunction or if the patient is taking medications that reduce urinary excretion of potassium such as ACE inhibitors and diuretics saving potassium.
Examples of drugs that reduce urinary excretion of potassium include:
* ACE inhibitors,
* ARBs,
* NSAIDs,
* Potassium-sparing diuretics such as:
o spironolactone (Aldactone),
o triamterene (Dyrenium), and
o trimethoprim-sulfamethoxazole (Bactrim).
Despite the mild hyperkalemia is common with these medications, severe hyperkalemia is usually not occur unless these medications are administered to patients with renal dysfunction.
Diagnosis hyperkalemia
Blood was drawn from a vein (such as blood tests, etc.). Blood potassium concentration is determined in the laboratory. If hyperkalemia is suspected, an electrocardiogram (ECG or EKG) often done, because the ECG may show changes typical for hyperkalemia in cases of moderate to severe / severe. ECG will also be able to identify arrhythmias, cardiac arrhythmia resulting from hyperkalemia.
Treating hyperkalemia
Treatment of hyperkalemia should be distinguished for each person based on the underlying cause of hyperkalemia, the severity of the symptoms or the appearance of ECG changes, and the overall health status of patients. Mild hyperkalemia usually treated without hospitalization, especially if the patient is healthy, normal ECG, and no other conditions related such as acidosis and worsening renal function. Emergency care is necessary if hyperkalemia is severe and has caused changes in the ECG. Severe hyperkalemia is best treated in hospital, often in the ICU (intensive care unit), under the observation of heart rhythm continuously.
Treatment of hyperkalemia may include any of the following measures, alone or in combination:
* A diet low potassium (for mild cases).
* Stopping medications that increase blood potassium levels.
* Income from intravenous glucose and insulin, which promote the movement of potassium from the extracellular space back into the cells.
* Calcium intravenously to temporarily protect the heart and muscles from the effects of hyperkalemia.
* Inclusion of sodium bicarbonate to counteract acidosis and to promote the movement of potassium from the extracellular space back into the cells.
* Entered a diuretic to reduce the total storage-potassium through an increased secretion of potassium in the urine. It is important to note that most diuretics increase renal potassium excretion. Only the potassium-sparing diuretics mentioned above reduce renal potassium excretion.
* Drugs that stimulate beta-2 adrenergic receptors, such as albuterol and epinephrine, have also been used to guide the potassium back into cells.
* Drugs that are known as cation-exchange resins, which bind potassium and lead to excretion via the gastrointestinal tract.
* Dialysis, especially if other measures have failed or if renal failure is present.
Treatment of hyperkalemia naturally also includes treatment of the causes of any underlying (eg, kidney disease, adrenal disease, tissue destruction) of hyperkalemia.
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