In hyperkalemia, the level of potassium in blood is too high.
- A high potassium level has many causes, including kidney disorders, drugs that affect kidney function, and consumption of too much supplemental potassium.
- Usually, hyperkalemia must be severe before it causes symptoms, mainly abnormal heart rhythms.
- Doctors usually detect hyperkalemia when blood tests or electrocardiography is done for other reasons.
- Treatment includes reducing consumption of potassium, stopping drugs that may cause hyperkalemia, and using drugs to increase potassium excretion.
Potassium is one of the body's electrolytes, which are minerals that carry an electric charge when dissolved in body fluids such as blood. The body needs potassium for nerve and muscle cells to function, but too much potassium can also interfere with function.
Causes of Hyperkalemia
Usually, hyperkalemia results from several simultaneous problems, including the following:
- Kidney disorders that prevent the kidneys from excreting enough potassium
- Drugs that prevent the kidneys from excreting normal amounts of potassium (a common cause of mild hyperkalemia)
- A diet high in potassium
- Treatments that contain potassium
The most common cause of mild hyperkalemia is
- The use of drugs that decrease blood flow to the kidneys or prevent the kidneys from excreting normal amounts of potassium
Hyperkalemia can develop after a large amount of potassium is released from the cells. The rapid movement of potassium from cells into blood can overwhelm the kidneys and result in life-threatening hyperkalemia.
By itself, increased intake of potassium does not often cause hyperkalemia because normal kidneys do a good job in excreting any extra potassium.
What Makes the Potassium Level Increase?
Drugs or Other Circumstances
Decreased excretion in urine
Angiotensin-converting enzyme (ACE) inhibitors
Cyclosporine (used to prevent rejection of organ transplants)
Diuretics that help the kidneys conserve potassium, such as eplerenone, spironolactone, and triamterene
Nonsteroidal anti-inflammatory drugs
Tacrolimus (used to prevent rejection of organ transplants)
Trimethoprim (an antibiotic)
Release of potassium from cells
Burns, if severe
Diabetes mellitus (especially diabetic ketoacidosis)
Muscle breakdown (rhabdomyolysis)
Exercise if strenuous and prolonged
A diet containing potassium-rich foods (such as beans, dark leafy greens, potatoes, fish, and bananas)
Intravenous treatments that contain potassium, such as total parenteral nutrition and blood transfusions
Symptoms of Hyperkalemia
Mild hyperkalemia causes few, if any, symptoms. Sometimes, people may develop muscle weakness. In a rare disorder called hyperkalemic familial periodic paralysis, people have attacks of weakness that can progress to paralysis.
When hyperkalemia becomes more severe, it can cause abnormal heart rhythms. If the level is very high, the heart can stop beating.
Diagnosis of Hyperkalemia
- Measurement of potassium level in the blood
Usually, hyperkalemia is first detected when routine blood tests are done or when a doctor notices certain changes on an electrocardiogram (ECG).
To identify the cause, doctors evaluate a person's medical history and routine laboratory test results, determine which drugs people have been taking, and do additional blood tests to check for evidence of diabetes mellitus, acidosis, muscle breakdown, or kidney disorders.
Treatment of Hyperkalemia
- Drugs to increase potassium excretion
The disorder that is causing hyperkalemia is treated.
For mild hyperkalemia, reducing consumption of potassium or stopping drugs that prevent the kidneys from excreting potassium may be all that is needed. If the kidneys are functioning, a diuretic that increases potassium excretion may be given.
If needed, a resin that absorbs potassium from the digestive tract and passes out of the body in the stool can be given by mouth or enema. Sodium polystyrene sulfonate is a potassium-absorbing resin that is effective but used only for short periods because it can cause excess sodium to be retained. Patiromer is a resin drug that can be used for longer periods. It is useful for people who require drugs that usually raise potassium levels, such as angiotensin-converting enzyme (ACE) inhibitors for treatment of heart or kidney disease.
Moderate to severe hyperkalemia
For moderate to severe hyperkalemia, the potassium level must be reduced immediately. Doctors monitor the heart continuously during treatment. Calcium is given intravenously to protect the heart, but calcium does not lower the potassium level. Then insulin and glucose are given, which move potassium from blood into cells, thus lowering the potassium level in blood. Albuterol (used mainly to treat asthma) may be given to help lower the potassium level. It is inhaled.
If these measures do not work or if people have kidney failure, dialysis may be necessary to remove the excess potassium.
Drugs Mentioned In This Article
|Generic Name||Select Brand Names|
|Sodium polystyrene sulfonate||KALEXATE|
|Trimethoprim||No US brand name|