Hyperkalemia

What is Hyperkalemia?

Hyperkalemia refers to a condition in which the level of potassium in your blood is higher than normal, typically above 5.0 to 5.5 mEq/L. Mild elevations often don’t cause any symptoms, but very high levels of potassium can lead to serious heart rhythm problems, muscle weakness, or even paralysis. Although symptoms tend to appear once the potassium levels reach 6.5 to 7 mEq/L, the speed at which these levels increase can matter more than the actual number. For example, if your potassium level rises slowly over time, you might not feel any symptoms even if your level is quite high. In contrast, a rapid increase may cause serious symptoms even if the levels are not extremely high. It’s worth noting that infants generally have higher normal potassium levels than children and adults.

Sometimes, you may have an artificially high reading of potassium in your blood – this is known as pseudohyperkalemia. This can happen due to the way your blood sample was collected or handled, or other factors. In cases where high potassium levels appear without an obvious reason, it’s important to verify the readings before starting any aggressive treatment. Truly high potassium levels, or true hyperkalemia, can be caused by consuming too much potassium, shifts of potassium from inside cells to the outside, or due to your kidneys not properly excreting potassium. The urgency of treatment depends on the severity of symptoms, how high your potassium levels are, and what is causing them to rise.

What Causes Hyperkalemia?

Hyperkalemia, or high potassium levels in the blood, can sometimes be falsely diagnosed. This can occur if the blood sample is damaged in a way that allows potassium inside red blood cells to be measured with the rest of the potassium in the blood. This misleading result, known as pseudohyperkalemia, is more likely to occur if blood is taken with a syringe rather than a vacuum device. Other factors that could cause this include using a tourniquet, excessive fist-clenching during the blood draw, or high white blood cell or platelet counts.

Eating foods that are high in potassium is not usually a cause of hyperkalemia unless you have kidney disease. Foods that are rich in potassium include dried fruits, seaweed, nuts, molasses, avocados, Lima beans, various vegetables such as spinach, potatoes, tomatoes, broccoli, beetroot, carrots, and squashes. Fruits like kiwi, mango, orange, bananas, and cantaloupe, and red meats are also high in potassium. These foods might pose a risk for people with severe kidney disease or for those who take certain medications. High potassium levels can also be increased significantly by intravenous feeding, certain medications, and large amounts of blood transfusion.

High blood potassium levels can also occur if too much potassium moves from inside the cells into the bloodstream. This can be a result of muscle damage from an overwhelming injury, extreme exercise, or certain blood disorders. Metabolic acidosis, in which the body’s fluids contain too much acid, can also cause this shift of potassium. This condition is commonly due to a decrease in blood volume, which can occur in conditions like sepsis or dehydration. Insufficient insulin and a severe form of diabetes can increase potassium in the blood, despite a lack of overall potassium in the body. Some medications and skeletal muscle disorders can also cause these shifts. Also, chemotherapy can lead to high potassium levels by causing mass die-off of cancer cells.

Another reason for high blood potassium levels is decreased kidney function. Both sudden and long-term kidney disease can reduce the ability of the kidneys to remove potassium from the body, but this usually doesn’t happen until kidney function becomes seriously decreased. This can be due to damage to the kidneys themselves or a sudden decrease in body fluids through dehydration or bleeding, or a decrease in blood flow due to heart failure or cirrhosis, a liver disease. Also, conditions that prevent proper kidney function can also lead to high blood potassium levels.

Risk Factors and Frequency for Hyperkalemia

Hyperkalemia, a condition where there’s too much potassium in your blood, is not common in the general population, affecting less than 5% of people worldwide. However, it happens more often in hospitalized patients, affecting up to 10% of these individuals. This is usually due to medications and kidney problems. Other high-risk groups include people with diabetes, cancer, those who are very young or very old, and those with acidosis. It’s also uncommon in children, though it can occur in up to 50% of premature babies. Men tend to be more affected than women, probably because of their larger muscle mass and higher rates of muscle deterioration, as well as a higher prevalence of nerve and muscle disease. Non-Black patients and older people are also at higher risk.

Presently, it’s important to note that a certain class of drugs, ACE inhibitors, could lead to hyperkalemia. This is a particular concern for people with high-risk conditions like diabetes, heart failure, and peripheral vascular disease.

Signs and Symptoms of Hyperkalemia

Hyperkalemia is a condition in which the levels of potassium in your blood are higher than normal. It’s not uncommon for people with this condition to not show any symptoms; often, it’s during routine laboratory tests or tests for other health issues that high potassium is detected. Conditions like kidney disease and diabetes can increase the risk of hyperkalemia. Some other causes can include chemotherapy, severe physical injury (like a crush), or muscle pain, which could be a sign of rhabdomyolysis – a serious condition where damaged muscle breaks down rapidly.

Similarly, certain medications such as digoxin, diuretics that conserve potassium, non-steroidal anti-inflammatory drugs, ace-inhibitors, or receiving potassium via an IV, can also contribute to developing hyperkalemia. These medications are often used for specific health treatments like parenteral nutrition or if you’ve been given potassium penicillin or succinylcholine. If people with hyperkalemia do experience symptoms, these can potentially include feelings of weakness or fatigue, heart palpitations, or even fainting.

In terms of physical signs, high blood pressure and swelling can suggest kidney disease. Signs of low blood supply to your body’s tissues can also appear. If a patient has rhabdomyolysis, their muscles might be tender. Yellowing skin or eyes, a condition known as jaundice, might be observed in the patients with conditions where the blood cells break down too quickly. Lastly, muscle weakness, a loss of muscle tone, or decreased reflexes can also be potential symptoms of hyperkalemia.

Testing for Hyperkalemia

If your doctor suspects you have high levels of potassium in your blood, a condition called hyperkalemia, they will likely order an electrocardiogram (ECG) as the first test. This is crucial because the most dangerous aspect of hyperkalemia is that it can cause irregular heart rhythms, or dysrhythmias, that could potentially lead to death.

The ECG results can show changes linked to the level of potassium in your blood:

* If your potassium level is between 5.5 to 6.5 mEq/L, the ECG will show tall, peaked waves.
* If your potassium level is between 6.5 to 7.5 mEq/L, the ECG will show a loss of certain waves.
* If your potassium level is between 7 to 8 mEq/L, the ECG will show a widening of a specific part of the wave.
* If your potassium level is between 8 to 10 mEq/L, you could have irregular heart rhythms, a unique wave pattern, and possibly, a stagnant heart rhythm.

Please note that how quickly your potassium levels rise can be more important than the actual level. Patients with long-term hyperkalemia might have relatively normal ECGs even when potassium levels are high. Conversely, patients with sudden increases in potassium might show serious ECG changes even at lower levels.

In addition to the ECG, your doctor may order other tests such as creatinine and blood urea nitrogen tests to check your kidney function or a urinalysis to screen for kidney disease. They may also want to check your calcium levels as low calcium can worsen the heart-related effects of high potassium. Testing your glucose and blood gas levels can also be important, especially if you have diabetes or suspected acidosis, a condition when your body fluids contain too much acid.

Lastly, your doctor may perform additional tests for certain conditions if no obvious cause for the hyperkalemia is found. Before starting aggressive treatment, it is crucial to confirm the diagnosis, especially if you’re not showing any symptoms or typical ECG changes linked to high potassium, as false-positive results are common.

Treatment Options for Hyperkalemia

The urgency of treating high potassium levels (hyperkalemia) depends on how quickly the condition developed, the exact level of potassium, the severity of symptoms, and the cause. Hyperkalemia can cause muscle weakness, paralysis, or changes in heart rhythms (ECGs). If these symptoms accompany a potassium level above 5.5 mEq/L in patients at risk for ongoing hyperkalemia, or if the patient’s potassium level is confirmed to be 6.5 mEq/L, aggressive treatment is usually carried out.

The way to handle hyperkalemia usually follows these steps:

1. Stop any outside sources of potassium right away.
2. Find the cause that can be reversed, and start treating it and the high potassium level at the same time.

Calcium treatment can help stabilize the heart’s reaction to high potassium levels. It should be started first if heart damage is found. It’s important to know that calcium doesn’t lower the level of potassium in your blood. It’s mainly used to prevent heart rhythm problems caused by high potassium. Calcium gluconate is usually the first choice as it is less likely to cause irritation or tissue damage compared to calcium chloride, especially when given through IV lines.

Other treatments include insulin and sugar solutions, or just insulin if the patient’s blood sugar is already high. These treatments move potassium back into cells and lower the level of potassium in the blood. They require close monitoring to ensure that the patient’s blood sugar does not drop too low.

Beta-2 adrenergic agents such as albuterol are also used to move potassium back inside cells. These are given in much higher doses than those typically used for treatment of asthma and other lung diseases. It’s also helpful to give sodium bicarbonate to patients with metabolic acidosis, a condition where the body has too much acid. However, a medicine called intravenous epinephrine should not be used to manage high potassium levels due to an increased risk of causing chest pain.

Depending on the situation, medications that increase potassium excretion, such as loop or thiazide diuretics, may be given. These are generally used in patients who are not passing enough urine and have too much fluid in their body. However, they should not be used alone in patients with symptoms.

Substances that bind with potassium in the gut and help the body to get rid of it, like patiromer, can also be helpful. These are especially useful in patients with kidney disease who can’t undergo immediate dialysis. On the other hand, sodium polystyrene sulfonate, a commonly used potassium binding substance, is being used less often due to its lack of effectiveness and side effects, particularly bowel tissue death in elderly patients. Dialysis, a process that cleans the blood, should be performed in patients with severe kidney impairment or in the final stage of kidney disease.

The treatments do, however, come with their own risks such as low potassium levels, failure to control high potassium levels, low calcium levels caused by giving bicarbonate, low blood sugar due to insulin, metabolic alkalosis from bicarbonate therapy and fluid loss from diuretics.

What else can Hyperkalemia be?

The following conditions can often show similar symptoms, making diagnosis complex, such as:

• Acute tubular necrosis
• Congenital adrenal hyperplasia
• Digitalis toxicity, a reaction to heart medicine
• Electrical burn injuries
• Head trauma
• Hypocalcemia (low calcium levels)
• Metabolic acidosis, a condition when your body produces too much acid
• Rhabdomyolysis, a severe muscle injury
• Thermal burns
• Tumor lysis syndrome, a condition that occurs when a large number of cancer cells die

Recognizing the signs of these conditions can ensure a more accurate and expedient diagnosis.

What to expect with Hyperkalemia

The outlook is generally very good for patients with a mild, short-term rise in potassium levels (hyperkalemia), as long as the cause is quickly identified and treated. However, if there’s a sudden, extreme increase in potassium levels, it can cause irregular heartbeats (cardiac arrhythmias) that can be deadly in up to two-thirds of cases if not treated urgently. High potassium levels also increase the risk of death in patients who are in the hospital.

Possible Complications When Diagnosed with Hyperkalemia

Potential complications:

• Heart stopping (cardiac arrest)
• Feeling weak (weakness)
• Irregular heartbeat (arrhythmias)
• Loss of muscle function (paralysis)

Preventing Hyperkalemia

Patients usually don’t need to follow a specific diet unless their case is very severe. If a patient has other health issues or is taking medications that can cause high levels of potassium in the blood (known as hyperkalemia), they should be given information about monitoring their levels of urea and electrolytes. This monitoring will be based on their doctor’s recommendations.