Hypernatremia: what is it, causes, symptoms, treatment, prognosis

What is hypernatremia?

Hypernatremia is an increased concentration of sodium ions in the blood that can occur as a result of decreased fluid intake. The condition may not cause any symptoms, but it can increase the risk of other health problems and even death.

Hypernatremia is a particularly serious problem in hospitalized patients, where it can affect about 2% of patients. Infants and the elderly are at greater risk during hospitalization.

Symptoms and Signs

People with hypernatremia may not have any symptoms, especially if the sodium concentration increases gradually.

In infants, hypernatremia can cause symptoms such as:

• increased breathing rate;
• muscle weakness;
• lethargy;
• insomnia;
• shrill cry;
• coma.

In an adult with hypernatremia, symptoms may be slightly different, for example:

• intense thirst;
• nausea and vomiting;
• fussiness;
• muscle weakness.

Symptoms of hypernatremia are more likely if sodium levels become extremely high. Symptoms are also more likely if the condition develops suddenly rather than gradually (the latter is more common).

In general, people hospitalized with hypernatremia have a higher risk of medical complications and death than people who do not have hypernatremia. One study of people admitted to an intensive care unit found a 33% mortality rate among people with hypernatremia upon admission to the hospital.

One of the possible complications of hypernatremia is intracranial bleeding (cerebral hemorrhage). This can happen when hypernatremia results in a decrease in the size of brain cells, increasing the likelihood of destruction of blood vessels in the brain. This is the most serious potential complication of this condition.

Causes of hypernatremia

Importance of sodium concentration

Hypernatremia is defined as an increased concentration of sodium ions in the blood. Sodium ions are electrolytes, small charged particles that play a number of important roles. These sodium ions are of the same type as the common salt component (sodium chloride). Sodium ions are the most abundant ion found outside cells and in the bloodstream.

The correct concentration of sodium in the blood is very important for the body. It is responsible for how the body regulates the amount of water in the cells. This helps to make sure they don't swell excessively or shrink too hard. It is also important to keep your blood pressure in the correct range. Sodium in the blood also plays a complex role in maintaining the function of nerve cells and in transporting substances into and out of cells.

Since the concentration of sodium ions in the blood is very important, the body has ways to regulate it. One way is to use antidiuretic hormone (ADH), which is secreted by the pituitary gland in the brain. When you are dehydrated, your kidneys excrete less water through your urine so you don't lose moisture. It also heightens the feeling of thirst. It helps to increase the amount of water in the body, which lowers the concentration of sodium in the blood.

However, even with this adaptability, the body is sometimes unable to keep the sodium concentration within the normal range. When the concentration becomes too high, it is called hypernatremia. (Hyponatremia - another opposite problem in which the sodium concentration becomes too low. It has various causes and leads to other potential problems.)

Specific Causes of Hypernatremia

Hypernatremia usually results from the loss of water in the body. This can be due to decreased water consumption or increased water loss. Less commonly, hypernatremia can occur when a person takes too much salt / sodium (in such cases, it is often occurs in hospitalized patients who receive intravenous fluids containing too much sodium).

Insufficient water consumption has a number of possible causes. Water simply may not be available. Or, for various reasons, a person may not drink as much as they should. This can happen, for example, for the following reasons:

• dementia (dementia);
• severe depression or other mental health problems;
• the patient is on sedatives;
• a brain disorder that affects thirst and ADH production (for example, Parkinson's disease, a brain tumor).

The increased loss of water in the body can also have various causes, as excess water enters through the gastrointestinal tract, urine, or other routes. Some of them:

• diarrhea;
• vomit;
• fever;
• excessive sweating;
• severe burns;
• rapid breathing;
• taking diuretics;
• different types of genetic and acquired kidney disease;
• elevated blood glucose levels (for example, due to type 2 diabetes);
• hyperaldosteronism;
• diabetes insipidus.

Certain medications can also cause hypernatremia as a side effect. These include lithium, phenytoin, and amphotericin.

Population at risk

Infants and the elderly are most at risk for hypernatremia. Obviously, babies cannot control their fluid intake on their own. They can easily become dehydrated due to stomach ailments or if they have trouble breastfeeding.

Older people usually have a less sensitive response to thirst, a decreased ability to form concentrated urine, and a decrease in water reserves. They may also have additional medical problems that increase their risk, or they may be taking medications with potential side effects.

Hypernatremia and nutrition

Hypernatremia does NOT result from eating a lot of salty foods. The salt that a person gets through food is not enough to cause hypernatremia, even if you eat a lot of foods high in salt. However, overeating salt can lead to other health problems, such as high blood pressure (arterial hypertension).

Diagnostics

Blood test.

A blood sodium test is required to diagnose hypernatremia. With this test, hypernatremia is usually determined when serum sodium is greater than 145 (in mEq / L). Severe symptoms most often appear if the sodium content in the human body is even higher, say, 160 or more. A blood sodium test is usually done in conjunction with other basic tests for electrolytes and other important blood products.

Medical history, analyzes and other laboratory tests.

The doctor should also diagnose the cause of the high sodium content. This is important because different causes have different treatments.

For this, medical history is critical. The doctor should be aware of the symptoms when they started and other medical problems. The physical examination is also a key component of the diagnosis. For example, a doctor may notice signs of dehydration, such as dry mouth or sagging skin.

Often, a clinician can diagnose an underlying cause with just one case history and clinical examination. For example, if a person is known to have not drunk enough water, the cause of hypernatremia is usually clear. But sometimes additional tests may be required. These may differ depending on the surrounding circumstances, and include:

• A blood test for the content of electrolytes and other components of the main metabolic analyzer.
• Urine tests for volume and concentration.

Other research may be required depending on the context and available data. For example, a doctor can see how well the body produces concentrated urine in response to desmopressin (which acts like ADH). This can help the doctor diagnose different types of diabetes insipidus, if any. Or some people may need a CT scan of the head to make sure there is no brain hemorrhage.

Treatment of hypernatremia

Treatment for hypernatremia depends to some extent on the underlying cause. It's important to start by looking at what caused the increased sodium levels in the body. For example, a person with central diabetes insipidus may require treatment with desmopressin. It is also important to assess whether the drug may be causing the hypernatremia.

It is very important to replenish fluid supplies. This can sometimes be done orally. In other cases, the person needs to receive intravenous fluids to increase the amount of water in the blood (and therefore lower the sodium concentration).

It is important for the medical team to gradually resolve the hypernatremia. Treating hypernatremia too quickly can cause cerebral edema in some cases. Another possible risk is seizures (convulsions). Therefore, it is very important that doctors give the body the opportunity to adapt. People with hypernatremia that have developed over a long period of time should have gradual fluid intake than people who have developed it more quickly.

You will also need to re-monitor your blood sodium levels to make sure the levels are back to normal.

Forecast

The prognosis for hypernatremia is generally very good. This is especially the case for early detection of a disease and the elimination or control of underlying problems.

Hypernatremia can often be treated outside the hospital. If hospitalization is required, close monitoring will help ensure a positive outcome.