Hypernatremia in Adults - Causes, Symptoms, Diagnosis, and Treatment

Introduction:

Sodium plays a significant role in fluid balance, muscle contraction, and nerve impulse generation. Hypernatremia is often mild and does not require medical intervention. Hypernatremia is diagnosed when sodium concentration in blood serum is higher than 145 milliequivalents per liter. At the same time, hyponatremia refers to a serum sodium level of less than 135 mEq/l. Hypernatremia is a hyperosmolar condition caused by decreased total body water (TBW) relative to electrolyte content. Hypernatremia is often confused with sodium homeostasis, but it is not related to it.

What Are the Causes of Hypernatremia?

The common causes of hypernatremia are:

• Inadequate fluid intake.

• Excessive water loss.

• Hypernatremia is caused by a relative inadequacy of water in relation to sodium which can result from net water loss, which includes pure water loss and hypotonic water loss. It can also be caused due to hypertonic gain from iatrogenic sodium loading.

• In rare cases, excessive intake of sodium.

Health issues leading to hypernatremia are:

• Dehydration.

• Fever.

• Vomiting.

• Delirium.

• Kidney disease

• Uncontrolled diabetes.

• Diabetes insipidus.

• Severe diarrhea.

• Dementia.

• Having large areas of burned skin.

Certain medications causing hypernatremia are:

• Diuretics.

• Sodium bicarbonate.

• Sodium chloride.

• Corticosteroids.

• Anabolic steroids.

• Adrenocorticotropic steroids.

• Androgens.

• Estrogens.

What Is Water Homeostasis?

Water homeostasis signifies that a disruption in the water balance leads to abnormality in serum sodium. Water homeostasis is mediated by:

• Excessive thirst.

• Arginine vasopressin.

• Kidney disease.

Who Is More Likely to Develop Hypernatremia?

The risk factors for hypernatremia include:

• Infants.

• Older adults.

• People with an altered mental state.

• Individuals who are receiving intravenous treatments.

• People receive enteral nutrition through nasogastric feeding.

• Certain medical disorders also increase the risk for hypernatremia, such as dehydration, severe diarrhea, vomiting, fever, dementia, poorly controlled diabetes, large areas of burns on the skin, kidney disease, and diabetes insipidus.

What Are the Symptoms of Hypernatremia?

The symptoms of hypernatremia depend on the severity and magnitude of the rise in plasma sodium.

• Increased thirst.

• Fatigue.

• Lethargy.

• Irritability and restlessness.

• Confusion.

• Altered state of mind.

• Changes in mood.

• Muscle twitching.

• Muscle spasms and muscle weakness.

• Seizures.

• Unconsciousness and coma.

• In severe cases of hypernatremia, the symptoms are neurologic, as elevated serum sodium levels lead to the contraction of brain cells as water shifts to attenuate the rising extracellular fluid osmolality.

How Is Hypernatremia Diagnosed?

• In most cases, underlying health conditions such as kidney disease or diabetes often lead to hypernatremia.

• Physicians can diagnose hypernatremia by assessing the person’s medical history and physical examination.

• In case hypernatremia is suspected, laboratory tests such as blood tests are ordered to determine the amount of serum sodium, and urine tests are also used to identify high levels of sodium and urine concentration.

How Is Hypernatremia Treated?

The onset of hypernatremia can be rapid and develop within 24 hours, or the onset may be more slowly over time (between 24 to 48 hours). The treatment management involves:

• Correction of the fluid imbalance or loss by drinking more water.

• Correction of the sodium imbalance in the body.

• Management of the underlying health conditions such as diabetes, diarrhea, dehydration, kidney issues, etc.

• In mild cases, treatment management is through fluid intake. While in more severe cases, intravenous drip is the treatment of choice as fluids are supplied to the blood rapidly through the intravenous route.

• Fluid concentration is adjusted accordingly while monitoring for sodium levels.

• Only hypotonic fluids are substituted. These include pure water, 5 % dextrose, 0.2 % saline, or 0.45 % saline.

• Isotonic saline is contraindicated in the treatment of hypernatremia, except in the case of frank circulatory compromise and extracellular fluid volume depletion resulting in hemodynamic instability.

• Addressing the underlying causes, such as stopping gastrointestinal loss, controlling pyrexia, and hyperglycemia, correcting hypocalcemia, and moderating lithium-induced polyuria.

• It is recommended to correct hypocalcemia by calcium infusion.

• Correcting the prevailing hypertonicity where the correction rate depends on the duration of hypernatremia to avoid cerebral edema.

• Avoiding rapid or excessive correction.

• Monitor infusion regimen at regular intervals based on the individual’s electrolyte levels and clinical status.

• It is recommended to consider peritoneal dialysis if serum sodium is greater than 180 mmol/L.

What Is the Goal of the Treatment of Hypernatremia?

The goal of treatment includes:

• Reducing the serum sodium concentration to less than 145 mmol/L.

• Make allowance for ongoing obligatory losses of hypotonic fluid that will aggravate the hypernatremia.

• In individuals with seizures, anticonvulsive therapy and ventilation is mandatory.

What Are the Complications of Hypernatremia?

Hypernatremia can lead to serious complications if not treated. One of the most dangerous complications of hypernatremia is brain hemorrhage which stems from the veins rupturing in the brain. It is also estimated that hypernatremia mortality rates are around 20 to 60 %. The presence of encephalopathy results in a poor prognosis and carries a mortality rate as high as 50 %.

How Can Hypernatremia Be Prevented?

Hypernatremia can be prevented by following these measures:

• To stay well-hydrated, drink plenty of water.

• Increase fluid intake as needed, in hot climates, or during physical activity.

• Have a balanced, healthy diet.

• Management of underlying medical conditions such as diabetes and kidney disease.

What Is the Physiology of Hypernatremia?

Hypernatremia is a medical condition characterized by the shift of water from the tissues into the bloodstream, which causes cell shrinkage. It also causes changes in hormone levels to regulate the amount of sodium, which leads to increased thirst and concentrated urine.

What Happens During Hypernatremia?

Hypernatremia occurs when there is extreme water loss or increased sodium levels in the body. Hypernatremia results in altered regulation of sodium concentration in the blood due to changes in water intake or water loss. Changes in the fluid can be caused by the following:

• Increased thirst.

• Changes in urine concentration.

What Is the Prognosis of Hypernatremia?

The prognosis of hypernatremia is generally good. The recovery from hypernatremia is good if the condition is identified early, medical intervention is started early, and the underlying medical conditions are corrected or controlled.

Conclusion:

Hypernatremia is a common electrolyte problem resulting in a rise in serum sodium concentration to a value exceeding 145 mmol/L. Hypernatremia is mild in many cases and does not cause serious problems. However, in order to prevent or reverse hypernatremia it is important to correct the high sodium levels.