From the Guidelines
Hypernatremia should be treated by addressing the underlying cause and restoring proper fluid balance, with a recommended reduction rate of 10-15 mmol/l/24 h to avoid cerebral oedema, seizures, and neurological injury. The primary causes of hypernatremia include incorrect replacement of transepidermal water loss, inadequate water intake, or excessive sodium intake, which can be iatrogenic, especially in very low birth weight infants (VLBWI) 1.
Treatment Approach
For hypernatremia, the treatment approach should be based on the aetiology, which should be ascertained by assessment of the infant's intravascular volume and hydration status 1.
- In case of symptomatic hypovolaemia, plasma volume should be replaced.
- A rapid correction of hypernatremia may induce cerebral oedema, seizures, and neurological injury, thus a gradual approach is recommended.
- The goal is to reduce serum sodium levels while restoring proper fluid balance, avoiding rapid changes that can lead to complications.
Specific Considerations
- Increase fluid intake, preferably water or other hypotonic fluids, to help correct the imbalance.
- Reduce sodium intake in the diet to prevent further elevation of sodium levels.
- Treat any underlying conditions causing fluid loss, such as diarrhea or excessive sweating.
- For severe cases or those unable to drink, administer intravenous (IV) hypotonic fluids, such as 5% dextrose in water or 0.45% saline solution, and calculate the free water deficit to replace it gradually.
Monitoring and Adjustment
- Monitor serum sodium levels every 2-4 hours during treatment to adjust the rate of correction as needed.
- Avoid rapid correction, aiming for a reduction rate of 10-15 mmol/l/24 h as recommended 1.
- Address any underlying medical conditions contributing to hypernatremia to prevent recurrence.
From the Research
Causes of Hypernatremia
- Hypernatremia is a common electrolyte disorder that reflects an imbalance in the water balance of the body, often resulting from an increased loss of free water compared to sodium excretion 2
- It is rarely based on excessive sodium intake 2
- Mild hypernatremia is often caused by dehydration resulting from an impaired thirst mechanism or lack of access to water 3
- Other causes of hypernatremia include diabetes insipidus 3, 2
Symptoms of Hypernatremia
- The clinical presentation is often characterized by a central nervous system dysfunction (confusion, coma) and pronounced thirst (in awake patients) 2
- Severe symptoms of hypernatremia can be fatal if not properly managed 4
Treatment of Hypernatremia
- Treatment starts with addressing the underlying etiology and correcting the fluid deficit 3
- When sodium is severely elevated, patients are symptomatic, or intravenous fluids are required, hypotonic fluid replacement is necessary 3
- The treatment of hypernatremia involves replacing the (absolute or relative) loss of free water by hypotonic infusions, or in case of diabetes insipidus, by application of Desmopressin (Minirin) 2
- Rapid changes in serum sodium concentration may have deleterious consequences (osmotic demyelination syndrome), so preexisting hypernatremia (>48h) should not be reduced by more than 8-10 mmol/l/day 2
- For acute hypernatremia (< 24 hours), hemodialysis is an effective option to rapidly normalize the serum sodium levels 2
- Treatment should be based on the underlying cause and volume status of the patient, and may involve a combination of fluid replacement, medication, and other therapies 4, 5, 6