From the Guidelines
When managing hypernatremia, it is crucial to choose the correct fluid to avoid complications, and half-normal saline should be used for patients who are both hypernatremic and volume depleted, while D5W is suitable for hypernatremic patients who are euvolemic or hypervolemic. The management of hypernatremia should be based on the etiology and the patient's intravascular volume and hydration status, as stated in the guidelines on pediatric parenteral nutrition: fluid and electrolytes 1.
Key Considerations
- The correction rate of hypernatremia should not exceed 10-15 mmol/L per 24 hours to prevent cerebral edema, seizures, and neurological injury, as recommended by the guidelines 1.
- For patients with symptomatic hypovolemia, plasma volume should be replaced, and the choice of fluid should be based on the patient's volume status.
- The free water deficit can be calculated using the formula: Free water deficit = Total body water × [(current Na⁺/desired Na⁺) - 1], to determine the volume of fluid needed.
Fluid Choices
- Half-normal saline (0.45% NaCl) provides both free water and some sodium, making it suitable for patients who are both hypernatremic and volume depleted.
- D5W (5% dextrose in water) provides nearly 100 mL of free water per 100 mL of solution, making it suitable for hypernatremic patients who are euvolemic or hypervolemic.
Monitoring and Treatment
- Serum sodium levels should be frequently monitored, especially in the first 24-48 hours of treatment, to avoid overcorrection or undercorrection.
- The underlying cause of hypernatremia should be addressed while correcting the sodium level to prevent recurrence.
From the Research
Management of Hypernatremia
- Hypernatremia is defined as a serum sodium level above 145 mmol/L 2
- The treatment of hypernatremia involves correcting the underlying cause and correcting the free water deficit 3
- In general, the choice of fluid for correcting hypernatremia depends on the underlying cause and the severity of the condition
Choice of Fluid
- Half normal saline (0.45% sodium chloride) may be used to correct hypernatremia in patients with hypovolemia or those who require a more gradual correction of serum sodium levels
- Dextrose water (5% dextrose in water) may be used to correct hypernatremia in patients with euvolemia or those who require a more rapid correction of serum sodium levels, however, there is limited evidence to support the use of dextrose water in this setting 4
- Isotonic saline (0.9% sodium chloride) is not typically used to correct hypernatremia, as it may worsen the condition