From the Research
In hypernatremia, D5W (5% dextrose in water) is preferred for severe hypernatremia without volume depletion, while D5 half normal saline is better for patients with concurrent volume depletion or when a more gradual correction is desired to prevent cerebral edema. The key difference between D5 half normal saline and D5W in the treatment of hypernatremia lies in their sodium content and the rate of correction they facilitate. D5W contains no sodium, providing free water only, which makes it more effective for pure free water replacement and faster correction of hypernatremia 1. On the other hand, D5 half normal saline contains 77 mEq/L of sodium, offering some sodium while still being hypotonic relative to plasma.
Key Considerations
- The choice between D5 half normal saline and D5W depends on the presence of volume depletion and the desired rate of correction.
- D5W is ideal for severe hypernatremia without volume depletion due to its ability to provide free water only, facilitating a faster correction of hypernatremia.
- D5 half normal saline is more suitable for patients with concurrent volume depletion or when a more gradual correction is desired to prevent cerebral edema.
- The dextrose in both solutions provides calories and helps prevent hypoglycemia, with each liter supplying 170 calories.
Correction Rate
When correcting hypernatremia, the rate should not exceed 10 mEq/L/day (or 0.5 mEq/L/hour) to avoid rapid shifts in osmolality that could cause cerebral edema 2, 3. However, recent evidence suggests that faster correction rates may be safe and beneficial in certain contexts, such as severe admission-related hypernatremia, particularly within the first 24 hours 1.
Monitoring
Regular monitoring of serum sodium, fluid status, and neurological signs is essential during treatment with either fluid to ensure safe and effective correction of hypernatremia 4. This approach helps in adjusting the treatment plan as needed to prevent complications and improve patient outcomes.