From the Research
For hypernatremia with a sodium level of 149 mEq/L, the recommended fluid is hypotonic solution, preferably 0.45% sodium chloride (half-normal saline) or 5% dextrose in water (D5W). In mild cases like this (sodium <150 mEq/L), oral rehydration with water or other hypotonic fluids can be effective if the patient can tolerate oral intake. The rate of correction should be gradual, typically aiming to lower sodium by no more than 8-10 mEq/L in 24 hours to avoid cerebral edema. For intravenous administration, calculate the free water deficit using the formula: Free water deficit = Total body water × [(current sodium/desired sodium) - 1], where total body water is approximately 60% of body weight in men and 50% in women. Replace half of this deficit in the first 24 hours and the remainder over the next 1-2 days. Continuous monitoring of serum sodium levels is essential during correction. The underlying cause of hypernatremia should also be addressed, whether it's inadequate water intake, excessive water loss, or iatrogenic causes, as stated in the most recent study 1.
Key Considerations
- The goal is to correct the sodium level gradually to prevent cerebral edema.
- Oral rehydration is suitable for mild cases, while intravenous administration may be necessary for more severe cases or when oral intake is not tolerated.
- Calculating the free water deficit is crucial for determining the amount of hypotonic fluid to administer.
- Monitoring serum sodium levels closely during correction is vital to avoid overcorrection or undercorrection.
Treatment Approach
- Identify and address the underlying cause of hypernatremia.
- Use hypotonic solutions (0.45% sodium chloride or 5% dextrose in water) for correction.
- Aim for a gradual correction rate of 8-10 mEq/L in 24 hours.
- Calculate and replace the free water deficit accordingly.
- Continuously monitor serum sodium levels during the correction process, as recommended by recent guidelines 1.
Underlying Cause
- Inadequate water intake.
- Excessive water loss.
- Iatrogenic causes. It is essential to address the underlying cause to prevent recurrence and ensure proper management of hypernatremia, as discussed in 1.