From the Research
The recommended initial volume of 3% hypertonic saline for correcting hyponatremia is 150 mL, as a bolus infusion, with the possibility of repeating the dose based on the patient's response and serum sodium levels, as supported by the most recent and highest quality study 1.
Key Considerations
- The amount of 3% hypertonic saline needed to correct sodium depends on the patient's current sodium level, target sodium level, and body weight.
- Typically, the formula used is: sodium deficit (mmol) = total body water × (desired sodium - current sodium), where total body water is approximately 0.6 × weight in kg for men and 0.5 × weight in kg for women.
- Each 100 mL of 3% hypertonic saline contains 51.3 mEq of sodium.
- The correction rate should generally not exceed 8-10 mEq/L in 24 hours (or 0.5-1 mEq/L/hour) to avoid osmotic demyelination syndrome, particularly in chronic hyponatremia.
Monitoring and Adjustments
- Close monitoring of serum sodium levels every 2-4 hours during correction is essential.
- The patient should be in a monitored setting, ideally an ICU, when receiving hypertonic saline.
- Symptoms of hyponatremia, duration of hyponatremia, and underlying conditions also influence the appropriate correction rate and volume.
- Reducing bolus-volume and reevaluation before repeating bolus infusion might prevent overcorrection, as suggested by 1.
Additional Guidance
- Administration of desmopressin to terminate an unwanted water diuresis is an effective strategy to avoid or reverse overcorrection, as noted in 2.
- Combined 3% saline solution and desmopressin appears to be a valid strategy for correcting severe hyponatremia, but studies comparing the regimen with other therapeutic strategies are needed, as mentioned in 3.