From the Research
To prevent osmotic demyelination syndrome (ODS), sodium correction should not exceed 8-10 mEq/L in 24 hours when administering hypertonic saline, with the most recent and highest quality study suggesting that the goal is to raise sodium by 4-6 mEq/L in the first 6 hours for patients with severe symptoms, then slow down to stay within the 24-hour limit 1.
Key Considerations
- For severe hyponatremia (sodium <120 mEq/L), use 3% hypertonic saline at 1-2 mL/kg/hr initially, with frequent monitoring of serum sodium levels every 2-4 hours to adjust the infusion rate.
- Patients at highest risk for ODS include those with chronic hyponatremia (>48 hours), alcoholism, malnutrition, liver disease, or potassium depletion.
- The risk of ODS increases dramatically when correction exceeds 12 mEq/L in 24 hours or 18 mEq/L in 48 hours.
- If correction occurs too rapidly, consider using desmopressin (DDAVP) 2-4 μg IV or hypotonic fluids to re-lower sodium levels and prevent ODS, as supported by a study on the concurrent administration of desmopressin and hypertonic saline 2.
Administration and Monitoring
- Administer hypertonic saline as a bolus injection or continuous infusion, with the choice depending on the patient's symptoms and sodium level.
- Monitor serum sodium levels frequently to adjust the infusion rate and prevent overcorrection, as emphasized in a study on the treatment of symptomatic hyponatremia with hypertonic saline 3.
- Consider using a central venous line for administration, especially in patients with severe symptoms or those requiring high doses of hypertonic saline.
Special Considerations
- For asymptomatic or mildly symptomatic patients, even slower correction is preferred to minimize the risk of ODS.
- In patients with chronic hyponatremia, consider using a slower correction rate to avoid rapid changes in serum osmolality.
- Be aware of the potential for rapid sodium level correction and take steps to prevent it, such as using desmopressin or hypotonic fluids, as discussed in a review of the use of hypertonic saline for hyponatremia 1.