From the Research
Hypernatremia should be corrected at a rate not exceeding 0.5 mmol/L per hour, as there is no significant difference in mortality or neurologic outcomes between rapid and slow correction rates, as shown in a study published in the Clinical Journal of the American Society of Nephrology in 2019 1.
Treatment Approach
The treatment of hypernatremia involves addressing the underlying cause while carefully correcting sodium levels.
- For mild to moderate cases (145-160 mEq/L), oral rehydration with water or hypotonic fluids is recommended.
- For severe cases (>160 mEq/L) or symptomatic patients, intravenous hypotonic fluids like 0.45% saline or 5% dextrose in water should be administered.
Correction Rate
The correction rate should be gradual, with the goal of not exceeding 0.5 mmol/L per hour, as supported by the study published in 2019 1.
Monitoring and Calculation
- The volume and rate of fluid replacement should be calculated based on the patient's estimated water deficit.
- Frequent monitoring of serum sodium levels (every 2-4 hours initially) is essential to guide therapy.
Underlying Causes
Underlying causes such as diabetes insipidus may require specific treatments like desmopressin (DDAVP) at doses of 1-2 mcg IV/SC or 10-20 mcg intranasally twice daily, as discussed in a study published in Neuro Endocrinology Letters in 2010 2.
Pathophysiology
Hypernatremia develops when water loss exceeds sodium loss or when sodium intake exceeds water intake, disrupting the body's osmotic balance, as explained in a review published in Best Practice & Research Clinical Endocrinology & Metabolism in 2016 3. This imbalance causes water to move out of cells, potentially leading to brain cell shrinkage and neurological symptoms including altered mental status, seizures, and coma in severe cases.