Management of Severe Hyponatremia

Hyponatremia Correction : General Principle

• The rate of sodium correction should be 6 to 12 mEq per L in the first 24 hours and 18 mEq per L or less in 48 hours.
• An increase of 4 to 6 mEq per L is usually sufficient to reduce symptoms of acute hyponatremia.
• Chronic hypernatremia should be corrected at a rate of 0.5 mEq per L per hour, with a maximum change of 8 to 10 mEq per L in a 24-hour period.
• Rapid correction of sodium can result in osmotic demyelination (previously called central pontine myelinolysis).
• Overcorrection is common and is typically caused by rapid diuresis secondary to decreasing ADH levels. Every attempt should be made not to overcorrect sodium levels.

Severe Hyponatremia Sodium Correction

• One study of 25 patients with severe symptoms and sodium levels less than 120 mEq per L showed that concurrent treatment with a weight-based dose of 3% saline and 1 to 2 mcg of desmopressin every six to eight hours resulted in a rate of correction of 3 to 7 mEq per L per hour without causing overcorrection.
•  Guidelines from the European Society of Endocrinology recommend infusing one dose of 150 mL of 3% saline over 20 minutes, with sodium monitoring every 20 minutes until symptoms resolve. This regimen may be repeated if the patient remains symptomatic or until the goal sodium target of 5 mEq per L is achieved

Reference: 

1. Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia, AAFP 2015