How Rapidly Should Hyponatremia Be Corrected? Hyponatremia Correction Rate

Hyponatremia is defined as serum sodium concentration of less than 135mEq/L.

Mild Hyponatremia: Serum Sodium: 130-134 mEq/L

Moderate Hyponatremia: Serum Sodium: 125-129 mEq/L

Severe Hyponatremia: Serum Sodium: < 125 mEq/L

Correction Rate

If a patient has mild hyponatremia, then only water restriction may improve the serum sodium concentration.

If the duration of hyponatremia is less than 48 hours.

If the duration of hyponatremia is less than 2 days and the patient is symptomatic then the maximum correction rate should be 1-2 mEq/L per hour until patient’s symptoms improve. Once patient’s symptoms improve, decrease the correction rate to 0.5mEq/L per hour or simply 12mEq per 24 hours.

Rapid correction hyponatremia may lead to Central Pontine Myelinolysis, which is a life-threatening condition, which causes, flaccid paralysis, dysarthria, dysphagia, and death.

If the duration of hyponatremia is more than 48 hours

If the duration is more than 48 hours, then keen the correction rate at 0.5mEq/L per hour or 12mEq/L per 24 hours. Additional measures include;

1. Restrict fluid,
2. Treat the underlying cause,
3. If it is mild hyponatremia, no correction is needed, fluid restriction alone is usually sufficient enough to improve the serum sodium level.

Management of underlying cause must be continued along with the correction of hyponatremia.