How to correct hyponatremia (low sodium levels)?

From the Guidelines

Correcting hyponatremia in patients with cirrhosis and ascites requires a tailored approach based on the etiology, chronicity, severity, and urgency of the condition, with the goal of preventing cerebral edema and osmotic demyelination syndrome (ODS) 1.

Key Considerations

• The management of hyponatremia in cirrhotic patients depends on whether the condition is acute or chronic, with acute hyponatremia requiring rapid correction and chronic hyponatremia necessitating a more gradual approach to avoid ODS 1.
• For hypovolemic hyponatremia, treatment involves discontinuing diuretics and laxatives and providing fluid resuscitation with 5% IV albumin or crystalloid solution, preferably lactated Ringer’s solution 1.
• Euvolemic hyponatremia should be managed based on the specific underlying cause, while hypervolemic hyponatremia requires fluid restriction, reduction or discontinuation of diuretics and laxatives, administration of hyperoncotic albumin, and/or vasopressin receptor antagonists (“vaptans”) 1.

Treatment Approach

• For mild hyponatremia (Na 126-135 mEq/L) in cirrhosis without symptoms, no specific management is required apart from monitoring and water restriction 1.
• For moderate hyponatremia (120-125 mEq/L), water restriction to 1,000 mL/day and cessation of diuretics is recommended, while severe hyponatremia (<120 mEq/L) requires a more severe restriction of water intake with albumin infusion 1.
• The use of vasopressin receptor antagonists can raise serum sodium but should be used with caution for a short term (≤30 days) 1.
• Hypertonic saline is reserved for short-term treatment of patients with symptomatic or severe hyponatremia or those with imminent liver transplantation (LT) 1.

Correction Rate

• The goal rate of increase of serum sodium in patients with cirrhosis is 4-6 mEq/L per 24-hour period, not to exceed 8 mEq/L per 24-hour period to ameliorate the risk of ODS 1.
• Regular monitoring of serum sodium (every 2-4 hours initially in severe cases) is essential to ensure appropriate correction rates and prevent complications 1.

From the FDA Drug Label

Tolvaptan tablets should be initiated and re-initiated in patients only in a hospital where serum sodium can be monitored closely. Too rapid correction of hyponatremia (e.g., > 12 mEq/L/24 hours) can cause osmotic demyelination resulting in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma and death. In susceptible patients, including those with severe malnutrition, alcoholism or advanced liver disease, slower rates of correction may be advisable The usual starting dose for tolvaptan tablets is 15 mg administered once daily without regard to meals. Increase the dose to 30 mg once daily, after at least 24 hours, to a maximum of 60 mg once daily, as needed to achieve the desired level of serum sodium. Avoid fluid restriction during the first 24 hours of therapy. Patients receiving tolvaptan tablets should be advised that they can continue ingestion of fluid in response to thirst

To correct hyponatremia, initiate tolvaptan in a hospital setting where serum sodium can be closely monitored. The recommended starting dose is 15 mg once daily, which can be increased to 30 mg once daily after at least 24 hours, and up to a maximum of 60 mg once daily as needed. Avoid fluid restriction during the first 24 hours of therapy and advise patients to drink in response to thirst. Monitor serum sodium levels closely to avoid too rapid correction (> 12 mEq/L/24 hours), which can cause serious neurologic sequelae. In susceptible patients, such as those with severe malnutrition, alcoholism, or advanced liver disease, slower rates of correction may be advisable 2.

From the Research

Correction of Hyponatremia

To correct hyponatremia, the following steps can be taken:

• Identify the cause of hyponatremia, if possible, as treatment should not be delayed while a diagnosis is pursued 3
• Categorize patients according to their fluid volume status: hypovolemic, euvolemic, or hypervolemic 3, 4, 5
• Treat the underlying cause of hyponatremia, if possible 3, 4, 6

Treatment Based on Volume Status

Treatment of hyponatremia varies based on the patient's volume status:

• Hypovolemic hyponatremia: treated with normal saline infusions 3, 5
• Euvolemic hyponatremia: treated by restricting free water consumption or using salt tablets or intravenous vaptans 3, 4, 5
• Hypervolemic hyponatremia: treated primarily by managing the underlying cause (e.g., heart failure, cirrhosis) and free water restriction 3, 4, 5

Severe Hyponatremia

Severely symptomatic hyponatremia is a medical emergency:

• Requires emergency infusions with 3% hypertonic saline to increase the serum sodium level by 4-6 mEq/L within 1-2 hours 3, 4, 6, 7
• The correction limit is 10 mEq/L within the first 24 hours to avoid osmotic demyelination syndrome 3, 4, 5, 7

Monitoring and Avoiding Overcorrection

It is essential to monitor the patient's sodium levels and avoid overcorrection:

• Use calculators to guide fluid replacement and avoid overly rapid correction of sodium concentration 3
• Avoid excessive rapid correction, as it can lead to irreversible neurological complications, including central osmotic demyelination 4, 5, 7