What is the treatment for severe hyponatremia (low sodium levels) of 117 mmol/L?

From the Guidelines

Severe hyponatremia with a sodium level of 117 mmol/L requires prompt treatment with hypertonic saline in symptomatic patients or those with imminent liver transplant. The treatment approach depends on whether the patient is symptomatic and the rate at which hyponatremia developed. For symptomatic patients with severe hyponatremia, initial treatment involves administration of 3% hypertonic saline at a rate of 1-2 mL/kg/hour, with a goal to increase serum sodium by 4-6 mmol/L in the first 24 hours to alleviate acute symptoms, as recommended by the American Association for the Study of Liver Diseases 1. Sodium levels should be monitored every 2-4 hours during correction. The rate of correction should not exceed 8-10 mmol/L in 24 hours to avoid osmotic demyelination syndrome, as cautioned in the guidelines on the management of ascites in cirrhosis 1. Once symptoms improve, the correction rate should be slowed. Fluid restriction to less than 1-1.5 L/day is typically implemented. Underlying causes must be addressed, which may include discontinuing offending medications, treating SIADH with fluid restriction or medications, or managing adrenal insufficiency. Frequent monitoring of serum sodium, neurological status, and fluid balance is essential throughout treatment to ensure safe correction and prevent complications, as emphasized in the EASL clinical practice guidelines for the management of patients with decompensated cirrhosis 1 and the KASL clinical practice guidelines for liver cirrhosis: ascites and related complications 1.

Some key points to consider in the treatment of severe hyponatremia include:

• The use of hypertonic saline is reserved for short-term treatment of patients with symptomatic or severe hyponatremia or those with imminent liver transplant 1.
• The goal rate of increase of serum sodium is 4-6 mEq/L per 24-hour period, not to exceed 8 mEq/L per 24-hour period to ameliorate the risk of osmotic demyelination syndrome 1.
• Hypertonic sodium chloride administration may improve hyponatremia but can worsen fluid overload and ascites, and should be used with caution 1.
• Frequent monitoring of serum sodium levels is necessary to avoid excessive correction and prevent complications such as central pontine myelinolysis or seizures 1.

From the Research

Indications for Hypertonic Saline in Severe Hyponatremia

• Severe hyponatremia is defined as a serum sodium level of less than 135 mEq/L, with symptoms ranging from mild to severe, including seizures or coma 2.
• Hypertonic saline is recommended for the treatment of severely symptomatic hyponatremia, with the goal of increasing the serum sodium level by 4-6 mEq/L within 1-2 hours, but not exceeding 10 mEq/L within the first 24 hours 2, 3.
• The use of hypertonic saline in patients with moderate or severe symptoms of hyponatremia is generally accepted, but there is less agreement on other aspects of its use, such as dosing and administration modality 3.
• A real-life observational study found that treatment with 150 mL of 3% hypertonic saline resulted in a significant increase in serum sodium levels, but with a high rate of overcorrection, especially in severely symptomatic patients 4.

Treatment Approach

• The approach to managing hyponatremia should consist of treating the underlying cause, and hypertonic saline should be reserved for patients with severely symptomatic hyponatremia 2.
• Urea and vaptans can be effective treatments for the syndrome of inappropriate antidiuresis and hyponatremia in patients with heart failure, but have adverse effects 2, 5, 6.
• The treatment of hyponatremia should be individualized, taking into account the patient's fluid volume status, symptom severity, and underlying cause 2, 6.

Key Considerations

• Overly rapid correction of chronic hyponatremia can cause osmotic demyelination, a rare but severe neurological condition 2.
• Diuresis should be monitored, as symptoms caused by hypovolemia can be misinterpreted as severely symptomatic hyponatremia 4.
• Reducing bolus-volume and reevaluating before repeating bolus infusion may help prevent overcorrection 4.