What are the implications of hyponatremia (sodium level of 127 mEq/L)?

From the Guidelines

Hyponatremia with a sodium level of 127 mEq/L requires medical attention, and treatment should focus on correcting the underlying cause while avoiding rapid correction to prevent central pontine myelinolysis, with a goal to increase serum sodium by 4-6 mEq/L per 24-hour period, not to exceed 8 mEq/L per 24-hour period, as recommended by the most recent guidelines 1.

Implications of Hyponatremia

Hyponatremia at this level can cause symptoms such as headache, confusion, seizures, and weakness, and is associated with a poor prognosis and multiple complications, especially in patients with liver cirrhosis and ascites 1.

Treatment Approach

The management of hyponatremia depends on the underlying cause, but may include:

• Fluid restriction to 1,000 mL/day and cessation of diuretics for moderate hyponatremia (120-125 mEq/L) 1
• Albumin infusion for severe hyponatremia (<120 mEq/L) 1
• Hypertonic saline administration for short-term treatment of patients with symptomatic or severe hyponatremia, or those with imminent liver transplant (LT) 1
• Vasopressin receptor antagonists for short-term use (≤30 days) in cirrhosis, with caution 1

Key Considerations

• The goal rate of increase of serum sodium should not exceed 8 mEq/L per 24-hour period to ameliorate the risk of osmotic demyelination syndrome (ODS) 1
• Severe hyponatremia (<120 mEq/L) at the time of LT increases the risk of ODS, and multidisciplinary coordinated care may mitigate this risk 1
• Mild hyponatremia (Na 126-135 mEq/L) in cirrhosis without symptoms does not require specific management apart from monitoring and water restriction 1

From the Research

Implications of Hyponatremia

The implications of hyponatremia, defined as a serum sodium level of less than 135 mEq/L, are significant and can be severe. A sodium level of 127 mEq/L is considered moderate to severe hyponatremia 2, 3.

Symptoms and Signs

• Mild symptoms include nausea, vomiting, weakness, headache, and mild neurocognitive deficits 3
• Severe symptoms include delirium, confusion, impaired consciousness, ataxia, seizures, and, rarely, brain herniation and death 3, 4, 5, 6
• Symptom severity depends on the rapidity of development, duration, and severity of hyponatremia 2

Management and Treatment

• Treatment should not be delayed while a diagnosis is pursued, and the approach to managing hyponatremia should consist of treating the underlying cause 2, 3
• For most patients, management is based on whether the patient is hypovolemic, euvolemic, or hypervolemic 2, 3, 4, 5
• Hypovolemic hyponatremia is treated with normal saline infusions, while euvolemic hyponatremia includes restricting free water consumption or using salt tablets or intravenous vaptans 3, 4, 5
• Hypervolemic hyponatremia is treated primarily by managing the underlying cause and free water restriction 3, 4, 5
• Severely symptomatic hyponatremia is a medical emergency and requires immediate treatment with hypertonic saline to reverse hyponatremic encephopathy 2, 3, 4, 5, 6

Complications

• Overly rapid correction of hyponatremia may cause osmotic demyelination, a rare but severe neurological condition, which can result in parkinsonism, quadriparesis, or even death 2, 3, 4, 5, 6
• Hyponatremia is a secondary cause of osteoporosis, and mild chronic hyponatremia is associated with cognitive impairment, gait disturbances, and increased rates of falls and fractures 2