From the Guidelines
Sodium 126 mEq/L indicates severe hyponatremia, which is a medical emergency requiring immediate treatment. The patient should be transferred to an intensive care unit for close monitoring and correction of sodium levels. Initial treatment typically involves 3% hypertonic saline infusion at 1-2 mL/kg/hr, with sodium levels checked every 2-4 hours to ensure the correction rate doesn't exceed 8-10 mEq/L in the first 24 hours, as recommended by recent guidelines 1. Rapid correction risks osmotic demyelination syndrome, a potentially devastating neurological complication.
Key Considerations
- The underlying cause must be identified and addressed simultaneously, which could include medication effects, SIADH, heart failure, liver disease, or excessive water intake, as noted in 1 and 1.
- Symptoms like seizures, altered mental status, or coma may require more aggressive initial correction.
- Once the patient is stabilized, a slower correction rate of 4-6 mEq/L per day should be maintained until sodium reaches safe levels (>130 mEq/L).
- Fluid restriction and possibly oral salt supplementation or vasopressin receptor antagonists may be needed for ongoing management depending on the underlying cause, with vasopressin antagonists being considered for short-term use in patients with severe hyponatremia and cognitive symptoms, as suggested in 1.
Management Approach
- For patients with hyponatremia due to heart failure, the use of vasopressin antagonists like tolvaptan may be considered, as indicated in 1.
- In patients with cirrhosis and ascites, the management of hyponatremia is more controversial, with some advocating for water restriction and others for plasma expansion, as discussed in 1 and 1.
- The goal is to avoid severe hyponatremia, especially in patients awaiting liver transplantation, due to the risk of central pontine myelinolysis during fluid resuscitation in surgery, as warned in 1.
From the FDA Drug Label
Tolvaptan tablets are indicated for the treatment of clinically significant hypervolemic and euvolemic hyponatremia (serum sodium <125 mEq/L or less marked hyponatremia that is symptomatic and has resisted correction with fluid restriction) 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.
The implications of hyponatremia (sodium level of 126 mEq/L) are serious neurological symptoms if not properly managed.
- Rapid correction can cause osmotic demyelination syndrome, resulting in symptoms such as dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma, or death.
- Slower rates of correction may be advisable in susceptible patients, including those with severe malnutrition, alcoholism, or advanced liver disease 2.
From the Research
Implications of Hyponatremia
The implications of hyponatremia, defined as a serum sodium level of less than 135 mEq/L, can be severe and life-threatening. A sodium level of 126 mEq/L is considered moderate to severe hyponatremia 3, 4.
Symptoms and Signs
Symptoms and signs of hyponatremia can range from mild and nonspecific, such as:
- Weakness
- Nausea
- Headache
- Mild neurocognitive deficits to severe and life-threatening, including:
- Seizures
- Coma
- Delirium
- Confusion
- Impaired consciousness
- Ataxia
- Brain herniation and death 3, 4, 5, 6, 7
Complications
Hyponatremia can lead to various complications, including:
- Cognitive impairment
- Gait disturbances
- Increased rates of falls and fractures
- Osteoporosis
- Cerebral edema
- Brain herniation
- Respiratory arrest
- Osmotic demyelination syndrome (ODS), a rare but severe neurological condition that can result in parkinsonism, quadriparesis, or even death 3, 4, 5, 6, 7
Management
Management of hyponatremia depends on the underlying cause, severity, and duration of the condition, as well as the patient's volume status. Treatment strategies include:
- Restricting free water consumption
- Using salt tablets or intravenous vaptans
- Managing the underlying cause (e.g., heart failure, cirrhosis)
- Administering hypertonic saline for severely symptomatic hyponatremia
- Correcting the serum sodium level at a rate sufficient to reduce symptoms but not at an excessive rate that would create a risk of osmotic injury 3, 4, 5, 6, 7