From the Guidelines
For hyponatremic seizures, administer 3% hypertonic saline as a 2-3 mL/kg bolus (maximum 100-150 mL) over 10-20 minutes, as recommended by recent guidelines 1. This approach is supported by the most recent and highest quality studies, which emphasize the importance of rapid correction of serum sodium levels to stop seizures, while avoiding over-correction to prevent osmotic demyelination syndrome. The goal of treatment is to rapidly increase serum sodium by 4-6 mEq/L to stop seizures, not to fully correct the hyponatremia. After the initial bolus, switch to slower correction with a maximum increase of 8-10 mEq/L in the first 24 hours, as recommended by 1. Some studies suggest that continuous infusion, if needed, should be at 0.5-1 mL/kg/hour 1. During treatment, it is essential to monitor serum sodium every 2-4 hours, assess neurological status frequently, and watch for signs of fluid overload. Hypertonic saline works by rapidly increasing serum osmolality, reducing cerebral edema, and stabilizing neuronal membranes. The cautious approach to correction is necessary because too-rapid correction of chronic hyponatremia can lead to serious neurological complications, as highlighted by 1. Key considerations in treatment include:
- Rapid correction of serum sodium levels to stop seizures
- Avoiding over-correction to prevent osmotic demyelination syndrome
- Monitoring serum sodium and neurological status frequently
- Watching for signs of fluid overload
- Using continuous infusion if needed, at a rate of 0.5-1 mL/kg/hour.
From the Research
Dosing of Hypertonic Saline for Hyponatremic Seizure
- The dosing of hypertonic saline for hyponatremic seizure is a critical aspect of treatment, as it requires careful consideration of the rate of correction to avoid neurological complications 2, 3, 4, 5.
- According to the studies, the recommended dose of hypertonic saline is 3% saline, administered as an intravenous bolus of 4 to 6 mL/kg body weight 3.
- The goal of treatment is to increase the serum sodium level by 4 to 6 mEq/L within 1 to 2 hours, but not to exceed a correction limit of 10 mEq/L within the first 24 hours 2, 5.
- Rapid correction of hyponatremia can cause osmotic demyelination, a rare but severe neurological condition, which can result in parkinsonism, quadriparesis, or even death 2, 5.
- The use of hypertonic saline in combination with anti-convulsants, such as diazepam and phenytoin, may be effective in managing hyponatremic seizures 4.
- It is essential to monitor the serum sodium level closely during treatment and adjust the dose of hypertonic saline accordingly to avoid overcorrection or undercorrection 5, 6.
Key Considerations
- The rate of correction of hyponatremia is critical, and excessive correction can lead to neurological complications 2, 5.
- The use of hypertonic saline should be reserved for patients with severely symptomatic hyponatremia, such as those with seizures or coma 2.
- Patients with chronic hyponatremia require careful consideration of the rate of correction to avoid osmotic demyelination 5.
- The treatment of hyponatremia should be individualized based on the underlying cause and the patient's clinical presentation 6.