From the Guidelines
Criteria for Initiating 3% Saline in Hyponatremia
Initiation of 3% saline for the treatment of hyponatremia is recommended in patients with severe symptomatic hyponatremia, defined as serum sodium levels less than 125 mmol/L, accompanied by acute neurological symptoms such as seizures or coma 1.
- The treatment should be aimed at correcting the serum sodium level by no more than 8 mmol/L per day to avoid the risk of central pontine myelinolysis 1.
- Hypertonic sodium chloride administration should be limited to severely symptomatic hyponatremia, as defined by life-threatening manifestations, cardio-respiratory distress, abnormal and deep somnolence, seizures, and coma 1.
- In patients with cirrhosis, hypertonic sodium chloride administration can be considered in those who are expected to get a liver transplant within a few days, with careful monitoring to avoid rapid correction of serum sodium levels 1.
- The use of vaptans, such as tolvaptan, may also be considered for the treatment of hypervolemic hyponatremia, particularly in patients with cirrhosis, heart failure, or the syndrome of inappropriate antidiuretic hormone secretion (SIADH) 1.
- It is essential to monitor serum sodium levels and neurological status closely during treatment with 3% saline or vaptans to avoid complications such as hypernatremia, dehydration, and osmotic demyelination syndrome 1.
From the Research
Criteria for Initiating 3% Hypertonic Saline
The criteria for initiating 3% hypertonic saline in a patient with hyponatremia include:
- Severely symptomatic hyponatremia, characterized by signs of somnolence, obtundation, coma, seizures, or cardiorespiratory distress 2, 3, 4, 5, 6
- Acute hyponatremia (<48 hours) with severe symptoms, such as seizure, respiratory arrest, and coma 3, 5
- Chronic hyponatremia (>48 hours) with severe symptoms, where rapid correction is necessary to prevent brain damage 3, 5
Treatment Approach
The treatment approach for symptomatic hyponatremia with 3% hypertonic saline includes:
- Bolus-wise administration of 100-150 mL of 3% hypertonic saline, repeated up to two more times if necessary 2, 4, 6
- Continuous infusion of low-dose (20 mL/h) 3% saline as an alternative approach 4
- Monitoring of serum sodium levels and adjustment of treatment to prevent overcorrection 3, 4, 5, 6
- Consideration of factors that may aggravate the prognosis of hyponatremic encephalopathy, such as female gender, hypoxia, and young age 5
Key Considerations
Key considerations when initiating 3% hypertonic saline for hyponatremia include:
- The risk of osmotic demyelination with overly rapid correction of chronic hyponatremia 2, 3, 5
- The need for frequent measurements of serum sodium during the correction phase to avoid overcorrection 3, 4, 5, 6
- The importance of monitoring diuresis and adjusting treatment to prevent sodium fluctuations and overcorrection 6