How to correct hyponatremia?

Management of Hyponatremia with Sodium Level of 124 mmol/L

For a patient with hyponatremia (sodium 124 mmol/L), correction should be based on symptom severity, with a maximum increase of 8 mmol/L in 24 hours to prevent osmotic demyelination syndrome. 1

Initial Assessment

• Evaluate volume status and classify as hypovolemic, euvolemic, or hypervolemic hyponatremia to determine the underlying cause 1
• Check urine osmolality and sodium concentration to distinguish between SIADH and other causes 1
• Assess symptom severity (mild/asymptomatic vs. severe symptoms like seizures or coma) to guide correction rate 1

Treatment Based on Symptom Severity

For Severe Symptoms (seizures, coma)

• Administer 3% hypertonic saline with an initial goal to correct 6 mmol/L over 6 hours or until severe symptoms resolve 1
• Calculate sodium deficit using formula: Desired increase in Na (mEq/L) × (0.5 × ideal body weight in kg) 1
• Monitor serum sodium every 2 hours during initial correction 1
• Total correction should not exceed 8 mmol/L in 24 hours 1

For Mild/Asymptomatic Hyponatremia

• Treatment depends on volume status and underlying cause 1
• For euvolemic hyponatremia (SIADH): Implement fluid restriction to 1 L/day 1
• For hypovolemic hyponatremia: Discontinue diuretics and administer isotonic saline (0.9% NaCl) for volume repletion 1
• For hypervolemic hyponatremia (cirrhosis, heart failure): Implement fluid restriction to 1-1.5 L/day 1

Special Considerations

• Patients with advanced liver disease, alcoholism, malnutrition, or prior encephalopathy require more cautious correction (4-6 mmol/L per day) due to higher risk of osmotic demyelination syndrome 1
• Avoid fluid restriction in patients with cerebral salt wasting (CSW) as it can worsen outcomes 1
• Tolvaptan should be initiated only in a hospital setting where serum sodium can be monitored closely 2
• Too rapid correction of hyponatremia (>12 mEq/L/24 hours) can cause osmotic demyelination resulting in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma, and death 2

Pharmacological Options

• For SIADH resistant to fluid restriction, consider:

  • Oral sodium chloride supplements 1
  • Tolvaptan (vasopressin receptor antagonist) starting at 15 mg once daily, may increase to 30 mg after 24 hours if needed 2
  • Urea as an effective and safe alternative treatment 3

• For hypervolemic hyponatremia in cirrhosis:

  • Consider albumin infusion alongside fluid restriction 1
  • Avoid hypertonic saline unless life-threatening symptoms are present 1

Monitoring and Follow-up

• Monitor serum sodium levels frequently during correction 1
• For severe symptoms: Check sodium every 2 hours initially 1
• For mild/asymptomatic: Check sodium daily 1
• Watch for signs of osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) typically occurring 2-7 days after rapid correction 1
• If overcorrection occurs, consider relowering with electrolyte-free water or desmopressin 1

Common Pitfalls to Avoid

• Overly rapid correction exceeding 8 mmol/L in 24 hours leading to osmotic demyelination syndrome 1
• Inadequate monitoring during active correction 1
• Using fluid restriction in cerebral salt wasting 1
• Failing to recognize and treat the underlying cause 1
• Using hypertonic saline in hypervolemic hyponatremia without life-threatening symptoms 1