How to manage hyponatremia?

Management of Hyponatremia with Sodium Level of 120

For patients with severe hyponatremia (sodium <120 mmol/L), diuretics should be stopped and volume expansion with colloid or saline should be initiated, while avoiding increasing serum sodium by >12 mmol/L per 24 hours. 1

Assessment of Hyponatremia

When evaluating a patient with a sodium level of 120 mmol/L, consider:

1. Volume status assessment - categorize as:

   • Hypovolemic hyponatremia
   • Euvolemic hyponatremia
   • Hypervolemic hyponatremia

2. Symptom severity:

   • Mild: nausea, weakness, headache, mild cognitive deficits
   • Severe: delirium, confusion, impaired consciousness, ataxia, seizures 2, 3

3. Duration - acute (<48 hours) vs. chronic (>48 hours) 4

Management Algorithm

1. Severe Symptomatic Hyponatremia (with neurological symptoms)

• Immediate intervention required:
  • Administer 3% hypertonic saline to increase sodium by 4-6 mEq/L within 1-2 hours 2
  • Target no more than 8-10 mEq/L increase in first 24 hours to prevent osmotic demyelination syndrome 5
  • Monitor serum sodium every 2 hours for severe symptoms, every 4 hours for mild symptoms 5

2. Asymptomatic or Mildly Symptomatic Hyponatremia

For Hypovolemic Hyponatremia:

• Isotonic (0.9%) saline infusion 4
• Discontinue diuretics if applicable 5
• Treat underlying cause (e.g., vomiting, diarrhea, excessive sweating)

For Euvolemic Hyponatremia:

• Fluid restriction (<1 L/day) 5
• Consider vasopressin receptor antagonists (tolvaptan) for SIADH 6, 4
• Identify and address underlying causes (medications, SIADH)

For Hypervolemic Hyponatremia:

• Fluid restriction 5
• Treat underlying condition (heart failure, cirrhosis, renal disease) 7
• Salt restriction (90 mmol salt/day or 5.2 g salt/day) 1

Specific Recommendations Based on Sodium Level

For sodium level of 120 mmol/L:

1. Stop diuretics 1
2. Volume expansion with colloid or saline 1
3. Avoid increasing serum sodium by >12 mmol/L per 24 hours 1, 5

Important Considerations

• Water restriction is controversial in patients with ascites and hyponatremia. Some experts recommend water restriction, while others suggest it may exacerbate central hypovolemia and worsen ADH secretion 1

• Alcohol cessation is crucial if alcohol-induced liver injury is the underlying cause 1

• Avoid rapid correction of chronic hyponatremia to prevent osmotic demyelination syndrome 2, 7

• Vasopressin receptor antagonists (vaptans) like tolvaptan may be considered for euvolemic hyponatremia, but monitor for adverse effects including risk of rapid correction 6, 4

Common Pitfalls to Avoid

1. Overly rapid correction of sodium (>8-10 mEq/L in 24 hours) risking osmotic demyelination 5, 2

2. Water restriction in hypovolemic patients which may worsen their condition 5

3. Failing to identify and treat the underlying cause of hyponatremia 7

4. Continuing diuretics in patients with severe hyponatremia (Na <120 mmol/L) 1

5. Inadequate monitoring of serum sodium levels during correction 5

By following this structured approach based on volume status, symptom severity, and sodium level, management of hyponatremia can be optimized to improve outcomes while minimizing risks of treatment complications.