How to treat hypernatremia?

Treatment of Hypernatremia

The treatment of hypernatremia should focus on correcting the underlying water deficit while ensuring a safe rate of correction to prevent neurological complications. 1, 2, 3

Assessment and Diagnosis

Before initiating treatment, determine:

1. Volume status: Hypovolemic, euvolemic, or hypervolemic
2. Duration: Acute (<48 hours) or chronic (>48 hours)
3. Severity of symptoms: Mild (confusion, weakness) vs. severe (seizures, coma)
4. Underlying cause: Water loss, sodium gain, or both

Treatment Algorithm

Step 1: Determine Rate of Correction

• For chronic hypernatremia (>48 hours): Decrease serum sodium by no more than 8-10 mmol/L/day 1
• For acute hypernatremia (<24 hours): More rapid correction is acceptable, but still monitor closely 1

Step 2: Calculate Water Deficit

Water deficit (L) = Total body water × [(Current Na⁺/140) - 1]

• Total body water = Weight (kg) × 0.6 (for men) or 0.5 (for women)

Step 3: Choose Appropriate Fluid

For Hypovolemic Hypernatremia:

• Initial phase: Isotonic saline (0.9% NaCl) to restore hemodynamic stability
• Maintenance phase: Hypotonic solutions (0.45% NaCl or 5% dextrose) 2, 3

For Euvolemic Hypernatremia:

• Primary treatment: Hypotonic fluids (0.45% NaCl or 5% dextrose in water) 2
• For diabetes insipidus: Add desmopressin (Minirin) 1

For Hypervolemic Hypernatremia:

• Primary treatment: Loop diuretics plus hypotonic fluids 3
• For severe cases: Consider hemodialysis 1

Step 4: Monitor and Adjust

• Check serum sodium every 2-4 hours during active correction
• Adjust fluid rate based on sodium levels and clinical response
• Monitor for signs of cerebral edema if correction is too rapid

Special Considerations

For Diabetes Insipidus

• Central diabetes insipidus: Desmopressin 1-2 μg IV/SC or 10-20 μg intranasally 1
• Nephrogenic diabetes insipidus: Treat underlying cause, consider thiazide diuretics, NSAIDs, or amiloride 3

For Critically Ill Patients

• More frequent monitoring of serum sodium (every 2-4 hours)
• Consider continuous renal replacement therapy for severe cases with hemodynamic instability 4

For Patients with Liver Disease

• Avoid rapid correction due to increased risk of osmotic demyelination syndrome 5
• For patients with cirrhosis awaiting liver transplantation, multidisciplinary coordination is essential 5

Complications to Watch For

• Cerebral edema: From overly rapid correction of chronic hypernatremia
• Osmotic demyelination syndrome: More common in liver disease patients 5
• Volume overload: Particularly in patients with heart or renal failure

Prevention Strategies

• Ensure adequate free water intake in patients at risk
• Avoid excessive sodium administration
• Regular monitoring of electrolytes in high-risk patients
• Adjust fluid therapy based on daily weights and fluid balance

Remember that hypernatremia represents a deficit of water relative to sodium, and treatment should focus on safely replacing this deficit while addressing the underlying cause.