What is the treatment for hypernatremia?

Treatment of Hypernatremia

Hypernatremia treatment should focus on correcting the underlying water deficit with hypotonic fluids administered at a controlled rate to avoid rapid correction, which can lead to cerebral edema and neurological complications. 1

Assessment and Classification

Before initiating treatment, assess:

1. Severity of hypernatremia
2. Volume status (hypovolemic, euvolemic, or hypervolemic)
3. Onset (acute vs. chronic)
4. Presence of neurological symptoms

Volume Status Assessment

• Hypovolemic hypernatremia: Signs of dehydration, orthostatic hypotension, tachycardia
• Euvolemic hypernatremia: No signs of dehydration or fluid overload
• Hypervolemic hypernatremia: Edema, fluid overload (rare - usually from excessive sodium administration)

Treatment Algorithm

Step 1: Stabilize Critical Patients

• For severely symptomatic patients (seizures, altered consciousness), provide immediate but controlled fluid replacement

Step 2: Calculate Water Deficit

• Water deficit (L) = 0.6 × body weight (kg) × [(current Na⁺/140) - 1]
• This estimates the free water needed to correct sodium to normal levels

Step 3: Determine Rate of Correction

• For chronic hypernatremia (>48 hours): Decrease serum sodium by no more than 8-10 mEq/L per 24 hours 1
• For acute hypernatremia (<48 hours): Can correct more rapidly but still with caution

Step 4: Select Appropriate Fluid

Based on volume status:

Hypovolemic Hypernatremia

1. Initial volume resuscitation with isotonic fluids if hemodynamically unstable
2. Switch to hypotonic fluids (0.45% saline or 5% dextrose in water) once stabilized

Euvolemic Hypernatremia

• Primary treatment: 5% dextrose in water or other hypotonic fluids 2

Hypervolemic Hypernatremia

• Loop diuretics to remove excess sodium and water
• Restricted sodium intake
• Hypotonic fluid replacement if needed

Monitoring and Adjustments

• Check serum sodium every 2-4 hours initially in symptomatic patients
• Adjust fluid rate based on sodium correction rate
• Monitor for signs of cerebral edema (headache, altered mental status, seizures)
• Monitor urine output and other electrolytes

Special Considerations

Diabetes Insipidus

• For central diabetes insipidus: Consider desmopressin (DDAVP)
• For nephrogenic diabetes insipidus: Treat underlying cause, consider thiazide diuretics

Elderly and Pediatric Patients

• Higher risk for complications
• May require slower correction rates
• More frequent monitoring

Pitfalls and Caveats

• AVOID TOO RAPID CORRECTION: Rapid correction can lead to cerebral edema, seizures, and permanent neurological damage 2
• AVOID OVERCORRECTION: The water deficit calculation is an estimate; clinical response should guide therapy
• RECOGNIZE ONGOING LOSSES: Continue to account for ongoing fluid losses (fever, diarrhea, etc.)
• TREAT UNDERLYING CAUSE: Identify and address the root cause (limited water access, excessive diuretic use, diabetes insipidus) 1

Remember that hypernatremia rarely develops in patients with adequate access to water and normal thirst mechanisms, so addressing these factors is crucial for prevention of recurrence 2.