What is the treatment for central salt wasting?

Treatment of Central Salt Wasting

The treatment of central salt wasting (CSW) requires aggressive volume resuscitation with isotonic or hypertonic saline and fludrocortisone therapy, with the specific approach determined by symptom severity. 1

Diagnosis Confirmation

Before initiating treatment, confirm the diagnosis of CSW by distinguishing it from SIADH:

• CSW characteristics:
  • Hypovolemia (clinical signs, low CVP if available)
  • Hyponatremia (serum sodium <131 mmol/L)
  • Elevated urine osmolality
  • Elevated urine sodium (>20 mEq/L)
  • Inappropriate natriuresis despite hypovolemia

Treatment Algorithm Based on Symptom Severity

Severe Symptoms (seizures, altered mental status, coma)

1. Immediate intervention:

   • Administer 3% hypertonic saline to increase serum sodium by 4-6 mEq/L in first 1-2 hours 1
   • Transfer to ICU for close monitoring
   • Monitor serum sodium every 2 hours
   • Calculate sodium deficit: Desired increase in Na (mEq) × (0.5 × ideal body weight) 2

2. Ongoing management:

   • Continue hypertonic saline as needed
   • Do not exceed correction rate of 8 mmol/L in 24 hours 1
   • Start fludrocortisone 50-100 μg/day, can increase to 150-200 μg/day 1

Moderate Symptoms (nausea, vomiting, headache)

1. Volume repletion:

   • Isotonic saline (0.9% NaCl) for volume expansion 1
   • Consider 3% hypertonic saline if symptoms worsen
   • Monitor serum sodium every 4-6 hours

2. Pharmacologic therapy:

   • Fludrocortisone 50-100 μg/day 1
   • Consider hydrocortisone in subarachnoid hemorrhage patients 2

Mild/No Symptoms

1. Volume repletion:

   • Isotonic saline for volume repletion 1
   • Monitor serum sodium every 6 hours

2. Maintenance therapy:

   • Fludrocortisone 50-100 μg/day 1, 3
   • Oral sodium chloride supplements if needed

Special Considerations

Subarachnoid Hemorrhage Patients

• Avoid fluid restriction even with mild hyponatremia (Na 131-135 mmol/L) due to risk of vasospasm (Class II evidence) 2, 1
• Maintain euvolemia or mild hypervolemia
• Fludrocortisone is strongly recommended (Class I evidence) 2
• Hydrocortisone may be used to prevent natriuresis (Class I evidence) 2

Monitoring Parameters

• Serum sodium levels (frequency based on severity)
• Volume status assessment
• Blood pressure (fludrocortisone may cause hypertension)
• Serum potassium (risk of hypokalemia with fludrocortisone)
• Daily weight
• Intake and output

Duration of Therapy

• Continue treatment until the underlying neurological condition resolves
• Fludrocortisone may be required for days to weeks 3, 4
• Taper medications gradually while monitoring sodium levels

Potential Pitfalls

1. Misdiagnosis as SIADH: Incorrectly treating CSW with fluid restriction can worsen hypovolemia and lead to cerebral ischemia 2, 5

2. Overly rapid correction: Exceeding correction rate of 8 mmol/L/24h risks osmotic demyelination syndrome 2, 1

3. Inadequate volume replacement: Failure to replace ongoing sodium and fluid losses can lead to persistent hyponatremia 3

4. Coexisting conditions: Be alert for possible concurrent diabetes insipidus, which can complicate management 6

5. Monitoring failures: Inadequate monitoring of electrolytes during active correction can lead to complications 1

The cornerstone of CSW treatment is addressing both the sodium deficit and volume depletion simultaneously, with fludrocortisone serving as an effective adjunct therapy to reduce ongoing natriuresis 2, 1, 3.