Management of Hyponatremia Overcorrection
For hyponatremia overcorrection, immediate administration of desmopressin (DDAVP) and hypotonic fluids (D5W or half-normal saline) is recommended to relower serum sodium and prevent osmotic demyelination syndrome. 1
Recognizing Overcorrection
Overcorrection is defined as:
- Increase in serum sodium >8-10 mEq/L in 24 hours
- Risk of osmotic demyelination syndrome (ODS), a potentially fatal neurological condition
Signs of overcorrection to monitor:
- Rapid rise in serum sodium levels
- Development of water diuresis (sudden decrease in urine specific gravity ≥0.010)
- High urine output
- Improvement in the underlying condition causing hyponatremia
Management Algorithm for Overcorrection
Step 1: Immediate Actions
- Stop all ongoing sodium-containing fluids
- Administer desmopressin (DDAVP) to prevent further water diuresis
- Typical dose: 2-4 μg IV/SC every 6-8 hours
- Begin hypotonic fluid administration:
- D5W (5% dextrose in water) or
- 0.45% saline (half-normal saline)
- Calculate rate based on current sodium level and target
Step 2: Calculate Target Sodium Reduction
- Determine how much the sodium needs to be relowered
- Target: Stay within the safe correction limit of 8 mEq/L in 24 hours from the starting sodium level
Step 3: Monitoring
- Check serum sodium every 2 hours until stabilized
- Monitor urine output and specific gravity every 4 hours
- Adjust fluid therapy based on sodium levels and clinical response
Risk Factors for Overcorrection
Common causes of overcorrection include:
Too much salt gained:
- Miscommunication about previously administered fluids 2
- Excessive administration of hypertonic saline or sodium-containing medications
Too much water lost:
- Unexpected hypoosmotic polyuria 2
- Resolution of the underlying cause of hyponatremia (e.g., SIADH, adrenal insufficiency)
- Water diuresis after volume repletion in hypovolemic patients
Prevention Strategies
- Use conservative correction goals (aim for 6 mEq/L daily increase) 3
- Calculate fluid requirements carefully and reassess frequently
- Consider prophylactic desmopressin in high-risk patients
- Monitor serum sodium every 2 hours in severe cases, every 4 hours in moderate cases 1
- Track fluid intake/output and daily weight
Special Considerations
- Patients with severe symptoms (seizures, coma) are at higher risk of overcorrection (38% vs 6% compared to moderate symptoms) 1
- Chronic hyponatremia (>48 hours) requires more cautious correction than acute hyponatremia
- Patients with liver disease, alcoholism, malnutrition, or hypokalemia are at higher risk for osmotic demyelination syndrome
Pitfalls to Avoid
- Failing to recognize water diuresis as a cause of overcorrection
- Misinterpreting hypovolemia as symptomatic hyponatremia 1
- Miscommunication between providers about previously administered fluids 2
- Continuing sodium-containing fluids after initial improvement
- Inadequate monitoring frequency during correction
Remember that therapeutic relowering of serum sodium has been shown to be safe and effective in preventing osmotic demyelination syndrome when overcorrection occurs 3.