Sodium Correction Rate in Hyponatremia
The recommended rate of sodium correction in hyponatremia should not exceed 8 mmol/L in 24 hours to prevent osmotic demyelination syndrome. 1
Correction Rates Based on Symptom Severity
Severe Symptoms (seizures, coma)
- Administer 3% hypertonic saline with an initial goal to correct 6 mmol/L over 6 hours or until severe symptoms resolve 1, 2
- Monitor serum sodium every 2 hours during initial correction 1
- Consider ICU admission for close monitoring during treatment 1
Mild/Asymptomatic Hyponatremia
- Limit correction to <8 mmol/L per 24 hours 1, 2
- For chronic hyponatremia, avoid rapid correction exceeding 1 mmol/L/hour 1
- Implement fluid restriction (1L/day) for mild/asymptomatic cases, particularly in SIADH 1, 2
Special Population Considerations
Patients with Liver Disease
- Use more cautious correction rates (4-6 mmol/L per day) due to higher risk of osmotic demyelination 1
- For cirrhotic patients, fluid restriction to 1-1.5 L/day for serum sodium <125 mmol/L 1
- Consider albumin infusion alongside fluid restriction in cirrhotic patients 1
Neurosurgical Patients
- Distinguish between SIADH and cerebral salt wasting (CSW) as treatment approaches differ significantly 1
- For CSW, treatment focuses on volume and sodium replacement rather than fluid restriction 1
- Avoid fluid restriction in subarachnoid hemorrhage patients at risk of vasospasm 1
Monitoring During Correction
- For severe symptoms: monitor serum sodium every 2 hours during initial correction 1
- For mild symptoms: monitor sodium every 4 hours initially, then daily 1
- Calculate sodium deficit using formula: Desired increase in Na (mEq/L) × (0.5 × ideal body weight in kg) 1
Management of Overcorrection
- If overcorrection occurs, consider relowering with electrolyte-free water or desmopressin 1
- Watch for signs of osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) typically occurring 2-7 days after rapid correction 1
Common Pitfalls to Avoid
- Overly rapid correction of chronic hyponatremia leading to osmotic demyelination syndrome 1
- Inadequate monitoring during active correction 1
- Using fluid restriction in CSW (can worsen outcomes) 1
- Failing to recognize and treat the underlying cause 1
- Using hypertonic saline in hypervolemic hyponatremia without life-threatening symptoms 1
Evidence-Based Recommendations
- Recent guidelines consistently recommend limiting correction to 8 mmol/L in 24 hours 1, 2, 3
- For severely symptomatic patients, a 4-6 mmol/L increase in the first 6 hours is recommended 2, 4
- Newer evidence suggests that bolus infusions of 3% saline may be preferable to continuous infusion for symptomatic hyponatremia 3
- Frequent monitoring is essential, with adjustment of therapy based on serum sodium levels and clinical response 1, 4