Treatment of ICU Confusion Secondary to Hyponatremia (Sodium 126 mmol/L)
For an ICU patient with confusion and sodium of 126 mmol/L, administer 3% hypertonic saline immediately with a target correction of 6 mmol/L over 6 hours or until confusion resolves, but never exceed 8 mmol/L total correction in 24 hours to prevent osmotic demyelination syndrome. 1
Immediate Emergency Management
This patient has severe symptomatic hyponatremia requiring urgent intervention. Confusion represents a neurological manifestation that mandates hypertonic saline, not fluid restriction. 1
Initial Treatment Protocol
- Administer 3% hypertonic saline as 100 mL boluses over 10 minutes, which can be repeated up to three times at 10-minute intervals until symptoms improve 1
- Target correction: Increase sodium by 6 mmol/L over the first 6 hours or until confusion resolves 1
- Absolute maximum: Do not exceed 8 mmol/L correction in 24 hours 1, 2
- ICU admission required for close monitoring during active correction 1
Critical Monitoring Requirements
- Check serum sodium every 2 hours during the initial correction phase 1
- After symptoms resolve, continue monitoring every 4 hours 1
- Watch for signs of overcorrection and osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) which typically occur 2-7 days after rapid correction 1
Volume Status Assessment and Subsequent Management
After stabilizing the acute confusion, determine the underlying etiology by assessing volume status:
For Hypovolemic Hyponatremia
- Urine sodium <30 mmol/L suggests volume depletion 1
- Once acute symptoms resolve, transition to isotonic (0.9%) saline for volume repletion 1
- Discontinue any diuretics 1
For Euvolemic Hyponatremia (SIADH)
- Urine sodium >20 mmol/L with high urine osmolality (>500 mOsm/kg) suggests SIADH 1
- After acute correction, implement fluid restriction to 1 L/day 1
- If no response to fluid restriction, add oral sodium chloride 100 mEq three times daily 1
- Avoid fluid restriction during the first 24 hours of hypertonic saline therapy 2
For Hypervolemic Hyponatremia (Heart Failure/Cirrhosis)
- Evidence of edema, ascites, or jugular venous distention 1
- After acute correction, implement fluid restriction to 1-1.5 L/day 1
- Avoid hypertonic saline unless life-threatening symptoms persist, as it worsens fluid overload 1
- Consider albumin infusion in cirrhotic patients 1
High-Risk Population Considerations
If this patient has any of the following, use even more cautious correction rates (4-6 mmol/L per day maximum): 1
- Advanced liver disease
- Alcoholism
- Malnutrition
- Prior encephalopathy
These patients have substantially higher risk of osmotic demyelination syndrome even with standard correction rates. 1
Management of Overcorrection
If sodium rises >8 mmol/L in 24 hours: 1
- Immediately discontinue hypertonic saline
- Switch to D5W (5% dextrose in water) to relower sodium 1
- Consider desmopressin to slow or reverse the rapid rise 1
- Target bringing the total 24-hour correction back to ≤8 mmol/L from baseline 1
Common Pitfalls to Avoid
- Never use fluid restriction as initial treatment for confusion from hyponatremia—this is a medical emergency requiring hypertonic saline 1
- Never exceed 8 mmol/L correction in 24 hours in standard patients or 6 mmol/L in high-risk patients 1, 2
- Never use normal saline for symptomatic hyponatremia—it corrects too slowly for neurological symptoms 1
- Inadequate monitoring during active correction can lead to osmotic demyelination syndrome 1
- In neurosurgical patients, distinguish cerebral salt wasting from SIADH, as cerebral salt wasting requires volume replacement, not fluid restriction 1
Post-Acute Phase Management
Once confusion resolves and sodium reaches 130-135 mmol/L: