How should I manage a patient with acute confusion and moderate hyponatremia?

Management of Acute Confusion and Moderate Hyponatremia (Sodium 126 mmol/L)

For a patient presenting with acute confusion and a sodium of 126 mmol/L, immediately assess symptom severity and volume status to determine if this requires emergent hypertonic saline or can be managed with fluid restriction and isotonic saline—the presence of confusion indicates symptomatic hyponatremia that demands prompt but carefully controlled correction. 1

Immediate Assessment and Classification

Your patient has moderate hyponatremia (sodium 120-125 mmol/L range, though 126 is just above this threshold) with neurological symptoms (confusion), which elevates the urgency 1, 2. The confusion indicates this is symptomatic hyponatremia requiring active treatment, not just observation 3.

Critical first steps:

• Determine acuity: Is this acute (<48 hours) or chronic (>48 hours)? 1, 3 Acute onset allows faster correction; chronic requires extreme caution to avoid osmotic demyelination syndrome 1
• Assess volume status: Look for orthostatic hypotension, dry mucous membranes, decreased skin turgor (hypovolemic); peripheral edema, ascites, jugular venous distention (hypervolemic); or absence of both (euvolemic) 1, 2
• Check urine sodium and osmolality: Urine sodium <30 mmol/L suggests hypovolemia; >20-40 mmol/L with high urine osmolality suggests SIADH 1, 4

Treatment Based on Symptom Severity

For Moderate Symptoms (Confusion, Nausea, Headache)

You do NOT need 3% hypertonic saline for confusion alone at sodium 126 mmol/L unless the patient progresses to severe symptoms (seizures, coma, severely altered mental status) 1, 2. The threshold for emergent hypertonic saline is typically sodium <120-125 mmol/L WITH severe neurological manifestations 1, 3.

Your treatment approach:

• If hypovolemic: Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/h initially, then 4-14 mL/kg/h based on response 1. Discontinue any diuretics 1
• If euvolemic (likely SIADH): Implement fluid restriction to 1 L/day as first-line treatment 1, 5. If no response, add oral sodium chloride 100 mEq three times daily 1
• If hypervolemic (heart failure, cirrhosis): Fluid restriction to 1-1.5 L/day 1, 5. Temporarily discontinue diuretics if sodium <125 mmol/L 1. Consider albumin infusion in cirrhotic patients 1

If Symptoms Progress to Severe (Seizures, Coma)

Only then administer 3% hypertonic saline with initial goal to correct 6 mmol/L over 6 hours or until severe symptoms resolve 1, 2. Give 100 mL boluses over 10 minutes, repeatable up to three times at 10-minute intervals 1.

Critical Correction Rate Guidelines

The single most important safety principle: NEVER exceed 8 mmol/L correction in any 24-hour period 1, 2, 6. This is the absolute ceiling to prevent osmotic demyelination syndrome 1.

Target correction rates:

• Standard risk patients: 4-8 mmol/L per day, maximum 10-12 mmol/L in 24 hours 1
• High-risk patients (liver disease, alcoholism, malnutrition, prior encephalopathy): 4-6 mmol/L per day, absolute maximum 8 mmol/L in 24 hours 1, 7

For your patient with confusion at sodium 126 mmol/L: Aim to increase sodium by approximately 4-6 mmol/L in the first 24 hours, which should be sufficient to improve symptoms while maintaining safety 1, 7.

Monitoring Protocol

• Check sodium every 4-6 hours during active correction 1
• For severe symptoms requiring hypertonic saline: Check every 2 hours initially 1
• Watch for osmotic demyelination syndrome signs (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) typically 2-7 days after rapid correction 1

Common Pitfalls to Avoid

Do not use 3% hypertonic saline for mild-moderate symptoms at sodium 126 mmol/L—this risks overcorrection 1, 5. Reserve hypertonic saline for severe neurological symptoms or sodium <120 mmol/L with symptoms 1, 3.

Do not apply fluid restriction to hypovolemic patients—this worsens outcomes 1. Volume status assessment is critical 2, 4.

Do not ignore the underlying cause—identify and treat the etiology (medications, SIADH, heart failure, cirrhosis) to prevent recurrence 1, 5.

Do not correct faster than 8 mmol/L in 24 hours—overcorrection causes irreversible brain damage 1, 6, 7. If overcorrection occurs, immediately switch to D5W and consider desmopressin to relower sodium 1, 7.

Special Considerations

If the patient has cirrhosis: Use even more conservative correction (4-6 mmol/L per day maximum) and consider albumin infusion alongside fluid restriction 1, 5. Avoid hypertonic saline unless life-threatening symptoms develop 1.

If neurosurgical patient: Distinguish between SIADH (treat with fluid restriction) and cerebral salt wasting (treat with volume and sodium replacement, NEVER fluid restriction) 1.

Tolvaptan consideration: Only for refractory euvolemic or hypervolemic hyponatremia after standard measures fail 8. Not first-line for acute symptomatic presentation 8. In cirrhosis, carries 10% risk of GI bleeding versus 2% with placebo 8.