What is the immediate treatment for a patient with restlessness and severe hyponatremia?

Immediate Treatment for Severe Hyponatremia with Restlessness

For a patient with restlessness and severe hyponatremia, immediately administer 100 mL of 3% hypertonic saline IV over 10 minutes, targeting a sodium correction of 6 mmol/L over 6 hours or until symptoms resolve, with a maximum correction of 8 mmol/L in 24 hours. 1, 2

Emergency Management Protocol

Hypertonic saline administration:

• Give 100 mL bolus of 3% hypertonic saline IV over 10 minutes as first-line treatment 2, 3
• Repeat the bolus every 10 minutes if restlessness or other severe symptoms persist, up to three total boluses 2
• Target an initial sodium increase of 4-6 mEq/L in the first hour to abort severe symptoms 2, 4

Critical correction limits:

• Correct 6 mmol/L over the first 6 hours OR until severe symptoms resolve 1, 2
• Never exceed 8 mmol/L correction in 24 hours to prevent osmotic demyelination syndrome 1, 5, 2
• If 6 mmol/L is corrected in 6 hours, limit further correction to only 2 mmol/L in the following 18 hours 1

Monitoring Requirements

Intensive monitoring protocol:

• Check serum sodium every 2 hours during initial correction phase 1, 2, 6
• Transfer to ICU for close monitoring 1, 2
• Monitor strict intake and output 1, 2
• Obtain daily weights 1, 2

Determining the Underlying Cause

Essential diagnostic workup (do not delay treatment):

• Assess extracellular fluid volume status (hypovolemic, euvolemic, or hypervolemic) 5, 2, 3
• Obtain serum and urine osmolality 5, 2, 7
• Measure urine sodium concentration 5, 2, 7
• Check serum uric acid level 5, 2

Distinguish between SIADH and cerebral salt wasting:

• SIADH: euvolemic, urine sodium >20 mEq/L, urine osmolality >500 mOsm/kg 2, 6, 7
• Cerebral salt wasting: hypovolemic with high urine sodium despite volume depletion 2

Post-Acute Management Based on Etiology

For SIADH (euvolemic):

• Implement fluid restriction to 1 L/day after acute phase 1, 2, 6
• Add oral sodium chloride 100 mEq three times daily if no response to fluid restriction 1, 2
• Monitor sodium every 4 hours after severe symptoms resolve 1, 6

For cerebral salt wasting (hypovolemic):

• Continue volume and sodium replacement with isotonic or hypertonic saline 1, 2
• Consider fludrocortisone for severe symptoms or in subarachnoid hemorrhage patients 1, 2
• Never use fluid restriction as this worsens outcomes 1, 5, 2

For hypervolemic hyponatremia (heart failure, cirrhosis):

• Implement fluid restriction to 1-1.5 L/day 5, 3, 8
• Temporarily discontinue diuretics if sodium <125 mmol/L 5
• Consider albumin infusion in cirrhotic patients 5

Critical Pitfalls to Avoid

Overcorrection risks:

• Exceeding 8 mmol/L correction in 24 hours causes osmotic demyelination syndrome 1, 5, 2, 3
• Patients with advanced liver disease, alcoholism, or malnutrition require even slower correction (4-6 mmol/L per day) 1, 5, 6
• If overcorrection occurs, immediately give desmopressin and D5W to relower sodium 5, 4

Treatment errors:

• Using fluid restriction in cerebral salt wasting worsens outcomes 1, 5, 2
• Inadequate monitoring during active correction leads to complications 1, 5
• Failing to recognize and treat the underlying cause results in recurrence 5, 2, 6