What is the treatment for severe hyponatremia with a sodium level of 119 mmol/L?

Management of Severe Hyponatremia with Sodium Level of 119 mmol/L

For severe hyponatremia with a sodium level of 119 mmol/L, treatment should be based on symptom severity, with 3% hypertonic saline for severe symptoms and fluid restriction with sodium supplementation for mild or asymptomatic cases, while ensuring correction does not exceed 8 mmol/L in 24 hours to prevent osmotic demyelination syndrome. 1

Initial Assessment and Classification

• Hyponatremia with sodium level of 119 mmol/L is classified as severe hyponatremia (<120 mmol/L) and requires immediate intervention 1
• Assessment of volume status (hypovolemic, euvolemic, or hypervolemic) is essential to determine appropriate treatment approach 1
• Evaluation of symptom severity should guide the urgency and aggressiveness of treatment 1

Treatment Based on Symptom Severity

For Severe Symptoms (seizures, coma, severe confusion)

• Administer 3% hypertonic saline immediately with an initial goal to correct 6 mmol/L over 6 hours or until severe symptoms resolve 1, 2
• Can be administered as boluses of 100 mL over 10 minutes, which can be repeated up to three times at 10-minute intervals until symptoms improve 1
• Consider ICU admission for close monitoring during treatment 1
• Monitor serum sodium every 2 hours during initial correction 1

For Mild Symptoms or Asymptomatic

• Implement fluid restriction to 1 L/day as the cornerstone of treatment, especially for SIADH 1, 2
• Add oral sodium chloride 100 mEq three times daily if no response to fluid restriction 2
• Consider high protein diet to augment solute intake 2
• Monitor sodium levels every 4-6 hours initially 2

Correction Rate Guidelines

• Total correction should not exceed 8 mmol/L in 24 hours to prevent osmotic demyelination syndrome 1, 2
• For patients with advanced liver disease, alcoholism, malnutrition, or prior encephalopathy, use more cautious correction (4-6 mmol/L per day) due to higher risk of osmotic demyelination 1
• If overcorrection occurs, consider relowering with electrolyte-free water or desmopressin 1

Treatment Based on Volume Status

For Hypovolemic Hyponatremia

• Discontinue diuretics and administer isotonic saline (0.9% NaCl) for volume repletion 1
• A urinary sodium <30 mmol/L has a positive predictive value of 71-100% for response to 0.9% saline infusion 1

For Euvolemic Hyponatremia (SIADH)

• Fluid restriction to 1 L/day is first-line treatment 1, 2
• Consider pharmacological options for resistant cases: oral urea, tolvaptan, demeclocycline, or lithium 1, 3
• Tolvaptan should be initiated in a hospital setting where serum sodium can be closely monitored 3
• Tolvaptan starting dose is 15 mg once daily, which can be increased to 30 mg after 24 hours if needed 3

For Hypervolemic Hyponatremia (cirrhosis, heart failure)

• Implement fluid restriction to 1-1.5 L/day 1
• Consider albumin infusion for patients with cirrhosis 1
• Avoid hypertonic saline unless life-threatening symptoms are present 1

Special Considerations

• Distinguish between SIADH and cerebral salt wasting (CSW) in neurosurgical patients, as treatment approaches differ significantly 1
• For CSW, treatment focuses on volume and sodium replacement, with severe symptoms requiring ICU admission with 3% hypertonic saline and fludrocortisone 1
• Avoid fluid restriction in CSW as it can worsen outcomes 1

Monitoring and Follow-up

• Calculate sodium deficit using formula: Desired increase in Na (mEq/L) × (0.5 × ideal body weight in kg) 1, 2
• Watch for signs of osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) typically occurring 2-7 days after rapid correction 1
• Even mild hyponatremia is associated with neurocognitive problems, including falls and attention deficits 4

Common Pitfalls to Avoid

• Overly rapid correction exceeding 8 mmol/L in 24 hours can lead to osmotic demyelination syndrome 1, 2
• Inadequate monitoring during active correction 1
• Using fluid restriction in CSW 1
• Failing to recognize and treat the underlying cause 1
• Using hypertonic saline in hypervolemic hyponatremia without life-threatening symptoms 1