How to correct severe hyponatremia (low sodium level) of 112 mmol/L?

Management of Severe Hyponatremia (Sodium 112 mmol/L)

For severe hyponatremia with sodium of 112 mmol/L, initiate treatment with fluid restriction to 1,000 mL/day, discontinue diuretics, and consider albumin infusion, with a maximum correction rate of 8 mEq/L in 24 hours to prevent osmotic demyelination syndrome. 1, 2

Initial Assessment and Classification

• Sodium of 112 mmol/L is classified as severe hyponatremia (<120 mmol/L)
• Determine volume status (hypovolemic, euvolemic, or hypervolemic) as this guides treatment approach
• Check for neurological symptoms (seizures, altered mental status, coma) which would require more urgent correction
• Identify underlying cause (medications, SIADH, liver disease, heart failure)

Treatment Algorithm

Step 1: Immediate Management

• If symptomatic (seizures, altered consciousness):

  • Administer 3% hypertonic saline to raise sodium by 4-6 mEq/L in first 1-2 hours 2
  • Monitor sodium levels every 2-4 hours during active correction
  • Target initial correction: 4-6 mEq/L in first 1-2 hours for severe symptoms 2

• If asymptomatic or mildly symptomatic:

  • Implement fluid restriction to 1,000 mL/day 1
  • Discontinue diuretics if applicable 1, 2
  • Consider albumin infusion for patients with cirrhosis 1, 2

Step 2: Ongoing Management Based on Volume Status

For Hypovolemic Hyponatremia:

• Administer isotonic saline or 5% albumin for volume repletion 2
• Discontinue diuretics if applicable 2

For Euvolemic Hyponatremia:

• Strict fluid restriction (<1,000 mL/day) 1, 2
• Consider vasopressin receptor antagonists (vaptans) for short-term use (≤30 days) 1, 3

For Hypervolemic Hyponatremia:

• Fluid restriction (<1,000 mL/day) 1
• Albumin infusion may be beneficial, especially in cirrhotic patients 1, 2
• Consider vaptans for short-term use only (≤30 days) with caution 1

Critical Safety Parameters

• Maximum correction rate: 8 mEq/L in 24 hours to prevent osmotic demyelination syndrome (ODS) 1, 2
• High-risk patients: For patients with advanced liver disease, alcoholism, malnutrition, or hypokalemia, limit correction to 4-6 mEq/L per day 1, 2
• Monitoring frequency: Check serum sodium every 2-4 hours during active correction 2
• Overcorrection management: If sodium increases too rapidly, consider administering desmopressin or electrolyte-free water to relower sodium 1, 2, 4

Vaptan Considerations

If using tolvaptan (vasopressin receptor antagonist):

• Must be initiated in a hospital setting where sodium can be closely monitored 3
• Starting dose: 15 mg once daily, can be increased to 30 mg after 24 hours if needed 3
• Maximum duration: 30 days (to minimize risk of liver injury) 3
• Contraindicated in hypovolemic hyponatremia and in patients unable to sense thirst 3
• Not for urgent correction of severe neurological symptoms 3

Pitfalls and Caveats

• Avoid fluid restriction in first 24 hours if using vaptans to prevent overly rapid correction 3
• Avoid hypertonic saline in cirrhotic patients as it may worsen ascites and edema 2
• Do not use vaptans for ADPKD due to risk of hepatotoxicity 3
• Risk factors for ODS: advanced liver disease, alcoholism, severe hyponatremia, malnutrition, hypokalemia, hypophosphatemia, hypoglycemia, low cholesterol, and prior encephalopathy 1, 2
• Seizure management: For seizures due to hyponatremia, focus on correcting sodium rather than initiating anti-seizure medications 2

Follow-up

• Continue monitoring sodium levels after active correction phase
• Resume fluid restriction after discontinuation of vaptans 3
• Address underlying cause of hyponatremia for long-term management
• Consider multidisciplinary approach for patients with cirrhosis who may need liver transplantation 1