Does a patient with hyponatremia (low sodium level) require admission?

Management of Hyponatremia with Sodium Level of 126 mmol/L

A patient with a serum sodium level of 126 mmol/L requires hospital admission if they are symptomatic or have risk factors for rapid deterioration. 1

Assessment Based on Symptom Severity

• Hyponatremia (serum sodium <135 mmol/L) is associated with increased mortality, with sodium levels <130 mmol/L linked to a 60-fold increase in fatality (11.2% versus 0.19%) 2
• Symptoms should guide management decisions:
  • Mild symptoms: nausea, headache, weakness, neurocognitive deficits 3
  • Severe symptoms: delirium, confusion, impaired consciousness, ataxia, seizures 3
• Hyponatremia increases fall risk - 21% of hyponatremic patients present with falls compared to 5% of normonatremic patients 2

Admission Criteria

• Admit patients with sodium of 126 mmol/L if any of the following are present:

  • Symptomatic presentation (especially neurological symptoms) 1
  • Rapid onset (<48 hours) 1
  • Severe hyponatremia (<120 mmol/L) 1, 3
  • Underlying conditions requiring close monitoring (cirrhosis, heart failure, neurosurgical conditions) 1
  • Inability to tolerate oral intake 1

• Outpatient management may be appropriate if:

  • Patient is asymptomatic 1, 4
  • Chronic, stable hyponatremia 1
  • No risk factors for rapid deterioration 1
  • Reliable follow-up is available 1

Treatment Approach Based on Volume Status

• Determine volume status to guide treatment (hypovolemic, euvolemic, or hypervolemic) 1, 5
• For hypovolemic hyponatremia:
  • Discontinue diuretics 1
  • Administer isotonic saline for volume repletion 1, 3
• For euvolemic hyponatremia (SIADH):
  • Fluid restriction to 1 L/day 1, 6
  • Consider oral sodium chloride 100 mEq three times daily if needed 6
• For hypervolemic hyponatremia:
  • Fluid restriction to 1-1.5 L/day 1
  • Consider albumin infusion in cirrhotic patients 1

Monitoring and Safety Considerations

• Correction rate should not exceed 8 mmol/L in 24 hours to prevent osmotic demyelination syndrome 1, 7
• Monitor serum sodium every 4-6 hours during initial correction 6
• Watch for signs of overcorrection, especially with diuresis 8
• For severe symptoms requiring 3% hypertonic saline, ICU admission is necessary 1

Special Considerations

• Distinguish between SIADH and Cerebral Salt Wasting in neurosurgical patients, as treatment approaches differ significantly 1
• Avoid fluid restriction in patients with cerebral salt wasting as this can worsen outcomes 1
• Patients with advanced liver disease, alcoholism, or malnutrition require more cautious correction rates (4-6 mmol/L per day) 1

Common Pitfalls to Avoid

• Failing to recognize and treat the underlying cause 1
• Overly rapid correction leading to osmotic demyelination syndrome 1, 7
• Inadequate monitoring during active correction 1
• Using fluid restriction in cerebral salt wasting 1
• Misdiagnosing volume status leading to inappropriate treatment 1