What is the management for a patient with severe hyponatremia (sodium level of 114 mmol/L)?

Management of Severe Hyponatremia (Sodium 114 mmol/L)

For a patient with severe hyponatremia (sodium 114 mmol/L), immediately assess symptom severity: if severe neurological symptoms are present (seizures, altered mental status, coma), administer 3% hypertonic saline with a target correction of 6 mmol/L over 6 hours or until symptoms resolve, but never exceed 8 mmol/L total correction in 24 hours to prevent osmotic demyelination syndrome. 1

Immediate Assessment Required

Determine symptom severity first - this dictates urgency of treatment:

• Severe symptoms (seizures, coma, altered mental status, respiratory distress) = medical emergency requiring immediate hypertonic saline 1, 2
• Mild/moderate symptoms (nausea, headache, weakness) = less urgent, allows time for diagnostic workup 1, 2
• Asymptomatic = focus on underlying cause and gradual correction 1

Assess volume status through physical examination:

• Hypovolemic signs: orthostatic hypotension, dry mucous membranes, decreased skin turgor, tachycardia 1
• Euvolemic: no edema, normal blood pressure, moist mucous membranes 1
• Hypervolemic: peripheral edema, ascites, jugular venous distention, pulmonary congestion 1

Emergency Treatment for Severe Symptoms

If severe neurological symptoms are present:

• Administer 3% hypertonic saline immediately as 100 mL boluses over 10 minutes 1, 2
• Can repeat up to 3 times at 10-minute intervals until symptoms improve 1
• Target: increase sodium by 6 mmol/L over first 6 hours 1, 3
• Absolute limit: do not exceed 8 mmol/L correction in 24 hours 1, 3, 4
• Check sodium levels every 2 hours during initial correction 1
• Consider ICU admission for close monitoring 1

Treatment Based on Volume Status (After Stabilization)

Hypovolemic Hyponatremia

• Discontinue diuretics immediately 1
• Administer isotonic saline (0.9% NaCl) for volume repletion 1
• Urine sodium typically <30 mmol/L suggests hypovolemia 1
• Once euvolemic, reassess and adjust management 1

Euvolemic Hyponatremia (SIADH)

• Fluid restriction to 1 L/day is cornerstone of treatment 1
• If no response, add oral sodium chloride 100 mEq three times daily 1
• For resistant cases, consider tolvaptan 15 mg once daily (start low, titrate carefully) 1, 5
• Monitor for overly rapid correction with vaptans 5

Hypervolemic Hyponatremia (Heart Failure, Cirrhosis)

• Fluid restriction to 1-1.5 L/day 1
• Temporarily discontinue diuretics if sodium <125 mmol/L 1
• For cirrhosis: consider albumin infusion alongside fluid restriction 1
• Avoid hypertonic saline unless life-threatening symptoms present (worsens fluid overload) 1

Critical Correction Rate Guidelines

Standard patients:

• Maximum 8 mmol/L per 24 hours 1, 3, 4
• No more than 18 mmol/L per 48 hours 3

High-risk patients (cirrhosis, alcoholism, malnutrition, prior encephalopathy):

• More cautious: 4-6 mmol/L per day maximum 1, 4
• These patients have significantly higher risk of osmotic demyelination syndrome 1

Monitoring Protocol

• Severe symptoms: check sodium every 2 hours initially 1
• After symptom resolution: check every 4 hours 1
• Once stable: daily monitoring until target reached 1
• Watch for signs of osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) typically appearing 2-7 days after rapid correction 1

Management of Overcorrection

If sodium increases >8 mmol/L in 24 hours:

• Immediately discontinue current fluids 1
• Switch to D5W (5% dextrose in water) 1
• Consider desmopressin to slow or reverse rapid rise 1, 4
• This intervention may prevent osmotic demyelination syndrome 1, 4

Common Pitfalls to Avoid

• Never use fluid restriction as initial treatment for severe symptomatic hyponatremia - this is a medical emergency requiring hypertonic saline 1
• Never exceed 8 mmol/L correction in 24 hours in chronic hyponatremia (>48 hours duration) 1, 3
• Never use hypertonic saline in hypervolemic hyponatremia without life-threatening symptoms (worsens edema/ascites) 1
• Never ignore mild hyponatremia - even levels of 130-135 mmol/L increase fall risk and mortality 1, 6
• Inadequate monitoring during active correction leads to overcorrection and potential osmotic demyelination 1