What is the management for a patient with hyponatremia of 132 mmol/L?

Management of Hyponatremia at 132 mmol/L

For a sodium level of 132 mmol/L, observation with close monitoring is appropriate, as this represents mild hyponatremia that typically does not require active treatment unless symptoms are present or there is an underlying condition requiring intervention. 1

Initial Assessment

Your first step is determining the patient's volume status and symptom severity:

• Assess for symptoms: Even mild hyponatremia can cause nausea, weakness, headache, and mild cognitive deficits 2, 3
• Volume status evaluation: Look specifically for orthostatic hypotension, dry mucous membranes, decreased skin turgor (hypovolemic); peripheral edema, ascites, jugular venous distention (hypervolemic); or absence of these findings (euvolemic) 1
• Obtain key labs: Serum osmolality, urine osmolality, urine sodium, and assess for medications that may contribute (diuretics, antidepressants, SSRIs) 1, 3

Management Based on Clinical Context

If Asymptomatic with No Clear Cause

• Continue current therapy with monitoring of serum electrolytes 1
• No water restriction is needed at this sodium level 1
• Recheck sodium in 1-2 weeks to ensure stability 3

If on Diuretics

• Continue diuretic therapy but monitor serum electrolytes closely 1
• For sodium 126-135 mmol/L with normal creatinine, diuretics can be safely continued 1
• Only discontinue diuretics if sodium drops below 125 mmol/L or if creatinine is elevated 1

If Hypervolemic (Heart Failure, Cirrhosis)

• Fluid restriction is NOT required at 132 mmol/L unless sodium continues to decline 1
• Focus on treating the underlying condition (optimizing heart failure management, managing ascites) 3, 4
• Consider fluid restriction only if sodium drops below 125 mmol/L (restrict to 1-1.5 L/day) 1

If Euvolemic (Possible SIADH)

• Investigate underlying causes: malignancy, pulmonary disease, CNS disorders, medications 2, 3
• Fluid restriction to 1 L/day may be considered if SIADH is confirmed and sodium is trending downward 1, 3
• At 132 mmol/L, observation is often sufficient unless there is active decline 1

Critical Safety Considerations

Never use hypertonic saline at this level unless severe neurological symptoms develop (seizures, altered mental status, coma) 1, 2. A sodium of 132 mmol/L does not meet criteria for emergent correction.

Avoid overly aggressive treatment: The goal is not to normalize sodium rapidly, but to prevent further decline and address underlying causes 1. If correction becomes necessary, never exceed 8 mmol/L increase in 24 hours to prevent osmotic demyelination syndrome 1, 2.

Common Pitfalls to Avoid

• Don't ignore mild hyponatremia completely: Even at 132 mmol/L, there is increased risk of falls (21% vs 5% in normonatremic patients) and cognitive impairment 1, 2
• Don't reflexively restrict fluids: At 132 mmol/L, fluid restriction is rarely indicated and may worsen patient quality of life unnecessarily 1
• Don't stop investigating the cause: Identifying medications (especially diuretics, SSRIs, antidepressants) or underlying conditions (hypothyroidism, adrenal insufficiency) is essential 3, 4

When to Escalate Treatment

Consider more aggressive management if:

• Sodium drops below 130 mmol/L 1
• Patient develops symptoms (confusion, nausea, weakness) 2, 3
• Rapid decline in sodium over 24-48 hours 3
• Underlying high-risk condition (cirrhosis with ascites, severe heart failure) 5

The key principle at 132 mmol/L is watchful waiting with attention to the underlying cause, not aggressive correction. 1, 3