How should I manage a patient with severe hypernatremia (serum sodium 162 mmol/L) who is taking Laxis (alprazolam)?

Management of Severe Hypernatremia in a Patient on Lasix (Furosemide)

Immediately discontinue the furosemide and begin aggressive free water replacement with hypotonic fluids, targeting a correction rate no faster than 8-10 mmol/L per 24 hours to prevent cerebral edema. 1

Immediate Actions

Stop the loop diuretic immediately – furosemide is likely contributing to ongoing free water losses and worsening the hypernatremia through excessive urinary water excretion relative to sodium. 2, 3

Assess volume status and underlying cause:

• Check for signs of dehydration: dry mucous membranes, decreased skin turgor, orthostatic hypotension, tachycardia 4, 5
• Review medication list for other contributing agents
• Evaluate for diabetes insipidus if polyuria is present despite hypernatremia 4, 3
• Assess patient's access to water and ability to drink (impaired thirst mechanism, altered mental status, restricted mobility) 5

Fluid Replacement Strategy

Calculate the free water deficit using the formula: Water deficit (L) = 0.6 × body weight (kg) × [(current Na/140) - 1] 4

Choose hypotonic fluids for replacement:

• Use 5% dextrose in water (D5W) or 0.45% saline for correction 4, 3
• D5W is preferred as it provides pure free water without additional osmotic load 1
• Avoid isotonic saline (0.9% NaCl) as it will worsen hypernatremia 3

Administer fluids at a controlled rate:

• Target correction of no more than 8-10 mmol/L per 24 hours for chronic hypernatremia (>48 hours duration) 1, 3, 5
• For acute hypernatremia (<24 hours), faster correction may be tolerated, but close monitoring is still essential 3
• Replace half the calculated deficit over the first 24 hours, then the remainder over the next 24-48 hours 4

Critical Monitoring

Check serum sodium every 2-4 hours initially during active correction to ensure you're not correcting too rapidly or too slowly 4, 5

Monitor for signs of cerebral edema if correction occurs too rapidly: headache, nausea, vomiting, seizures, altered mental status 3, 6

Track ongoing losses: measure urine output and insensible losses (typically 500-1000 mL/day) and replace these in addition to the calculated deficit 4, 5

Special Considerations

If the patient has impaired consciousness or cannot drink:

• Intravenous hypotonic fluid replacement is mandatory 6, 5
• Consider nasogastric tube for water administration if IV access is limited 5

If diabetes insipidus is suspected (high urine output with dilute urine despite hypernatremia):

• Consider desmopressin (DDAVP) administration 4, 3
• This is particularly important if hypernatremia persists despite adequate free water replacement

For severe hypernatremia (>152 mmol/L) with inadequate response to fluid replacement:

• Hemodialysis may be considered for rapid correction in acute cases (<24 hours) 7
• However, be extremely cautious as dialysis can drop sodium too rapidly (>20 mmol/L in 2 hours has been reported) 7
• Close monitoring during dialysis is essential to prevent overcorrection 3

Common Pitfalls to Avoid

Do not correct chronic hypernatremia too rapidly – exceeding 8-10 mmol/L per day risks cerebral edema from rapid osmotic shifts 1, 3, 5

Do not use isotonic saline – this delivers excessive sodium and can paradoxically worsen hypernatremia 3

Do not delay treatment while pursuing extensive diagnostic workup – begin correction immediately while investigating the cause 4

Do not restart the furosemide until eunatremia is achieved and the underlying cause is addressed 2

Do not rely solely on calculations – frequent sodium monitoring is essential as actual correction rates often differ from predicted rates 5

Underlying Cause Management

Once stabilized, investigate why the patient developed hypernatremia on furosemide:

• Was the diuretic dose excessive? 2
• Does the patient have inadequate water intake or impaired thirst? 5
• Is there an underlying condition (heart failure, cirrhosis) that led to diuretic use? 2
• Consider alternative diuretic strategies or lower doses once sodium normalizes 2