What is the appropriate D5W (5% Dextrose in Water) rate to correct hyponatremia from overcorrection?

D5W Rate for Correcting Overcorrection of Hyponatremia

To correct hyponatremia from overcorrection (sodium level from 133 to 124), administer D5W (5% dextrose in water) to relower sodium levels while ensuring the correction rate does not exceed 8 mmol/L in 24 hours. 1, 2

Assessment of Overcorrection

• Overcorrection is defined as a sodium correction rate exceeding 8 mmol/L in 24 hours, which puts the patient at risk for osmotic demyelination syndrome (ODS) 1
• Immediately discontinue any current fluids that may be contributing to the overcorrection 1
• Calculate the desired decrease in sodium (from 133 to 124 = 9 mmol/L) 1

D5W Administration Protocol

• Administer D5W to relower sodium levels back to a safe correction range 3
• Calculate the D5W rate using the formula: Desired decrease in Na (mEq/L) × (0.5 × ideal body weight in kg) 1
• For example, for a 70 kg patient requiring a 9 mmol/L decrease:
  • D5W volume needed = 9 mmol/L × (0.5 × 70 kg) = 315 mL 1
  • This can be administered over 6-8 hours, with close monitoring 1, 4

Adjunctive Therapy

• Consider adding desmopressin (1-2 μg parenterally every 6-8 hours) concurrently with D5W to prevent further water diuresis that could worsen the situation 5, 4
• This combination therapy has been shown to effectively and safely relower sodium levels without complications 4

Monitoring Requirements

• Monitor serum sodium levels every 2-4 hours during active correction 1, 2
• Adjust D5W rate based on sodium level response 1
• Target a correction rate that brings the total 24-hour change to no more than 8 mmol/L from the starting point 1, 6

Special Considerations

• Patients with advanced liver disease, alcoholism, malnutrition, or prior encephalopathy require even more cautious correction (4-6 mmol/L per day) 1
• Watch for signs of osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) which typically occur 2-7 days after rapid correction 1, 7

Common Pitfalls to Avoid

• Inadequate monitoring during active correction can lead to under or overcorrection 1
• Failing to recognize and address the underlying cause of the initial hyponatremia 1
• Not adjusting the D5W rate based on the patient's response 1, 3
• Delaying treatment of overcorrection, which increases the risk of osmotic demyelination syndrome 7, 5