What is the appropriate rate of D5 (Dextrose 5%) and water administration for a patient with hypernatremia?

D5W Administration Rate for Hypernatremia Management

For patients with hypernatremia, D5W (5% dextrose in water) should be administered at a rate calculated to correct serum sodium at no more than 8 mEq/L per day, with an initial rate of 25-30 mL/kg/24 hours in adults as maintenance fluid. 1

Rationale for Using D5W in Hypernatremia

D5W is the preferred fluid for hypernatremia treatment because:

• It provides free water without adding sodium load
• The dextrose is metabolized, leaving only water behind
• It creates no renal osmotic load, allowing for gradual sodium correction 1
• It avoids the risk of worsening hypernatremia that can occur with sodium-containing solutions 1

Calculation of Administration Rate

Initial Rate for Adults:

• Start with maintenance rate: 25-30 mL/kg/24 hours 1
• Example: For a 70 kg adult, initial rate would be 1,750-2,100 mL/24 hours

Adjustment Factors:

1. Severity of hypernatremia
2. Rate of development (acute vs. chronic)
3. Clinical symptoms
4. Ongoing losses

Maximum Correction Rate:

• Sodium correction should not exceed 8 mEq/L/day to prevent neurological complications 1, 2
• More cautious correction (≤6 mEq/L/day) is recommended for chronic hypernatremia (>48 hours)

Monitoring Requirements

• Check serum sodium levels every 2-4 hours initially
• Monitor clinical status, neurological condition, and fluid balance continuously 1
• Track body weight daily
• Adjust rate based on sodium correction achieved

Special Considerations

For Pediatric Patients:

Calculate maintenance fluid requirements based on weight:

• First 10 kg: 100 mL/kg/24 h
• 10-20 kg: Add 50 mL/kg/24 h
• Remaining weight: Add 20 mL/kg/24 h 1

For Patients with Comorbidities:

• Heart Failure: Monitor closely for fluid overload
• Renal Failure: May require slower infusion rates
• Diabetes: Monitor blood glucose frequently as D5W provides glucose load

Pitfalls to Avoid

1. Too rapid correction: Can lead to cerebral edema and neurological damage
2. Using sodium-containing solutions: NaCl 0.9% should be avoided as it increases renal osmotic load 1
3. Inadequate monitoring: Failure to check sodium levels frequently can lead to under or overcorrection
4. Not accounting for ongoing losses: Additional free water may be needed to replace continuing losses

Alternative Approaches

For patients with severe hypernatremia who cannot tolerate large fluid volumes:

• Consider adding desmopressin to reduce free water losses 3
• In patients on renal replacement therapy, consider adding calculated amounts of D5W prefilter to prevent overcorrection 4

Remember that the goal is gradual correction of hypernatremia while addressing the underlying cause. Rapid correction can lead to serious neurological complications including cerebral edema.