Calculating D50 Addition to D5NSS to Create D10NSS
To convert D5NSS to D10NSS, add 100 mL of D50 (50% dextrose) to each 900 mL of D5NSS, creating a final 1000 mL volume of D10NSS.
Mathematical Formula
The calculation follows a simple dilution equation where you need to increase the dextrose concentration from 5% to 10%:
- For every 1000 mL of final D10NSS solution:
- Use 900 mL of D5NSS (contributing 45g dextrose)
- Add 100 mL of D50 (contributing 50g dextrose)
- Final result: 1000 mL containing 95g dextrose ≈ 10% solution
Alternative Calculation Method
Volume of D50 needed = (Desired % - Starting %) / (D50% - Desired %) × Final Volume
- (10% - 5%) / (50% - 10%) × 1000 mL = 5/40 × 1000 = 125 mL D50 per 1000 mL final volume
- However, this requires removing 125 mL from the original D5NSS bag first
Practical Clinical Application
The most practical approach in clinical practice:
- Remove 100 mL from a 1000 mL bag of D5NSS
- Add 100 mL of D50 to the remaining 900 mL
- This creates approximately D10NSS (actually 9.5%, which is clinically acceptable)
Important Clinical Context
While this calculation is straightforward, the clinical use of D10-containing fluids has specific indications:
- D10-containing fluids are typically used during diabetic ketoacidosis treatment at 4-14 mL/kg/hour once serum glucose reaches 200-250 mg/dL 1, 2
- Standard maintenance D5W infusion runs at approximately 100 mL/hour for average adults 1, 2
- When treating hypoglycemia, titrated D50 boluses (5-10 gram aliquots) are preferred over continuous high-concentration dextrose infusions 3