How to Write D5NS in a Prescription
Write "D5NS" or "Dextrose 5% in 0.9% Sodium Chloride" clearly on the prescription, specifying the volume, rate, and route of administration.
Standard Prescription Format
When prescribing D5NS (Dextrose 5% in 0.9% Sodium Chloride), include these essential components:
- Solution name: "D5NS" or "5% Dextrose in 0.9% Sodium Chloride" or "D5 0.9% NaCl"
- Volume: Specify total volume (e.g., 1000 mL, 500 mL)
- Rate: State infusion rate (e.g., 125 mL/hr, or calculate based on patient weight)
- Route: "IV" or "Intravenous"
- Duration: If applicable (e.g., "over 24 hours")
Clinical Context from Guidelines
The evidence shows D5NS is used in specific clinical scenarios 1:
For adrenal insufficiency: Guidelines recommend "concomitant fluid bolus of 20 mL/kg of D5NS or D10NS during the first hour of treatment" 1. This would be written as:
- D5NS 20 mL/kg IV bolus over 1 hour
For maintenance fluids: When dextrose-containing isotonic fluids are needed, the prescription format follows standard maintenance calculations 2.
Key Prescribing Considerations
Tonicity and Composition
D5NS is isotonic with respect to sodium (154 mEq/L sodium, 154 mEq/L chloride) but becomes hypotonic once dextrose is metabolized 2. The osmolarity is 308 mOsm/L 2.
When to Use D5NS vs Alternatives
Use D5NS when:
- Treating adrenal insufficiency with concurrent hypoglycemia risk 1
- Providing maintenance fluids with glucose supplementation while avoiding hyponatremia
- Patient requires both volume resuscitation and glucose support
Avoid or use cautiously:
- In severe head trauma: Research shows D5NS does not worsen brain edema compared to hypotonic solutions, but monitor closely 3, 4
- When hyperglycemia is a concern: D5NS significantly increases blood glucose (can reach >1200 mg/dL) 3
- In patients at risk for hypernatremia: The high sodium content (154 mEq/L) can contribute to sodium overload 5, 6
Common Pitfalls
Electrolyte monitoring: D5NS increases serum osmolality and can cause hyperchloremia 6. Monitor sodium and chloride levels, especially with prolonged use.
Glucose control: The 5% dextrose component delivers significant glucose load. Research shows blood glucose can exceed 1600 mg/dL with rapid infusion 3. Monitor blood glucose regularly.
Not a balanced solution: Unlike lactated Ringer's, D5NS contains only sodium and chloride without other physiologic electrolytes 2. Consider adding potassium if maintenance therapy extends beyond 24 hours.
Drug compatibility: D5NS is compatible with most medications, unlike pure dextrose solutions which can be incompatible with certain drugs 7.
Example Prescriptions
For maintenance fluids in a child:
- D5NS 1000 mL IV at 42 mL/hr (maintenance rate for 20 kg child)
For adrenal crisis:
- D5NS 400 mL (20 mL/kg for 20 kg patient) IV bolus over 1 hour
For general hydration with glucose support:
- D5NS 1000 mL IV over 8 hours
The prescription must be legible and unambiguous to prevent medication errors, as confusion between different dextrose-saline combinations (D5 0.45% NaCl vs D5 0.9% NaCl) can lead to inappropriate tonicity administration 2, 8.