Noradrenaline in 5% Dextrose: Preparation and Administration
Norepinephrine must be diluted in 5% dextrose (D5W) or 5% dextrose with sodium chloride before administration, as dextrose-containing solutions protect against oxidation and loss of potency. 1
Standard Preparation Protocol
For vasopressor infusion, add 4 mg (4 mL) of norepinephrine to 1,000 mL of D5W to yield a concentration of 4 mcg/mL. 1 This is the FDA-approved standard dilution that balances safety with clinical utility.
Alternative Concentrations
- More concentrated solution: If fluid restriction is necessary, prepare 1 mg (1 mL) in 250 mL D5W for 4 mcg/mL concentration 2
- For infusion pumps: An alternative 1:100,000 solution (1 mg in 100 mL saline or D5W) can be used 2
- The degree of dilution should be adjusted based on clinical fluid volume requirements 1
Dosing Guidelines
Initial Dosing
- Start with 2-3 mL/minute (8-12 mcg/minute) of the 4 mcg/mL solution 1
- Titrate to achieve target MAP of 65 mmHg 3, 4
Maintenance Dosing
- Average maintenance: 0.5-1 mL/minute (2-4 mcg/minute) 1
- For the standard 4 mcg/mL concentration, infuse at 1-4 mcg/min (15-60 drops/minute with microdrop apparatus) 2
- Maximum rate: up to 10 mcg/min 2
High-Dose Considerations
Occasionally, much larger doses (as high as 68 mg base daily) may be necessary if hypotension persists, but always suspect and correct occult blood volume depletion first 1. Central venous pressure monitoring is helpful in this situation.
Critical Administration Requirements
Route and Access
- Administer into a large central vein using a plastic IV catheter well-advanced centrally 1
- Avoid catheter tie-in techniques as they promote stasis 1
- Use an IV drip chamber or metering device for accurate flow rate estimation 1
Blood Pressure Targets
- Target systolic BP: 80-100 mmHg in normotensive patients 1
- In previously hypertensive patients: raise BP no higher than 40 mmHg below pre-existing systolic pressure 1
Important Safety Considerations
Diluent Selection
Do not use saline solution alone - administration in saline without dextrose is not recommended due to rapid oxidation and loss of potency 1. While norepinephrine is stable in both D5W and normal saline for up to 7 days at room temperature 5, the FDA label specifically recommends dextrose-containing solutions for protection against oxidation 1.
Mixing Technique
Critical preparation step: When manually preparing syringes, use the "Bubble-Flip" method (aspirate 5 mL air, then invert) to ensure homogeneous mixing 6. Simple inversion without air or no mixing at all produces dangerous concentration variability (up to 39% within-syringe variation), which can cause hemodynamic instability 6.
Stability and Storage
- Solutions are stable for up to 61 days at 4°C when protected from light 7
- At room temperature (23°C) under ambient light: stable for 7 days 5
- Without light protection: only 90% concentration retained after 39 days 7
Volume Resuscitation First
Blood volume depletion must be corrected as fully as possible before administering norepinephrine 1. The only exception is when intraaortic pressures must be maintained emergently to prevent cerebral or coronary ischemia - in this case, norepinephrine can be given concurrently with volume replacement 1.
Discontinuation
Reduce infusion gradually - avoid abrupt withdrawal 1. Treatment duration varies; some cases of vascular collapse from acute MI have required up to 6 days of therapy 1.
Pediatric Dosing
For children requiring IV epinephrine infusion (similar preparation principles): 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution; maximum 0.3 mg) 2. Alternative "rule of 6": 0.6 × body weight (kg) = mg diluted to 100 mL saline; then 1 mL/h delivers 0.1 mcg/kg/min 2.
Context-Specific Use
Septic Shock
Norepinephrine is the first-choice vasopressor for septic shock 3, 4. Consider adding vasopressin (up to 0.03 U/min) or epinephrine if additional agents are needed 3, 4.
Anaphylaxis
For refractory hypotension in anaphylaxis after epinephrine injections and volume resuscitation, dopamine (400 mg in 500 mL D5W at 2-20 mcg/kg/min) is preferred over norepinephrine 2. Epinephrine infusions in D5W are the primary catecholamine for anaphylaxis 2.