Low Dose Norepinephrine in 500 ml Dextrose
The low dose of norepinephrine in 500 ml dextrose is 4 mg (4 mL) of norepinephrine added to 500 ml of dextrose solution, creating a concentration of 8 mcg/mL. 1
Preparation of Norepinephrine Solution
According to the FDA drug label, norepinephrine should be diluted in dextrose-containing solutions prior to infusion:
- Standard dilution: Add 4 mg (4 mL) of norepinephrine to 500 ml of 5% dextrose solution
- This creates a concentration of 8 mcg/mL (compared to 4 mcg/mL when diluted in 1000 mL)
- Dextrose-containing solutions provide protection against significant loss of potency due to oxidation 1
- Administration in saline solution alone is not recommended
Administration Guidelines
- Initial dosing typically starts at 0.1-0.5 mcg/kg/min with careful monitoring of blood pressure response 2
- Target mean arterial pressure (MAP) of 65 mmHg as recommended by the Surviving Sepsis Campaign 3
- Administer through a large vein, preferably via a central venous catheter to reduce risk of extravasation 1
- An IV drip chamber or other suitable metering device is essential to permit accurate flow rate monitoring 1
Dosage Titration
- After observing the response to an initial dose of 2-3 mL/min (16-24 mcg/min), adjust the rate to establish and maintain adequate blood pressure 1
- Average maintenance dose ranges from 0.5-1 mL/min (4-8 mcg/min) 1
- Dosage should be titrated according to the patient's response, with great individual variation in requirements 1
- For previously hypertensive patients, blood pressure should be raised no higher than 40 mmHg below the preexisting systolic pressure 1
Important Considerations
- Blood volume depletion should always be corrected as fully as possible before vasopressor administration 1
- Monitor for potential adverse effects including tachyarrhythmias, increased myocardial oxygen consumption, and tissue necrosis if extravasation occurs 2, 4
- Weight-based dosing may not be necessary in obese patients, as they typically require lower weight-based doses but similar total doses compared to non-obese patients 5, 6
- Reduce infusion gradually when discontinuing to avoid abrupt withdrawal 1
Special Situations
- In profound, life-threatening hypotension, early administration of norepinephrine simultaneously with fluid resuscitation may be beneficial 7
- Higher concentrations may be necessary when large volumes of fluid are clinically undesirable 1
- More dilute solutions should be used when large volumes of fluid are needed at a flow rate that would involve excessive pressor doses 1
By following these guidelines for low-dose norepinephrine preparation in 500 ml dextrose, clinicians can effectively manage hypotension while minimizing risks associated with vasopressor therapy.