How to administer intravenous (IV) noradrenaline (norepinephrine) for hypotension?

How to Administer Intravenous Noradrenaline (Norepinephrine)

Norepinephrine should be administered as a continuous infusion via central venous access when possible, but can be safely given through a large-bore peripheral IV for short durations (<24 hours) at low doses with strict monitoring protocols. 1, 2

Preparation and Concentration

• Standard concentration: Add 4 mg norepinephrine to 250 mL D5W to yield 16 μg/mL 1
• Alternative concentration for anaphylaxis: Add 1 mg norepinephrine to 100 mL saline (1:100,000 solution) 1
• Pediatric "rule of 6": 0.6 × body weight (kg) = number of milligrams diluted to total 100 mL saline; then 1 mL/h delivers 0.1 μg/kg/min 1

Dosing

• Initial adult dose: Start at 0.5 mg/h (approximately 0.1-0.5 μg/kg/min) 1, 3
• Titration: Increase by 0.5 mg/h every 4 hours as needed, up to maximum 3 mg/h 1
• Pediatric dosing: 0.1-1.0 μg/kg/min starting dose, may require up to 5 μg/kg/min in some cases 1
• Anaphylaxis dosing: 30-100 mL/h (5-15 μg/min) of 1:100,000 solution 1

Route of Administration

Central Venous Access (Preferred)

• Central line is preferred to minimize extravasation risk 1, 2
• Use when prolonged infusion (>24 hours) or high doses are anticipated 1

Peripheral IV Access (Acceptable Alternative)

• Can be used safely for low-dose, short-duration (<24 hours) infusions 1, 4, 5, 6
• Requires large-bore vein (18-20 gauge preferred) 1
• Recent evidence shows extravasation occurs in only 2-3.4% of cases with no major tissue injury when protocols are followed 4, 6, 7
• Intraosseous access is acceptable when IV access is unavailable during resuscitation 3

Critical Pre-Administration Requirements

Address hypovolemia FIRST before starting norepinephrine - give fluid boluses (10-20 mL/kg crystalloid) to optimize cardiac output, as vasoconstriction in hypovolemic patients causes severe organ hypoperfusion despite "normal" blood pressure 2, 8

Monitoring Protocol

Initial Titration Phase

• Blood pressure and heart rate every 5-15 minutes during initial titration 1, 8
• Continuous cardiac monitoring essential due to arrhythmia risk 2
• For peripheral IV: check insertion site every 2 hours for signs of extravasation 1, 5

Ongoing Monitoring

• Assess for adequate tissue perfusion: capillary refill, urine output >50 mL/h, mental status 1
• Monitor extremities for signs of ischemia (coldness, pallor, decreased pulses) in susceptible patients 2
• Verify blood return from IV site regularly 5

Management of Extravasation

If extravasation occurs, immediately infiltrate the affected area with phentolamine 1, 3, 2:

• Adults: 5-10 mg phentolamine diluted in 10-15 mL of 0.9% saline, injected intradermally into ischemic area using fine needle 2
• Pediatrics: 0.1-0.2 mg/kg (up to 10 mg) phentolamine diluted in 10 mL saline 1
• Must be given within 12 hours for maximal effectiveness 2
• Apply local nitroglycerin paste as adjunct therapy 7

Important Precautions

Contraindications and Warnings

• Avoid in mesenteric or peripheral vascular thrombosis - may extend infarction 2
• Do not mix with sodium bicarbonate or alkaline solutions in IV line (causes inactivation) 1
• Contains sodium metabisulfite - may cause allergic reactions in susceptible patients, especially asthmatics 2

Discontinuation

• Never stop abruptly - gradually reduce infusion rate while expanding blood volume with IV fluids to prevent rebound hypotension 2

Special Clinical Scenarios

• For anaphylaxis: Only use after failure of multiple epinephrine injections and volume resuscitation 1
• Beta-blocker toxicity: Norepinephrine is more effective than dopamine for hypotension 8
• Cardiac arrest: High-dose IV norepinephrine (1-10 mg/min infusion) may be used for refractory arrest 8

Common Pitfalls to Avoid

• Starting norepinephrine before adequate fluid resuscitation leads to worsened organ perfusion 2
• Using small peripheral veins increases extravasation risk - always use large-bore access 1
• Failing to check peripheral IV sites frequently (every 2 hours minimum) 5
• Delaying phentolamine administration after extravasation reduces its effectiveness 2
• Mixing with incompatible solutions like sodium bicarbonate 1