What is the initial preparation and dosage for a norepinephrine (vasopressor) drip order?

Norepinephrine Drip Order

Prepare norepinephrine by adding 4 mg to 250 mL of D5W (yielding 16 μg/mL concentration), start the infusion at 8-12 μg/min (2-3 mL/min), and titrate to achieve a mean arterial pressure of 65 mmHg. 1, 2

Standard Preparation

• Add 4 mg of norepinephrine to 250 mL of D5W to create a concentration of 16 μg/mL 1, 3
• Alternative standard concentration: Add 4 mg to 1000 mL of D5W for a 4 μg/mL solution 1
• Do not dilute in saline alone—dextrose-containing solutions are required to prevent oxidation and loss of potency 1
• Solutions remain chemically stable for 7 days at room temperature under ambient light in either D5W or normal saline 4

Initial Dosing

• Start at 8-12 μg/min (equivalent to 2-3 mL/min of the 16 μg/mL solution) 1
• After observing initial response, adjust to maintenance dose of 2-4 μg/min (0.5-1 mL/min) 1
• Typical dosing range for septic shock: 0.1-2 mcg/kg/min 3
• Maximum doses can reach 3 mg/hour or higher if hypotension persists, though occult hypovolemia must be ruled out 1, 3

Critical Pre-Administration Requirements

• Correct hypovolemia with crystalloid boluses (minimum 30 mL/kg) before or concurrent with vasopressor initiation 3, 1
• Vasoconstriction in hypovolemic patients causes severe organ hypoperfusion despite "normal" blood pressure readings 3
• Central venous pressure monitoring helps detect and treat occult volume depletion 1

Administration Route

• Central venous access is strongly preferred to minimize extravasation risk 3, 1
• If central access is unavailable, peripheral IV can be used temporarily with strict site monitoring 3
• Use a large vein with a plastic IV catheter advanced centrally and securely fixed 1
• An IV drip chamber or metering device is essential for accurate flow rate measurement 1

Target Blood Pressure

• Target mean arterial pressure (MAP) of 65 mmHg for septic shock 2, 3
• For previously hypertensive patients, raise blood pressure no higher than 40 mmHg below pre-existing systolic pressure 1
• Alternative targets: systolic blood pressure 80-100 mmHg or increase MAP by 10 mmHg with urine output >50 mL/h 3

Monitoring Protocol

• Monitor blood pressure and heart rate every 5-15 minutes during initial titration 3
• Place arterial catheter as soon as practical for continuous monitoring 2
• Watch for signs of excessive vasoconstriction: cold extremities, decreased urine output, tissue ischemia 3, 1
• Monitor for arrhythmias and hypertension 3

Titration Guidelines

• Titrate dose based on blood pressure response and tissue perfusion 1
• Increase by 0.5 mg/h every 4 hours as needed, up to maximum 3 mg/h 3
• Reduce infusion gradually when discontinuing—avoid abrupt withdrawal 1
• Continue until adequate blood pressure and tissue perfusion are maintained without therapy 1

Extravasation Management

• If extravasation occurs, immediately infiltrate phentolamine 5-10 mg diluted in 10-15 mL saline into the affected site 3, 1
• Pediatric phentolamine dose: 0.1-0.2 mg/kg up to 10 mg 3
• Norepinephrine can cause tissue necrosis and sloughing if extravasation is not promptly treated 3

Important Precautions

• Do not mix norepinephrine with sodium bicarbonate or alkaline solutions—they inactivate the drug 3, 1
• Avoid contact with iron salts, alkalis, or oxidizing agents 1
• Do not use if solution is pinkish, darker than slightly yellow, or contains precipitate 1
• Norepinephrine is the first-choice vasopressor over dopamine, epinephrine, or phenylephrine for initial management 2