What is the starting dose of norepinephrine for a 70kg patient with hypotension?

Norepinephrine Drip Dosage for 70kg Patient with Hypotension

For a 70kg patient with hypotension, the recommended starting dose of norepinephrine is 0.05-0.1 μg/kg/min, which equates to approximately 3.5-7 μg/min. 1, 2

Preparation and Administration

• Dilute 8mg of norepinephrine in 92mL of normal saline (NS) to create a concentration of 8mg/100mL (80 μg/mL) 2
• Administer through a central venous line whenever possible to prevent tissue necrosis from extravasation 1
• For a 70kg patient with hypotension, initial infusion rate should be 2-3 mL/hour (2.7-4 μg/min) based on the concentration above 2

Titration Guidelines

• After observing the response to the initial dose, adjust the rate to establish and maintain a low normal blood pressure (usually 80-100 mmHg systolic) 2
• Target mean arterial pressure (MAP) of 65-100 mmHg to ensure vital organ perfusion 1
• Average maintenance dose typically ranges from 2-4 μg/min (0.03-0.06 μg/kg/min for a 70kg patient) 2
• Titrate according to patient response; great individual variation occurs in dose requirements 2

Dosing Considerations

• For severe hypotension (systolic BP ≤70 mmHg), higher initial doses may be required 1
• In previously hypertensive patients, raise blood pressure no higher than 40 mmHg below the preexisting systolic pressure 2
• Doses >0.4 μg/kg/min (>28 μg/min for a 70kg patient) are considered high-dose and associated with increased mortality 3
• Dosing ranges can be categorized as:
  • Low: <0.2 μg/kg/min (<14 μg/min for 70kg) 3
  • Intermediate: 0.2-0.4 μg/kg/min (14-28 μg/min for 70kg) 3
  • High: >0.4 μg/kg/min (>28 μg/min for 70kg) 3

Monitoring Requirements

• Continuous hemodynamic monitoring is essential during administration 1
• Monitor for signs of extravasation; if it occurs, infiltrate 5-10 mg of phentolamine diluted in 10-15 mL of saline into the site 1
• Assess peripheral perfusion regularly (skin temperature, capillary refill) 1

Important Precautions

• Always correct volume depletion before or concurrently with norepinephrine administration 1, 2
• If blood pressure remains inadequate despite increasing doses, consider adding a second vasopressor agent 1
• Avoid abrupt withdrawal; reduce infusion gradually when discontinuing 2
• For refractory hypotension, consider escalating the dose (doubling the bolus dose) or adding alternative vasopressors 4

Clinical Pearls

• Weight-based dosing may not be necessary in obese patients, as they typically require similar absolute doses but lower weight-based doses compared to non-obese patients 5, 6
• Early administration of norepinephrine may be beneficial in profound hypotension, especially with low diastolic pressure (≤40 mmHg) 7
• Norepinephrine is approximately 13 times more potent than phenylephrine when administered as an infusion 8