How to administer norepinephrine for hypotension?

Norepinephrine Administration for Hypotension

For hypotension management, norepinephrine should be administered intravenously at an initial rate of 0.1-0.5 mcg/kg/min, titrated to maintain a target mean arterial pressure (MAP) of 65 mmHg, with continuous hemodynamic monitoring. 1

Preparation and Administration

Standard Preparation

• For infusion pump use:

  • Add 1 mg (1 mL) of norepinephrine to 100 mL of normal saline to create a 1:100,000 solution (10 mcg/mL)
  • Initial rate: 30-100 mL/hr (5-15 mcg/min), titrated based on clinical response 2

• Alternative preparation (microdrop method):

  • Add 1 mg (1 mL) of norepinephrine to 250 mL of D5W to yield a 4.0 mcg/mL concentration
  • Infuse at 1-4 mcg/min (15-60 drops/min with microdrop apparatus)
  • Maximum rate: 10 mcg/min for adults and adolescents 2

Pediatric Dosing

• Recommended dose: 0.01 mg/kg (0.1 mL/kg of a 1:10,000 solution; maximum 0.3 mg) 2
• Alternative "rule of 6" dosing: 0.6 × weight (kg) = mg diluted to total 100 mL saline; then 1 mL/hr delivers 0.1 mcg/kg/min 2

Administration Route and Monitoring

Central vs. Peripheral Administration

• Traditionally administered through central venous catheters (CVCs)
• Recent evidence suggests peripheral administration may be safe for:
  • Low doses (<0.5 mcg/kg/min)
  • Short duration (<24 hours)
  • When using proper protocols with vigilant monitoring 3, 4

Required Monitoring

• Continuous arterial blood pressure monitoring is essential 1
• Check IV site every 2 hours for signs of extravasation 3
• Monitor tissue perfusion markers (lactate levels, urine output, capillary refill) 1
• Electrocardiographic monitoring when available 2

Clinical Response Management

Inadequate Response

• If inadequate response after 10 minutes:
  • Escalate norepinephrine dose (doubling the bolus dose) 2
  • Consider starting continuous infusion if more than three boluses needed 2
  • Add vasopressin (up to 0.03 U/min) or epinephrine as second agents 2
  • Consider additional fluid administration up to 20-30 mL/kg 2

Refractory Hypotension

• Add norepinephrine infusion (0.05-0.5 mcg/kg/min) 2
• Consider vasopressin (1-2 IU bolus with or without infusion at 2 units/hr) 2
• For patients on beta-blockers: add IV glucagon (1-2 mg) 2
• Consider extracorporeal life support in extreme cases 2

Complications and Management

Extravasation

• If extravasation occurs, infiltrate the site with 5-10 mg phentolamine diluted in 10-15 mL saline 1
• Monitor for tissue necrosis, which is a serious complication 1

Other Potential Complications

• Supraventricular arrhythmias (7.25 times higher risk compared to vasopressin) 1
• Increased myocardial oxygen consumption (caution in coronary artery disease) 1
• Decreased cardiac output due to increased afterload 1
• Digital ischemia from peripheral vasoconstriction 1

Special Considerations

Drug Interactions

• Never mix with alkaline solutions like sodium bicarbonate (leads to inactivation) 1

Contraindications and Cautions

• Relative contraindication in hypovolemia - correct volume status first 1
• Use with caution in patients with ischemic heart disease 1
• Avoid in patients with mesenteric or peripheral vascular thrombosis 1

By following these guidelines for norepinephrine administration, you can effectively manage hypotension while minimizing the risk of adverse effects and complications.