What is the recommended initial dose of noradrenaline (norepinephrine) for treating shock, specifically septic shock?

Norepinephrine Dosing for Shock

The recommended initial dose of norepinephrine for treating shock is 0.1-0.5 mcg/kg/min (7-35 mcg/min in a 70-kg adult), with titration to maintain a target mean arterial pressure (MAP) of 65 mmHg. 1

Initial Dosing and Administration

• According to the American College of Critical Care Medicine and the Society of Critical Care Medicine, the initial dose of norepinephrine should be 0.1-0.5 mcg/kg/min 1
• The FDA label recommends starting with 8-12 mcg/min (0.25-0.375 mL/min of standard concentration) and adjusting to maintain blood pressure (usually 80-100 mmHg systolic) 2
• Administration should be through a central venous line whenever possible to avoid tissue necrosis from extravasation 1
• An arterial catheter should be placed for continuous blood pressure monitoring 1

Titration and Maintenance

• Titrate by 0.05-0.1 μg/kg/min every 5-15 minutes to achieve target MAP 1
• The average maintenance dose ranges from 2-4 mcg/min (0.0625-0.125 mL/min) according to the FDA label 2
• Target MAP should be 65 mmHg for most patients, but may need to be higher (75-85 mmHg) in patients with chronic hypertension 1, 3

Timing of Initiation

• Early administration of norepinephrine is beneficial in septic shock 4, 5
• The CENSER trial demonstrated that early norepinephrine administration (at 0.05 μg/kg/min) was associated with better shock control by 6 hours (76.1% vs 48.4%) compared to standard treatment 5
• Early norepinephrine administration may reduce fluid requirements and improve outcomes 4, 5

Monitoring and Precautions

• Monitor for:

  • Tissue perfusion markers (lactate clearance, urine output, skin perfusion, mental status)
  • Renal and liver function
  • Cardiac function, especially in patients with underlying heart disease (risk of arrhythmias)
  • Signs of extravasation 1

• Ensure adequate fluid resuscitation before and during norepinephrine administration, as it is relatively contraindicated in hypovolemia 1

• Use cautiously in patients with ischemic heart disease as it may increase myocardial oxygen requirements 1

Special Considerations

• If extravasation occurs, infiltrate 5-10 mg phentolamine diluted in 10-15 mL saline into the site to prevent tissue necrosis 1
• Norepinephrine has been shown to be superior to other vasopressors in minimizing the occurrence of arrhythmias 6
• For refractory shock, consider adding vasopressin (0.01-0.04 U/min) rather than continuing to escalate norepinephrine doses 1, 3

Common Pitfalls to Avoid

• Delaying norepinephrine initiation in profound shock (e.g., diastolic BP ≤ 40 mmHg) while waiting for fluid resuscitation to be completed 4
• Using peripheral IV access for prolonged norepinephrine administration (increases risk of extravasation)
• Abrupt discontinuation (can cause marked hypotension) - reduce infusion rate gradually 2
• Failure to monitor for and address underlying causes of shock while administering vasopressors 1