What is the standard dose of norepinephrine (NE) for critically ill patients in Australia?

Standard Norepinephrine Dosing in Australia for Critically Ill Patients

The standard dose of norepinephrine for critically ill patients in Australia is 0.05-0.1 μg/kg/min initially, titrated by 0.05-0.1 μg/kg/min every 5-15 minutes to achieve a target mean arterial pressure (MAP) of 65 mmHg. 1

Initial Dosing and Titration

• Starting dose: 0.05-0.1 μg/kg/min
• Titration: Increase by 0.05-0.1 μg/kg/min every 5-15 minutes
• Target: MAP ≥65 mmHg

Clinical Application and Indications

Norepinephrine is the first-choice vasopressor for managing shock, particularly:

• Septic shock: First-line agent as recommended by the Surviving Sepsis Campaign 2
• Cardiogenic shock: Used after adequate fluid resuscitation
• Distributive shock: Effective in restoring vascular tone

Administration Considerations

• Administer via central venous access to minimize risk of extravasation
• Continuous hemodynamic monitoring is essential
• Arterial line placement is recommended for accurate blood pressure monitoring
• Monitor for signs of peripheral ischemia, especially with higher doses

Special Considerations

• In severe hemorrhagic shock with systolic BP <80 mmHg, consider adding vasopressin (up to 0.03 U/min) to reduce norepinephrine requirements 1
• For refractory shock not responding to standard doses, norepinephrine can be increased, but doses >1 μg/kg/min are associated with mortality rates exceeding 80% 3
• Early administration of norepinephrine (simultaneously with fluid resuscitation) may be beneficial in patients with profound hypotension (diastolic BP ≤40 mmHg) 4

Monitoring Parameters

• Blood pressure (target MAP ≥65 mmHg)
• Heart rate
• Urine output (target ≥0.5 mL/kg/h)
• Skin perfusion
• Mental status
• Lactate clearance
• Renal and liver function tests

Potential Complications

• Excessive vasoconstriction leading to organ ischemia
• Tachyarrhythmias
• Extravasation can cause severe skin injury
• Myocardial ischemia, particularly in patients with pre-existing cardiac conditions

Adjunctive Therapies

If norepinephrine alone is insufficient to maintain target MAP:

1. Add vasopressin up to 0.03 U/min 1
2. Consider epinephrine as a second-line agent 2, 1
3. Consider hydrocortisone (up to 300 mg/day) in patients requiring escalating vasopressor doses 1

The early use of norepinephrine in septic shock has been shown to increase shock control rates and may be associated with lower incidences of cardiogenic pulmonary edema and new-onset arrhythmias 5.