Norepinephrine Starting Dose for Shock Treatment
The recommended starting dose of norepinephrine for treating shock is 0.05-0.1 μg/kg/min, which should be titrated by 0.05-0.1 μg/kg/min every 5-15 minutes to achieve a target mean arterial pressure (MAP) ≥65 mmHg. 1
Dosing Guidelines and Administration
Initial Dosing
- Start at 0.05-0.1 μg/kg/min 1
- Administer via central venous access when possible
- Can be safely administered through peripheral venous access or intraosseous route for short periods (up to 3-4 hours) in emergency situations 2
Titration
- Increase by 0.05-0.1 μg/kg/min every 5-15 minutes 1
- Titrate to achieve:
- MAP ≥65 mmHg (primary target)
- Adequate urine output (≥0.5 mL/kg/hr)
- Improved tissue perfusion
- Decreased serum lactate
Maximum Dosing
- Clinical studies show that doses up to 2.5 ± 2.2 μg/kg/min may be required in severe cases 2
- Doses above 1 μg/kg/min are associated with mortality rates over 80%, suggesting need for adjunctive therapies 3
Timing of Administration
Early administration of norepinephrine is beneficial for patients with shock:
- Profound and durable hypotension is an independent factor of increased mortality 4
- Early norepinephrine administration increases cardiac output and improves microcirculation 4
- It helps avoid excessive fluid administration and potential fluid overload 4, 5
- Early administration is associated with higher shock control rates by 6 hours (76.1% vs 48.4%) 6
Refractory Shock Management
When shock is refractory to norepinephrine:
- Consider adding vasopressin at a fixed dose of up to 0.03 U/min 1
- Vasopressin is particularly useful as it acts on different vascular receptors than α1-adrenergic receptors 4
- Epinephrine may be considered as an additional agent, particularly with evidence of myocardial depression 1
Monitoring During Administration
- Establish arterial line monitoring when using vasopressors 1
- Monitor:
- Blood pressure (continuous)
- Heart rate
- Urine output
- Skin perfusion
- Mental status
- Lactate clearance
- Renal and liver function tests 1
- Watch for adverse effects:
- Arrhythmias
- Hypertension (resolves with dose reduction)
- Tissue ischemia from extravasation
Special Considerations
- In patients with chronic hypertension, consider targeting a higher MAP 4
- For profound hypotension (diastolic BP ≤40 mmHg or diastolic shock index ≥3), consider earlier administration of norepinephrine 5
- Pediatric patients may require higher doses than those suggested in adult literature 2
- Extravascular administration can result in severe skin injury; phentolamine (0.1-0.2 mg/kg up to 10 mg diluted in 10 mL of 0.9% sodium chloride) injected intradermally at extravasation site may help counteract dermal vasoconstriction 7
Remember that norepinephrine should be administered after or simultaneously with appropriate fluid resuscitation, but prolonged hypotension should not be allowed while waiting for fluid resuscitation to restore blood pressure.