Initiating Noradrenaline (Norepinephrine) in Septic Shock
Norepinephrine should be initiated as the first-choice vasopressor in septic shock patients, with an initial target mean arterial pressure (MAP) of 65 mmHg, administered through a central venous catheter and titrated based on continuous arterial blood pressure monitoring. 1, 2, 3
Preparation and Administration
- Dilute norepinephrine before administration: add 4 mg (4 mL) to 1,000 mL of 5% Dextrose Injection or sodium chloride solutions containing 5% dextrose to produce a 4 mcg/mL solution 4
- Administer through a central venous catheter into a large vein (avoid leg veins in elderly or patients with occlusive vascular disease) 4
- Place an arterial catheter as soon as practical for continuous blood pressure monitoring 3, 5
- Ensure adequate fluid resuscitation before or concurrent with vasopressor initiation (at least 30 mL/kg of IV crystalloid fluid within the first 3 hours) 1, 5
Initial Dosing and Titration
- Begin with an initial dose of 8-12 mcg per minute via intravenous infusion 4
- Monitor blood pressure every 2 minutes until desired hemodynamic effect is achieved, then every 5 minutes for the duration of the infusion 4
- Titrate to maintain a MAP of at least 65 mmHg 1, 2, 3
- Typical maintenance intravenous dosage is 2-4 mcg per minute 4
- Higher MAP targets (80-85 mmHg) may be considered in patients with chronic hypertension 5
Monitoring and Assessment
- Continuously monitor arterial blood pressure 3, 5
- Assess tissue perfusion through multiple parameters: blood lactate concentrations, skin perfusion, mental status, and urine output 1
- Consider measuring cardiac output when using vasopressors to ensure adequate tissue perfusion 5
Management of Refractory Hypotension
- If target MAP cannot be achieved with maximum doses of norepinephrine, add vasopressin (0.01-0.03 U/min, up to 0.03 U/min) 1, 3, 5
- Early addition of vasopressin (within 3 hours) may lead to faster shock resolution 6
- Epinephrine can be added as an alternative second agent when norepinephrine and vasopressin are insufficient 1, 3
- Dopamine should only be used as an alternative to norepinephrine in highly selected patients with low risk of tachyarrhythmias or with bradycardia 1, 5
- Phenylephrine is not recommended except in specific circumstances (e.g., when norepinephrine causes serious arrhythmias) 1, 2
Discontinuation
- When discontinuing the infusion, reduce the flow rate gradually 4
- Avoid abrupt withdrawal to prevent rebound hypotension 4
- Continue fluid resuscitation while weaning vasopressors 1
Important Considerations and Pitfalls
- Correct hypovolemia before or during norepinephrine therapy; if patient doesn't respond to therapy, suspect occult hypovolemia 4
- Norepinephrine has been shown to be superior to dopamine with lower rates of arrhythmias and improved mortality 1, 7
- Store diluted norepinephrine solution for up to 24 hours at room temperature and protect from light 4
- Avoid contact with iron salts, alkalis, or oxidizing agents 4
- Whole blood or plasma, if indicated to increase blood volume, should be administered separately 4