Noradrenaline Dosing for Shock

Initial Dosing Parameters

The American College of Critical Care Medicine recommends starting noradrenaline at 0.1-0.5 mcg/kg/min, titrated to achieve a mean arterial pressure (MAP) of 65 mmHg, in a 70 kg adult, which translates to approximately 0.5 mg/h when using standard concentration preparations 1
The initial dosing is based on a strong recommendation from the Surviving Sepsis Campaign guidelines, which emphasizes the importance of adequate fluid resuscitation with at least 30 mL/kg crystalloid bolus before or concurrent with norepinephrine initiation 1

The Surviving Sepsis Campaign guidelines strongly recommend administering a minimum 30 mL/kg crystalloid bolus before or concurrent with norepinephrine initiation, as vasoconstriction in hypovolemic patients causes severe organ hypoperfusion despite "normal" blood pressure 1

Central venous access is strongly preferred to minimize extravasation risk and tissue necrosis, and an arterial catheter should be placed as soon as practical for continuous blood pressure monitoring 1
Blood pressure and heart rate should be monitored every 5-15 minutes during initial titration, and tissue perfusion markers such as lactate clearance, urine output, mental status, and capillary refill should be assessed 1

The dose should be increased by 0.5 mg/h every 4 hours as needed, to a maximum of 3 mg/h, targeting MAP ≥65 mmHg, with individualized targets based on chronic hypertension status 1
Titration should be guided by MAP ≥65 mmHg, normalization of capillary refill, age-appropriate heart rate, urine output >50 mL/h for at least 4 hours, and lactate clearance ≥10% from baseline 1

When norepinephrine reaches 0.25 mcg/kg/min and hypotension persists, vasopressin 0.03 units/min should be added as second-line therapy, based on the VASST trial, which showed that patients requiring ≥15 mcg/min of norepinephrine had significantly elevated mortality 1, 2

In pregnant patients, noradrenaline should be started at 0.02 mcg/kg/min with a target MAP of 65 mmHg, and more restrictive initial fluid boluses of 1-2 L should be considered due to lower colloid oncotic pressure and higher pulmonary edema risk 1
In pediatric patients, noradrenaline should be started at 0.1 mcg/kg/min, titrating to desired clinical effect, with a typical range of 0.1-1.0 mcg/kg/min, and maximum doses up to 5 mcg/kg/min may be necessary in some children 1

Dopamine should not be used as first-line therapy, as it is associated with higher mortality and more arrhythmias compared to norepinephrine, and should only be used in highly selected patients with absolute bradycardia and low risk of tachyarrhythmias 2, 3
Phenylephrine should not be used as first-line therapy, as it may raise blood pressure while worsening tissue perfusion, and should be reserved for specific circumstances such as norepinephrine-induced serious arrhythmias or salvage therapy when other agents have failed 2, 3

If extravasation occurs, phentolamine 5-10 mg diluted in 10-15 mL of saline should be infiltrated intradermally at the site to prevent tissue necrosis, with a pediatric dose of 0.1-0.2 mg/kg up to 10 mg 1