What is the recommended dose of noradrenaline (norepinephrine) for treating severe hypotension or septic shock?

Norepinephrine Dosing in Septic Shock

Start norepinephrine immediately as the first-line vasopressor when septic shock is recognized, targeting a mean arterial pressure (MAP) of 65 mmHg, and administer it via central venous access with continuous arterial blood pressure monitoring. 1, 2

Initial Dosing and Administration

• Norepinephrine is the first-choice vasopressor for septic shock based on superior efficacy and safety compared to all alternatives 3, 1, 2
• Administer via central venous access with continuous arterial blood pressure monitoring 1, 2
• Target MAP of 65 mmHg in most patients; consider higher targets (80-85 mmHg) only in patients with chronic hypertension 1, 4
• Give at least 30 mL/kg IV crystalloid within the first 3 hours before or alongside vasopressor therapy 1, 4

Typical dosing range: While guidelines don't specify exact starting doses, norepinephrine is typically initiated at 0.05-0.1 mcg/kg/min and titrated to effect, with no absolute maximum dose defined in guidelines 3, 1

Timing: Early Administration is Critical

Start norepinephrine early—do not delay for prolonged fluid resuscitation alone. The evidence strongly supports early initiation:

• Early norepinephrine administration (within 93 minutes vs 192 minutes) significantly increases shock control by 6 hours (76.1% vs 48.4%, p<0.001) 5
• Early use increases cardiac output, improves microcirculation, and prevents fluid overload 6, 7, 8
• Prolonged severe hypotension is an independent mortality risk factor 6
• Early norepinephrine reduces cardiogenic pulmonary edema (14.4% vs 27.7%, p=0.004) and new-onset arrhythmia (11% vs 20%, p=0.03) 5

Use low diastolic arterial pressure as a trigger to initiate norepinephrine urgently, as this indicates depressed vascular tone. 8

Escalation for Refractory Hypotension

When target MAP is not achieved with norepinephrine alone:

• Add vasopressin 0.03 units/minute (range 0.01-0.03 units/min, maximum 0.03-0.04 units/min) to raise MAP or decrease norepinephrine requirements 3, 1, 2
• Vasopressin should never be used as the initial single vasopressor 1, 2, 4
• Add epinephrine as an alternative second agent when additional support is needed 3, 1, 4
• Add dobutamine if persistent hypoperfusion exists despite adequate fluid loading and vasopressors, particularly with evidence of myocardial depression 3, 1

High-Dose Norepinephrine

Very high doses of norepinephrine (>4 mcg/kg/min) are safe and effective in catecholamine-resistant septic shock:

• High-dose norepinephrine significantly increases MAP and systemic vascular resistance while decreasing lactate concentrations 9
• Survival rate of 33.4% was achieved in otherwise extremely high mortality patients 9
• Do not arbitrarily cap norepinephrine doses—escalate as needed before adding multiple additional agents 6, 9

Agents to Avoid

• Dopamine should only be used in highly selected patients with low risk of tachyarrhythmias or absolute/relative bradycardia, as it is associated with higher mortality and more arrhythmias compared to norepinephrine 3, 1, 2
• Do not use low-dose dopamine for renal protection—this is strongly discouraged and has no benefit 2, 4
• Phenylephrine is not recommended except when norepinephrine causes serious arrhythmias, cardiac output is known to be high with persistently low blood pressure, or as salvage therapy 1, 2

Monitoring Requirements

• Continuous arterial blood pressure monitoring is essential for all patients on vasopressors 1, 2, 4
• Place arterial catheter as soon as practical 2, 4
• Consider cardiac output monitoring, especially when using pure vasopressors like vasopressin 2, 4
• Monitor lactate clearance, urine output (target ≥0.5 mL/kg/h), mental status, and skin perfusion to complement hemodynamic targets 1, 5

Common Pitfalls

• Do not delay norepinephrine for prolonged fluid resuscitation—early administration improves outcomes 8, 5
• Do not use vasopressin as monotherapy—it must be added to norepinephrine 1, 2, 4
• Do not exceed vasopressin 0.03-0.04 units/minute except for salvage therapy 1, 2
• Avoid excessive vasoconstriction—monitor for digital ischemia, decreased urine output, rising lactate, or worsening organ dysfunction despite adequate MAP 2