What is the recommended dose of noradrenaline (norepinephrine) for a patient in cardiogenic shock?

Norepinephrine Dosing in Cardiogenic Shock

Start norepinephrine at 0.2-1 mcg/kg/min (equivalent to approximately 8-12 mcg/min for a 70 kg patient) only after inotropic therapy and fluid resuscitation have failed to restore systolic blood pressure >90 mmHg with persistent signs of inadequate organ perfusion. 1

Algorithmic Approach to Vasopressor Initiation

Step 1: Optimize Volume Status First

• Administer a fluid challenge of 250 mL over 10 minutes if clinically indicated and no signs of overt fluid overload are present 2, 1
• Do not give fluids if there are signs of volume overload (elevated JVP, pulmonary edema, bibasilar crackles) 3

Step 2: Initiate Inotropic Support

• Start dobutamine at 2-3 mcg/kg/min as first-line inotropic therapy, titrating up to 15-20 mcg/kg/min based on clinical response 4
• Dobutamine is the recommended first-line agent to increase cardiac output in cardiogenic shock 1, 3

Step 3: Add Norepinephrine Only When Necessary

• Add norepinephrine only when the combination of inotropic therapy plus fluid challenge fails to restore systolic blood pressure >90 mmHg with persistent signs of inadequate organ perfusion 2, 1
• This sequential approach is critical because cardiogenic shock is typically associated with high systemic vascular resistance, and premature vasopressor use can increase afterload on an already failing heart, potentially worsening cardiac output 1

Specific Norepinephrine Dosing

Initial Dose

• Start at 0.2-1 mcg/kg/min (approximately 8-12 mcg/min for a 70 kg patient) 1
• The FDA label recommends an initial dose of 8-12 mcg of base per minute 5

Maintenance Dose

• The average maintenance dose ranges from 2-4 mcg of base per minute 5
• Titrate to maintain systolic blood pressure >90 mmHg and mean arterial pressure ≥65 mmHg 1, 3

Administration Route

• Administer through a central line ideally to avoid tissue necrosis from extravasation 1
• If extravasation occurs, infiltrate the area immediately with 10-15 mL of saline containing 5-10 mg of an adrenergic blocking agent 5

Hemodynamic Targets and Monitoring

Blood Pressure Goals

• Target systolic blood pressure >90 mmHg 2, 1
• Target mean arterial pressure ≥65 mmHg 1, 3

Perfusion Markers to Monitor Serially

• Urine output 1, 4
• Serum lactate clearance 1, 4
• Mixed or central venous oxygen saturation 1
• Mental status 1, 4
• Skin perfusion 1

Essential Monitoring

• Establish arterial line monitoring for continuous blood pressure assessment 3
• Continuous ECG telemetry to detect arrhythmias 4

Critical Pitfalls to Avoid

Do Not Use Vasopressors as First-Line Agents

• Never initiate norepinephrine before optimizing volume status and starting inotropic therapy 1
• Using vasopressors first-line can increase afterload on an already failing heart, worsening cardiac output and end-organ perfusion 1

Discontinue as Soon as Possible

• All vasopressors should be discontinued as soon as hemodynamics stabilize due to their propensity to increase myocardial oxygen demand and risk of arrhythmias 1
• Reduce the infusion rate gradually to avoid rebound hypotension 5

Avoid Epinephrine in Cardiogenic Shock

• Epinephrine is not recommended as an inotrope or vasopressor in cardiogenic shock and should be restricted to cardiac arrest 2
• Recent evidence shows epinephrine use is independently associated with increased 90-day mortality (OR 5.2) and marked worsening of cardiac and renal biomarkers 6

Alternative and Adjunctive Therapies

When Norepinephrine Plus Dobutamine Fails

• Consider levosimendan as an alternative or additional agent, especially in patients on chronic beta-blocker therapy 1, 3
• Vasopressin may be added at doses up to 0.03 units/min to reduce norepinephrine requirements 1

Mechanical Circulatory Support

• Evaluate for mechanical circulatory support (IABP, ventricular assist devices) rather than escalating to multiple vasopressors, as vasopressors are only a bridge therapy 1
• Consider mechanical support in patients not responding adequately to pharmacologic therapy 3, 4

Evidence Considerations

The recommendation for norepinephrine as the preferred vasopressor in cardiogenic shock is based on European Society of Cardiology guidelines 2, 1, though observational data suggests potential harm. One retrospective study found norepinephrine use was associated with increased 30-day mortality (41% vs 30%, OR 1.61) 7, while another study showed short-term norepinephrine up-titration was well-tolerated hemodynamically 8. The key is using norepinephrine judiciously as a second-line agent only after optimizing inotropic support, not as first-line therapy.