What is the dosing and administration protocol for noradrenaline (norepinephrine) and dopamine in septic shock?

Dosing and Administration Protocol for Norepinephrine and Dopamine in Septic Shock

Norepinephrine should be used as the first-choice vasopressor in septic shock, with an initial target mean arterial pressure (MAP) of 65 mmHg. 1

Vasopressor Selection Algorithm

First-Line Agent: Norepinephrine

• Norepinephrine is the recommended first-choice vasopressor for septic shock due to superior efficacy and safety profile compared to dopamine 1, 2
• Norepinephrine has been associated with decreased all-cause mortality compared to dopamine, with an absolute risk reduction of 11% 2
• Norepinephrine demonstrates a better hemodynamic profile and fewer adverse events, particularly cardiac arrhythmias 2, 3

Second-Line/Alternative Agent: Dopamine

• Dopamine should only be used as an alternative to norepinephrine in highly selected patients with:
  • Low risk of tachyarrhythmias 1
  • Absolute or relative bradycardia 1
• Dopamine is associated with significantly higher incidence of cardiac arrhythmias (19.4% vs 3.4% with norepinephrine) 4

Norepinephrine Administration Protocol

Preparation:

• Standard concentration: 4-8 mg norepinephrine in 250 mL D5W or NS (16-32 mcg/mL) 5
• Administration requires central venous access 1
• Arterial catheter placement is recommended for all patients requiring vasopressors as soon as practical 1

Dosing:

• Initial dose: 0.5 mcg/kg/min 6
• Titration range: 0.5-5.0 mcg/kg/min 6
• Titrate to achieve target MAP of 65 mmHg 1
• Consider higher MAP targets (e.g., 80-85 mmHg) in patients with chronic hypertension 5

Monitoring:

• Continuous arterial blood pressure monitoring 1
• Monitor for signs of improved tissue perfusion:
  • Improved urine output 6
  • Decreased lactate levels 2
  • Improved central venous pressure 2

Dopamine Administration Protocol

Preparation:

• Standard concentration: 400-800 mg dopamine in 250 mL D5W or NS (1600-3200 mcg/mL)
• Administration requires central venous access 1
• Arterial catheter placement is recommended 1

Dosing:

• Initial dose: 2.5 mcg/kg/min 6
• Titration range: 2.5-25 mcg/kg/min 6
• Titrate to achieve target MAP of 65 mmHg 1

Monitoring:

• Continuous cardiac monitoring for arrhythmias 4, 3
• Continuous arterial blood pressure monitoring 1
• Monitor for tachycardia, which occurs more frequently with dopamine (24.6%) than with norepinephrine (5.9%) 4

Management of Refractory Hypotension

If target MAP cannot be achieved with maximum doses of initial vasopressor:

1. Add vasopressin (up to 0.03 U/min) to norepinephrine to either:

   • Raise MAP to target 1
   • Decrease norepinephrine dosage 1

2. Alternative: Add epinephrine to norepinephrine when additional agent is needed 1

3. For patients with persistent hypoperfusion despite adequate fluid loading and vasopressors:

   • Consider adding dobutamine (up to 20 μg/kg/min) 1
   • Titrate to endpoints reflecting improved perfusion 1
   • Reduce or discontinue if worsening hypotension or arrhythmias occur 1

Important Considerations and Pitfalls

• Do not use low-dose dopamine for renal protection - this practice is strongly discouraged by current guidelines 1
• Early administration of norepinephrine is beneficial to restore organ perfusion and avoid fluid overload 5
• Phenylephrine is not recommended except in specific circumstances:
  • When norepinephrine causes serious arrhythmias 1
  • When cardiac output is high but blood pressure remains low 1
  • As salvage therapy when other vasopressors have failed 1
• Continuous monitoring for arrhythmias is essential, especially with dopamine 4, 3
• Adequate fluid resuscitation should precede or accompany vasopressor therapy 1