What is the preferred medication, epinephrine (adrenaline) or norepinephrine (noradrenaline), for managing hypotension in return of spontaneous circulation (ROSC)?

Norepinephrine is Preferred Over Epinephrine for Post-ROSC Hypotension

Norepinephrine should be used as the first-line vasopressor for managing hypotension following return of spontaneous circulation (ROSC) rather than epinephrine. 1

Rationale for Vasopressor Selection Post-ROSC

Physiological Considerations

• Epinephrine's β-adrenergic effects can:

  • Increase myocardial oxygen demand
  • Reduce subendocardial perfusion
  • Potentially cause proarrhythmic effects 2
  • Lead to tachycardia and hypertension in the post-resuscitation period 3

• Norepinephrine offers:

  • More selective α-adrenergic effects with less pronounced β-adrenergic stimulation
  • Better hemodynamic stability post-ROSC
  • Lower risk of rearrest compared to epinephrine 4

Evidence Supporting Norepinephrine Post-ROSC

A 2024 national survey of emergency medicine pharmacists found that 81% prefer norepinephrine as first-choice vasopressor for post-ROSC hypotension, while only 17% preferred epinephrine 1. This represents current clinical practice across diverse geographic regions and hospital settings.

A 2024 retrospective study examining prehospital administration of vasopressors after ROSC found that:

• Patients receiving epinephrine were three times more likely to experience rearrest compared to those receiving norepinephrine (adjusted OR 3.28,95% CI 2.25-5.08)
• Patients receiving epinephrine had lower odds of having pulses upon hospital arrival (OR 0.52,95% CI 0.32-0.83) 4

Clinical Approach to Post-ROSC Hypotension

1. Initial assessment:

   • Identify underlying shock etiology (cardiogenic, distributive, hypovolemic, or obstructive) 5
   • Ensure adequate fluid resuscitation before or concurrent with vasopressor initiation

2. Vasopressor selection:

   • Start with norepinephrine as first-line agent for post-ROSC hypotension
   • For cardiogenic shock with persistent tachycardia, norepinephrine remains particularly beneficial 5

3. Monitoring:

   • Continuous cardiac monitoring for arrhythmias
   • Frequent blood pressure measurements
   • Monitor for signs of end-organ perfusion

Important Considerations and Pitfalls

• While epinephrine is the cornerstone of treatment during cardiac arrest 2, its role changes after ROSC is achieved
• Epinephrine's β-adrenergic effects that increase coronary and cerebral perfusion pressure during CPR may become detrimental after ROSC
• The 2024 AHA guidelines focus on epinephrine during cardiac arrest but do not specifically address post-ROSC vasopressor selection 2
• Avoid extravasation of vasopressors into tissues, which can cause local necrosis 6
• Monitor for potential renal impairment with vasopressor use 6

Conclusion

While epinephrine remains the primary vasopressor during cardiac arrest, the evidence supports norepinephrine as the preferred agent for managing hypotension following ROSC. This approach is associated with greater hemodynamic stability and lower risk of rearrest in the post-resuscitation period.