What is the best course of action for a patient post-Return Of Spontaneous Circulation (ROSC) with a rapidly declining heart rate and impending re-arrest when epinephrine is the only available medication?

Emergency Management of Post-ROSC Bradycardia with Impending Re-Arrest

Administer epinephrine 1 mg IV/IO immediately and prepare to resume full CPR if re-arrest occurs, as this represents a continuation of the cardiac arrest resuscitation rather than post-resuscitation hemodynamic support. 1

Immediate Actions

The clinical scenario you describe—rapidly declining heart rate post-ROSC with impending re-arrest—should be treated as ongoing cardiac arrest requiring standard ACLS protocols. 2, 1

• Give epinephrine 1 mg IV/IO immediately if the patient is deteriorating toward re-arrest, as this follows the standard cardiac arrest algorithm where epinephrine is administered every 3-5 minutes during active resuscitation 2
• Prepare for immediate resumption of CPR if pulses are lost, as re-arrest is imminent in this scenario 1
• Identify and treat reversible causes (the H's and T's) simultaneously: hypovolemia, hypoxia, hydrogen ion (acidosis), hypo/hyperkalemia, hypothermia, tension pneumothorax, tamponade, toxins, thrombosis (pulmonary or coronary) 2, 1

Critical Distinction: Active Arrest vs. Post-ROSC Hemodynamic Support

The key clinical judgment here is recognizing that a "rapidly declining heart rate with impending re-arrest" represents ongoing arrest physiology, not stable post-ROSC hemodynamic management. 1

• During active cardiac arrest or impending re-arrest: Use 1 mg IV/IO boluses of epinephrine every 3-5 minutes 2
• After stable ROSC with hemodynamic support needs: Transition to continuous vasopressor infusions (epinephrine 0.05-2 mcg/kg/min, or preferably norepinephrine) rather than repeated boluses 1, 3, 4

Why Epinephrine is Appropriate in This Scenario

Epinephrine increases rates of ROSC through alpha-adrenergic vasoconstriction, which is exactly what is needed when facing imminent re-arrest. 2

• The 2020 AHA Guidelines establish epinephrine as the standard vasopressor during cardiac arrest, with Class 1 (strong) recommendation 2, 1
• For non-shockable rhythms (which bradycardia progressing to asystole represents), epinephrine should be given as soon as feasible 2
• Earlier epinephrine administration is associated with higher rates of ROSC, particularly in non-shockable rhythms 2

Important Caveats About Epinephrine Use

While epinephrine increases ROSC, it does not improve long-term neurological outcomes and may worsen post-resuscitation syndrome. 2, 5

• Higher cumulative doses of epinephrine are associated with worse outcomes: Research shows doses >7 mg are associated with failure to achieve ROSC, and higher doses correlate with increased cardiocirculatory death post-ROSC 6, 5
• Epinephrine administration before ROSC is associated with higher rates of re-arrest: Studies show 3-4 times higher odds of prehospital re-arrest in patients who received epinephrine 7, 8
• Each additional milligram of epinephrine increases odds of cardiocirculatory death: Adjusted OR of 3.45 for 1 mg, 12.28 for 2-5 mg, and 23.71 for >5 mg 5

Transition Planning After ROSC

If ROSC is achieved, immediately transition from bolus epinephrine to a continuous vasopressor infusion for hemodynamic support. 1, 3

• Norepinephrine may be preferable to epinephrine infusion for post-ROSC hemodynamic support, as recent studies show epinephrine infusions are associated with 3.28 times higher odds of re-arrest compared to norepinephrine 4, 8
• Epinephrine infusion dosing (if used): 0.05-2 mcg/kg/min IV, titrated to maintain adequate mean arterial pressure 3
• Focus on the post-resuscitation bundle: Optimize oxygenation (avoid hypoxia and hyperoxia), maintain normal PaCO₂, target specific hemodynamic goals, and implement temperature management 1

Practical Algorithm

1. Patient with declining HR post-ROSC → Give epinephrine 1 mg IV/IO immediately 2, 1
2. Simultaneously assess for reversible causes (H's and T's) 2, 1
3. If re-arrest occurs → Resume full CPR and continue epinephrine 1 mg every 3-5 minutes 2
4. If ROSC maintained → Transition to continuous vasopressor infusion (preferably norepinephrine over epinephrine) 1, 4
5. Implement post-resuscitation care bundle and prepare for ICU transfer 1

Common Pitfall to Avoid

Do not hesitate to give the epinephrine bolus in this scenario due to concerns about post-ROSC complications—the immediate threat of re-arrest takes priority over longer-term concerns. 1 The patient is not in stable post-ROSC hemodynamic support phase; they are in imminent re-arrest requiring active resuscitation medications. However, be mindful that each dose increases the cumulative burden and associated complications, so aggressive identification and treatment of reversible causes is essential. 6, 5