What is the treatment for refractory ventricular fibrillation (VFib)?

Treatment for Refractory Ventricular Fibrillation

For refractory ventricular fibrillation, treatment should include administration of amiodarone or lidocaine, consideration of double sequential external defibrillation, and escalation to extracorporeal CPR (ECPR) when available for cases that remain resistant to pharmacological and electrical therapies. 1

Definition and Initial Approach

Refractory ventricular fibrillation (VF) refers to VF that persists or recurs after ≥1 shocks. The primary goals of treatment are to:

1. Continue high-quality CPR with minimal interruptions
2. Deliver appropriate defibrillation
3. Administer antiarrhythmic medications
4. Identify and treat reversible causes

Pharmacological Management

First-Line Antiarrhythmic Medications

• Amiodarone: 300 mg IV bolus initially, followed by a second dose of 150 mg if needed 1, 2

  • FDA-approved for initiation of treatment and prophylaxis of frequently recurring VF and hemodynamically unstable VT in patients refractory to other therapy 2
  • Available in two formulations: one containing polysorbate (may cause hypotension) and one containing captisol (no vasoactive effects) 1

• Lidocaine: 1-1.5 mg/kg IV initial bolus (approximately 100 mg), followed by 0.5-0.75 mg/kg if needed 1, 3

  • May be particularly beneficial in VF associated with acute myocardial ischemia 3

The 2018 AHA guidelines state that either amiodarone or lidocaine may be considered for shock-refractory VF/pVT, with no clear preference between the two agents 1.

Additional Pharmacological Considerations

• Magnesium Sulfate: 8 mmol bolus followed by 2.5 mmol/h infusion, particularly when VF is associated with acute myocardial infarction or suspected hypomagnesemia 1, 4

• Epinephrine: 0.01 mg/kg (1 mg) IV/IO every 3-5 minutes during cardiac arrest 1

Electrical Therapy

• Single-shock strategy is recommended rather than stacked shocks 1
• Minimize time between chest compressions and shock delivery 1
• Double Sequential External Defibrillation (DSED): For cases refractory to conventional defibrillation, using two defibrillators simultaneously may be considered 5
  • This approach has been described as a viable option for patients with persistent VF despite multiple conventional shocks

Advanced Interventions

• Extracorporeal CPR (ECPR): Should be considered for select patients with refractory cardiac arrest when the suspected etiology is potentially reversible 1, 6
  • Studies show significantly higher rates of sustained return of spontaneous circulation (95.0% vs 47.5%) and good neurological function at discharge (40.0% vs 7.5%) compared to conventional CPR 6

Algorithmic Approach to Refractory VF

1. Ensure high-quality CPR

   • Push hard (at least 2 inches/5 cm) and fast (100-120/min)
   • Allow complete chest recoil
   • Minimize interruptions in compressions
   • Avoid excessive ventilation
   • Rotate compressor every 2 minutes

2. Defibrillate

   • Use single-shock strategy
   • Resume CPR immediately after shock

3. Administer antiarrhythmic medication after 3rd shock

   • Amiodarone 300 mg IV bolus OR
   • Lidocaine 1-1.5 mg/kg IV bolus

4. Continue CPR and defibrillation sequence

   • Consider second dose of antiarrhythmic if VF persists
     • Amiodarone 150 mg IV bolus OR
     • Lidocaine 0.5-0.75 mg/kg IV bolus

5. Identify and treat reversible causes (Hs and Ts):

   • Hypovolemia
   • Hypoxia
   • Hydrogen ion (acidosis)
   • Hypo/hyperkalemia
   • Hypothermia
   • Tension pneumothorax
   • Tamponade (cardiac)
   • Toxins
   • Thrombosis (coronary or pulmonary)

6. For persistent VF despite above measures:

   • Consider double sequential external defibrillation
   • Consider magnesium sulfate if suspected hypomagnesemia or torsades de pointes
   • Consider ECPR if available and patient is appropriate candidate

Important Considerations and Caveats

• Establishing vascular access for drug administration should not compromise the quality of CPR or timely defibrillation 1
• Antiarrhythmic drugs have been associated with increased rates of ROSC and hospital admission, but none have yet been proven to increase long-term survival or survival with good neurological outcome 1
• The benefit of antiarrhythmic drugs appears to be greatest for patients with witnessed arrest when the drug is given early 7
• For patients with refractory VF, resuscitation efforts should continue as long as a shockable rhythm persists 8
• Post-ROSC care should include targeted temperature management for at least 24 hours and consideration of early coronary angiography 1