What is the management for a cardiac arrest due to ventricular fibrillation (VF) in a Cardiac Arrest Life Support (CALS) setting?

Management of Ventricular Fibrillation in Cardiac Arrest Life Support

For ventricular fibrillation (VF) cardiac arrest, immediate defibrillation with minimal interruptions to high-quality CPR is the cornerstone of management, followed by epinephrine administration and consideration of antiarrhythmic drugs for refractory cases. 1, 2

Initial Response and Recognition

• Immediately recognize VF on cardiac monitor as disorganized electrical activity without discernible QRS complexes 1
• Begin high-quality CPR with minimal interruptions at a rate of 100-120 compressions per minute and a depth of at least 2 inches (5 cm) 1, 2
• Attach a monitor/defibrillator as soon as possible to confirm rhythm 1

Defibrillation Protocol

• For witnessed VF arrest, deliver an immediate unsynchronized shock 1, 2
  • Initial shock energy: 200J for monophasic or manufacturer's recommended dose (typically 120-200J) for biphasic defibrillators 1, 2
  • If initial shock is unsuccessful, deliver a second shock at 200-300J, and a third shock at 360J if necessary 1, 2
• For unwitnessed arrest or prolonged VF, consider 2 minutes of CPR before the first shock 1
• Resume CPR immediately after each shock, beginning with chest compressions, without waiting for rhythm analysis 1, 2

Medication Administration

• Establish IV/IO access while continuing CPR 1, 3
• Administer epinephrine 1mg IV/IO every 3-5 minutes throughout resuscitation 1, 2
• For refractory VF (persisting after 2-3 shocks), administer amiodarone 1, 4:
  • First dose: 300 mg IV/IO bolus
  • Second dose: 150 mg IV/IO if needed
• If amiodarone is unavailable, consider lidocaine 1-1.5 mg/kg IV/IO, with a second dose of 0.5-0.75 mg/kg if needed 1

Advanced Airway Management

• Consider advanced airway placement after initial shocks if personnel are available 1, 3
• Once advanced airway is placed, deliver 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions 1
• Use waveform capnography to confirm and monitor endotracheal tube placement 1, 3

Ongoing Management

• Minimize interruptions in chest compressions, including during rhythm checks 1, 2
• Rotate compressors every 2 minutes to maintain high-quality compressions 3
• Continue cycles of:
  • 2 minutes of CPR
  • Brief rhythm check
  • Shock if VF persists
  • Immediate resumption of CPR 1, 2

Special Considerations

• Consider and treat potential reversible causes (Hs and Ts) 1:
  • Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo/hyperkalemia, Hypothermia
  • Tension pneumothorax, Tamponade, Toxins, Thrombosis (pulmonary and coronary)
• For refractory VF despite standard treatment, consider:
  • Double sequential defibrillation (using two defibrillators simultaneously) 5
  • Esmolol as a novel treatment approach before cessation of resuscitative efforts 5
  • Change in defibrillator pad position 2

Post-Resuscitation Care

• After return of spontaneous circulation (ROSC), maintain adequate ventilation and oxygenation 1
• Correct electrolyte abnormalities, particularly potassium and magnesium 1
• Consider targeted temperature management for comatose survivors 1

Common Pitfalls to Avoid

• Avoid excessive ventilation (>10 breaths/minute), which can decrease cardiac output during CPR 1, 3
• Don't delay defibrillation for witnessed VF arrest 1, 2
• Avoid prolonged pulse checks; if pulse is not definitely felt within 10 seconds, resume CPR 3
• Don't use synchronized cardioversion for VF (always use unsynchronized shocks) 1
• Avoid interrupting chest compressions for more than 10 seconds, even for intubation or IV access 1, 2

Amiodarone Administration Details

• For refractory VF, administer amiodarone 300 mg IV/IO bolus 4
• After the first 24 hours, continue maintenance infusion at 0.5 mg/min (720 mg per 24 hours) 4
• For breakthrough episodes of VF, use 150 mg supplemental infusions of amiodarone (mixed in 100 mL of D5W and infused over 10 minutes) 4
• Do not exceed an initial infusion rate of 30 mg/min to minimize the risk of hypotension 4