Procedure

Defibrillation

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Defibrillation, Unsynchronized Shock, Double Simultaneous Defibrillation, Dual Simultaneous Defibrillation

  • See Also
  1. Defibrillator Equipment
  2. Synchronized Cardioversion
  • Indications
  1. Ventricular Fibrillation
  2. Pulseless Ventricular Tachycardia
  • Precautions
  1. Avoid placing Defibrillator pads directly over cardiac Defibrillators or Pacemakers
  2. Attempt removal of metal piercings and jewelry if no delays
  • Types
  1. Monophasic
    1. Shock one-way travels from one electrode to another
  2. Biphasic
    1. Shock round-trip travels from one electrode to another and back again
  • Doses
  1. Pediatric
    1. Initial: 2-4 J/kg
    2. Subsequent: 4 J/kg
    3. May increase up to 10 J/kg (or maximum adult dose)
  2. Adult
    1. Monophasic: Start 200 J (may increase to 300 J, then 360 J)
    2. Biphasic: Start 120-200 J (use manufacturers recommendations per specific device)
  • Technique
  • Pearls for successful Defibrillation
  1. Successful Defibrillation of Ventricular Fibrillation requires Defibrillation of 95% of the heart
  2. Lateral pad placement over the cardiac apex is important for success
  3. Reduce impedence (minimize barriers to electrical transmission)
    1. Stop bag-valve-mask during Defibrillation (air in chest increases impedence)
    2. Dry a diaphoretic patient
    3. Shave excessive hair interfering with transmission
  4. Optimize perfusion
    1. Optimal Chest Compressions
    2. Epinephrine
  5. Consider external Dual Simultaneous Defibrillation
    1. See below
  6. References
    1. Shinar and Cheskes in Herbert (2016) EM:Rap 16(6): 5-6
  • Technique
  • Dual Simultaneous Defibrillation
  1. Definition
    1. Two Defibrillators attached to chest for simultaneous shock
    2. Doubles current delivered to the heart
  2. Protocol
    1. Apply a second set of Defibrillator pads
    2. Second pad positions
      1. Adjacent to first set (e.g. right parasternal and cardiac apex) or
      2. Opposite positions (e.g. anterior-posterior)
    3. Charge each Defibrillator
    4. Clear all staff from touching patient before discharge
    5. Deliver shocks simultaneously
  3. References
    1. Warrington (2017) Crit Dec Emerg Med 31(8): 23
    2. Cheskes (2020) Resuscitation 150:178-84 +PMID:32084567 [PubMed]