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Cardiac arrest - out of hospital care - Management
How do I manage someone with a shockable rhythm (VF/VT)?

  • Attempt defibrillation if ventricular fibrillation (VF) or ventricular tachycardia (VT) is identified.
    • Start defibrillation immediately if the cardiac arrest was witnessed by a healthcare professional and a defibrillator is immediately available.
    • Give cardiopulmonary resuscitation (CPR) for 2 minutes (about five cycles at a ratio of 30 compressions to two rescue breaths) before starting defibrillation if the cardiac arrest was not witnessed by a healthcare professional or a defibrillator is not immediately available.
  • Attempt defibrillation (one shock: 150–200 J biphasic or 360 J monophasic).
    • If using an automated external defibrillator, the machine will automatically choose the correct strength for each shock.
  • Immediately resume CPR (with a 30:2 ratio of compressions to rescue breaths) without reassessing the rhythm or feeling for a pulse. Without interrupting CPR:
    • Attempt to gain venous access as soon as possible.
  • Secure the airway by a supraglottic airway device (such as laryngeal mask airway [LMA]), or a tracheal tube for those who have experience in tracheal intubation.
    • Once the airway is secured, ventilate the lungs at a rate of about 10 breaths per minute and continue chest compressions without pausing during ventilation.
      • The lungs may also be ventilated by means of a pocket mask or bag-valve-mask device (BVMD) with or without an oropharyngeal airway (OPA), but it should be noted that this method does not secure the airway against the aspiration of regurgitated gastric contents.
    • If an oropharyngeal airway (Guedel airway) or nasopharyngeal device is used, continue CPR with a 30:2 ratio of compressions to rescue breaths.
  • Continue CPR for 2 minutes, then pause briefly to check the monitor:
    • If VF/VT persists:
      • Give a further (second) shock (150–360 J biphasic or 360 J monophasic).
      • Resume CPR immediately and continue for 2 minutes.
      • Pause briefly to check the monitor.
      • If VF/VT persists, give adrenaline 1 mg intravenously (IV) followed immediately by a (third) shock (150–360 J biphasic or 360 J monophasic).
      • Resume CPR immediately and continue for 2 minutes.
      • Pause briefly to check the monitor.
      • If VF/VT persists, give amiodarone 300 mg IV followed immediately by a (fourth) shock (150–360 J biphasic or 360 J monophasic). If amiodarone is not available, give lidocaine 1 mg/kg (but not if amiodarone has been given already).
      • Resume CPR immediately and continue for 2 minutes.
      • Continue to give a further shock after each 2 minute period of CPR and after confirming that VF/VT persists.
      • Give adrenaline 1 mg IV immediately before alternate shocks (i.e. approximately every 3–5 minutes).
    • If organized electrical activity is seen, check for a pulse or other sign of life (such as movement).
      • If a pulse or other sign of life is present, start post-resuscitation care.
      • If no pulse or other sign of life is present, continue CPR and manage as for non-shockable cardiac arrest.
    • If asystole is seen, continue CPR and manage as for non-shockable cardiac arrest.
  • Identify any potentially reversible causes of cardiac arrest and manage as appropriate.

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