What are the immediate steps I should take in the emergency management of a patient in ventricular fibrillation?

Immediate steps in the emergency management of a patient presenting with ventricular fibrillation (VF) include:

• Call for emergency help and ensure the patient is on a monitored cardiac arrest pathway. Early recognition and activation of the resuscitation team is critical NICE NG196.
• Start high-quality cardiopulmonary resuscitation (CPR) immediately. This involves chest compressions at a rate of 100-120 per minute and a depth of 5-6 cm, allowing full chest recoil between compressions NICE NG196.
• Defibrillation should be delivered as soon as a defibrillator is available. Use a biphasic defibrillator with an initial shock of 150-200 joules, escalating if subsequent shocks are needed NICE NG196. Early defibrillation is the most effective treatment for VF Long & Gottlieb 2025.
• Continue CPR immediately after each shock without delay to assess rhythm or pulse. Minimising interruptions in chest compressions improves outcomes NICE NG196.
• Establish airway and provide oxygenation and ventilation as appropriate. Use bag-valve-mask ventilation or advanced airway if trained personnel are available NICE NG196.
• Administer intravenous adrenaline (epinephrine) 1 mg every 3-5 minutes during resuscitation if VF persists after defibrillation attempts. This is recommended to improve coronary and cerebral perfusion NICE NG196.
• Consider reversible causes (the 4 Hs and 4 Ts) during resuscitation and treat accordingly. These include hypoxia, hypovolaemia, hypo/hyperkalaemia, hypothermia, tension pneumothorax, tamponade, toxins, and thrombosis NICE NG196.
• Recent literature supports the use of alternate defibrillation strategies to reduce time in VF, such as prompt repeated shocks and minimising pauses in compressions, which may improve survival Cheskes et al. 2025Long & Gottlieb 2025.

In summary, the immediate management of VF focuses on rapid defibrillation combined with high-quality CPR, airway management, adrenaline administration, and identification of reversible causes, integrating both UK guideline recommendations and recent evidence on defibrillation strategies.