A study of patients in cardiac arrest due to ventricular arrhythmias to determine if manual pressure augmentation during defibrillation improves neurological outcome and survival

INTERVENTION: Patients in the treatment arm who have a shockable rhythm (VF or VT) will undergo defibrillation of 200J. During shock delivery, paramedics will apply manual maximum pressure to both defibrillation patches while the charge is delivered. If return of spontaneous circulation (ROSC) is not achieved, CPR is continued. Every 2 minutes, a rhythm check will be conducted and if the patient is still in a shockable rhythm, another shock will be given with manual pressure augmentation. This process will be repeated each time a shock is given as per the standard resuscitation protocol until ROSC is achieved or resuscitation is ceased. The treatment will be administered by Advanced Life Support and Mobile Intensive Care paramedics and training will be provided via a single 30 minute online learning module and face to face scenario training prior to the trial commencing. Paramedics will also have ongoing access to a trial intranet page with Q&A content and training videos. Trial participation will be voluntary for paramedics and a review of ambulance patient care records will be conducted for each arrest to determine if the intervention was utilised. CONDITION: Cardiac Arrest;Coronary Heart Disease;Ventricular Arrhythmia; ; Cardiac Arrest ; Coronary Heart Disease ; Ventricular Arrhythmia Cardiovascular ‐ Coronary heart disease PRIMARY OUTCOME: Conversion of shockable rhythm ‐ this data will be collected from Ambulance patient care records and Zoll data collected from the Zoll monitors utilised to monitor patients during cardiac arrest.[End of arrest (return of spontaneous circulation or death)] Survival to hospital discharge ‐ this data will be obtained from the Victorian Ambulance Cardiac Arrest Registry (VACAR) which routinely collects hospital outcome data[Hospital discharge] SECONDARY OUTCOME: Acceptability and ease of use of manual pressure augmentation by paramedics as assessed by a study‐specific questionnaire administered to paramedics who have utilised MPA.[Within 2 weeks post arrest] Neurological outcome at 12 months post cardiac arrest measured by Glasgow Outcome Scale‐Extended (GOS‐E). This will be obtained from VACAR data, as 12 month follow‐up is routinely conducted by VACAR.[Hospital discharge and 12 months post arrest] Paramedic compliance using manual pressure augmentation as determined by review of ambulance patient care records[At the conclusion of the study] Survival to hospital as determined by pulse present on arrival to hospital by manual assessment and Zoll monitor[Arrival to hospital] INCLUSION CRITERIA: Adults (18 years of age and over) Confirmed out‐of‐hospital cardiac arrest In a shockable rhythm (ventricular fibrillation or ventricular tachycardia) at the time of ambulance arrival Suitable for resuscitation to commence/continue by paramedics