Trends in out-of-hospital-cardiac-arrest of presumed cardiac aetiology in Melbourne, Australia (2000-2009)

  • Ms Janet Bray, Ambulance Victoria, Australia
  • Dr Conor Deasy, Ambulance Victoria, Monash University, Australia
  • Dr Stephen Bernard, Ambulance Victoria, Monash University, Australia
  • Dr Peter Cameron, Ambulance Victoria, Monash University, Australia
  • Mr Alex Currell, Ambulance Victoria, Australia
  • Dr Karen Smith, Ambulance Victoria, Monash University, Australia

Introduction: Ambulance Victoria has made significant changes in resuscitation practices for out-of-hospital-cardiac-arrest (OHCA) over the past decade. This study examines 10-year trends in survival and changes to known predictors of survival for OHCA (presumed cardiac) in Melbourne, Australia.
Methods: Since 2000, all cardiac arrest cases attended by emergency medical services (EMS) in Melbourne (Australia) were entered into the Victorian Ambulance Cardiac Arrest Registry (VACAR). Adult presumed cardiac OHCA occurring between 2000 and 2009, where resuscitation was attempted were analysed. EMS witnessed OHCA were excluded.
Results: Over the decade, 10764 OHCA met inclusion criteria. Both negative and positive changes were seen in known predictors of survival over this time: EMS response time lengthened (median 7.0 minutes to 7.8 minutes, p<0.001); asystolic arrest increased (38% to 46%, p<0.001), and bystander CPR rates increased after changes to dispatcher CPR instructions in 2007 (43% to 54%, p<0.001). The number of patients with a return of pulse prehospital has almost doubled, both overall (21% to 38%, p<0.001) and by initial cardiac rhythm (VF/VT 30% to 64%, p<0.001, asystole 10% to 20%, p=0.003, PEA 24% to 37%, p<0.001). However, the only improvement in survival to hospital discharge was seen in patients with VF/VT (14% to 32%, p<0.001).
Discussion: In Melbourne, survival to hospital for all arresting rhythms and survival to hospital discharge for VF/VT has steadily increased over the last decade, with 2009 rates double those seen in 2000. Efforts to further improve these rates are ongoing.