title: Extracorporeal membrane oxygenation to support cardiopulmonary resuscitation in a sheep model of refractory ischaemic cardiac arrest.
abstract: BACKGROUND
  Survival after out-of-hospital cardiac arrest remains limited. It is therefore imperative to develop new resuscitation techniques. We aimed to determine the potential role of extracorporeal membrane oxygenation assisted CPR (ECPR) in an animal model of refractory ischaemic cardiac arrest.
  
  
  METHODS
  Twelve sheep were assigned to either ECPR (n=6) or 'conventional' (n=6) resuscitation. All sheep had coronary occlusion, followed by induction of ventricular fibrillation (VF). CPR was than commenced for 10 min in both groups, followed by randomisation to ECPR or CPR for a further 10 min. At 23 min post induction of VF, advanced life support measures were commenced with direct cardioversion, adrenaline and amiodarone. Outcomes measures included rates of return of spontaneous circulation (ROSC), and analysis of VF wave form.
  
  
  RESULTS
  Baseline haemodynamics were similar between the two groups. CPR consistently produced coronary perfusion pressures (CPP) greater than 15 mmHg in both groups, with significantly increased CPP post commencement of ECMO in the ECPR group (17.84±2 mmHg vs 22.94±3 mmHg, p=0.04). Number of shocks, pH, lactate and oxygenation were also comparable. Significantly greater rates of ROSC were seen in the ECPR sheep, 3/6 (50%) vs 0/6 (0%) (p=0.032), which was also associated with significantly increased VF amplitude measures (0.51±0.08 mV vs 0.42±0.06 mV, p=0.04).
  
  
  CONCLUSIONS
  This study indicates that ECPR increases return of circulation and coronary perfusion pressure in a sheep model of ischaemic VF arrest. Our findings have supported the development of a pilot trial into the effectiveness and feasibility of ECPR in the clinical setting.
authors: Baker IDI Heart and Diabetes Institute, Melbourne, Australia. d.stub@alfred.org.au
authors: Dion
authors: D
authors: Stub
authors: Melissa
authors: M
authors: Byrne
authors: Vincent
authors: V
authors: Pellegrino
authors: David M
authors: DM
authors: Kaye
mesh_terms: D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004195:Disease Models, Animal; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000097:blood / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D058687:Out-of-Hospital Cardiac Arrest / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D012756:Sheep