title: Does therapeutic hypothermia during extracorporeal cardiopulmonary resuscitation preserve cardiac function?
abstract: Extracorporeal cardiopulmonary resuscitation (E-CPR) is increasingly used as a rescue method in the management of cardiac arrest and provides the opportunity to rapidly induce therapeutic hypothermia. The survival after a cardiac arrest is related to post-arrest cardiac function, and the application of therapeutic hypothermia post-arrest is hypothesized to improve cardiac outcome. The present animal study compares normothermic and hypothermic E-CPR considering resuscitation success, post-arrest left ventricular function and magnitude of myocardial injury.
  
  
  
  After a 15-min untreated ventricular fibrillation, the pigs (n = 20) were randomized to either normothermic (38 °C) or hypothermic (32-33 °C) E-CPR. Defibrillation terminated ventricular fibrillation after 5 min of E-CPR, and extracorporeal support continued for 2 h, followed by warming, weaning and a stabilization period. Magnetic resonance imaging and left ventricle pressure measurements were used to assess left ventricular function pre-arrest and 5 h post-arrest. Myocardial injury was estimated by serum concentrations of cardiac TroponinT and Aspartate transaminase (ASAT).
  
  
  
  E-CPR resuscitated all animals and the hypothermic strategy induced therapeutic hypothermia within minutes without impairment of the resuscitation success rate. All animals suffered a severe global systolic left ventricular dysfunction post-arrest with 50-70% reductions in stroke volume, ejection fraction, wall thickening, strain and mitral annular plane systolic excursion. Serum concentrations of cardiac TroponinT and ASAT increased considerably post-arrest. No significant differences were found between the two groups.
  
  
  
  Two-hour therapeutic hypothermia during E-CPR offers an equal resuscitation success rate, but does not preserve the post-arrest cardiac function nor reduce the magnitude of myocardial injury, compared to normothermic E-CPR. Trial registration FOTS 4611/13 registered 25 October 2012.
authors.affiliation: Division of Emergencies and Critical Care, Department of Research and Development, Oslo University Hospital, Oslo, Norway. haaber@ous-hf.no.|Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway. haaber@ous-hf.no.
authors.forename: Harald A
authors.initials: HA
authors.lastname: Bergan
authors.affiliation: The Intervention Centre, Rikshospitalet, Oslo University Hospital, Oslo, Norway.
authors.forename: Per S
authors.initials: PS
authors.lastname: Halvorsen
authors.affiliation: Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Department of Cardiology, Rikshospitalet, Oslo University Hospital, Oslo, Norway.
authors.forename: Helge
authors.initials: H
authors.lastname: Skulstad
authors.affiliation: Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|The Intervention Centre, Rikshospitalet, Oslo University Hospital, Oslo, Norway.
authors.forename: Erik
authors.initials: E
authors.lastname: Fosse
authors.affiliation: Division of Emergencies and Critical Care, Department of Research and Development, Oslo University Hospital, Oslo, Norway.
authors.forename: Jan F
authors.initials: JF
authors.lastname: Bugge
mesh_terms: D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001831:Body Temperature / Q000187:drug effects; D016887:Cardiopulmonary Resuscitation; D002316:Cardiotonic Agents / Q000494:pharmacology; D004554:Electric Countershock; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects; D007036:Hypothermia, Induced; D008279:Magnetic Resonance Imaging; D013194:Staining and Labeling; D034421:Sus scrofa; D020107:Troponin T / Q000097:blood; D014693:Ventricular Fibrillation / Q000097:blood / Q000503:physiopathology / Q000628:therapy
chemical_list: D002316:Cardiotonic Agents; D020107:Troponin T; D001219:Aspartate Aminotransferases
keywords: Cardiac function; Cardiopulmonary resuscitation; Extracorporeal circulation; Extracorporeal membrane oxygenation; Therapeutic hypothermia