title: Clinical outcomes after rescue extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest.
abstract: OBJECTIVE
  Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to have survival benefit in patients who had in-hospital cardiac arrest (IHCA). However, limited data are available on the role of extracorporeal membrane oxygenation (ECMO) for out-of-hospital cardiac arrest (OHCA). Therefore, we aimed to investigate clinical outcomes and predictors of in-hospital mortality in patients who had OHCA and who underwent ECPR.
  
  
  METHODS
  From January 2004 to December 2013, 235 patients who received ECPR were enrolled in a retrospective, single-centre, observational registry. Among those, we studied 35 adult patients who had OHCA. The primary outcome was in-hospital mortality.
  
  
  RESULTS
  Among 35 patients with a median age of 55 years (IQR 45-64), 29 (82.9%) of whom were male, ECMO implantation was successful in all and 10 patients (28.6%) lived to be discharged from the hospital. In 18 cases (51.4%), first monitored rhythms were identified as ventricular tachycardia/ventricular fibrillation, that is, shockable rhythm. There were no differences between in-hospital survivors and non-survivors regarding median time of arrest to cardiopulmonary resuscitation (CPR) (survivors: 23.5 min (IQR 18.8-27.3) vs non-survivors: 20.0 min (IQR 15.0-24.5); p=0.41) and median time of CPR to ECMO pump-on (survivors: 61.0 min (IQR 39.8-77.8) vs non-survivors 50.0 min (IQR 44.0-72.5); p=0.50). In 23 cases (65.7%), ischaemic heart disease was diagnosed and successful revascularisation was achieved in a significantly higher proportion of the survivor group (8/10 (80.0%)) than the non-survivor group (8/25 (32.0%)) (p=0.02). Witnessed arrest (HR=3.96; 95% CI 1.38 to 11.41; p=0.01), bystander CPR (HR=4.05; 95% CI 1.56 to 10.42; p=0.004) and successful revascularisation (HR=2.90; 95% CI 1.23 to 6.86; p=0.02) were independent predictors of survival-to-discharge in patients who had OHCA in univariate Cox regression analysis.
  
  
  CONCLUSIONS
  Survival rate for ECPR in the setting of OHCA remains poor. Our findings suggest that ECMO implantation should be very carefully considered in highly selected patients who had OHCA with little no-flow time and a reversible cause.
authors.affiliation: Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Tae Sun
authors.initials: TS
authors.lastname: Ha
authors.affiliation: Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Yang
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yang Hyun
authors.initials: YH
authors.lastname: Cho
authors.affiliation: Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Chi Ryang
authors.initials: CR
authors.lastname: Chung
authors.affiliation: Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Chi-Min
authors.initials: CM
authors.lastname: Park
authors.affiliation: Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyeongman
authors.initials: K
authors.lastname: Jeon
authors.affiliation: Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Gee Young
authors.initials: GY
authors.lastname: Suh
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy*; D018579:Patient Selection; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome
keywords: cardiac arrest; emergency care systems; resuscitation