title: Epidemiology, trends, and outcome of out-of-hospital cardiac arrest of non-cardiac origin.
abstract: BACKGROUND
  The majority of victims who experience out-of-hospital cardiac arrest (OHCA) have ventricular fibrillation (VF) as the presenting rhythm and are thought to have a cardiac etiology for their arrest. Over the past decade, the incidence of VF OHCA has declined. The aims of this study were to describe the epidemiology of OHCA of non-cardiac origin in Olmsted County MN and to determine the trends that have occurred over time.
  
  
  METHODS
  All residents with a traumatic OHCA from 1995 to 2005 were included for analysis. OHCA data were collected prospectively according to the Utstein method. Cardiac arrests were classified as cardiac or non-cardiac in origin and the etiology determined based on autopsy reports, electronic medical records, and/or emergency medical services reports.
  
  
  RESULTS
  During the study period, 414 OHCAs were identified, 90 (21.7%) of which were classified as non-cardiac. Mean age was 61.5+/-19.7 years. Response time was 7.73+/-2.9 min, and 40 (44.4%) were bystander-witnessed. Sixty-eight (75.6%) arrests occurred at home, 13 (14.4%) in a public place, and 9 (10%) in other locations. Bystander CPR was performed in 17 (18.9%) cases. The presenting rhythm was VF in 2 (2.2%) cases, PEA in 54 (60%), and asystole in 34 (37.8%). Eight (8.9%) patients survived to hospital discharge. Respiratory failure (35.6%), unknown (15.6%), and pulmonary embolism (13.3%) were the most common etiologies. The mean percentage of arrests due to a non-cardiac cause in three sequential time-periods (1995-1999, 2000-2002, 2003-2005) was 9.4%, 20.1% and 37.7%, respectively.
  
  
  CONCLUSIONS
  Over the study period, 21.7% of OHCAs were non-cardiac in origin. PEA was the most common presenting rhythm and respiratory failure the most common etiology. 8.9% of patients survived. The decreasing number of VF arrests may be a contributing factor to the increasing proportion of OHCAs of non-cardiac etiology observed in the out-of-hospital setting.
authors.affiliation: Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Erik P
authors.initials: EP
authors.lastname: Hess
authors.forename: Ronna L
authors.initials: RL
authors.lastname: Campbell
authors.forename: Roger D
authors.initials: RD
authors.lastname: White
mesh_terms: D000465:Algorithms; D016887:Cardiopulmonary Resuscitation / Q000706:statistics & numerical data*; D004332:Drowning / Q000453:epidemiology*; D062787:Drug Overdose / Q000453:epidemiology*; D004632:Emergency Medical Services / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D011655:Pulmonary Embolism / Q000453:epidemiology*; D012131:Respiratory Insufficiency / Q000453:epidemiology*; D016896:Treatment Outcome