title: Etiology of out-of-hospital cardiac arrest diagnosed via detailed examinations including perimortem computed tomography.
abstract: BACKGROUND
  The spectrum of the etiology of out-of-hospital cardiopulmonary arrest (OHCPA) has not been established. We have performed perimortem computed tomography (CT) during cardiopulmonary resuscitation.
  
  
  OBJECTIVE
  To clarify the incidence of non-cardiac etiology (NCE), actual distribution of the causes of OHCPA via perimortem CT and its usefulness.
  
  
  METHODS
  Population-based observational case series study.
  
  
  METHODS
  We reviewed the medical records of 1846 consecutive OHCPA cases and divided them into two groups: 370 showing an obvious cause of OHCPA with NCE (trauma, neck hanging, terminal stage of malignancy, and gastrointestinal bleeding) and others.
  
  
  RESULTS
  Of a total OHCPA, perimortem CT was performed in 57.5% and 62.5% were finally diagnosed as NCE: Acute aortic dissection (AAD) 8.07%, pulmonary thrombo-embolization (PTE) 1.46%, hypoxia due to pneumonia 5.25%, asthma and acute worsening of chronic obstructive pulmonary disease 2.06%, cerebrovascular disorder (CVD) 4.48%, airway obstruction 7.64%, and submersion 5.63%. The rates of patients who survived to hospital discharge were 6-14% in patients with NCE. Out of the 1476 cases excluding obvious NCE of OHCPA, 66.3% underwent perimortem CT, 14.6% of cases without obvious NCE and 22.1% of cases with perimortem CT were confirmed as having some NCE.
  
  
  CONCLUSIONS
  Of the total OHCPA the incidences of NCE was 62.5%; the leading etiologies were AAD, airway obstruction, submersion, hypoxia and CVD. The rates of cases converted from cardiac etiology to NCE using perimortem CT were 14.6% of cases without an obvious NCE.
authors.affiliation: Critical Care and Emergency Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Moriwaki
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tahara
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kosuge
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Suzuki
keywords: Etiology of out-of-hospital cardiac arrest; out-of-hospital cardiac arrest with non-cardiac etiology; perimortem computed tomography; perimortem imaging