title: Abnormal breathing of sudden cardiac arrest victims described by laypersons and its association with emergency medical service dispatcher-assisted cardiopulmonary resuscitation instruction.
abstract: BACKGROUND
  Current guidelines for cardiopulmonary resuscitation (CPR) emphasise that emergency medical service (EMS) dispatchers should identify sudden cardiac arrest (CA) with abnormal breathing and assist lay rescuers performing CPR. However, lay rescuers description of abnormal breathing may be inconsistent, and it is unclear how EMS dispatchers provide instruction for CPR based on the breathing status of the CA victims described by laypersons.
  
  
  RESULTS
  To investigate the incidence of abnormal breathing and the association between the EMS dispatcher-assisted CPR instruction and layperson CPR, we retrospectively analysed 283 witnessed CA cases whose information regarding breathing status of CA victims was available from population-based prospective cohort data. In 169 cases (59.7%), laypersons described that the CA victims were breathing in various ways, and that the victims were 'not breathing' in 114 cases (40.3%). Victims described as breathing in various ways were provided EMS dispatch-instruction for CPR less frequently than victims described as 'not breathing' (27.8% (47/169) vs 84.2% (96/114); p<0.001). Multivariate logistic regression showed that EMS dispatch-instruction for CPR was associated significantly with layperson CPR (adjusted OR, 11.0; 95% CI, 5.72 to 21.2).
  
  
  CONCLUSIONS
  This population-based study indicates that 60% of CA victims showed agonal respiration, which was described as breathing in various ways at the time of EMS call. Although EMS dispatch-instruction was associated significantly with an increase in layperson CPR, abnormal breathing was associated with a much lower rate of CPR instruction and, in turn, was related to a much lower rate of bystander CPR.
authors.affiliation: Department of Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Hidetada
authors.initials: H
authors.lastname: Fukushima
authors.affiliation: Department of Neurosurgery, Nara Saiseikai Gose Hospital, Gose, Nara, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Imanishi
authors.affiliation: Department of Health Service, Kyoto University Health Service, Kyoto, Kyoto, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Iwami
authors.affiliation: Department of Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Seki
authors.affiliation: Department of Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kawai
authors.affiliation: Department of Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Norimoto
authors.affiliation: Department of Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Urisono
authors.affiliation: Department of Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Hata
authors.affiliation: Department of General Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nishio
authors.affiliation: Department of Community Health and Epidemiology, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Saeki
authors.affiliation: Department of Community Health and Epidemiology, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Kurumatani
authors.affiliation: Department of Emergency and Critical Care Medicine, Nara Medical University, Kashihara, Nara, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Okuchi
mesh_terms: D016887:Cardiopulmonary Resuscitation; D004631:Emergency Medical Service Communication Systems; D004632:Emergency Medical Services; D006801:Humans; D058687:Out-of-Hospital Cardiac Arrest / Q000503:physiopathology* / Q000628:therapy*; D012120:Respiration Disorders / Q000503:physiopathology*; D012189:Retrospective Studies; D016019:Survival Analysis
keywords: cardiopulmonary resuscitation; emergency medical services