title: Impact of bystander-performed ventilation on functional outcomes after cardiac arrest and factors associated with ventilation-only cardiopulmonary resuscitation: A large observational study.
abstract: OBJECTIVE
  To determine the effectiveness of ventilations in bystander cardiopulmonary resuscitation (BCPR) and to identify the factors associated with ventilation-only BCPR.
  
  
  METHODS
  From out-of-hospital cardiac arrest (OHCA) data prospectively collected from 2005 to 2011 in Japan, we extracted data for 210,134 bystander-witnessed OHCAs with complete datasets but no prehospital involvement of physician [no BCPR, 115,733; ventilation-only, 2093; compression-only, 61,075; and conventional (compressions+ventilations) BCPR, 31,233] and determined the factors associated with 1-month neurologically favourable survival using simple and multivariable logistic regression analyses. In 91,885 patients with known BCPR durations, we determined the factors associated with ventilation-only BCPR.
  
  
  RESULTS
  The rate of survival in the no BCPR, ventilation-only, compression-only and conventional group was 2.8%, 3.9%, 4.5% and 5.0%, respectively. After adjustment for other factors associated with outcomes, the survival rate in the ventilation-only group was higher than that in the no BCPR group (adjusted OR; 95% CI, 1.29; 1.01-1.63), but lower than that in the compression-only (0.76; 0.59-0.96) or conventional groups (0.70; 0.55-0.89). Conventional CPR had the highest OR for survival in almost all OHCA subgroups. The adjusted OR (95% CI) for survival after dividing BCPR into ventilation and compression components was 1.19 (1.11-1.27) and 1.60 (1.51-1.69), respectively. Older guidelines, female sex, younger patient age, bystander-initiated CPR without instruction, early BCPR and short BCPR duration were associated with ventilation-only BCPR.
  
  
  CONCLUSIONS
  Ventilation is a significant component of BCPR, but alone is less effective than compression in improving neurologically favourable survival after OHCAs.
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan. Electronic address: tetsumae@med.kanazawa-u.ac.jp.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Maeda
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan. Electronic address: kamitaka911@gmail.com.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Kamikura
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan. Electronic address: ytanaka.md@gmail.com.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Cardiology, Noto General Hospital, A64-6-4 Fijihashi-machi, Nanao, Ishikawa 926-0816, Japan. Electronic address: yamashita@noto-hospital.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamashita
authors.affiliation: Department of Pediatrics, Ishikawa Prefectural Central Hospital, 2-1 Kuratsuki-Higashi, Kanazawa, Ishikawa 920-8201, Japan. Electronic address: min-kubo3e@ipch.jp.
authors.forename: Minoru
authors.initials: M
authors.lastname: Kubo
authors.affiliation: Department of Medical Science and Technology, Hiroshima International University, 555-36 Kurose-gakuendai, Higashi-hiroshima, Hiroshima 739-2695, Japan; Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan. Electronic address: y-takei@hs.hirokoku-u.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takei
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan. Electronic address: hidinaba@med.kanazawa-u.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Inaba
mesh_terms: D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy*; D010820:Physicians; D011446:Prospective Studies; D015996:Survival Rate
keywords: Bystander cardiopulmonary resuscitation; Out-of-hospital cardiac arrest; Ventilation