title: Relationship Between the Duration of Cardiopulmonary Resuscitation and Favorable Neurological Outcomes After Out-of-Hospital Cardiac Arrest: A Prospective, Nationwide, Population-Based Cohort Study.
abstract: BACKGROUND
  The determination of appropriate duration of in-the-field cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) patients is one of the biggest challenges for emergency medical service providers and clinicians. The appropriate CPR duration before termination of resuscitation remains unclear and may differ based on initial rhythm. We aimed to determine the relationship between CPR duration and post-OHCA outcomes.
  
  
  RESULTS
  We analyzed the records of 17 238 OHCA patients (age ≥18 years) who achieved prehospital return of spontaneous circulation. Data were prospectively recorded in a nationwide, Japanese database between 2011 and 2012. The time from CPR initiation to prehospital return of spontaneous circulation (CPR duration) was calculated. The primary end point was 1-month survival with favorable neurological outcomes (Cerebral Performance Category [CPC] scale; CPC 1-2). The 1-month CPC 1-2 rate was 21.8% (n=3771). CPR duration was inversely associated with 1-month CPC 1-2 (adjusted unit odds ratio: 0.95, 95% CI: 0.94-0.95). Among all patients, a cumulative proportion of >99% of 1-month CPC 1-2 was achieved with a CPR duration of 35 minutes. When sorted by the initial rhythm, the CPR duration producing more than 99% of survivors with CPC 1-2 was 35 minutes for shockable rhythms and pulseless electrical activity, and 42 minutes for asystole.
  
  
  CONCLUSIONS
  CPR duration was independently and inversely associated with favorable 1-month neurological outcomes. The critical prehospital CPR duration for OHCA was 35 minutes in patients with initial shockable rhythms and pulseless electrical activity, and 42 minutes in those with initial asystole.
authors.affiliation: Department of Emergency and Critical Care Medicine, Kanazawa University Hospital, Kanazawa, Japan gotoyosh@med.kanazawa-u.ac.jp.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Emergency and Critical Care Medicine, Kanazawa University Hospital, Kanazawa, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Funada
authors.affiliation: Department of Cardiology, Yawata Medical Center, Komatsu, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Goto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001775:Blood Circulation; D016887:Cardiopulmonary Resuscitation / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009460:Neurologic Examination; D016017:Odds Ratio; D058687:Out-of-Hospital Cardiac Arrest / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D020127:Recovery of Function; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*
keywords: cardiopulmonary resuscitation; epidemiology; heart arrest; resuscitation