title: Effect of bystander initiated cardiopulmonary resuscitation on ventricular fibrillation and survival after witnessed cardiac arrest outside hospital.
abstract: OBJECTIVE
  To describe the proportion of patients who were discharged from hospital after witnessed cardiac arrest outside hospital in relation to whether a bystander initiated cardiopulmonary resuscitation.
  
  
  METHODS
  All patients with witnessed cardiac arrest outside hospital before arrival of the ambulance and in whom cardiopulmonary resuscitation was attempted by the emergency medical service in Gothenburg during 1980-92.
  
  
  RESULTS
  Cardiopulmonary resuscitation was initiated by a bystander in 18% (303) of 1,660 cases. In this group 69% had ventricular fibrillation at first recording compared with 51% in the remaining patients (P < 0.001). Among patients in whom cardiopulmonary resuscitation had been initiated by a bystander 25% were discharged alive versus 8% of the remaining patients (P < 0.001). Independent predictors of survival were in order of significance: initial arrhythmia (P < 0.001), interval between collapse and arrival of first ambulance (P < 0.001), cardiopulmonary resuscitation initiated by a bystander (P < 0.001), and age (P < 0.01). Among patients who were admitted to hospital alive 30% of patients in whom cardiopulmonary resuscitation had been initiated by a bystander compared with 58% of remaining patients (P < 0.001) had brain damage and died in hospital. Corresponding figures for death in association with myocardial damage were 18% and 29% respectively (P < 0.01).
  
  
  CONCLUSIONS
  Cardiopulmonary resuscitation initiated by a bystander maintains ventricular fibrillation and triples the chance of surviving a cardiac arrest outside hospital. Furthermore, it seems to protect against death in association with brain damage as well as with myocardial damage.
authors: Division of Cardiology, Sahlgrenska Hospital, Gothenburg, Sweden.
authors: J
authors: J
authors: Herlitz
authors: L
authors: L
authors: Ekström
authors: B
authors: B
authors: Wennerblom
authors: A
authors: A
authors: Axelsson
authors: A
authors: A
authors: Bång
authors: S
authors: S
authors: Holmberg
mesh_terms: D000367:Age Factors; D002545:Brain Ischemia / Q000517:prevention & control; D016887:Cardiopulmonary Resuscitation / Q000401:mortality; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000517:prevention & control; D011379:Prognosis; D015996:Survival Rate; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000401:mortality