title: Medical futility in asystolic out-of-hospital cardiac arrest.
abstract: OBJECTIVE
  To study the factors associated with short- and long-term survival after asystolic out-of-hospital cardiac arrest, with a reference to medical futility.
  
  
  METHODS
  This is a retrospective observational study conducted in Helsinki, Finland during 1 January 1997 to 31 December 2005. All out-of-hospital cardiac arrests were prospectively registered in the cardiac arrest database. Of 3291 arrests, 1455 had asystole as the first registered rhythm. These patients represent the study population.
  
  
  RESULTS
  A short time interval to the initiation of advanced life support (ALS) was associated with a long-term benefit, but a short first responding unit (FRU) response time had only a short-term benefit. Conversion of asystole into a shockable rhythm provided only a short-term benefit. The prognosis was poor if the FRU response time was over 10 min or the ALS response time was over 11 min in bystander-witnessed arrests, and if the duration of resuscitation was over 8 min in emergency medical services (EMS)-witnessed arrests. Bystander-CPR was associated with increased 30-day mortality. The 30-day survival rate after an unwitnessed arrest (n=548) was 0.5%. All survivors in this group were either hypothermic or were victims of near-drowning.
  
  
  CONCLUSIONS
  Resuscitation should be withheld in cases of unwitnessed asystole, excluding cases of hypothermia and near-drowning. The prognosis is poor if the FRU response time is over 10 min or the ALS response time is over 10-15 min in bystander-witnessed arrests. The decision of whether or not to attempt resuscitation should not be influenced by the presence of bystander-CPR. Early initiation of ALS should be prioritised in the treatment of out-of-hospital asystole.
authors.affiliation: Helsinki Emergency Medical Services (EMS), Department of Anaesthesiology and Intensive Care Medicine, Helsinki University Central Hospital, Helsinki, Finland. Taneli.vayrynen@hus.fi
authors.forename: T
authors.initials: T
authors.lastname: Väyrynen
authors.forename: M
authors.initials: M
authors.lastname: Kuisma
authors.forename: T
authors.initials: T
authors.lastname: Määttä
authors.forename: J
authors.initials: J
authors.lastname: Boyd
mesh_terms: D000293:Adolescent; D000328:Adult; D022561:Advanced Cardiac Life Support / Q000401:mortality / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D001925:Brain Damage, Chronic / Q000453:epidemiology / Q000209:etiology; D016887:Cardiopulmonary Resuscitation / Q000401:mortality / Q000706:statistics & numerical data*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D019983:Guideline Adherence / Q000706:statistics & numerical data; D006323:Heart Arrest / Q000209:etiology / Q000401:mortality* / Q000628:therapy; D017052:Hospital Mortality; D006801:Humans; D007035:Hypothermia / Q000150:complications; D008297:Male; D018447:Medical Futility; D008875:Middle Aged; D015701:Near Drowning / Q000150:complications; D017410:Practice Guidelines as Topic; D011379:Prognosis; D016414:Resuscitation Orders; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome