title: Independent evaluation of an out-of-hospital termination of resuscitation (TOR) clinical decision rule.
abstract: OBJECTIVE
  Recently, investigators described a clinical decision rule for termination of resuscitation (TOR) designed to help determine whether to terminate emergency medical services (EMS) resuscitative efforts for out-of-hospital cardiac arrests (OOHCA). The authors sought to evaluate the hypothesis that TOR would predict no survival for patients in an independent cohort of patients with OOHCA.
  
  
  METHODS
  This was a retrospective cohort analysis conducted in the state of Arizona. Consecutive, adult, OOHCA were prospectively evaluated from October 2004 through October 2006. A statewide OOHCA database utilizing Utstein-style reporting from 30 different EMS systems was used. Data were abstracted from EMS first care reports and hospital discharge records. The TOR guidelines predict that no survival to hospital discharge will occur if 1) an OOHCA victim does not have return of spontaneous circulation (ROSC), 2) no shocks are administered, and 3) the arrest is not witnessed by EMS personnel. Data were entered into a structured database. Continuous data are presented as means (+/-standard deviations [SD]) and categorical data as frequency of occurrence, and 95% confidence intervals (CIs) were calculated as appropriate. The primary outcome measure was to determine if any cohort member who met TOR criteria survived to hospital discharge.
  
  
  RESULTS
  There were 2,239 eligible patients; the study group included 2,180 (97.4%) patients for whom the data were complete; mean age was 64 (+/-11) years, and 35% were female. The majority of patients in the study group met at least one or more of the TOR criteria. A total of 2,047 (93.8%) patients suffered from cardiac arrest that was unwitnessed by EMS; 1,653 (75.8%) had an unwitnessed arrest and no ROSC. With respect to TOR, 1,160 of 2,180 (53.2%) patients met all three criteria; only one (0.09%; 95% CI = 0% to 0.5%) survived to hospital discharge.
  
  
  CONCLUSIONS
  The authors evaluated TOR guidelines in an independent, statewide OOHCA database. The results are consistent with the findings of the TOR investigation and suggest that this algorithm is a promising tool for TOR decision-making in the field.
authors.affiliation: Bureau of Emergency Medical Services and Trauma Systems, Arizona Department of Health Services, Phoenix, AZ, USA. PRichmanMD@aol.com
authors.forename: Peter B
authors.initials: PB
authors.lastname: Richman
authors.forename: Tyler F
authors.initials: TF
authors.lastname: Vadeboncoeur
authors.forename: Vatsal
authors.initials: V
authors.lastname: Chikani
authors.forename: Lani
authors.initials: L
authors.lastname: Clark
authors.forename: Bentley J
authors.initials: BJ
authors.lastname: Bobrow
mesh_terms: D001130:Arizona / Q000453:epidemiology; D016887:Cardiopulmonary Resuscitation / Q000592:standards*; D016001:Confidence Intervals; D003661:Decision Support Techniques; D004632:Emergency Medical Services / Q000592:standards*; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D018447:Medical Futility; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D016414:Resuscitation Orders; D012189:Retrospective Studies; D016019:Survival Analysis; D028761:Withholding Treatment / Q000592:standards*