title: [Inappropriate analyses of automated external defibrillators used during out-of-hospital cardiac arrests].
abstract: OBJECTIVE
  To estimate the frequency of therapeutic errors and to evaluate the diagnostic accuracy in the recognition of shockable rhythms by automated external defibrillators.
  
  
  METHODS
  A retrospective descriptive study.
  
  
  METHODS
  Nine basic life support units from Biscay (Spain).
  
  
  METHODS
  Included 201 patients with cardiac arrest, since 2006 to 2011.
  
  
  METHODS
  The study was made of the suitability of treatment (shock or not) after each analysis and medical errors identified. The sensitivity, specificity and predictive values with 95% confidence intervals were then calculated.
  
  
  RESULTS
  A total of 811 electrocardiographic rhythm analyses were obtained, of which 120 (14.1%), from 30 patients, corresponded to shockable rhythms. Sensitivity and specificity for appropriate automated external defibrillators management of a shockable rhythm were 85% (95% CI, 77.5% to 90.3%) and 100% (95% CI, 99.4% to 100%), respectively. Positive and negative predictive values were 100% (95% CI, 96.4% to 100%) and 97.5% (95% CI, 96% to 98.4%), respectively. There were 18 (2.2%; 95% CI, 1.3% to 3.5%) errors associated with defibrillator management, all relating to cases of shockable rhythms that were not shocked. One error was operator dependent, 6 were defibrillator dependent (caused by interaction of pacemakers), and 11 were unclassified.
  
  
  CONCLUSIONS
  Automated external defibrillators have a very high specificity and moderately high sensitivity. There are few operator dependent errors. Implanted pacemakers interfere with defibrillator analyses.
authors.affiliation: Bilbao SAMUR-Protección Civil, Bilbao, Vizcaya, España. sendoa.ballesteros@gmail.com
authors.forename: Sendoa
authors.initials: S
authors.lastname: Ballesteros Peña
mesh_terms: D047548:Defibrillators; D004868:Equipment Failure / Q000706:statistics & numerical data*; D006801:Humans; D058687:Out-of-Hospital Cardiac Arrest / Q000175:diagnosis* / Q000628:therapy*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity