title: Rhythm analysis and charging during chest compressions reduces compression pause time.
abstract: OBJECTIVE
  Prolonged chest compression interruptions immediately preceding and following a defibrillation shock reduce shock success and survival after cardiac arrest. We tested the hypothesis that compression pauses would be shorter using an AED equipped with a new Analysis during Compressions with Fast Reconfirmation (ADC-FR) technology, which features automated rhythm analysis and charging during compressions with brief reconfirmation analysis during compression pause, compared with standard AED mode.
  
  
  METHODS
  BLS-certified emergency medical technicians (EMTs) worked in pairs and performed two trials of simulated cardiac resuscitation with a chest compression sensing X Series defibrillator (ZOLL Medical). Each pair was randomized to perform a trial of eight 2-min compression intervals (randomly assigned to receive four shockable and four non-shockable rhythms) with the defibrillator in standard AED mode and another trial in ADC-FR mode. Subjects were advised to follow defibrillator prompts, defibrillate if "shock advised," and switch compressors every two intervals. Compression quality data were reviewed using RescueNet Code Review (ZOLL Medical) and analyzed using paired t-tests.
  
  
  RESULTS
  Thirty-two EMT-basic prehospital providers (59% male; median 25 years age [IQR 22-27]) participated in the study. End of interval compression interruptions were significantly reduced with ADC-FR vs. AED mode (p<0.001). For shockable rhythms, pre-shock pause was reduced significantly with ADC-FR compared with AED use (7.35±0.16s vs. 12.0±0.22s, p<0.001) whereas post-shock pause was similar (2.08±0.14s vs. 1.77±0.14s, p=0.1).
  
  
  CONCLUSIONS
  Chest compression interruptions associated with rhythm analysis and charging are reduced with use of a novel defibrillator technology, ADC-FR, which features automated rhythm analysis and charging during compressions.
authors.affiliation: Emerson Hospital, Concord, MA, USA. Electronic address: Robert_Partridge_MD@brown.edu.
authors.forename: R
authors.initials: R
authors.lastname: Partridge
authors.affiliation: ZOLL Medical, Chelmsford, MA, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Tan
authors.affiliation: ZOLL Medical, Chelmsford, MA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Silver
authors.affiliation: ZOLL Medical, Chelmsford, MA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Riley
authors.affiliation: ZOLL Medical, Chelmsford, MA, USA.
authors.forename: F
authors.initials: F
authors.lastname: Geheb
authors.affiliation: Armstrong Ambulance, Arlington, MA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Raymond
mesh_terms: D000328:Adult; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D047548:Defibrillators; D004554:Electric Countershock / Q000379:methods*; D004634:Emergency Medical Technicians; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D058687:Out-of-Hospital Cardiac Arrest / Q000628:therapy*; D011897:Random Allocation; D017180:Tachycardia, Ventricular / Q000628:therapy; D014693:Ventricular Fibrillation / Q000628:therapy; D055815:Young Adult
keywords: AED; Cardiac resuscitation; Cardiac rhythm analysis; Chest compressions