title: Waveform analysis-guided treatment versus a standard shock-first protocol for the treatment of out-of-hospital cardiac arrest presenting in ventricular fibrillation: results of an international randomized, controlled trial.
abstract: BACKGROUND
  Ventricular fibrillation (VF) waveform properties have been shown to predict defibrillation success and outcomes among patients treated with immediate defibrillation. We postulated that a waveform analysis algorithm could be used to identify VF unlikely to respond to immediate defibrillation, allowing selective initial treatment with cardiopulmonary resuscitation in an effort to improve overall survival.
  
  
  RESULTS
  In a multicenter, double-blind, randomized study, out-of-hospital cardiac arrest patients in 2 urban emergency medical services systems were treated with automated external defibrillators using either a VF waveform analysis algorithm or the standard shock-first protocol. The VF waveform analysis used a predefined threshold value below which return of spontaneous circulation (ROSC) was unlikely with immediate defibrillation, allowing selective treatment with a 2-minute interval of cardiopulmonary resuscitation before initial defibrillation. The primary end point was survival to hospital discharge. Secondary end points included ROSC, sustained ROSC, and survival to hospital admission. Of 6738 patients enrolled, 987 patients with VF of primary cardiac origin were included in the primary analysis. No immediate or long-term survival benefit was noted for either treatment algorithm (ROSC, 42.5% versus 41.2%, P=0.70; sustained ROSC, 32.4% versus 33.4%, P=0.79; survival to admission, 34.1% versus 36.4%, P=0.46; survival to hospital discharge, 15.6% versus 17.2%, P=0.55, respectively).
  
  
  CONCLUSIONS
  Use of a waveform analysis algorithm to guide the initial treatment of out-of-hospital cardiac arrest patients presenting in VF did not improve overall survival compared with a standard shock-first protocol. Further study is recommended to examine the role of waveform analysis for the guided management of VF.
authors: Office of Medical Affairs, Fire Department of New York, 9 MetroTech Center, Brooklyn, NY 11201, USA. freesej@fdny.nyc.gov
authors: John P
authors: JP
authors: Freese
authors: Dawn B
authors: DB
authors: Jorgenson
authors: Ping-Yu
authors: PY
authors: Liu
authors: Jennifer
authors: J
authors: Innes
authors: Luis
authors: L
authors: Matallana
authors: Krishnakant
authors: K
authors: Nammi
authors: Rachael T
authors: RT
authors: Donohoe
authors: Mark
authors: M
authors: Whitbread
authors: Robert A
authors: RA
authors: Silverman
authors: David J
authors: DJ
authors: Prezant
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016887:Cardiopulmonary Resuscitation; D047548:Defibrillators; D019468:Disease Management; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007391:International Cooperation; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000209:etiology / Q000628:therapy*; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000150:complications / Q000628:therapy*; D055815:Young Adult
keywords: atrial fibrillation; cardiopulmonary resuscitation; defibrillation, electric; resuscitation