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Double Sequential External Defibrillation

Double Sequential External Defibrillation was successfully used in a pilot study by Cheskes, et al. and published in the journal Resuscitation in 20202. A large trial is necessary to show if DSED is successful in increasing neurologically intact survival to hospital discharge. However, the pilot did provide proof of concept. In the pilot study of 150 patients, ventricular fibrillation was treated with standard defibrillation x 3 shocks, in all patients. After three shocks, patients were randomized into three groups: standard defibrillation, vector change (anterior posterior), or double sequential defibrillation. Findings from the pilot study of 150 patients included:

Termination of VF

  • Standard group: 66.6%
  • Vector change group: 82.0%
  • Dual sequential group: 76.3%
  • ROSC was achieved in 25.0%, 39.3% and 40.0% of standard, VC and DSED groups, respectively.

Return Of Spontaneous Circulation

  • Standard group: 25%
  • Vector change group: 39.3%
  • Dual sequential group: 40%

Protocol For Dual Sequential Defibrillation

“…paramedics will apply a second set of defibrillation pads in the anterior-posterior configuration (Fig. 1) Application of the second set of defibrillation pads for the second defibrillator will occur during the 2-min cycle of CPR following the third defibrillation attempt, minimizing any interruptions in CPR. All subsequent defibrillation attempts will be carried out by sequential defibrillation shocks provided by two defibrillators. To ensure that shocks are not administered at the exact same moment, we will employ a short (less than 1 s) delay to provision of the second defibrillator shock. This will be accomplished by having a single paramedic pressing the “shock” button on each defibrillator in rapid succession as opposed to simultaneously. This technique will be performed across all sites when randomized to the DSED arm to maintain consistency in application within the trial.”

Fig. 1
1. Standard placement 2. AP placement for VC group 3.DSED group received both. Source


  1. Drennan, I.R., Dorian, P., McLeod, S. et al. DOuble SEquential External Defibrillation for Refractory Ventricular Fibrillation (DOSE VF): study protocol for a randomized controlled trial. Trials 21, 977 (2020). https://doi.org/10.1186/s13063-020-04904-z
  2. Cheskes S, Dorian P, Feldman M, McLeod S, Scales DC, Pinto R, Turner L, Morrison LJ, Drennan IR, Verbeek PR. Double sequential external defibrillation for refractory ventricular fibrillation: The DOSE VF pilot randomized controlled trial. Resuscitation. 2020 May;150:178-184. doi: 10.1016/j.resuscitation.2020.02.010. Epub 2020 Feb 19. PMID: 32084567.

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