Norwegian Study Identifies 574 Annual Candidates for Initial Double Sequential Defibrillation

A nationwide assessment of out-of-hospital cardiac arrest in Norway found that an average of 574 patients each year required two or more defibrillations, defining a potential candidate cohort for evaluating double sequential external defibrillation as an initial resuscitation strategy.

The retrospective observational cohort study evaluated adult patients aged 18 and older who experienced out-of-hospital cardiac arrest across Norway during an eight-year period from 2016 through 2023. Investigators sought to quantify patients meeting predefined criteria for early double sequential external defibrillation, as the potential impact of such clinical strategies in the Norwegian population remained unknown.

Defibrillation serves as a vital intervention for survival among patients presenting with shockable arrhythmias, including ventricular fibrillation and pulseless ventricular tachycardia. When patients require multiple defibrillation attempts to achieve return of spontaneous circulation, every unsuccessful attempt extends the duration spent without spontaneous circulation, prompting the need to explore strategies that decrease time to resuscitation.

To evaluate potential candidates for initial double sequential external defibrillation, the study protocol identified patients who received two or more defibrillation attempts during cardiopulmonary resuscitation. Over the full eight-year surveillance window, emergency personnel administered defibrillation shocks to 7,280 patients undergoing cardiopulmonary resuscitation.

Among the 7,280 patients who received shocks during cardiopulmonary resuscitation, 4,591 individuals—representing 63 percent of the shocked cohort—received two or more defibrillation attempts. This total corresponded to an annual average of 574 patients requiring repeated electrical shocks across Norway.

Survival analysis within the cohort receiving multiple defibrillations revealed that 1,935 patients, or 42 percent, survived the initial cardiac arrest event. When examining longer-term outcomes, 1,282 patients, accounting for 28 percent of the multiple-shock group, survived to 30 days.

The authors concluded that while approximately 574 patients annually meet the criteria for treatment with initial double sequential external defibrillation, these findings indicate a relatively small candidate population for future trials investigating the strategy within Norway alone.

Subject of Research: Candidate population for initial double sequential external defibrillation in Norwegian cardiac arrest patients

Article Title: Potential use of double sequential external defibrillation (DSED) in out-of-hospital cardiac arrest as initial strategy – a nationwide assessment

Article References: Nordviste, V., Lode, I., Tjelmeland, I. B. M., Kramer-Johansen, J., Rehn, M., & Brede, J. R. (2026). Potential use of double sequential external defibrillation (DSED) in out-of-hospital cardiac arrest as initial strategy – a nationwide assessment. BMC Emergency Medicine. https://doi.org/10.1186/s12873-026-01787-2

Image Credits: AI Generated

DOI: 10.1186/s12873-026-01787-2

Keywords: double sequential external defibrillation, out-of-hospital cardiac arrest, ventricular fibrillation, pulseless ventricular tachycardia, cardiopulmonary resuscitation, return of spontaneous circulation, shockable arrhythmia, defibrillation attempts, 30-day survival, event survival, Norway, retrospective cohort study, observational study, adult cardiac arrest, emergency medicine, candidate population