Early Double Sequential Defibrillation in Out-of-hospital Cardiac Arrest (DOUBLE-D)

"A Pilot Study Assessing Feasibility of a Randomized Trial Comparing the Effect of Early Double Sequential Defibrillation as Soon as Possible in OHCA With a Shockable Rhythm (VT/VF) Compared to Standard Defibrillation"

Some of the patients affected by Out-of-hospital cardiac arrest (OHCA) with ventricular fibrillation (VF)/ventricular tachycardia (VT) do not respond to initial defibrillation. The survival decreases with number of defibrillations required to terminate VF/VT. In 2022, one prospective cluster randomized trial showed increased survival among (OHCA) patients in refractory VF using Double Sequential Defibrillation (DSD).

To evaluate feasibility and safety this randomized pilot trial will compare the effect of double defibrillation strategy initiated as soon as possible after the first defibrillation with continued resuscitation using standard defibrillation, in patients with Out of Hospital Cardiac arrest (OHCA). The results from this pilot trial will form the basis for design of a larger multicenter survival study.

Study Overview

• Status: Completed
• Conditions: Cardiac Arrest; Sudden Cardiac Death; Sudden Cardiac Arrest; Fibrillation, Ventricular
• Intervention / Treatment: Device: Double Sequential Defibrillation (DSD); Device: Standard defibrillation

Detailed Description

The Dubbel-D study is an academic, investigator initiated, open-label pilot study with a randomized controlled trial (RCT) design conducted in the prehospital emergency medical services, i.e. ambulance organizations. The trial will be conducted by participating ambulance units attending OHCA´s. These units will perform screening for inclusion, randomization, intervention or control treatment and initial follow-up.

In all cases of OHCA a defibrillator should always be attached with the standard pad placement, anterio-lateral (A-L) position first. This is in accordance with standard of care. If there is VT/VF or an automated external defibrillator (AED) suggests defibrillation, defibrillation should be performed, and immediate chest compressions resumed. Thereafter, the patient can be screened for inclusion. If two study specific defibrillators (Corpulse 3) on site and no exclusion criteria (age below 18 years, obvious pregnancy, known preexisting Do Not Attempt Resuscitation order) the patient can be included and randomized.

Randomization will be performed by drawing a scratch-card with concealed allocation that will be stored with the EMS defibrillators. All scratch-cards will be pre-randomized in a 3:1 ratio in blocks consisting of 4-8-12 and stratified by region and ambulance provider.

If the patient is randomized to the intervention group, the ambulance crew team will apply the second defibrillator with electrodes placed in the anterio-posterior (A-P) position as soon as possible. Defibrillation is performed by one person defibrillating both defibrillators in a sequential manner "Double Sequential Defibrillation" (DSD). All consecutive defibrillations will thereafter be performed with the DSD strategy until ROSC, termination of resuscitation or decision to move the patient to hospital.

If randomized to the control group, the ambulance crew team will continue Advanced Life Support (ACLS) in accordance with standard of care. Defibrillation is performed with standard electrode placement (A-L position) using a single defibrillator. If an AED is the first defibrillator attached to the patient, the ambulance crew should shift from an AED to their own manual defibrillator, but the mode of defibrillation should remain in A-L position and only one defibrillator should be used for each defibrillation and continue until ROSC, termination of resuscitation or decision to move the patient to hospital.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Sweden
  • Halland County
    • Halmstad, Halland County, Sweden, 30238
      • Emergency medical services Region Halland
  • Västra Götalandsregionen
    • Gothenburg, Västra Götalandsregionen, Sweden, 411 04
      • Sahlgrenska Universitetssjukhuset, Ambulans och Prehospital Akutsjukvård
  • Västra Götalandsregionen
    • Alingsås, Västra Götalandsregionen, Sweden, 441 39
      • Sjukhusen i väster, ambulanssjukvården Alingsås/Lerum

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Out-of-Hospital patients with Ventricular Fibrillation/ Ventricular Tachycardia at rhythm analysis after ambulance arrival and at least one defibrillation performed in standard (Antero-Lateral) position

Exclusion Criteria:

• Age below 18 years
• Obvious pregnancy
• Known preexisting Do Not Attempt Resuscitation order

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Double Sequential Defibrillation (DSD); If the patient is randomized to the DSD group, the ambulance crew team will apply the second defibrillator with electrodes placed in the A-P position as soon as possible. Defibrillation is performed by one person defibrillating both defibrillators in a sequential manner "Double Sequential Defibrillation" (DSD). All consecutive defibrillations will thereafter be performed with the DSD strategy until ROSC, termination of resuscitation or decision to move the patient to hospital.	Device: Double Sequential Defibrillation (DSD); The second defibrillator will be applyed with electrodes placed in the A-P position
Active Comparator: Standard defibrillation; If the patient is randomized to the standard defibrillation group, the ambulance crew team will continue Advanced life support in accordance with standard of care and continue to perform standard defibibrillation using one defibrillator. All consecutive defibrillations will thereafter be performed with the standard defibrillation strategy until ROSC, termination of resuscitation or decision to move the patient to hospital.	Device: Standard defibrillation; Standard defibrillation uning one defibrillator

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of early double sequential external defibrillation (DSD)	Number of EMS defibrillations prior to randomization (target > 80% before third defibrillation)	day 1
Adherence to double sequential external defibrillation (DSD)	Among patients randomized to DSD, proportion that received DSD (target > 80%)	day 1
Cross-over	Among patients randomized to standard, proportion that received DSD (target < 10%)	day 1
Feasibility of double sequential external defibrillation (DSD)	Proportion of eligible patients included and randomized (target > 80%)	day 1
Safety of double sequential external defibrillation	Major adverse events (e.g. defibrillator malfunction)	day 1
Safety of CPR during double sequential external defibrillation	Chest compression fraction (hands off time during CPR, target > 80% in both groups)	day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Return of spontaneous circulation (ROSC)	Proportion of patients with sustained return of spontaneous circulation (ROSC) at hospital arrival	day 1
Number of defibrillations to sustained ROSC	Total number of defibrillations to sustained ROSC	day 1
Survival to hospital admission	Pateint is admitted to hospital alive	day 1
Survival to discharge	Survival to hospital discharge	day 1-180
30 day survival	Survival at 30 days	day 30
Neurological function at 30 days	Neurological function (modified Rankin Scale, mRS 1-6, and Cerebral Performance Category, CPC 1-5) at 30 days	day 30
Neurological function and Health related Quality of life at 90 and 180 days	Neurological function (modifiied Rankin Scale and Cerebral Performance Category) and Health-related Quality of life at 90 and 180 days (CPC 1-5, mRS 1-6)	day 90 and 180

Collaborators and Investigators

• Sponsor: Karolinska Institutet
• Investigators: Principal Investigator: Gabriel Riva, MD, PhD, Karolinska Institutet; Principal Investigator: Akil Awad, MD, PhD, Karolinska Institutet; Study Chair: Andreas Claesson, RN, PhD, Karolinska Institutet; Study Chair: Carl Magnusson, RN, PhD, Sahlgrenska University; Study Chair: Leif Svensson, MD, PhD, Karolinska Institutet; Study Chair: Johan Israelsson, RN, PhD, Linné University; Study Chair: Emma Blick-Nordqvist, MD, Karolinska Institutet; Study Chair: Martin Jonsson, Msc, PhD, Karolinska Institutet; Study Chair: Jacob Hollenberg, MD, PhD, Karolinska Institutet; Study Chair: Sheldon Cheskes, MD, University of Toronto

Publications and helpful links

General Publications

• Cheskes S, Verbeek PR, Drennan IR, McLeod SL, Turner L, Pinto R, Feldman M, Davis M, Vaillancourt C, Morrison LJ, Dorian P, Scales DC. Defibrillation Strategies for Refractory Ventricular Fibrillation. N Engl J Med. 2022 Nov 24;387(21):1947-1956. doi: 10.1056/NEJMoa2207304. Epub 2022 Nov 6.

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2024
• Primary Completion (Actual): May 31, 2025
• Study Completion (Actual): September 23, 2025

Study Registration Dates

• First Submitted: May 29, 2024
• First Submitted That Met QC Criteria: June 3, 2024
• First Posted (Actual): June 7, 2024

Study Record Updates

• Last Update Posted (Estimated): October 1, 2025
• Last Update Submitted That Met QC Criteria: September 25, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Cardiopulmonary resuscitation; Defibrillation; Double sequential defibrillation
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Death; Death, Sudden; Pathological Conditions, Signs and Symptoms; Heart Arrest; Death, Sudden, Cardiac; Ventricular Fibrillation
• Other Study ID Numbers: CIV-ID-24-01-045759

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No