Initial Double Sequential External Defibrillation in Out of Hospital Cardiac Arrest

Overview

Double Sequential External Defibrillation (DSED) represents an alternative treatment of refractory ventricular fibrillation (rVF) in out-of-hospital cardiac arrest (OHCA). The procedure consists of two defibrillators that administer shocks at the same time. Currently, the procedure is not initiated before at least three failed attempts with one defibrillator. This can delay the potential benefits of establishing DSED earlier in the treatment. Studies have shown that early defibrillation is crucial for survival in OHCA patients, and in 2022, a clinical trial showed that survival in patients treated with DSED was higher compared to standard treatment. The effect of initiating OHCA treatment is unknown. The DUALDEFIB trial seeks to investigate if treating OHCA patients with DSED as an initial treatment will increase survival and provide improved neurological outcome.

The project is investigator-initiated, prospective, two-group randomized controlled trial (RCT). Prior to the RCT, a pilot feasibility trial of 3-4 months will be performed, including three ambulance bases in mid-Norway. All OHCA patients will be included until validity and feasibility of the study is accomplished. The pilot study will be followed by the RCT. Outcome measurements in the RCT are aimed to be the same as in the pilot study. Ambulance bases will be randomized to either DSED or standard procedure for six months before crossover with the other treatment for six months. Ambulances included in the project will carry two defibrillators. Both defibrillators will be established for initial defibrillation with DSED in OHCA patients. The pads are placed in anterior-lateral position (standard placement) and anterior-posterior position (over sternum and beneath left scapula). Shocks are administered in rapid succession with less than one second apart. All other treatment will be according to existing guidelines. The included patients are OHCA patients with age over 18 years presenting with a shockable rhythm. Excluded patients are patients with obvious or suspected pregnancy, incarcerated patients or patients with no-resuscitation order. The patients that meet the inclusion criteria will be registered by the ambulance personnel through a secure webpage. Primary outcome is survival to hospital admission. Secondary outcomes are survival to hospital discharge, 30 days, 90 days and 1 year survival, in addition to neurological status. Patients from the pilot will be included in the RCT intervention group.