Title: DOSE VF (DOuble SEquential External Defibrillation for Refractory VF) Trial <br/>Author: Caleb Chan<br/><a href='http://umem.org/profiles/alumni/1583/'>[Click to email author]</a><hr/><p> DOSE VF (DOuble SEquential External Defibrillation for Refractory VF) Trial </p> <p> <strong>Background </strong>- High quality data regarding the use of double sequential external defibrillation (DSED) and vector-change (VC) defibrillation in refractory vfib is limited</p> <p> <strong>Study</strong></p> <p> -Three-group, cluster-randomized, controlled trial in six Canadian paramedic services</p> <p> -Study population: </p> <p style="margin-left: 40px;"> -OHCA with refractory vfib (initial presenting rhythm of vfib or pulseless VT that was still present after three consecutive rhythm analyses and standard defibrillations separated by 2 minute intervals of CPR) of presumed cardiac etiology (405 patients)</p> <p> -Some notable exclusion criteria: </p> <p style="margin-left: 40px;"> -suspected drug overdose, hypothermia, traumatic cardiac arrest</p> <p> -Protocol:</p> <p style="margin-left: 40px;"> -First 3 defib attempts in the standard (anterior-lateral) position</p> <p style="margin-left: 40px;"> -If remained in vfib after three consecutive shocks randomized to one of:</p> <p style="margin-left:1in;"> 1. Standard defib for all subsequent attempts (136 pts)</p> <p style="margin-left:1in;"> 2. VC defib (all subsequent attempts in anterior-posterior position) (144 pts)</p> <p style="margin-left:1in;"> 3. DSED (applied second set of pads in AP position) with near simultaneously (<1 sec) defib shocks (125 pts)</p> <p> <strong>Results</strong></p> <p> -Primary outcome: survival to hospital discharge</p> <p style="margin-left: 40px;"> -38 patients (30.4%) in the DSED group vs. 18 (13.3%) in the standard group (RR 2.21; 95% CI, 1.33 to 3.67) (Fragility index of 9)</p> <p style="margin-left: 40px;"> -31 patients (21.7%) in the VC group (RR [vs. standard], 1.71; 95% CI, 1.01 to 2.88) (Fragility index of 1)</p> <p> -Notable secondary outcome: survival with a good neurologic outcome</p> <p style="margin-left: 40px;"> -34 patients (27.4%) who received DSED vs. 15 patients (11.2%) with standard defibrillation (RR, 2.21; 95% CI, 1.26 to 3.88)</p> <p style="margin-left: 80px;"> </p> <p> <strong>Takeaways/Caveats:</strong></p> <p> -68% of arrests witnessed, 58% received bystander CPR, median response time of 7.4-7.8 min</p> <p> -Did not reach planned sample size 2/2 COVID pandemic</p> <p> -No reporting of post-arrest care (e.g. TTM, PCI)</p> <p> -Overall rates of survival and good neuro outcome on the higher side even with standard of care</p> <p> -More/larger studies needed, but can consider DSED for refractory vfib, particularly if you are in a setting without more advanced circulatory support/resources</p> <p> </p> <p> </p> <fieldset><legend>References</legend>
<p> Cheskes S, Verbeek PR, Drennan IR, et al. Defibrillation strategies for refractory ventricular fibrillation. N Engl J Med. Published online November 6, 2022:NEJMoa2207304.</p> </fieldset>