Category: Critical Care
Posted: 11/8/2022 by Caleb Chan, MD
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DOSE VF (DOuble SEquential External Defibrillation for Refractory VF) Trial
Background - High quality data regarding the use of double sequential external defibrillation (DSED) and vector-change (VC) defibrillation in refractory vfib is limited
Study
-Three-group, cluster-randomized, controlled trial in six Canadian paramedic services
-Study population:
-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)
-Some notable exclusion criteria:
-suspected drug overdose, hypothermia, traumatic cardiac arrest
-Protocol:
-First 3 defib attempts in the standard (anterior-lateral) position
-If remained in vfib after three consecutive shocks randomized to one of:
1. Standard defib for all subsequent attempts (136 pts)
2. VC defib (all subsequent attempts in anterior-posterior position) (144 pts)
3. DSED (applied second set of pads in AP position) with near simultaneously (<1 sec) defib shocks (125 pts)
Results
-Primary outcome: survival to hospital discharge
-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)
-31 patients (21.7%) in the VC group (RR [vs. standard], 1.71; 95% CI, 1.01 to 2.88) (Fragility index of 1)
-Notable secondary outcome: survival with a good neurologic outcome
-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)
Takeaways/Caveats:
-68% of arrests witnessed, 58% received bystander CPR, median response time of 7.4-7.8 min
-Did not reach planned sample size 2/2 COVID pandemic
-No reporting of post-arrest care (e.g. TTM, PCI)
-Overall rates of survival and good neuro outcome on the higher side even with standard of care
-More/larger studies needed, but can consider DSED for refractory vfib, particularly if you are in a setting without more advanced circulatory support/resources
Cheskes S, Verbeek PR, Drennan IR, et al. Defibrillation strategies for refractory ventricular fibrillation. N Engl J Med. Published online November 6, 2022:NEJMoa2207304.
