DOSE VF
Defibrillation Strategies for Refractory Ventricular Fibrillation
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Overview
For refractory VF in OHCA, double sequential and vector-change defibrillation improved survival to discharge compared with standard shocks.
Clinical takeaway
DOSE VF supports changing the defibrillation strategy—double sequential shocks or an anterior-posterior vector—when VF stays refractory to standard pads.
Key result
Survival to discharge was higher with DSED than with standard defibrillation (30.4% vs 13.3%; RR 2.21).
Practice impact
For refractory VF, consider DSED or vector-change defibrillation rather than repeating the same pad position.
Evidence
Study design
Cluster-randomized trial with crossover among six Canadian paramedic services comparing double sequential external defibrillation, vector-change defibrillation, and standard defibrillation.
Enrollment
405
Follow-up
Survival and neurologic outcome assessed at hospital discharge.
Geography
Canada
Clinical question
Do double sequential external defibrillation or vector-change defibrillation improve survival to hospital discharge compared with standard defibrillation in refractory ventricular fibrillation?
Population
- Adults with refractory ventricular fibrillation during out-of-hospital cardiac arrest.
Intervention
Double sequential external defibrillation or vector-change defibrillation (anterior-posterior pad position).
Comparator
Standard defibrillation.
Primary outcome
Survival to hospital discharge.
DSED increased survival to hospital discharge compared with standard defibrillation; vector-change defibrillation also improved survival.
Relative risk / 2.21 / 95% CI 1.33-3.67
Key results
- Survival to hospital discharge was more common with DSED than with standard defibrillation (30.4% vs 13.3%; RR 2.21; 95% CI 1.33-3.67).
- Survival to hospital discharge was more common with vector-change defibrillation than with standard defibrillation (21.7% vs 13.3%; RR 1.71; 95% CI 1.01-2.88).
- DSED, but not vector-change defibrillation, was associated with a higher percentage of patients having a good neurologic outcome (modified Rankin scale score of 2 or lower) than standard defibrillation (RR 2.21; 95% CI 1.26-3.88 vs RR 1.48; 95% CI 0.81-2.71).
Harms
Not listed.
Clinical Use
Practice impact
- For refractory ventricular fibrillation, consider double sequential external defibrillation or vector-change defibrillation rather than repeating standard pad placement.
Applicability
- Most applicable to adults with refractory ventricular fibrillation during out-of-hospital cardiac arrest treated by paramedic services that can deliver a second shock vector or a second defibrillator.
Limitations
- The trial was cluster-randomized with crossover and was stopped early because of the coronavirus disease 2019 pandemic.
- A p-value for the primary survival comparisons is not reported in the abstract.
- Vector-change defibrillation improved survival but was not associated with the same neurologic benefit reported for DSED.
Common misinterpretations
- Vector-change improved survival, but the reported neurologic benefit was for DSED, not vector-change defibrillation.
- Early stopping was for the pandemic, not because a harm boundary was crossed.
Related evidence
Citation
Cheskes S, Verbeek PR, Drennan IR, et al. Defibrillation Strategies for Refractory Ventricular Fibrillation. N Engl J Med. 2022;387(21):1947-1956. doi:10.1056/NEJMoa2207304
Among patients with refractory ventricular fibrillation, survival to hospital discharge occurred more frequently among those who received DSED or VC defibrillation than among those who received standard defibrillation.
- PMID
- 36342151