For refractory ventricular fibrillation (VF) in out-of-hospital cardiac arrest, the DOSE VF trial delivered a striking result: compared with standard defibrillation, double sequential external defibrillation (DSED) and vector-change defibrillation improved survival to hospital discharge (30.4% and 21.7% respectively versus 13.3%), with DSED also more than doubling the rate of good neurologic outcome. These strategies are most applicable to EMS systems able to deploy a second defibrillator. On the pharmacological side, the evidence is sobering: neither amiodarone nor lidocaine significantly improved survival or neurologic outcome versus placebo in shock-refractory VF. Investigational rescue approaches such as esmolol infusion and left stellate ganglion block are supported only by small studies. The clear message is that defibrillation strategy — not antiarrhythmic drugs — offers the greatest leverage in refractory VF.
Further reading: DOSE VF (Cheskes et al., NEJM 2022); amiodarone, lidocaine, or placebo in cardiac arrest (Kudenchuk et al., NEJM 2016).