An unblinded, randomized controlled trial enrolled 405 patients with VF/VT out-of-hospital cardiac arrest refractory to three consecutive defibrillation attempts with anterior and lateral pad placement [78]. The trial randomized patients to continued usual care, change of pad placement to the AP position (termed "vector change") or the addition of AP pads with double sequential defibrillation from both anterior-lateral and AP pad locations. The study was halted after fewer than 50 percent of subjects were enrolled because of low recruitment during the COVID-19 pandemic. Both vector change and double sequential defibrillation improved the primary outcome of survival to hospital discharge (21.7 versus 30.4 versus 13.3 percent, respectively). Rates of VF termination and ROSC were higher in both intervention arms compared with usual care.
Outside of clinical trials, access to multiple defibrillators for a single patient may be limited. In addition, the use of multiple defibrillators adds complexity that could detract from high-quality CPR. In the absence of any proven benefit of double sequential defibrillation compared with vector change, we recommend vector change for management of shock-refractory VF/VT.
