Double-Sequential Defibrillation for Refractory VF/VT

[Kris Thompson]

I briefly eluded to using two defibrillators for refractory VF/VT in my post about esmolol. Basically, if the patient won't convert despite defibrillation at maximum energy on your monitor, you can add another defibrillator. You can do two anterior-lateral, two anterior-posterior, or one set applied in each configuration. Press both shock buttons at the same time (or have your partner press the other button - just decide if you'll shock on 1-2-3 or on 1-2-3-shock).

They've been doing this in the cath lab for years to convert very resistant rhythms like atrial fibrillation. I'm not sure why it's taken so long for us to adopt it for ventricular dyshythmias in the emergency and pre-hospital arenas.

There are multiple theories on why this works. Clearly, it could be from doubling the energy delivered! It could also be from a slight offset in the timing of electricity - basically that the electricity is delivered for a longer period of time. Or, because the electricity is distributed over a wider area of heart muscle. Likely, it's some combination of these factors.

I would try this if you have loaded the patient with anti-arrhythmics and attempted multiple shocks at maximum energy with persistent VT/VF.



Image from: rebelem.com/beyond-acls-dual-simultaneous-external-defibrillation/


References:

Cabañas, J. G., Myers, J. B., Williams, J. G., De Maio, V. J., & Bachman, M. W. (2015). Double sequential external defibrillation in out-of-hospital refractory ventricular fibrillation: a report of ten cases. Prehospital Emergency Care, 19(1), 126-130.

Fender, E., Tripuraneni, A., & Henrikson, C. A. (2013). Dual defibrillation for refractory ventricular fibrillation in a patient with a left ventricular assist device. The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation.

Gerstein, N. S., Shah, M. B., & Jorgensen, K. M. (2014). Simultaneous use of two defibrillators for the conversion of refractory ventricular fibrillation. J Cardiothorac Vasc Anesth.(Published online ahead of print January 22, 2014.) DOI, 10.

Hoch, D. H., Batsford, W. P., Greenberg, S. M., McPherson, C. M., Rosenfeld, L. E., Marieb, M., & Levine, J. H. (1994). Double sequential external shocks for refractory ventricular fibrillation. Journal of the American College of Cardiology, 23(5), 1141-1145.

Leacock, B. W. (2014). Double simultaneous defibrillators for refractory ventricular fibrillation. The Journal of emergency medicine, 46(4), 472-474.

Lybeck, A. M., Moy, H. P., & Tan, D. K. (2015). Double Sequential Defibrillation for Refractory Ventricular Fibrillation: A Case Report. Prehospital Emergency Care.

Wilson, E. E. (2015). Simultaneous Transthoracic Defibrillation With Two Defibrillators for Refractory Ventricular Fibrillation: A Literature Review. Advanced Emergency Nursing Journal, 37(1), 42-50.

[Tony Held]

100% agree that it's strange this is just now catching fire in emergency medicine.  We talked about this when I was in paramedic school (07-08), but we were largely discussing it as a far-out alternative.

There was an interesting comment made in the last EMCrit Podcast (191) estimating that 95% of the cardiac tissue must be adequately depolarized for defibrillation to be successful.  If this is the case (which makes sense), it would seem reasonable that for this therapy to be most effective, you would want anterior-posterior and anterior-lateral pad placement so that you have completely different vectors of defibrillation.  It would also make sense that having a slightly different timing would be beneficial because your initial defibrillation will occur during some of those myocardial cells' absolute refractory periods.  Drugs that extend refractory periods such as amiodarone or procainamide or Long QT syndrome would seem to be counterproductive to traditional defibrillation in the presence of ultra-excitation of the myocardial tissue.  Having a slight offset (milliseconds) to two defibrillations would increase your odds of being outside of the absolute refractory periods for the majority of the myocardium.


Scott Weingart. Podcast 191 – Cardiac Arrest Update. EMCrit Blog. Published on January 23, 2017. Accessed on January 29th 2017. Available at [emcrit.org/podcasts/cardiac-arrest-update/].

[abobka]

Hey guys. We use DSD at my new gig in OP. I haven't encountered an opportunity to use it yet but it's in the bag of tricks. When asked about why we do it, our medical director responded, "why not?" Hopefully I can work on getting some data to this board to see if it is making a difference.


JoCo Cardiac Arrest Protocol