Written by Clay Smith
What is DSD?
Double sequential defibrillation (DSD) means hooking up two external defibrillators and discharging them simultaneously in patients with refractory ventricular fibrillation (v-fib). The definition of “refractory” v-fib varies but usually means no response after 3-5 shocks. Options for treating refractory v-fib include moving pads to an anterior-posterior configuration, an esmolol drip, PCI, or ECMO. DSD is a novel option that keeps surfacing in case reports.
Whats the Evidence?
Evidence largely consists of case reports. There is a recent metaanalysis of two retrospective studies still in press with Resuscitation. In combining the 2 studies, with 499 total patients, 95 (19%) received DSD. There was no statistically significant difference in survival to discharge, ROSC, or event survival for those who received DSD vs those who did not.
Pros for DSD
Some case reports and retrospective studies seem to indicate improved survival and occasional miraculous saves in patients with refractory v-fib. As Dr. Corey Slovis said in his ACEP talk on this, “It’s a crowd pleaser.”
Cons Against DSD
It may fry your defibrillator(s). See this study in Annals of EM. DSD is off-label. The defibrillator may be damaged without your knowledge, which may make it ineffective for the next patient who needs it. It also voids the warranty on the machine. Whoops.
DSD may be an option for refractory v-fib, but there is no solid evidence that it works. It may cause hidden damage to the defibrillator and place subsequent patients at risk if it malfunctions or fails. Finally, this could cost your department a lot of money if the machine is damaged due to an off-label intervention that voids the warranty.
Once again, thanks to Corey Slovis for this talk.