Double Sequential Defibrillation

[DocMcCoy]

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Ok watching a medical drama on tv tonight where this came up. Patient with refractory Vtach successfully treated with double sequential defibrillation. My first thought was total bs but then went down a internet search rabbit hole and come to find this is a real thing. Personally never heard of it. Have any of you all seen/done this?
Would you consider it as a last ditch effort before calling it?

Still trying to understand if it is the total energy delivered or optimizing timing between shocks. Anyway thought it was interesting.

Any good quick reviews on history of cardioversion/defibrillation y’all recommend?

 

[Beeftenderloin]

Ok watching a medical drama on tv tonight where this came up. Patient with refractory Vtach successfully treated with double sequential defibrillation. My first thought was total bs but then went down a internet search rabbit hole and come to find this is a real thing. Personally never heard of it. Have any of you all seen/done this?
Would you consider it as a last ditch effort before calling it?

Still trying to understand if it is the total energy delivered or optimizing timing between shocks. Anyway thought it was interesting.

Any good quick reviews on history of cardioversion/defibrillation y’all recommend?

This is a hot topic in the EM FOAM world. I’ve seen it done before (when I was rotating in the ED). There’s some swine data as well as a few case series and some retroscpective studies done in humans but nothing “high quality” that’s I’ve seen.

The way it was explained to me is it’s not so much about the timing, it’s more about the vectors and the percent of the myocardium that’s actually “seeing” the shock. There’s a certain percentage of myocardium that must be depolarized in order for to actually convert. 2 sets of pads > more surface area > more myocardium being shocked > more likely to convert.

Just a CA1, but if I had a patient in refractory VF arrest and there was a second defibrillator around, I’d give it a shot.

What’s the worst that could happen? They’re already dead. ¯\_(ツ)_/¯

 

[LordPP]

It's very real. They even let medics do it: common practice in a lot of EMS systems.

Also, second what was said above; the basic idea is to depolarize as much muscle as possible. It doesn't really change the timing of shocks delivered.

 

[deleted875186]

I thought the intention was to get more of the second shock past the best wall, the first shock is supposed to decrease chest wall impedencr.

 

[DocMcCoy]

Thanks all. I was under the impression of impedance/timing. Otherwise why not just throw in bigger pads and throw more joules at the patient. Wonder if this would be more effective on the high BMI patients or big floppy hearts. I know I would get a lot of funny looks if I asked for a second defibrillator in my practice and frying a defibrillator would probably get me fired. I find it really interesting though and definitely identified a gap in my knowledge!

 

[Iso4ane]

I’ve seen argued that it also increases the energy density seen by the myocardium specifically in large people. Also, pad placement is important and I think that there are arguments for anterior-posterior placement of pads in the super obese, instead of the tradition placement, as the energy may travel mostly subq in the traditional placement.

 

[drmwvr]

What’s the worst that could happen? They’re already dead. ¯\_(ツ)_/¯

...they could survive....

 

[urge]

Ok watching a medical drama on tv tonight where this came up. Patient with refractory Vtach successfully treated with double sequential defibrillation. My first thought was total bs but then went down a internet search rabbit hole and come to find this is a real thing. Personally never heard of it. Have any of you all seen/done this?
Would you consider it as a last ditch effort before calling it?

Still trying to understand if it is the total energy delivered or optimizing timing between shocks. Anyway thought it was interesting.

Any good quick reviews on history of cardioversion/defibrillation y’all recommend?

I have seen triple for intractable v fib. True story. It worked. Until the pt went to v fib few seconds later.