# Joules for Cardioversion and Defibrillation



## HatchetHarry

Sup guys im studying for my 2nd cardiac test right now and I keep reading conflicting things about the required amount of joules.  Part of this confusion comes from there being both biphasic and monophasic monitors.  Ive tried googling but I find different answers.  

Are monophasic monitors the only ones that go up to 360 J?

The Lifepak monitors that are the standard at fire depts these days are they monophasic or biphasic?

how many J do u cardiovert at?
defibrillate?

thanks


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## redcrossemt

*MONOPHASIC*
Defibrillation is 360 J 
Cardioversion for atrial rhythms is 50-100-200-300-360 J
Cardioversion for v-tach is 100-200-300-360 J

*BIPHASIC *(use device-specific energies when known)
Defibrillation is 200 J 
Cardioversion for atrial rhythms is 30-50-75-120 J
Cardioversion for v-tach is 75-120-150-200 J

*PEDIATRIC*
First shock defibrillation, use 2 J/kg
Additional defibrillation attempts are at 4 J/kg
Pediatric cardioversion gets 0.5-1 J/kg first shock
Additional cardioversion shocks are at 2 J/kg.

I can find no reference to biphasic v. monophasic in PALS (or at least the quick reference card in the truck). Does anyone use device specific pediatric energies, or have a specific protocol to monophasic v. biphasic defibrillators for pediatric patients?


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## redcrossemt

HatchetHarry said:


> The Lifepak monitors that are the standard at fire depts these days are they monophasic or biphasic?



LifePak 12's are available in both flavors. I believe at some point they went to all biphasic production, but there are still lots of monophasic monitors in service today.



HatchetHarry said:


> Are monophasic monitors the only ones that go up to 360 J?



Negatory, ghost rider. Depends on the monitor. Our LifePak Biphasics go to 360 J. Our Zoll Biphasics only go to 200 J.

Bottom line, you will need to know what your service uses and what the energy levels are for that specific device in your protocols. For testing, you should be able to ask the proctor before you begin as to what energy levels are recommended for the device you are using. Most proctors shouldn't have an issue as long as you know either all of the monophasic or all of the biphasic energy recommendations.


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## omak42

so what you have been told so far is true....however the biphasics going up to 360 J is a little deceiving.....

heres how it works.  biphasic machines will measure the impedence between the two pads and shock accordingly despite what you have the energy set at.  however it will not shock with MORE than what you set it as.  so if the machine detects it needs to shock at 120 J based on the impedence and you have your machine set at 100 J, it will shock at 100 J.  but if you have your machine set at 150 J and it detects the impedence and decides to shock at 120 J, it will shock at the 120 J.  In talking to training officers that I know the highest anyone has ever seen it actually deliver a shock at was 143 J....pretty interesting.

Does that make sense?


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## redcrossemt

omak42 said:


> so what you have been told so far is true....however the biphasics going up to 360 J is a little deceiving.....
> 
> heres how it works.  biphasic machines will measure the impedence between the two pads and shock accordingly despite what you have the energy set at.  however it will not shock with MORE than what you set it as.  so if the machine detects it needs to shock at 120 J based on the impedence and you have your machine set at 100 J, it will shock at 100 J.  but if you have your machine set at 150 J and it detects the impedence and decides to shock at 120 J, it will shock at the 120 J.  In talking to training officers that I know the highest anyone has ever seen it actually deliver a shock at was 143 J....pretty interesting.
> 
> Does that make sense?



I don't believe that what you're saying is true for all defibrillators. I know it is true for Zoll, however.

Medtronic Lifepaks (Adaptiv Biphasic Technology) actually deliver true dosing - at up to 360 joules biphasic power. They do measure impedance, but adjust to deliver the correct amount of power by changing the voltage. Adaptiv also can change the shock duration, but again, it preserves the power output.


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## omak42

I was pretty sure that it was at least true for Medtronic Lifepaks also....Ive been trying to research it a little bit more though and cant seem to find anything yet


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## redcrossemt

http://www.biphasic.com/reference/adaptiv_summary.pdf

There's better technical documentation elsewhere, and a few papers published, but I can't find them right now. The above is a good summary of how Medtronic developed their protocols. They automatically vary duration and voltage, and vary power by user selection or ramping AED protocols, to try and achieve the best response in each patient.


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## omak42

haha good timing...i just found that article myself


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## redcrossemt

**ping**
Does anyone use device specific pediatric energies, or have a specific protocol to monophasic v. biphasic defibrillators for pediatric patients?


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## omak42

we do not have any device specific energy settings in our county.  the only thing we have is 2J/kg for inital and 4J/kg for subsequent shocks.....nothing states any difference between mono or biphasic machines


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## marineman

The way we were taught is that the national registry still uses monophasic values with each option ending in "or biphasic equivalent". 

What redcrossemt posted earlier is correct as far as monophasic values (according to the book, we don't use them so I don't know per protocol) but biphasic our protocols are very different. 

We use Zoll M series monitors, our protocols state
Defib @ 200J
Cardioversion for atrial rhythms is 75J, 100J, 120J
Cardioversion for ventricular rhythms is 200J


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## Melclin

omak42 said:


> so what you have been told so far is true....however the biphasics going up to 360 J is a little deceiving.....
> 
> heres how it works.  biphasic machines will measure the impedence between the two pads and shock accordingly despite what you have the energy set at.  however it will not shock with MORE than what you set it as.  so if the machine detects it needs to shock at 120 J based on the impedence and you have your machine set at 100 J, it will shock at 100 J.  but if you have your machine set at 150 J and it detects the impedence and decides to shock at 120 J, it will shock at the 120 J.  In talking to training officers that I know the highest anyone has ever seen it actually deliver a shock at was 143 J....pretty interesting.
> 
> Does that make sense?



That is interesting. I must remember to ask my lecturers for some resources for technical info on the physics involved with the mons/defibs. *Does anyone have anymore links for things like that?* Not so much the medicine, but the physics and technical side of the machinery. Good to understand everything from the ground up I reckon.


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