AED Protocol

[firedoc5]

It's very rare but there has been instances where the two minute CPR had converted the dysrhythmia. The compressions may have impacted the heart to correct it's self.

Also, beginning the CPR you do the Look, Listen, & Feel assessment. This can further confirm that they are in need of AED. Make sure they are in full arrest, and not just unresponsive. I've seen where someone has panicked by someone becoming unresponsive and started in CPR causing unnecessary trauma. And if AED is utilized when not needed then you can have a full arrest on your hands.

I'm sorry, but I still don't fully trust a computer to say whether a rhythm is shockable or not.

[*Lifeguard*]

Thanks for the replies. I guess I am looking for the importance of coronary perfussion and CPR for unwitnessed cardiac aresst patients. I think it is a big mistake initiating AED protocol to an unwitnessed cardiac patient without first giving adequate CPR.

[AnthonyM83]

I guess I am looking for the importance of coronary perfussion and CPR for unwitnessed cardiac aresst patients. I think it is a big mistake initiating AED protocol to an unwitnessed cardiac patient without first giving adequate CPR.

Well, I can guess the basic physiology behind it (that the oxygen primes the heart to beat properly after the shock), but as far as scientific importance, it's mainly based on studies showing that there's a higher chance of getting a viable rhythm from V-Fib when CPR has been done for 1 - 2 minutes prior. The importance is also based on the fact most adults go into cardiac arrest due to a dysrhythmia.

[defib_wizard]

firedoc: why don't you trust the aed? If you do your 2 min. of cpr and have it do the initial rhythm analysis you can doing an iv administering meds and setting up for intubation. Then if no shock is advised go to manual mode. This really helps when you are the only als and have to multitask.

[*Lifeguard*]

Hi Firedoc,

Thank you for your post. I was presented a question for my Paramedic class, which focuses on why protocols require 2 minutes of CPR, prior to AED protocol, for unwitnessed aresst patients.

[Kiwiology]

Our protocol says a witnessed arrest gets up to three shocks at max joules before CPR is started.

Without oxygen and nutrients, the fibrillating heart will loose its electrical activity (coarse VF) due to acidosis and hypoxia and degrade to fine VF and eventually to asystole.

Research (pg. 16) has shown that 1.5-3min of EMS CPR PRIOR to defibrillation (if call-to-arrival time was 3-5 minutes or more) improves survival rates because it delivers oxygen and substrate to the heart muscle (and as said above, may convert fine VF to coarse VF) thus increasing electrical activity (and size of the VF waveform) making defibrillation more effective at eliminating VF.

Dunno about you but I found that interesting 8)

[firedoc5]

One thing I forgot to mention in my earlier post is that when AED's first came out, and were actually still in a trial stage. There was an argument of that even if a dysrhythmia was successfully converted and no ALS or that ALS had a long response time, without Lidocaine, Bretylium, Procainamide, or other anti-dysrhythmic drug(s) they could revert back into full arrest more readily. Then you had to def-fib more. So, is it better to just do CPR until ALS get's there, or defib up to three times and have them convert only to go back to the original dysrhythmia needing to be shocked again? We had some think that with the additional shocks, it may have caused more damage to the cardiac muscle than the trauma of CPR alone.

You have to remember this was many years ago. I'm only posting this as food for thought and to let some of the younger medics what kinds of arguments there were when these kind of new things were being implemented.

As far as trusting computers to identify a rhythm, I've seen where artifact was picked up as coarse V-fib and verbally stating that it was a shockable rhythm. I'm not sure of the circumstances but I heard of when a patient was in a 3rd degree block the computer picked it up as low voltage sinus brady or something like that. It was over in another county closer to St. Louis and there was a write up about it in a newspaper. Along with a story of how a medic was shocked through the paddle buttons while testing a monitor. I'm sure the computers of today have much improved. But just things like that sticks in the back of my mind. I must truly be old school.

[toutdoors]

Our protocols state that if we witness the arrest, then we apply the AED and push the analyze button to determine if shock is advised or not.

If it is an unwitnessed arrest, even if CPR is being performed upon our arrival, then we, (FD) do two minutes of CPR, then let the AED analyze. Our AED's are also set up so that once you place pads, and turn the machine on, it begans a two minute countdown for you. This is nice, so that we all don't have to take off our shoes and socks to count to two minutes. The AED is programmed however, that after it starts up, it will state "If arrest was witnessed, push analyze." So for us, we want to get the AED on as soon as possible, allowing the two minute countdown to occur.

We use Lifepak 500's, and our department just purchased two new models that have a screen that shows the rhythm as well. The older ones do not have the screen. I have not had a chance to use the new model yet, except for our quarterly d-fib refresher training, it seems like a nice unit.

I thought that it was the "new standard" to go this route with AED treatment. By that I mean, the way I have described the protocols I work under. Not saying we are the only ones doing it the right way, just wondering, have I missed something here?

[Kiwiology]

.....without Lidocaine, Bretylium, Procainamide ... I must truly be old school.

Sure got that right, damn I haven't heard any of those drugs used in ACLS for years

[cfd32]

i completely trust the AED and how it picks up rhythms...there computer's and there smarter than us..lol