Chemical Fibrillators

[redmist]

I was called to a cardiac incident a couple days ago, but due to complications at the scene, I missed observing a portion of the Paramedic's Tx of the Pt.

According to the Pt, he had a history of SVT (Sino Ventricular Tachycardia). He had had attacks of SVT 3 times prior to the incident. When talking to an EMT-B on my squad who was at the scene (as the IC until the Paramedics arrived), I was informed that the Paramedics administered a drug that, "made the Pt flatline for about three seconds and then go back to a normal heart beat." This report was, to me, hearsay, and she might have misinterpreted the ECG.

I have done some of my own research, and this is what I have found:

1) Chemical fibrillators are used when the Pt has an unstable ECG rhythm, and it is best to put them into VF, so that they may be defibrillated. (The source of this info was another CFR.)

2) VT (Ventricular Tachycardia) is primarily treated with Lidocaine and Magnesium Sulfate.

I have two questions:

1) From this information, is it likely that the Pt was given a chemical fibrillator (keep in mind, the Paramedics did NOT defibrillate)?

2) How is SVT different than VT?

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redmist
CFR, Bard EMS

[Medic 321]

SVT stands for supra ventricular tach. The difference with v tach is that it is originating in the ventricles and presents as a wide complex tach. SVT originates high in the conduction system frequently in the Bundle of Kent near the SA node. The Tx of choice is Adenocard. It is a fast acting short lasting (5-10 seconds) that temporarily causes asystole. The problem with SVT is that it is usually too fast to see its origin on an ECG. Fujisawa, the maker of Adenocard publicly states that "Adenocard can be used as a diagnostic tool as well." If Adenocard does'nt break the SVT , your origin may be more atrial thus needing Cardizem or Verapamil.

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Tim Gifford FF/Paramedic

[redmist]

Thank you very much for the response.

As a follow up question, where does Lidocaine play into this? Is it only used for V Tach or am I wrong?

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redmist
CFR, Bard EMS

[PFD109NFD107]

Lidocaine is an anti-arrythmic that is used for ventricular dysrhythmias, which includes V-Tach. Some other uses are for V-Fib and PVC(Premature Ventricular Contractions).

[Dfib4Vfib]

Lidocaine would come into play if the patients rhythm did not changed after adenocard was adminstered or if you are unsure if the rhythm is SVT or VT. Usually you would look at the QRS complex to determine if it is wide or narrow.
So if you administered Adenocard 6mg, 12mg, 12mg with no effect but you noticed that the QRS complex was wide then you would adminster lidocaine 1-1.5 mg/kg IVP.
If Adenocard did not work but the QRS is still narrow then you would adminster Verapamil 2.5-5mg IV repeat in 15-30 min with a does of 5-10mg IV.
If by this time the patient was still in SVT you would synchronize cardiovert.
But if at anytime the patient became unstable ie.(low bp, chest pain, decrease LOC) you would synchronize cardiovert.
Hop that helps

[troll911]

Smart thinking to bring your (very good) questions here. I agree with all answers given and commend you on wishing to learn more for the well being of your patients. Your info from the other CFR was 1/3 correct and I would encourage you to get them informed of your newfound information.
Peace, TROLL

[medic951]

I agree with above. One thing to keep in mind is like everything in medicine, be watchful around the corner for new and better medications. It is so very important that as pre-hospital providers we stay on top of the new things out there. Lidocaine is good, but now we have the amiodarone in the arsonal for VT and VF. This is just an sample of things on the horizon. Thanks for bringing this point to life.

[redmist]

My pleasure, thank you all for responding.

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redmist
CFR, Bard EMS

[ALSfirefighter]

I'm a little late on this one, but I just wanted to join into a very professional and interesting topic.

Ditto for me Medic 321, the majority of times I have admin. Adenosine and it didn't work was due to the patient was in A-Fib. And as was stated the Adenosine has aided me in changing my diagnosis due to if it slows the rythem down it aids in interpretation.
Redmist: Lidocaine probably has more uses then you could believe. It is also included in our RSI protocol, (Rapid Sequence Induction), which it can aid it reducing gag reflex, so for head trauma, pt's who don't gag, can't cause an increase in their intercranial pressure. If you'd like to find out more about any medications your medics carry, I suggest going to a bookstore (Barnes and Noble usually always have them in stock), and buy a drug guide. Mosby's is very good for EMS and nursing. I don't know what region you are in but you should be able to get a copy of what they carry to do your own research.

[firemandougie]

Adenocard(adenosine)works very well for PSVT and also as a "rule out" for other v-tach's.
It is only pushed under authorization by medical control(in our deparmtnet) and only when patient is symptomatic.
Good luck in your quest!