I am studying for my provincial exam can anyone explain to my why cardioversions goal is to induce v-fib? This seems like a bad rhythm to me... I am an EMT student and realize this is out of scope I tend to learn/remember a bit better when I know the why behind things. And am apparently supposed to have some knowledge on this but not know it inside and out.
Cardioversion
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Anjel
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Cardioversion is for unstable tachycardia with a pulse. It's a lower dose defib that is times just right in cardiac cycle that it hits in hopes to convert them back to a normal perfusing stable rhythm.
If the person goes into Vfib then you defib at the highest energy setting and not synced.
It's good that you are thinking a head, just be careful not to get yourself too confused.
If the person goes into Vfib then you defib at the highest energy setting and not synced.
It's good that you are thinking a head, just be careful not to get yourself too confused.
Thankyou for your response for some reason we are expected to know these things.... Alberta is apparently bumping up scopes and mainly has ALS services so chances of working with a medic are high. Therefor coming out of school they want you to be aware of skills/knowledge in the medic level. They have not, however, increased the length of our schooling.
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Welcome to emtlife. I am the same way. It is easier for me to remember if I can know and understand why.
If the emt scope does expand.... I HIGHLY doubt it will include cardioversion. From what I have heard they are merging with the nocp scopes. It will be an interesting few years.
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mycrofft
Still crazy but elsewhere
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Technically, defibrillation aims at producing a short controlled asystole immediately followed by the proper pacemaker nodes re-assuming control. It is temporary without correcting the underlying situation.
Sort of like the conductor comes back from lunch and finds the orchestra noodling around in an uncoordinated fashion. He slams his baton onto the podium, and in the ensuing silence starts up the next piece.
This accounts for why asystole is not addressed by simple defib. The conductor came back in, but the orchestra had left.
Sort of like the conductor comes back from lunch and finds the orchestra noodling around in an uncoordinated fashion. He slams his baton onto the podium, and in the ensuing silence starts up the next piece.
This accounts for why asystole is not addressed by simple defib. The conductor came back in, but the orchestra had left.
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And the chances of getting them back is only slightly higher than bringing Elvis back... for they both have left the building!
SandpitMedic
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....
Cardiovert with a pulse
Defib with no pulse.
Pretty simple.
Refer to ACLS.
If you want to jump ahead, this is what class you should take.
Cardiovert with a pulse
Defib with no pulse.
Pretty simple.
Refer to ACLS.
If you want to jump ahead, this is what class you should take.
Christopher
Forum Deputy Chief
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Cardioversion's typical goal is to induce asystole in the area of concern.
(cardioversion and defibrillation are the same thing, one is just timed with respect to R-peak)
Sometimes it will induce VF.
Well, you're always looking to avoid v-fib.
You hope that with cardioversion you will interrupt the current electrical activity to allow the myocardium to get back to something more normal (hinges upon the right tissue's automaticity chiming in).
If we called it "depolarization" (instead of defibrillation) perhaps it would make it easier to understand the goal we have in mind.
Why do you synchronize your cardioversion? To avoid inducing VF.
Why, pray tell, would the presence or absence of a pulse during VT lessen this chance of inducing VF during cardioversion? (answer: it doesn't)
You most assuredly can synchronize your cardioversion of VT regardless of their palpable pulse status.
You only want to shy away from synchronized cardioversion when your cardiac monitor has a hard time finding the R-peak (check out the link above, you'll find it enlightening).
VF is a great example of something you can't synchronize against.
Polymorphic VT is another great example.
AFib is a great counterexample!
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Perfusing unstable torsades...cardiovert or defibrillate? Torsades is pretty unstable by itself anyways.
Ready, set, go!!
Had a medic student who was riding recently argue with me about this one.
Ready, set, go!!
Had a medic student who was riding recently argue with me about this one.
Christopher
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Your monitor will likely not synchronize correctly to PMVT/TdP and thus defibrillation should be attempted instead.
SandpitMedic
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Perfusing and unstable shouldn't be in the same sentence.
But the answer is defibrillation.
Also, Christopher... The goal is to avoid V-fib... To restart the heart like you restart your Nintendo. Back into a perusing rhythm. You sync to avoid R on T phenomenon, that is to say, to avoid sending the heart into VF. VF will always be pulseless, V-tach may or may not be pulseless.
If there is a pulse: you cardiovert- SVT/Unstable VT with a pulse/ unstable A fib RVR
If they are pulseless: you defibrillate- V-fib/Pulseless V-Tach/Torsades.
If they are stable with Torsades- which is highly unlikely- you can consider Mag- but you still need to defibrillate. It is a lethal dysrhythmia; they will not be "stable" for very long.
But the answer is defibrillation.
Also, Christopher... The goal is to avoid V-fib... To restart the heart like you restart your Nintendo. Back into a perusing rhythm. You sync to avoid R on T phenomenon, that is to say, to avoid sending the heart into VF. VF will always be pulseless, V-tach may or may not be pulseless.
If there is a pulse: you cardiovert- SVT/Unstable VT with a pulse/ unstable A fib RVR
If they are pulseless: you defibrillate- V-fib/Pulseless V-Tach/Torsades.
If they are stable with Torsades- which is highly unlikely- you can consider Mag- but you still need to defibrillate. It is a lethal dysrhythmia; they will not be "stable" for very long.
Christopher
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Incorrect. You can clearly have an unstable patient who is perfusing. I point you to any case of AF w/ WPW or 1:1 AFlutter. Both are unstable, and both have many case reports of perfusing patients. Perhaps this is simply a terminology problem.
I have a lot of problems with how ACLS bandies about the term "unstable".
I linked to a case report I presented in which R-on-T happened due to inappropriate synchronization (it includes some of the physiology behind this vulnerable period).
My point is simply that why you synchronize has nothing to do with the presence or absence of a palpable pulse. Your protocols may be written with this fact implied, but it has no basis in physiology.
This is the textbook strategy for these rhythms.
Agreed.
Anjel
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I was taught if the patient has a pulse but it is a fast wide and irregular rhythm (Torsades) then we defib.
Christopher
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Correct, your monitor might not synchronize well to TdP/PMVT and thus you might as well perform an unsynchronized cardioversion (aka defibrillation).
Ultimately TdP/PMVT is an early after-depolarization rhythm, i.e. "triggered", so worrying about R-on-T is somewhat moot.
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You weren't supposed to answer that
Sandpit, why not? I've seen perfusing torsades that was relatively asymptomatic and normotensive. Mag converted, no need for electricity. I agree that TDP is naturally unstable and is prone to rapid deterioration into VF but I've also always been taught that I the patient is oriented and talking to me I probably shouldn't be lighting them up. Definitely going to keep a damn close eye on them though.
SandpitMedic
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Agree
For the one in a million
For the one in a million
VFlutter
Flight Nurse
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You weren't supposed to answer that
Sandpit, why not? I've seen perfusing torsades that was relatively asymptomatic and normotensive. Mag converted, no need for electricity. I agree that TDP is naturally unstable and is prone to rapid deterioration into VF but I've also always been taught that I the patient is oriented and talking to me I probably shouldn't be lighting them up. Definitely going to keep a damn close eye on them though.
I have had a few patients like this. The most interesting was a patient who was septic s/p pacemaker insertion requiring removal of the device. He was bradycardic with long QT and frequent ectopy resulting in very frequent sustained runs of Torsades. Patient was hypotensive but never lost pulses and was actually fairly alert. This went on for several days and was refractory to mag. Eventually resolved on an Isuprel drip until they could get a temporary transvenous pacer.
mycrofft
Still crazy but elsewhere
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We need to add to the RULES OF EMTLIFE COMMON USEAGE here:
PULSES are auscultated or palpated. RHYTHMS are electrocardiographic.
A pulseless patient might be revived, but a rhythmless one...not so often.
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Anyone else been cardioverted?
PULSES are auscultated or palpated. RHYTHMS are electrocardiographic.
A pulseless patient might be revived, but a rhythmless one...not so often.
====
Anyone else been cardioverted?