So, once you have really good quality CPR going,
what's the next question you need to answer?
You've already decided your patient is pulseless,
you've already initiated compressions,
what do you need to know now?
The answer is of course, what is the cardiac rhythm.
And specifically is it a rhythm that we can treat with electricity?
Is it a shockable rhythm?
So shockable rhythms like we said before are more likely to survive.
Patients who can be shocked are more likely to live through a cardiac arrest.
But defibrillation is a very time sensitive intervention.
Meaning the faster you do it
the more likely it is that your patient is gonna benefit from it.
So for shockable rhythms,
we consider defibrillation to be more important than anything else you can do.
More important than CPR,
more important than ventilation,
more important than drugs or IV access;
it is the single most important thing that you can do.
So if you have a shockable rhythm you need to know early
and you need to treat it early.
Here's one of our shockable rhythms,
this is ventricular fibrillation.
It's very easy to identify. It's randomly fluctuating.
It goes up and down, there's no pattern,
there's no rhyme and reason,
there's no QRS complexes;
it's just a disorganized squiggle.
The second one is ventricular tachycardia.
Now, in V-Tach, there actually is organization to the QRS complexes
but they're wide and bizarre looking.
So anytime you have a fast rhythm with wide QRS complexes,
you should suspect that to be ventricular tachycardia.
And by the way, these are the two rhythms that the automated defibrillators
that you see in public places are looking for
when they determine whether or not a patient should be shocked in cardiac arrest.
So why do we only shock V-Fib and V-Tach?
These frustrates a lot of students
because you see on TV everybody in cardiac arrest gets shocked
and they all jump up and come right back to life, right?
Well, it doesn’t work that way in the real world
because the whole goal of using electricity
is to reorganize a rhythm that is disorganized.
Now, when you are in a nonshockable rhythm like PEA,
you have some major problems on the table,
but electrical disorganization is not one of them.
It's not an issue for patients in non shockable rhythm.
And at best, if you go in shock and nonshockable rhythm,
nothing will happen.
you could potentially hit the patient at the wrong point in the cardiac cycle
causing R-on-T phenomenon, and ultimately precipitate a dysrhythmia
like ventricular fibrillation.
So the last thing you wanna do in a cardiac arrest
is take somebody who has a normal rhythm
and turn it into V-fib that's clearly not benefitting anybody.
So we don’t perform defibrillation for any rhythm
except our two shockable rhythms, V-Fib and pulseless V-Tach.
I mentioned before that defibrillation is a time sensitive intervention,
and this graph clearly shows why.
So as you can see the more time that elapses as we move along the axis there
the lower the likelihood of survival for the patient.
So for patients in shockable rhythms
who are getting shocked within the first minute,
you can see a 35 to 40% of those patients are surviving.
But by the time we get out to 6 minutes,
it's less than 20% of the patients surviving.
So we really wanna make sure that as soon as we're humanely able to do so,
we assess the rhythm and we defibrillate if we identify a shockable rhythm.
Again, short time to defibrillation high likelihood of survival.
And as we go down to two, three, four, five, six, and more than six minutes;
you can see that the odds ratio or the likelihood that the patient is gonna survive the event
goes down consistently with every minute that passes.
It's really key to do this quickly.
Now once you've gotten your high quality CPR going
and you've assessed your rhythm and defibrillated if it's indicated,
what do you wanna do next?
Well, this is when you can start thinking about respiratory support for your patient.
So you can initiate bag-valve-ventilation in order to give your patient some oxygenation.
You wanna also coordinate your chest compressions with your breathing.
So you're gonna do 30 compressions followed by two breaths.
Thirty compressions followed by two breaths.
You will also, if you are in a hospital setting,
are gonna establish vascular access,
and you're gonna continue reassessing the rhythm
every five cycles or two minutes for the duration of the resuscitation.
Now, a lot of students ask me,
Doctor Jung, this is all great,
but this is like basic, basic stuff, right?
What about the cool stuff like putting in airways and pushing drugs?
Well, unfortunately, advanced interventions in cardiac arrests
don’t really make much of a difference.
This is a study that came out of Scandinavia
that really showed whether you're performing basic life support
or advanced life support,
your outcomes are very similar.
So in these two cases,
you can see the red line represents patients who got no IV access,
no IV drugs, and no advanced airway interventions,
and the green line represents patients that did receive those interventions
and you can see how very similar the outcomes for both groups were.
So bottom-line is it CPR and defibrillation is by far
the most important element of your resuscitation
and all the advanced stuff really doesn’t make as much of a difference as we'd like.
So let's get back to our case.
So we have our 58-year-old guy who collapsed at a sporting event.
What are we gonna do for him?
Well, like we already said,
one, we're gonna call for help as quickly as we can.
Two, we're gonna think CAB,
so we're gonna go to him and we're gonna decide
whether or not he has a carotid pulse.
If he doesn’t, we're gonna go ahead and initiate chest compressions.
And then once we can get access to a defibrillator,
which hopefully at a sporting event would be pretty quickly,
we're gonna put it on, assess the rhythm and defibrillate
if of course it's indicated.
Thank you very much.
I hope this was a helpful overview of the important points of cardiac arrest.