This video has two parts.
- Placing The Femoral Arterial Line In Cardiac Arrest 0:00 – 8:58
- Interpreting The Arterial Line Waveform During Cardiac Arrest 9:00- 11:19
Both parts are outstanding.
2,039 views Apr 9, 2023 ResusX:Podcast
All that follows is from the transcript of the above resource.
Placing The Femoral Arterial Line In Cardiac Arrest
0:00 – 8:58
[These are outstanding instructions on performing the procedure.]Introduction
I’ve gotten a lot of questions on the show about how to actually place an arterial line during cardiac arrest. So I figured I’d give this lecture to help you learn this vital skill.Now, I’m not going to teach you just how to do it in terms of being able to monitor, but coming down the pike are a whole bunch of endovascular therapies like REBOA that I think will be part of medical arrest within the next five years. So I’m going to teach you also how to access the femoral artery to be able to doprocedures like that as well.Needles
All right let’s talk about stuff. I do not like the needle that comes with the standard arterial kit. They’re tiny. They’re 20 gauge so they don’t show up well on ultrasound. They don’t reach obese patients. They’re fine if you have the time and you can just switch out if they’re too short but during your cardiac arrest you want one shot getting it. And that means using a better needle. Now you could just grab a needle from a central line kit or from a Cordis kit and those will work.
Those will be 18 gauge they’re much longer than the standard art line needles. That’ll get the job done. But since I don’t want to waste an entire kit just to steal a needle I actually have a purpose-built needle [that I use]. I don’t take money from any of these folks but a company called Pajunk makes the best one in my estimation.Tt is insanely crenellated soit’s echolucent. You can see it like aArterial Lines
Catherine [a previous speaker] said you could just use a standard u ICU art line but the problem with that is they don’t take the wires that you may use for any additional procedures like ECMO, like REBOA, or like your IR people being able to use it.
So really when you want to place during Cardiac Arrest is something that’s at least four French. It’s 18 gauge and that’ll allow you to do anything you want with this later on.And so what we have is we have four French sheaths. They
Could you use a central line if as long as they were narrow. Sure. They make five, a five French central line. Sure but ideally this [the four french sheath he mentions above is (I think what he is talking about) is just big enough and it’s as small as you get away with and it’s really what I like. So four French sheath*, all right.
Last revised by Derek Smith◉ on 26 Jun 2021
The French gauge (Fr) (also known as the French scale or system) is used to size catheters, and other instruments, in interventional radiology and surgery. In some parts of the world, the Charrière (Ch) is used as the name of the unit, in honor of its inventor.
The French system is simple, one increment on the French scale is equal to 1/3 millimeter, e.g. 8 Fr catheter is 8 x 0.33 mm = 2.67 mm in caliber.
Unlike the needle gauge system, the French system has no set lower or upper limit, and users generally find it a lot less confusing, as the French size is proportional to the diameter.
Some common French sizes with equivalent metric diameter and circumferences:
3 Fr is 1 mm (diameter) and 3.14 mm (circumference)
4 Fr is 1.33 mm and 4.19 mm
5 Fr is 1.67 mm and 5.24 mm
6 Fr is 2 mm and 6.28 mm
7 Fr is 2.33 mm and 7.33 mm
8 Fr is 2.67 mm and 8.34 mm
Resuming Dr. Weingart’s lecture:
Prep 2:45Let’s talk about prep. I prep my needle simply by taking it out of its holder because I don’t use a syringe on my needle for art lines at all in a cardiac arrest or otherwise so it makes it super easy. You want to get your wire prepped.Wire Placement 2:57
Vessel Location 3:39
All right let’s talk about vessel location.
Now you need to be able to find artery not using any of the standard stuff.
You can’t hit a vessel and see “oh it’s pulsatiting. Pulsatility disappears during Cardiac Arrest [because] they’re both pulsatile.
You can’t go by color [because] they [both] ook the same color during Cardiac Arrest.
The only thing you could use is their anatomy on ultrasound; the thick wall [femoral artery] versus the thin wall [femoral vein].
Then you find them both [using ultrasound].and then you compare [them] and say [that is the one that is the femoral artery].
That [ultrasound] is the only thing that legitimately will work during cardiac arrest.
So do not use these other techniques to find both vessels and that [ultrasound imaging] will allow you to compare [the walls] and say this one’s thick and this one’s thin.
And the vein gets really big during cardiac arrest and the artery [gets] really small so you really have to go looking for that artery wall.Finding the right spot 4:23
Then you want to find the right spot on the artery, which means you want to be not in The Superficial Artery where a lot of ED arterial lines are placed.
But [rather] you want to be in the common femoral artery.
But you don’t want to be so high in the common femoral artery that you risk retroperitoneal puncture [if you back wall it because you won’t be able to compress the puncture site].
So what you really want is do is–you want to be in the common femoral vessel which is distal to the inguinal ligament.
That’s [the common femoral artery] you move down the leg distally until it splits into two.
You then move back up until it just turns int0 one (that’s right at the bifurcation) and then you move two centimeters up from that [point]. That’s going to put you in that sweet spot between the inguinal ligament and the bifurcation and that’s exactly where you want your needle tip to enter the vessel.
That’s not where your needle enters the skin because you need some time to progress underneath the skin to get right under your probe face so that is where you want to hit the vessel wall.Hit the vessel 5:21
Right, let’s talk about hitting the artery.
All right, CPR is ongoing. That’s going to make this tougher. [But] it doesn’t make it impossible.
It makes it tougher [but] what makes it a lot easier is if you have mechanical CPR like a Lucas device [because there is] much less movement at the groin than with hand CPR.
So how do you then duplicate that nice placid effects [meaning little or no movement at the pelvis when you have people doing hand CPR?
You have a buddy hold the pelvis and really stabilize it and that takes away the movement the pelvis from that hand CPR.
But mechanical [CPR] makes everything so much easier.
all right now you have a lot of bad
techniques that you get in the habit of
in emergency medicine uh you you shake
shag right like so you you’re you’re
looking for your needle tip and it’s not
right in the plane you want so you turn
to the left and then you oh it’s more to
the right and and you find this very
inundating path uh to from the skin to
the vessel now you get away with it with
tiny little things but when you get used
to placing larger things like repos or
uh ecmocatheters uh you really need a
straight shot which means if you need to
adjust your annual you come all the way
out to the skin you readjust your angle
and then you could go in so one
continuous Motion One continuous angle
and that angle shouldn’t be steep which
is what happens with the standard
arterial line needles it’s like a
magnetic ingredients to hit that vessel
that will not work to allow big
catheters to flow in from the skin all
the way to the vessel so what you want
to do is a 45 degree angle which means
you need a longer needle and then you
want to hit that right spot on that
vessel which means the anterior wall not
side uh entry into that artery
I’ve hold my needle like a dart
and that gives me the most control and
I’ll stabilize on the patient’s leg
while and entering with that dart-like
motion all right now there’s two ways to
get the needle from the skin into the
vessel there’s the way the occurred
generation is most commonly trained in
which is this needle walking where you
know you have your probe you put the
probe right on over the needle you move
the probe a little the needle disappears
you move the needle you find it again
you move the probe it disappears and
that’s fine but it takes a while and it
prevents you from keeping the Probe on
the exact spot you want to hit on that
common Federal artery which is we’ve
already mentioned is super important so
that doesn’t work now what does work but
it’s very difficult is called vessel
trigonometry where you will actually put
your probe on where you want to hit the
vessel you’ll see how deep it is you’ll
actually enter with the needle at the
skin that far back from the probe phase
so if it’s two centimeters to handle put
your needle two centimeters back from
the probe phase and at a 45 degree angle
thanks to the laws of trigonometry at
the point where it is right above the
vessel is right under your probe face
and so that’s the first time you’ll see
the needle tip and then you can watch it
in real time puncture The Vessel like I
say it’s a pro level move and most of
the time we know teacher trainees this
so how do we safely do both keep the
probe over exactly where we want to hitNeedle Fan Placement
um allows to see the needle tip we do
the fan right so instead of removing the
probe we just change the angle of the
probe so we can see the needle and then
we fan in either fan needle fan needle
and then you get the best of both worlds
so that’s what I recommend learning allAttaching Wire
right attaching the wire you could do it
with your non-dominant hand but I really
like to re-grip the needle tip with my
uh my left hand on my right hand
dominant player I could do ambidextrous
but I’m better with my right and I
regret so I got in I regrip and then I
pick up the wire that’s right next to me
and place it into the Hub and since it’s
you know the wire is exposed I could do
that in one motion that’s how I like the
path the wire during this because it
gives the least amount of time to lose
your position in the vessel
Interpreting The Arterial Line Waveform During Cardiac Arrest
9:00- 11:19All right now one last wrinkle and I Idon’t know if you would have heard aboutthis before. It was a revelation to mewhen my buddy Pio Burberry uh actuallygot in touch with me and said you’redoing this [waveform interpterpretation] all wrong because up until that point I would get these incrediblylow diastolic blood pressures on my artline [waveform] and what you would actually sayis oh my God I need to tell more heavythey’re not getting any systemicvascular resistance and what it turnsout is the machines are giving you thewrong numbers you cannot use the numberson your arterial line ah tracing on themonitor. Like if it says 120 over minus 10 the diastolic is not minus 10. The systolic isfine but the diastolic is a lie and you cannot use those numbers you actually have to look at the waveform itself because what happens is the upstrokeof compressions whether it be mechanical or by hand is generating some negative pressure in there and that gives you a temporary low point you can see on point a The Black Arrow on this slidthat’s what the machine is going off but that is not that’s just a perturbation in the chest that is not representativeof the actual diastolic blood pressures it’s an anomaly and it’s because the