0:01

In comes the Barbeau test.

0:03

What's the Barbeau test?

0:05

This is very similar to the modified Allen's

0:07

test, but the difference here is that

0:08

we apply a pulse oximeter to the thumb.

0:11

And so, same thing, compressive forces.

0:13

And, you know, what we're sort of trying to look

0:16

at is we're looking at the changes in amplitude

0:18

of the pulse waveform and oxygen saturation.

0:21

The degree of waveform alteration is rated A

0:23

through D based on the degree of collateral

0:24

flow between radial and ulnar arteries.

0:27

Here we see sort of diminutive,

0:29

hyperperfused region.

0:30

And what we're looking at here is just

0:32

realizing that this Barbeau test is actually

0:35

particularly accurate, particularly sensitive

0:37

than the Allen's test, which is why we use it.

0:41

So Barbeau types and waveforms.

0:43

So we talked about A through D.

0:46

What we're looking at here is sort of normal.

0:49

Start of oximetry, okay, nice, good waveform.

0:52

After oximetry, nice, good

0:54

waveform, excellent collaterals.

0:56

Superficial palmar arches, exquisite.

0:59

So B, initially blunted, okay, returns

1:02

to normal after about two minutes, okay.

1:04

So this is something that, you know, after about

1:07

two minutes, this is particularly good, right?

1:09

So, a little blunted before, not

1:11

so blunted now, good collaterals.

1:13

Not excellent, but good, because

1:14

it was blunted initially.

1:16

Now, if there's complete loss initially,

1:17

with return to a dampened waveform after two

1:19

minutes, then I would say Houston should be

1:23

told that there might be a little problem.

1:25

But, you know, not well collateralized,

1:27

but, you know, just be mindful.

1:28

Still a candidate, but then D is kind of

1:31

like, you know, this is when the horse leaves

1:34

the barn before you wake up in the morning.

1:37

It's gone, it's gone.

1:37

So no waveform, which persists beyond two minutes.

1:40

So this just means that isolated

1:42

circulation between the ulnar and

1:44

the radial arteries, and so this is a

1:46

contraindication to radial artery access.