Lower Arm

How to: Axillary Nerve Block

Read more about How to: Axillary Nerve Block

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Dr. David Auyong reviews scanning techniques and sonographic landmarks for an ultrasound guided nerve block .

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Anesthesiology (Regional)

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How To Videos

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- Axillary nerve blocks are used for surgery,
usually below the elbow.
If properly executed, axillary nerve block
can be performed by identifying individual nerves
or just in depositing local anesthetic
below the artery and above the axillary artery.
Axillary nerve blocks under ultrasound
can improve safety because you can view
many of the small arteries and veins in the axilla,
and avoid intravascular injection.
To properly position for the axillary nerve block,
we have moved our patient to the opposite side of the bed,
and we will now abduct the arm 90 degrees.
For the axillary nerve block,
we usually use a linear probe.
Usually axillary nerve blocks are very shallow,
so I've put my initial depth setting
to about two and a half to three centimeters.
Usually, I also set the frequency settings
to general or resolution for the axillary nerve block.
To do a properly executed axillary nerve block,
identification of the artery and vein is important.
If you find the artery,
injection below and above the axillary artery
usually results in a good nerve block.
We initially place the probe in the axilla,
and identify a pulsating artery in the axilla.
This is your axillary artery.
Now, as you can see, the pulsating artery,
there is no vein in my initial picture.
This is because the vein is collapsed
with light pressure of the probe.
It is very important to identify the axillary vein,
so you do not inject into the axillary vein.
As I let up some pressure,
you can now see the axillary vein
superficial to my pulsating artery.
Other structures visualized in this shot
include the biceps and coracobrachialis
on the right side of the screen,
and either the latissimus dorsi,
or the triceps, on the left side of the screen,
depending on what level I am at.
Our needle approach to the axillary block
is always cranial to caudal in this direction.
The reason we come cranial to caudal
is for two reasons:
the axillary vein, as you see on the picture,
usually lies caudal,
and we do not wanna puncture the axillary vein
with a needle approach from the caudal side.
Also, it's much cleaner to go through the deltoid
or the biceps, rather than the axilla.
My initial needle insertion point
will direct the needle below the artery.
If you inject below the artery,
local anesthetic can spread backwards
along the latissimus dorsi, or triceps muscle,
to get to the radial and ulnar nerves.
Here, we can see the needle,
advancing through the biceps muscle.
Our first injection is gonna be below the artery,
and you can see the needle advancing to that area.
You can see the axillary artery, and the axillary vein.
The radial nerve is located deep to the axillary artery.
The ulnar nerve is located between the artery and vein,
and the median nerve is located at nine o'clock
on the axillary artery.
Now we see the needle being advanced above the artery.
You can see the local anesthetic has already been injected
deep to the artery,
and now the median nerve is sitting on top of the artery,
at twelve o'clock.
The needle is now pushing the artery down
and injecting local anesthetic all around the artery
and the median nerve.
We then advance the needle towards the ulnar nerve,
which is now directly in front of the needle.
Our goal is to get local anesthetic
around the ulnar nerve here.
Total volume injected appears to be large,
but it is only 20 milliliters so far.
Now the ulnar nerve is visible,
floating in the local anesthetic,
in the median on top of the artery.
Next, I would like to identify the musculocutaneous nerve.
The musculocutaneous nerve is the fourth nerve
of a properly executed axillary block.
I find the musculocutaneous nerve by moving slightly distal
along the arm.
I also wanna increase the depth,
and look for a hyperechoic nerve
within the biceps or coracobrachialis muscle.
Traditionally, the musculocutaneous nerve
can be oval or triangular.
The musculocutaneous nerve is one of the brightest,
or most hyperechoic nerves in the body,
and it's easily blocked with local anesthetic
in the realm of three to five milliliters.
Here we see a hyperechoic musculocutaneous nerve
surrounded by a hyperechoic fascia.
Our needle is being advanced to the lateral portion.
The local anesthetic is now being injected
below the musculocutaneous nerve,
and now above the musculocutaneous nerve,
to give complete surrounding of that nerve.
The needle is being advanced to the biceps muscle.
You can see the pulsatile axillary artery medial as well.

Brightcove ID

5765651694001

https://youtube.com/watch?v=rG7PXuXrqbU

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Dr. David Auyong reviews scanning techniques and sonographic landmarks for an ultrasound guided nerve block .

How To Perform A Supraclavicular Nerve Block

Read more about How To Perform A Supraclavicular Nerve Block

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The Sonosite SII ultrasound machine supports regional anesthetic techniques used during supraclavicular blocks – serving as an alternative or adjunct to general anesthesia needed for postoperative pain control for upper extremity surgeries (mid-humerus through the hand). Anesthesiologist Dr. David Auyong MD of Seattle, Washington here reviews scanning techniques and sonographic landmarks for the ultrasound guided nerve block. Dr. Auyong highlights patient position, the type of transducer used, the needle position and injection technique. The ability to image the plexus, rib, pleura, and subclavian artery increases safety due to improved monitoring of anatomy and needle placement.

Media Library Type

How To Videos

Media Library Tag

Subtitles

- The supraclavicular block is used
for surgery below the shoulder.
A proper supraclavicular block will effectively block
the elbow, forearm, wrist and hand.
The reason we use supraclavicular blocks
is because the nerves are located very tightly together
and our needle movements can usually get
all the brachial plexus with minimal movements
of the needle.
The supraclavicular block has made a resurgence
since using ultrasound.
The reason is we are able to visualize
some important structures, such as the first rib
the subclavian artery and the pleura.
To start a supraclavicular block,
it's very important to position the patient properly.
The way we position patients for the supraclavicular block,
is to move the pillow all the way over to the side,
so our hands have plenty of room
to come from the posterior side of the patient.
We also turn the patient's head away
from the site to be blocked.
Then we elevate the head of the bed
30 to 45 degrees.
And that gives us the ability to have
our hands in a comfortable position while we do the block.
We use a high frequency linear probe
for the supraclavicular block.
Our nerves should be found half a centimeter
to two centimeters below the skin.
I have oriented the probe so the left side
of the screen is anterior
and the right side of the screen is posterior.
In this setting we now see a bright white strip
going across the screen
with a pulsating subclavian artery
sitting on this bright white stripe.
This stripe can be either first rib
or it can be pleura.
Your needle tip should never be below this stripe.
We call the area below this stripe the no fly zone.
On the screen we now see from left to right
the anterior scaling on the left,
the pulsating subclavian artery,
the most important place to make sure
you have local anesthetic is between
the pulsating subclavian artery and the first rib.
This is because the inferior trunk lies in this area.
And some people have difficulty
with the supraclavicular block
because area is ulnar sparing.
Usually I do two injections for this supraclavicular block.
I put one injection down in the corner
between the pulsating artery and the first rib
and then I put a second injection up higher
by the superior trunk.
My needle position for the supraclavicular block
comes posterior to anterior
and starts about a centimeter away from the probe.
If I start a centimeter or more away from the probe
my needle angel will be flat
and it will be visualized better on the ultrasound machine.
It's very important to have my needle
completely in plane with the ultrasound probe
so it will be visualized during it's entire length.
Give some injection of local anesthetic.
Usually about one to two milliliters
to see the spread of the local anesthetic
on the ultrasound screen.
Injections below the nerves will push
the rest of the brachial plexus more shallow
making the rest of the block easier.
I usually inject about 20 to 30 millimeters
of local anesthetic in the supraclavicular region.
This example of a supraclavicular injection.
The first injection is lateral to the nerves.
Our needle is barely visible because it is at a steep angle.
As the needle is flattened out we will see it better.
You can see the pulsating subclavian artery
sitting on the first rib.
And you can even see pleura out more laterally.
As the injection is put into the pocket between
the artery and the first rib,
notice the artery is even lifted off
the first rib during this injection.
Now you can see the needle much better,
because it is at a flat needle angle.
You can see the nerve just posterior to the artery
and the hypoechoic local anesthetic spreading
below the nerves.

Brightcove ID

5750036243001

https://youtube.com/watch?v=YOOoNT27Irg

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How to: Axillary Nerve Block

How to: Axillary Nerve Block

How To Perform A Supraclavicular Nerve Block

How To Perform A Supraclavicular Nerve Block

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