Ultrasound regional anesthesia

Ultrasound Regional Anesthesia
Dr Mohsen abad
Pain interventionist
IN THE NAME OF GOD

Topics
• Supraclavicular blocks
• Infraclavicular blocks
• Axillary blocks
• TAP blocks
• Femoral nerve blocks
• Sciatic nerve blocks in the popliteal fossa
Number
of slides:
66

INTERSCALENE BLOCK:
Blockade occurs at the level of the superior and middle trunks
SUPRACLAVICULAR BLOCK:
Blockade occurs at the distal trunk-proximal division level.
INFRACLAVICULAR BLOCK:
Blockade occurs at the level of the cords
AXILLARY BLOCK:
Blockade occurs at the level of the terminal nerves.

Brachial Plexus Probe Orientation
• 1 Interscalene
• 2 Supraclavicular
• 3 Infraclavicular
• 4 Axillary
• 5 Mid Humeral

SUPRACLAVICULAR BLOCKS
• The advantages:
–brachial plexus is compact
–the nerve visibility is extremely good
–the structures
–are shallow (20- to 30-mm field

SUPRACLAVICULAR BLOCKS
• Indications for operations:
– on the elbow,
– forearm,
– hand
• Risk :
1. vascular puncture in an
area that is difficult to
compress
2. pneumothorax.

in-plane approach from medial to lateral to ensure
that the needle will pass over the subclavian artery can
be used to reach the brachial plexus

Current technique:
• patient position:
– semi-sitting
– head turned to the opposite side
– the arms flush with the body.

Key Points
• Proximity to the phrenic nerve
occurs if the block location is
too cephalad
• linear transducer (20- to 30-
mm footprint)
• The medial-to lateral and the
lateral-to-medial in-plane
approaches both have
excellent efficacy and safety
• The C5 ventral ramus (and other
contributions to the brachial
plexus) can pass over or through
the anterior scalene muscle rather
than between the scalene muscles.
• When this condition is identified,
the block is usually performed at a
more caudal position in the neck to
avoid incomplete brachial plexus
anesthesia

Supraclavicular block with ultrasound imaging.
A, In this external photograph of ultrasound-guided supraclavicular block, the needle
approaches the brachial plexus from medial to lateral.
B, Sonogram of supraclavicular block with ultrasound guidance. The block needle approaches
from medial to lateral within the plane of imaging for this procedure. Local anesthetic is observed
to distribute around the compact brachial plexus

INFRACLAVICULAR BLOCKS
Advantages
• complete brachial plexus
anesthesia
• is a stable place for a catheter
• provides anesthesia to the arm
• and hand.
• no manipulation of the arm is
necessary
Disadvantages
• Deeper block
• Needle or probe manipulations are
necessary

Current technique:
• Arm is abducted the to straighten the neurovascular
bundle: block is easier
• three arterial wall-hugging cords are named with respect
to the second part of the axillary artery: medial, lateral,
and posterior.
• artery is visualized in short-axis view deep to the
pectoralis major and minor muscles
• Most practitioners use an in-plane approach

posterior to the axillary artery for
single-shot or catheter placement
The ideal place for local anesthetic:

The cords of the brachial plexus do not need to
be directly visualized for successful block

External photograph of the
setup for infraclavicular block
shows the arm has
been abducted in this case
Sonogram of the cords of the
brachial plexus (yellow arrows)
are adjacent to the axillary artery
(A) and vein (V).
The neurovascular bundle lies
deep to the pectoralis major
(PMa) and pectoralis minor (PMi)
muscles in this anatomic region
Needle tip is in
position for
infraclavicular block and
the resulting local
anesthetic distribution

Sonographic Signs Indicating Infraclavicular Block Success
U-shaped distribution underneath the axillary
artery
Separation of cords from axillary artery
White wall appearance to the axillary artery
Reduction in axillary artery diameter
Dark streak underneath the axillary artery in the
long axis view

AXILLARY BLOCKS
• cardinal weakness has been the failure to block the
musculocutaneous (MCN) nerve
• provides surgical anesthesia:
– elbow
– more distal upper extremity
• The shallow depth of the neurovascular bundle (a 20-mm
field is typical) relativel easy with US guidance

AXILLARY BLOCKS
• the MCN nerve has a
characteristic change in
shape:
– adjacent to the artery (round)
– coracobrachialis muscle (flat)
– exiting the muscle (triangular)
• Both techniques can be used:
– in-plane
(with needle approaching from the
lateral side of the arm)
– out-of-plane
(with needle approaching from
distal to proximal)

AXILLARY BLOCKS
• The block is performed in the
proximal axilla
• transducer gently pressed
against the chest wall to
visualize the conjoint tendon
of the latissimus dorsi and
teres major
• A high-frequency linear probe
with a small footprint (25 to 50
mm)
• The ideal location for LA
injection is between the nerves
and the artery so that
separation between the two
structures occurs to ensure
distribution within the
neurovascular bundle

the median
(superficial
and lateral to
the artery)
the ulnar
(superficial
and medial to
the artery),
and
the radial
(posterior and
lateral or
medial to the
artery) nerves .

Axillary block with ultrasound guidance.
A, External photograph demonstrates the in-plane approach.
B, Sonogram of the neurovascular bundle in the short axis view shows the
needle tip in-plane after injection of the local anesthetic. The probe
compression is just sufficient to coapt the walls of the satellite veins. The
block is performed at the level of the conjoint tendon of the latissimus dorsi
and teres major (white arrows), which lies under the neurovascular
structures. The third part of the axillary artery (A) and nerves of the brachial
plexus—radial, ulnar, median, and musculocutaneous—in order from medial
to lateral (yellow arrows) are shown

Distribution of Blockade
• The axillary nerve itself is not blocked because it
departs from the posterior cord high up in the axilla.
• As a result, the skin over the deltoid muscle is not
anesthetized.
• Medial skin of the upper arm (intercostobrachial nerve,
T2) can be blocked by an additional subcutaneous
injection just distal to the axilla

Key points
• In an adult patient, 20 to 25 mL of local anesthetic is
usually adequate for successful blockade.
• Complete spread around the artery is necessary for
success but infrequently seen with a single injection.
• Two to three redirections and injections are usually
necessary for reliable blockade, as well as a separate
injection to block the musculocutaneous nerve.

These injections result in excellent clinical blocks.
The MCN nerve is usually blocked
within the coracobrachialis, where its flat shape gives a
large amount of surface area for rapid block

COMPARISON OF THE INFRACLAVICULAR AND AXILLARY
APPROACHES TO BRACHIAL PLEXUS BLOCK
Infraclavicular Block Axillary Block
Depth Deep (two muscles) Shallow
Onset Slower Faster
Tourniquet tolerance Better Good
Catheter success High Low

TRANSVERSUS ABDOMINIS PLANE AND
ILIOINGUINAL NERVE BLOCKS
TAP BLOCK

TAP BLOCK
• Four peripheral nerves, the subcostal, ilioinguinal,
iliohypogastric, and genitofemoral, primarily innervate
the lower abdominal wall.
• three nerves through the abdominal wall within the
layer between the TA and the IO muscles makes this the
desired anatomic location for regional block
• patient position: supine
• The transducer is placed between the iliac crest and
costal margin in the midaxillary line.

TAP BLOCK
• Injection is in the fascial layer that separates the IO and
the TA muscles
• 15 to 20 mL of dilute local anesthetic is injected
• Approach: in-plane from the ANT side and directed
toward the posterolateral corner of the TA muscle

The kayak sign demonstrates successful TAP injection.
The fascia between the IO and TA muscles is split apart in the shape
resembling a kayak

Ilioinguinal nerve block
with ultrasound
imaging.
The
transducer is rotated
and placed near the
iliac crest for
ilioinguinal
nerve block.

FEMORAL NERVE BLOCKS
• advantages US:
– more complete block
– local anesthetic volume
sparing
– fewer vascular punctures
• The femoral nerve usually lies
lateral to the femoral A in the
groove formed by the iliacus
and psoas muscles.
• Nerve: oval or triangular in
cross-sectional shape
• anteroposterior diameter of 3
mm and a mediolateral
diameter of 10 mm.

Key Points
• some tilting of the US probe is necessary for the sound
beam to meet the nerve perpendicularly for optimal
scanning
• some rotation : the FN has a slight medial-to-lateral
course;
• FN is covered by echobright adipose tissue and fascia,
the echogenic outer sheath of the nerve is difficult to
establish

Key Points
• a broad (35- to 50-mm footprint) linear transducer is
used
• Both approaches can be used :
– in-plane (from lateral to medial)
– out-of-plane (from distal to proximal).
• The fascia iliaca has a characteristic mediolateral slant

FEMORAL NERVE BLOCKS
The desired distribution:
• is local anesthetic layering
under or completely around
the femoral nerve
• When layering of LA is
restricted over the nerve, the
concern is that the fascia iliaca
is intact and that block failure
will result.

Cross-section at the block location below the inguinal crease. The femoral nerve lies
deep to the fascia lata and fascia. iliaca (iliopectineal fascia) and is separated from
the artery and vein(s).

Femoral nerve block with ultrasound imaging (inplane
approach).
A, External photograph shows the setup for femoral nerve
block.
B, The needle tip is in position before injecting adjacent to
the femoral nerve (yellow arrow). The femoral nerve lies
lateral to the femoral artery (A).
C, Local anesthetic surrounds the femoral nerve
after injection.

saphenous branch of the FN can be blocked in the
midthigh, deep to the sartorius muscle using US
guidance
advantage: that the quadriceps motor block is reduced.

Saphenous nerve block in the middle thigh with ultrasound imaging (in-planeapproach).
A, External photograph shows the setup for saphenous nerve block.
B, The needle tip has been placed through the Sartorius muscle adjacent to the saphenous nerve
(yellow arrow) and superficial femoral artery (A) before injection.
C, Local anesthetic surrounds the saphenous nerve after injection deep to the sartorius muscle

SCIATIC NERVE BLOCKS IN THE POPLITEAL
FOSSA

Sciatic nerve blocks in the popliteal fossa
• One of the most common approaches :
– using a lateral approach in supine position with the leg
elevated
• The division of the sciatic nerve:
– provides a broad target
– large surface area to promote clinical block characteristics
• the needle tip: between the tibial and common peroneal
near the division so that a single injection distributes to
both nerves

Popliteal block with ultrasound imaging (in-plane approach).
A, External photograph shows the setup for popliteal nerve block in the supine position. The leg is elevated,
and the transducer is applied to the posterior surface of the leg.
B, The needle approaches the bifurcation of the sciatic nerve in the plane of imaging from the lateral aspect of
the leg.
The needle tip is positioned between the tibial (long yellow arrow) and common peroneal (short yellow arrow)
nerves

Sciatic nerve blocks in the popliteal fossa
• The TN has a straighter course than the CPN and has
twice the cross-sectional area.
• Move the foot : the nerves have motions that can be
helpful for nerve identification in some patients.
• The advantages of this approach:
– are the convenient position,
– transducer position is remote from the site of needle entry,
– parallel in-plane approach of the block needle results in
optimal needle tip visibility

Ultrasound regional anesthesia

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