Performing the block: Brachial Plexus

Question 1

Landmarks for interscalene block

Answer 1

Interscalene groove:
Lateral to the clavicular head of the sternocleidomastoid

Question 2

Where was the needle introduced for interscalene before ultrasound?

Answer 2

level of cricoid cartliage
(C6)

Question 3

Ultrasound approach for the Interscalene block

Answer 3

• Rotate pts head to the contralateral side (away from us) 30 degrees or less
• Place the probe (parallel to the clavicle) over the lateral head of the SCM at the level of the thyroid/cricoid cartlidge
• Deep to the SCM we will visualize the anterior and middle scalene muscles along with the brachial plexus in between them
• You will see three stacked circles, these are the nerves C5, C6, C7 of the brachial plexus
• Inject local around these structures

Question 4

What needle insertion approach is used for an Interscalene block?

Answer 4

Lateral to medial with an in-plane apporach until it is close to the plexus

Question 5

Supraclavicular block landmarks

We are blocking Trunks and Divisions here

Answer 5

Identify the subclavian artery
The brachial plexus is superior and lateral to this (bunch of grapes terminology)

1st rib denotes the lung is inferior (deep) to this structure

Question 6

Ultrasound approach for the supraclavicular block

Answer 6

• Turn pts head 30 degrees to contralateral side
• Ultrasound probe placed in the supraclavicular fossa parallel to the superior border of the clavicle
• Angle slightly towards thorax
• Identify subclavian artery and 1st rib
• Brachial plexus is slightly superior and lateral to the artery
• Guide needle (lateral to medial in-plane) to the subclavian artery and superior to 1st rib
• Inject 20-30 mL of LA in 5 mL increments around the nerve bundle (above and below)
• Nerve bundle referred to as “bundle of grapes”

Question 7

Describe the “bundle of grapes” in ultrasound terminology

Answer 7

Hypoechoic circles surrounded by hyperechoic tissues

Remember grapes look like “O’s” so they are hypo

Question 8

What is the “corner pocket”?

Answer 8

Small triangle area between the subclavian artery and bundle of grapes just superior to the 1st rib

Injecting LA mostly in this area has shown to decrease the risk of hemidiaphragmatic paresis

Question 9

Infraclavicular block landmarks

Answer 9

Axillary artery:
the 3 cords of the plexus surround the artery in a lateral, medial, and posterial fashion

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Question 10

Ultrasound approach for the infraclavicular block

Answer 10

• Place the probe perpendicular to the clavicle just medial to the coracoid process
• Identify Axillary artery
• Identify the cords surrounding the artery
• Insert the needle (using a steep angle) just inferior to clavicle pointing from cephalad to caudal
• Inject local around the artery in a “U” pattern

Needle goes through the Pectoralis major and minor

Question 11

What muscles does the infraclavicular block go through?

Answer 11

Pectoralis major and minor:
Painful and may require sedation to perform this block

Question 12

Axillary block landmarks

Answer 12

With the arm abducted 90 degrees while the pt is supine and head turned away from us:
axillary artery pulse is felt between the biceps/coracobrachialis and the triceps muscles

Question 13

Transarterial Axillary Block

Answer 13

Without ultrasound:
22ga needle inserted and blood is aspiriated
Needle advanced until no blood
30-40ml of LA injected

Question 14

Ultrasound approach for axillary block

Answer 14

• palpate pectoralis major where it inserts into the humorous
• place probe immediately distal to this point
• identify radial, ulnar, and median nerves around the artery
• identify the musculocutaneous nerve between the biceps and coracobrachialis muscles
• Inject 5-7 mL of local around each nerve to total 20 mL

Question 15

How do we avoid displacing structures while injecting local?

Answer 15

we inject posterior to the artery first (radial nerve)