Upper Extremity PNB (Part 3)

Question 1

Derived from the posterior cord

Answer 1

Axillary nerve

Question 2

Motor innervation is deltoid and teres minor muscles that act on the shoulder joint

Answer 2

Axillary nerve

Question 3

Axillary nerve sensory innervation

Answer 3

is from the skin just below the point of the shoulder

Question 4

Characteristics of Axillary nerve movement in response to stimulation

Answer 4

teres minor (a rotator cuff muscle) stabilizes the glenohumeral joint and acts to externally rotate the shoulder joint

Question 5

Injuries or lesions of Axillary nerve (C 5, 6)

Answer 5

results in the inability of the deltoid muscle to abduct arm to a horizontal position

Question 6

Sensory deficit injury/lesion

Answer 6

lateral side of arm below point of shoulder

Question 7

Derived from the posterior cord and called “Great Extensor Nerve” because it innervates the extensor muscles of the elbow, wrist and fingers

Answer 7

Radial nerve

Question 8

Sensory innervation of radial nerve

Answer 8

from the skin on the dorsum of the hand on the radial side

Question 9

Characteristics of Movement in response to stimulation of radial nerve:

Answer 9

extension at elbow, supination of forearm, and extension of wrists and fingers

Question 10

Radial nerve (C5-T1): “drop wrist” results in

Answer 10

difficulty or inability to make a fist

Question 11

Injury often associated with arterial line placement

Answer 11

radial nerve injury

Question 12

Sensory Deficit in radial nerve

Answer 12

posterior lateral & arm; dorsum of hand index to thumb

Question 13

4 nerves of interest for a brachial plexus block

Answer 13

radial, musculocutaneous, ulnar and median

Question 14

Checking the 4 nerves of interest for a brachial plexus block- the 4 P’s:

Answer 14

Question 15

Upper Extremity Nerve Blocks: (%)

Answer 15

Brachial plexus
Musculocutaneous nerve block
IV regional block (Bier Block)
Wrist block
Digit block

Question 16

brachial plexus nerve blocks

Answer 16

Interscalene
Supraclavicular
Infraclavicular
Axillary

Question 17

Used to supplement brachial plexus block

Answer 17

Musculocutaneous nerve block

Question 18

Most proximal approach to the brachial plexus

Answer 18

Interscalene approach

Question 19

A paravertebral approach at the cervical roots in the neck

Answer 19

Interscalene approach

Question 20

Relatively easy place to enter the brachial plexus sheath and elicit a paresthesia

Answer 20

Interscalene approach

Question 21

Most suitable for procedures on the upper arm or shoulder

Answer 21

Interscalene approach

Question 22

why is Interscalene approach less suitable for procedures on the hand (ulnar nerve)

Answer 22

because C 8 – T 1 is harder to block from this approach

Question 23

Interscalene approach landmarks
1. ?
2. ?
3. ?
4. ?

Answer 23

1. Clavicle
2. Posterior border of sternocleidomastoid (SCM) muscle
3. External jugular
4. Cricoid cartilage

Question 24

Interscalene approach steps

Answer 24

• Standard monitors & “Crash Cart”
• Supine; head contralateral
• Sterile prep/drape
• Localize skin @ cricoid cartilage
• 22g. 1 ½ in. needle; 45-70 angle, perpendicular and advanced in a caudal direction
• Very shallow block
• May feel a “pop”
• elicit paresthesia or contraction in the arm
• confirm paresthesia
• stabilize the needle
• negative aspiration for blood
• 20-40 ml LA slowly & carefully
• Consider lidocaine 1 - 1.5%, bupivacaine 0.2 - 0.375%, or ropivacaine 0.2 - 0.5 %

Question 25

what do you check for after interscalene approach procedure

Answer 25

• Anesthesia is then evaluated in ~5 minutes
• Check for weakness of biceps or sensory anesthesia of forearm
• Ipsilateral phrenic nerve block (horners syndrome)

Question 26

Complications of interscalene blocks:

Answer 26

• Horner’s Syndrome
• Stellate ganglion
• Recurrent laryngeal nerve blockade
• Central blockade (epidural/subarachnoid)
• Vertebral artery injection with local
• Pneumothorax –>less common with this approach, but it is still possible… (close proximity of the apical pleura)

Question 27

what happens in Horner’s syndrome?

Answer 27

(nasal congestion, ptosis, miosis and anhidrosis) flushing of the face, and increased temperature of the arm

Question 28

what happens when a stellate ganglion is formed?

Answer 28

formed by the fusion of the inferior cervical and first thoracic sympathetic ganglia anterior to the vertebral body of C7

Blocking it (cervicothoracic sympathetic block) = SNS blockade of the ipsilateral face and arm, which presents as Horner’s syndrome (not really a complication)

Question 29

this block is suitable for surgery below the shoulder

Answer 29

Supraclavicular approach

Question 30

As plexus passes through here it is very compacted, therefore blockade via this approach achieves excellent anesthesia to the entire arm, including the hand

Answer 30

Supraclavicular approach

Question 31

Supraclavicular approach Landmarks:

Answer 31

clavicle and subclavian pulse

Question 32

Supraclavicular approach Steps (4)

Answer 32

Standard monitors and “crash cart”
Patient lying supine with head turned towards contralateral side with head of bed elevated to 30 degrees.
Shoulder down, arm bent @elbow, hand resting on abdomen or lap
Localize the site with lidocaine and a 25 g needle

Question 33

USG Supraclavicular Block (5)

Answer 33

• Needle: posterolateral to the transducer in an anteromedial direction
• Advance medially toward the subclavian artery until the tip is visualized near the brachial plexus
• LA spread visualized surrounding the plexus, (20–30 mL).
• most important injection location is the “corner pocket” between the artery, plexus, and first rib.
• Reduces the incidence of phrenic nerve block while still providing surgical anesthesia to the upper extremity

Question 34

Supraclavicular approach steps

Answer 34

Using a 22 g, 3.75 cm needle with 10 cc syringe, insert in a caudad direction the until 1st rib is contacted, remain perpendicular to rib. “Plumb- bob” meaning keep the needle straight downward like a brick mason plumb bob.
From rib, walk needle anterior/posterior until the nerve response is elicited.
If unable to elicit nerve response, artery can be used as a landmark via palpation or doppler.
Inject 30 to 40cc of 1.5% lidocaine or 0.375 - 0.5% bupivacaine or ropivacaine

Question 35

Complications of Supraclavicular (5)

Answer 35

• Pneumothorax happens most frequently (literature states 0.5 – 6 %) with this approach to brachial plexus blockade
• Hemothorax
• Horner’s syndrome (not really a complication)
• Recurrent laryngeal block
• Contraindicated in patients with severe pulmonary disease due to risk of phrenic nerve blockade

Question 36

Infraclavicular approach: level of block?

Answer 36

Brachial plexus blocked at level of cords

Question 37

Needle is directed under the clavicle, lateral to subclavian artery

Answer 37

Infraclavicular approach

Question 38

Infraclavicular approach landmarks:
1. ?
2. ?
3. ?
4. ?

Answer 38

1 coracoid process
2 clavicle
3 humerus
4 scapula

Question 39

Infraclavicular approach Steps

Answer 39

Supine, head directed in opposite direction, ipsilateral arm bent at +/- 90 degrees
2cm medial and 2cm caudad to coracoid process
Insert @ 45 degree angle towards the axilla
Brachial plexus stimulation is usually elicited between 5 - 8 cm on adults

Question 40

Infraclavicular approach complications (5)

Answer 40

pneumothorax, hemothorax, chylothorax, nerve injury, and hematoma

Question 41

Anesthetizes the cords surrounding the axillary artery where they have re-grouped into terminal branches

Answer 41

Axillary approach

Question 42

Facilitates surgery of the hand, forearm and +/- elbow

Answer 42

Axillary approach

Question 43

Usually excludes the musculocutaneous nerve

Answer 43

Axillary approach

Question 44

Landmark is the axillary pulse (artery)
Needle: 1 ½ inch

Answer 44

Axillary Block

Question 45

axillary block technique

Answer 45

Straddle the pulse between your two fingers; go above artery; insert 1-2cm

Question 46

USG Axillary Nerve Block image

Answer 46