Download Regional Anesthesia

Board Review
Regional Anesthesia
Gustavo A. Lozada, M.D.
Mass General
February 28, 2012
1. The components of the brachial plexus, from
proximal to distal, are:
A. Roots, Divisions, Cords, Trunks, Branches
B. Trunks, Roots, Cords, Divisions, Branches
C. Roots, Trunks, Divisions, Cords, Branches
D. Roots, Branches, Divisions, Cords, Trunks
1. The components of the brachial plexus, from
proximal to distal, are:
• Answer:
– (C) Roots, Trunks, Divisions, Cords,
Branches
• Remember: Randy Travis Drinks Cold Beer
2. The brachial plexus is formed by the
following nerve roots:
A.
B.
C.
D.
E.
C2, C3, C4, C5, C6
C6, C7, C8, T1, T2
C4, C5, C6, C7
C5, C6, C7, C8, T1
C6, C7, C8, T1
Brachial Plexus
• Roots:
– C5-T1 (anterior rami)
• Trunks:
– Superior: C5-6
– Middle: C7
– Inferior: C8-T1
• Divisions:
– 3 anterior
– 3 posterior
• Separate innervation of ventral and dorsal halves
of the upper extremity
Brachial Plexus
• Cords:
(based on relationship to axillary artery)
– Lateral – ant div of superior and middle trunks
– Posterior – post div of superior, middle, and inferior
trunk
– Medial – inferior trunk
Brachial Plexus
• Branches:
– Musculocutaneous N. : lateral cord
– Median N. : lateral root from lateral cord
medial root from medial cord
– Axillary N.: posterior cord
– Radial N.: posterior cord
– Ulnar N.: medial cord
2. The brachial plexus is formed by the
following nerve roots:
• Answer: (D) C5-T1
• The brachial plexus is formed by the C5-T1
roots
3. Which of the following correctly describes
the anatomic location of the brachial plexus?
A. Adjacent to the subclavian vein as it passes
between the scalene muscles
B. Between the middle and posterior scalene
muscles
C. Posterior to the first rib
D. Posterior to the subclavian artery
E. Posterior to the vertebral artery
3. Which of the following correctly describes the
anatomic location of the brachial plexus?
• Answer: (D) Posterior to the subclavian
artery
• The brachial plexus courses posterior to the
subclavian artery.
4. Which of the following peripheral nerve
blocks is MOST appropriate for rotator cuff
repair?
A. Axillary
B. Cervical Plexus
C. Infraclavicular
D. Interscalene
Interscalene Brachial Plexus Block
• Indications:
– Pain Relief from surgery of the shoulder and
upper arm
• Brachial plexus trunks
4. Answer: (D) Interscalene
A. Axillary block : for surgical procedures of the forearm and
hand, for lower arm procedures with musculocutaneous
block
B. Cervical Plexus block: for superficial and deep procedures
of the neck and supraclavicular fossa
C. Infraclavicular block: surgical procedures at the elbow,
forearm and hand
D. Interscalene block: for surgical procedures of shoulder
and proximal half of humerus(including rotator cuff
surgery)
5. Landmarks for an interscalene brachial
plexus block include the
A. posterior scalene muscle
B. thyroid cartilage
C. carotid artery
D. anterior scalene muscle
5. Answer: (D) Anterior scalene muscle
• Landmarks for the interscalene block include
the clavicular head of the sternocleidomastoid
muscle, the clavicle, the external jugular vein,
anterior and middle scalene muscles and
cricoid cartilage (C6).
• The posterior scalene muscle, thyroid
cartilage, and carotid artery are not landmarks
for this block.
6. Complications of the interscalene approach
to brachial plexus blockade include all of the
following except
A. Nasal congestion
B. Hoarseness
C. Ipsilateral diaphragmatic paralysis
D. Ipsilateral mydriasis
6. Answer: (D) ipsilateral mydriasis
• Horner’s Syndrome (ptosis, miosis, anhydrosis) is a
common complication from an interscalene brachial
plexus block from spread to the cervical plexus.
• Ipsilateral diaphragmatic paralysis occurs in over
95% of cases.
• Nasal congestion may be seen due to
sympathectomy
• Hoarseness can result in 2-3% of cases from recurrent
laryngeal nerve involvement.
• Mydriasis does not occur.
7. A 63-year-old man needing repair of a fracture of the distal
humerus has a history of severe chronic obstructive pulmonary
disease. Which of the following is MOST likely to provide
adequate surgical anesthesia while minimizing the risk of
respiratory complications?
A. Intravenous regional anesthesia (Bier block)
B. Interscalene nerve block
C. Supraclavicular nerve block
D. Combined axillary and musculocutaneous
nerve blocks
7. Answer: (D) Combined axillary and
musculocutaneous nerve blocks
A. An intravenous regional anesthetic would not provide
adequate surgical anesthesia for repair of a fracture of the
distal humerus.
B. Blockade of the phrenic nerve occurs in more than 95% of
patients receiving an interscalene nerve block
C. A supraclavicular nerve block provides adequate anesthesia
for repair of a fracture of the distal humerus but is
associated with phrenic nerve block(30-50%) and/or
pneumothorax.
D. Combined axillary and musculocutaneous nerve blocks
can provide adequate surgical anesthesia for distal humerus
procedures while minimizing the risk of pulmonary
complications.
Axillary Brachial Plexus Block
• Indications:
– Pain relief for surgery at or distal to the elbow
• Brachial plexus branches
8. A properly performed axillary nerve
block will anesthetize all of the following
except the:
A. Radial nerve
B. Median nerve
C. Ulnar nerve
D. Musculocutaneous nerve
8. A properly performed axillary nerve block
will anesthetize all of the following except the:
(D) Musculocutaneous Nerve
9. An axillary block is being performed for surgery
on the palmar aspect of the thumb. As the needle is
advanced with nerve-stimulator guidance, the patient
reports paresthesias in the fifth digit, and finger
flexion is seen at 0.4 volts. Which statement about
the needle position is MOST likely true?
A. The needle should be advanced to a deeper position.
B. The needle should be withdrawn and redirected more
superiorly.
C. The needle should be withdrawn and redirected more
inferiorly.
D. The needle is in an optimal position.
9. Answer: (B) The needle should be withdrawn
and redirected more superiorly
•
•
•
The stimulation pattern described indicates ulnar nerve
stimulation. Advancing to a deeper position in the axilla when
stimulating the ulnar nerve would not be expected to place the
needle closer to the desired median nerve. Advancing to a
deeper position when stimulating the ulnar nerve might recruit
fibers from the radial nerve.
The stimulation pattern described indicates ulnar nerve
stimulation. Withdrawing and redirecting inferiorly when
stimulating the ulnar nerve would not be expected to place the
needle tip closer to the desired median nerve.
The stimulation pattern described indicates ulnar nerve
stimulation. An optimal needle position would place the needle
tip next to the median nerve.
(B) Withdrawing and redirecting more superiorly would place the needle tip in
the proximity of the median nerve
10. During surgery of the forearm under axillary
block, a patient has pain in the lateral aspect of the
forearm and responds by flexing the elbow. The most
likely cause is inadequate block of which of the
following nerves?
A. Axillary
B. Intercostobrachial
C. Musculocutaneous
D. Radial
E. Ulnar
10. Answer: (C)
Musculocutaneous
A.
Axillary: the axillary nerve supplies the deltoid, teres minor,
and triceps muscles. (motor: abduction of the arm, flexion,
extension, rotation of shoulder) It is sensory to the shoulder
joint and skin covering the inferior region of the deltoid (lateral
upper arm.)
B.
Intercostobrachial: sensory to medial aspect of upper arm
C.
Musculocutaneous: motor to flexors of arm, sensory to
lateral side of forearm
D.
Radial: provides motor innervation to the dorsal arm muscles
(extensors) and the extrinsic extensors of the wrist and hand.
Sensory to most of the back of the hand, part of dorsal
forearm.
E.
Ulnar: sensory to dorsal and volar aspects of the ulnar side of
the hand, dorsal and volar sides of the medial half or the ring
finger and entire fifth digit. Motor to intrinsic muscles of the
hand (flexion of MCP joints and extension of the IP joints of
fingers and thumb adduction) and to flexors of wrist and DIP
joints of 4th and 5th digits.
11. Which statement about the supraclavicular
approach to the brachial plexus is MOST likely
true?
A. The point of needle entry is medial to the
clavicular head of the sternocleidomastoid.
B. Phrenic nerve block occurs in less than 5% of
cases.
C. The block provides reliable anesthesia for
shoulder surgery.
D. Ultrasound allows visualization of the nerves to
be blocked.
Supraclavicular Brachial Plexus Block
• Indications:
– Pain relief for any surgery on the upper extremity that
does not involve the shoulder
– Excellent for elbow and hand surgery
• Brachial plexus divisions
11. Answer: (D) Ultrasound allows
visualization of the nerves to be blocked
A. The point of needle entry is lateral to the
clavicular head of the sternocleidomastoid.
B. Hemidiaphragm paralysis due to phrenic nerve
blockade occurs in 30%–50% of patients.
C. The occurrence of anatomical variants in
brachial plexus anatomy means that the
supraclavicular approach is not reliable for
shoulder surgery.
12. A patient complains of difficulty talking 15
minutes after receiving an interscalene block. The
MOST likely cause is
A. cervical sympathetic block
B. phrenic nerve paralysis
C. vertebral artery injection
D. recurrent laryngeal nerve block
12. Answer: (D) recurrent laryngeal
nerve block
A. Cervical sympathetic block: results in Horner’s
syndrome (ptosis, miosis, anhydrosis) and nasal
congestion
B. Phrenic nerve paralysis: results in
hemidiaphragmatic paralysis
C. vertebral artery injection: results in neurological/
cardiac symptoms depending on dose injected
D. (D) recurrent laryngeal nerve block: results in
hoarseness
13. Which surface area of the upper extremity
is most likely to be unanesthetized by an
interscalene brachial plexus block?
A. Hypothenar eminence
B. Thenar eminence
C. Dorsolateral surface of the hand
D. Lateral aspect of the forearm
E. Lateral surface of the upper arm
13. Answer: (E) Hypothenar
eminence
A. Thenar eminence: Radial n.
B. Dorsolateral hand : Radial n.
C. Lateral aspect of forearm:
Musculocutaneous n.
D. Lateral surface of the upper arm:
Axillary n.
E. Hypothenar eminence: The
interscalene block can have
ulnar sparing. Ulnar nerve
provides sensory innervation to
the hypothenar eminence.
14. In performing a brachial plexus block at the
level of the axilla, the ulnar nerve is
MOST likely located
A. superior to the axillary artery
B. anterior to the axillary artery
C. posterior to the axillary artery
D. inferior to the axillary artery
14. Answer: (D) inferior to the axillary artery
• The key nerves of the brachial plexus present in the
axilla include the radial, median, and ulnar nerves.
These nerves are all located in relatively consistent
locations in relation to each other and the axillary artery.
Knowledge of the locations of these nerves can allow
utilization of techniques to target specific nerves.
• In relation to the axillary artery, the following
relationships are present regarding the nerves in the
axilla:
1. The median nerve is located superior to the axillary artery.
2. The ulnar nerve is located inferior to the axillary artery.
3. The radial nerve is located posterior to the axillary artery
15. Which of the following approaches to the brachial
plexus allows you to perform a block at the level of the
cords?
A. Interscalene
B. Supraclavicular
C. Infraclavicular
D. Axillary
Infraclavicular Brachial Plexus Block
• Indications:
– Pain relief for surgery of the elbow, forearm, and hand
• Brachial plexus cords
15. Which of the following approaches to the brachial
plexus allows you to perform a block at the level of the
cords?
• Answer: (C) Infraclavicular
16. You have performed an infraclavicular brachial plexus
nerve block for surgical anesthesia for a wrist fracture ORIF
with a mixture of 10 cc 2% mepivacaine and 30 cc 0.5%
bupivacaine. One hour later, before going to the OR, the
patient continues to have sensation in the dorsal aspect of the
thumb. Which of the following would be the most appropriate
next course of action:
A. Delay the case another 30 minutes
B. Perform a median nerve rescue block
C. Perform an ulnar nerve rescue block
D. Perform a radial nerve rescue block
• 16. Answer: (D) Perform a radial nerve rescue block
17. During a right toe amputation performed under
an ankle block, the patient complains of pain in the
dorsal space between the hallux and the second toe.
Which of the following nerves has been spared in the
ankle block:
A. Saphenous nerve
B. Sural nerve
C. Deep peroneal nerve
D. Superficial peroneal nerve
E. Posterior tibial nerve
Answer: (C) Deep peroneal nerve