Chapter 36 | REGIONAL ANESTHESIA | PNB

Question 1

Nerve that can be spared by an Interscalene block?

Answer 1

ULNAR NERVE (SECOND Intercostal Brachial Nerve (medial aspect of upper arm)

Question 2

Nerve root of Axillary nerve:

Answer 2

C5 - C6

Question 3

Nerve root of Musculocutaneous Nerve

Answer 3

C5 - C7

Question 4

Nerve root of MEDIAN NERVE

Answer 4

C6 - T1

Question 5

Nerve root of ULNAR NERVE

Answer 5

C8 - T1

Question 6

Artery that can be accidentally punctured during Interscalene block:

Answer 6

Vertebral Artery

Question 7

Horner syndrome as a complication of Interscalene nerve block is likely due to unintentional injury of which nerve?

A. Recurrent laryngeal nerve
B. Sympathetic cervical block
C. Inferior branch of laryngeal nerve
D. Phrenic Nerve

Answer 7

B. Sympathetic cervical block

Question 8

At what level of Brachial Plexus involves Interscalene block?

How many?

Answer 8

ROOTS (567)

3 ROOTS (C5, C6, and C7) Nerve roots

Question 9

What nerve root is spared in Interscalene block?

Answer 9

C8 and T1 roots (ULNAR distribution) are spared, hence it is not ideally done on HAND and FOREARM surgeries. * misses the INFERIOR ROOT that covers the ulnar nerve.

Question 10

At what level of Brachial Plexus involves Supraclavicular block?

Answer 10

TRUNK

Question 11

Also considered as the SPINAL BLOCK of the arm?

Answer 11

Supraclavicular Nerve Plexus Block

Question 12

Why is supraclavicular plexus block not a good block for SHOULDER injury?

Answer 12

It misses the SUPRASCAPULAR NERVE

Question 13

When nerve stimulator is employed while doing PNB, twitching of which part of the upper extremity indicates an adequate block?

Answer 13

Twitching of the HAND/FINGERS

Question 14

The trunks form three anterior and three posterior divisions, which recombine and becomes:

Answer 14

3 CORDS at the Infraclavicular region

Question 15

CONTRAINDICATION of PNB:

Answer 15

1.Patient or Parent of a pediatric patient REFUSAL
2. Local infection
3. Systemic anticoagulation
4. Severe systemic coagulopathy

Question 16

To accentuate the SCM for Interscalene Block:

Answer 16

Ask the patient to reach for the ipsilateral knee and rotating the head approximately 45 degrees to the nonoperative side

Question 17

Interscalene groove is at what level of the cervical vertebrae?

Answer 17

C6

Question 18

While localizing the nerve for Interscalene block, a diaphragmatic response was elicited by the anesthesia resident? This means:

Answer 18

The PHRENIC nerve is being stimulated and that the needle is too ANTERIOR!

Question 19

What accounts for most of the variability in the spread and regression of neuraxial anesthesia?

A. CSF volume
B. pKa of Local Anesthetic
C. Lipid solubility
D. Nerve Myelination

Answer 19

A. CSF volume

Question 20

4. All of the following nerves at the ankle are terminal branches of the sciatic nerve EXCEPT:

A. Posterior tibial nerve
B. Sural nerve
C. Saphenous nerve
D. Deep peroneal nerve
E. Superficial peroneal nerve

Answer 20

C. Saphenous Nerve

Saphenous nerve is a terminal branch of the femoral nerve

Question 21

Compared to opiate-only epidural infusion, use of a combination of local anesthetic and opioid epidural infusion leads to:

A. Increased incidence of motor blockade
B. Increased incidence of pruritus
C. Increased incidence of breakthrough pain
D. Decreased incidence of hypotension
E. Increased incidence of respiratory depression

Answer 21

A. Increased incidence of motor blockade

Question 22

All of the following nerves can be blocked in the axilla
EXCEPT

A. Axillary nerve
B. Musculocutaneous nerve
C. Median nerve
D. Ulnar nerve
E. Intercostal brachial nerve

Answer 22

A. Axillary nerve

Question 23

Which order of systemic local anesthetic toxicity is
correct?

A. Intercostal > caudal > epidural > sciatic > brachial plexus

B. Epidural > caudal > intercostal > brachial plexus > sciatic

C. Intercostal > caudal > epidural > brachial plexus > sciatic

D. Caudal > intercostal > brachial plexus > epidural > sciatic

E. Intercostal > caudal > epidural > sciatic > brachial plexus

Answer 23

C. Intercostal > caudal > epidural > brachial plexus > sciatic

Question 24

This block is indicated mostly for SURGICAL anesthesia of the shoulder and upper arm, and forearm but is often insufficient for the hand:

Answer 24

INTERSCALENE

Question 25

When performing an INTERSCALENE block with an ultrasound with an in-plane POSTERIOR approach, the needle
can be visualized going through which of the following
structures?

A. Middle scalene muscle
B. Anterior scalene muscle
C. Adjacent to the phrenic nerve
D. Sternocleidomastoid muscle
E. Adjacent to the internal jugular vein

Answer 25

A. Middle scalene muscle

In an ultrasound-guided posterior approach to the interscalene
block, the needle goes through the middle scalene muscle.

The trunks of the brachial plexus are located between the anterior and the middle scalene muscles. The anterior scalene muscle lies anterior to the trunks. The internal
jugular vein, the carotid artery, and the phrenic nerve are further anterior to the anterior scalene muscle. The sternocleidomastoid
muscle lies anterior and more superficial to the nerve trunks.

Question 26

TRUE or FALSE

An axillary block is not suitable for surgery of the upper arm

Answer 26

TRUE

An axillary block is not suitable for surgery of the upper arm.

Question 27

TRUE or FALSE

An interscalene block is performed at the level of the trunks and is the most proximal block of the brachial plexus, which is derived from C5–T1 nerve roots.

Answer 27

TRUE

The block is performed by aligning an in-plane needle to a linear, HIGH-frequency probe.

Question 28

TRUE or FALSE

The intercostobrachial nerve innervates the LATERAL aspect of the upper arm and is derived from T2, and hence is not blocked with any brachial plexus block.

Answer 28

FALSE

The intercostobrachial nerve innervates the MEDIAL aspect of the upper arm not the lateral aspect. It is derived from T2, and hence is NOT BLOCKED with any brachial plexus block.

Question 29

TRUE or FALSE

Interscalene block frequently spares the plexus’s lowest branches, the C8 and T1 fibers, which innervate the forearm’s caudad (ULNAR) border

Answer 29

TRUE

Interscalene spares ULNAR border

Question 30

A supraclavicular block is performed at the level of distal trunks/proximal divisions.

Answer 30

TRUE

Question 31

An infraclavicular block is performed at the level of the CORDS.

Answer 31

TRUE

Question 32

This groove lies immediately behind the lateral border of the clavicular head of the sternocleidomastoid muscle at the level of the cricoid cartilage (C6).

Answer 32

INTERSCALENE GROOVE

Question 33

TRUE or FALSE

When performing Interscalene Block using a nerve stimulator, A diaphragmatic or trapezius
twitches should be avoided, as they are associated with cervical plexus stimulation.

Answer 33

TRUE

Diaphragmatic or trapezius twitches should be avoided, as they are associated with cervical plexus
stimulation.

A diaphragmatic response indicates that the phrenic nerve is being stimulated and that the needle is too anterior.

Due to the compact arrangement of neck anatomy in children, an angled insertion may be needed (as opposed to perpendicular in adults) to avoid puncture of the VERTEBRAL artery or epidural/subarachnoid space.

Question 34

At the supraclavicular fossa, the brachial plexus (trunks/divisions) can be seen in the short axis as a tightly enclosed cluster (i.e., honeycomb like), superior and lateral to the subclavian artery

Answer 34

HONEYCOMB structure is seen SUPERIOR and LATERAL to the subclavian artery = INTERSCALENE BRACHIAL PLEXUS

Question 35

The plexus roots/trunks are typically seen as three or more round or ovalshaped hypoechoic structures sandwiched in the interscalene groove between the scalenus anterior and medius muscles

Answer 35

INTERSCALENE BRACHIAL PLEXUS BLOCK

Question 36

while performing Interscalene brachial plexus block, you accidentally injected LA at the INTERVERTEBRAL FORAMEN. This will produce:

Answer 36

SPINAL or EPIDURAL ANESTHESIA

If the needle is allowed to pass directly medially, it may enter the intervertebral foramen, and injection of local anesthetic may produce spinal or epidural anesthesia.

Question 37

The ________ passes posteriorly at the level of the sixth vertebra to lie in its canal in the transverse process that can be seen as a pulsatile structure deep to the
plexus

Answer 37

VERTEBRAL ARTERY

The vertebral artery passes posteriorly at the level of the sixth vertebra to lie in its canal in the transverse process that can be seen as a pulsatile structure deep to the plexus; direct injection into this vessel can rapidly produce central nervous system toxicity and convulsions.

Question 38

Horner syndrome is common in INTERSCALENE BRACHIAL PLEXUS BLOCK because:

Answer 38

spread to the sympathetic chain on the anterior vertebral body.

Question 39

“crampy” pain sensation produced during the FIRST INJECTION of LA while performing INTERSCALENE BLOCK

Answer 39

Neuropathy of the C6 root

Question 40

Which Rexed lamina layers in the gray matter of the spinal cord are involved in transmission of nociception?

Answer 40

125

I, II and V

Question 41

Which nerve can be spared by an infraclavicular block?

Answer 41

ULNAR NERVE

Question 42

Rectus sheath block target the terminal branches of which nerve?

Answer 42

9th, 10th, and 11th intercostal nerves within the rectus sheath!

Question 43

Ideally, where do we injection LA when doing a rectus sheath block ?

Answer 43

between POSTERIOR rectus sheath and the rectus abdominis muscle.

Question 44

TAP block is done by injecting a local anesthetic in which anatomical plane?

Answer 44

between the TRANSVERSUS abdominis and INTERNAL oblique muscles.

The TAP block aims to impede innervation of the abdominal wall UP to the level of T8 by injecting local anesthetic between the transversus abdominis and internal oblique
muscles

Question 45

This fascial plane runs from T1 and the cervical vertebrae to the medial sacral crest on both sides of the spine. It is believed that its analgesic mechanism involves blocking the DORSAL and VENTRAL rami of the spinal nerves and sympathetic fibers, with diffusion and spreading both cranially and caudally to encompass numerous vertebral levels:

A. Paravertebral space
B. ESP (Erector Spinae)
C. QL plane
D. SAP (Serratus AnteriorPlane)

Answer 45

B. ESP (Erector Spinae)