Chapter 76 Truncal Blocks: Intercostal, Paravertebral, Interpleural, Suprascapular, Ilioinguinal, and Iliohypogastric Nerve Blocks

Question 1

Epidural analgesia when compared to

paravertebral blocks for patients undergoing thoracotomy

Answer 1

fewer side effects including
pulmonary complications, hypotension, urinary
retention, and nausea and vomiting.

Question 2

paravertebral (PV) space

Answer 2

wedge-shaped area adjacent
to the vertebral column that contains the sympathetic
chain, the dorsal and ventral (intercostal) roots of the spinal
nerve, the white rami communicantes as well as fatty
tissue and intercostal vessels

Question 3

The base of the wedge constitutes

Answer 3

the medial border of the paravertebralspace and is formed by the vertebral body and the intervertebral
disc where there is communication with the epidural space via the intervertebral foramen

Question 4

The posterior border of the PV space

Answer 4

the superior costotransverse ligament which extends laterally to become continuous with the aponeurosis of the internal intercostal muscle.

Question 5

internal intercostal membrane runs

Answer 5

between the ribs

Question 6

superior costotransverse ligament runs from

Answer 6

the inferior border of the transverse process above to the superior border of the rib tubercle below.

Question 7

As the wedge tapers off

laterally, it is continuous with the

Answer 7

intercostal space

Question 8

Anterior and lateral to the PV space is the

Answer 8

parietal pleura

Question 9

Within the paravertebral space, the spinal nerves

Answer 9

do not have a fascial sheath and are easily susceptible
to local anesthetic blockade. There is however the endothoracic fascia, which is the deep investing fascia of the
thoracic cavity, within the PV space that can affect the
spread of injected solutions.

Question 10

Conventional techniques have described

Answer 10

loss-of-resistance approach to reach the PV space. A small-gauge Tuohy needle is inserted 2.5 cm lateral to the
superior edge of the spinous process perpendicular to all
planes and advanced until contact is made with the transverse process (TP). The needle is then withdrawn to the skin, redirected caudad or cephalad by 15 degrees and advanced deep to the superior costotransverse ligament at which point loss of resistance is achieved. To avoid pleural puncture, the needle
is advanced 1 cm (and no further than 1.5 cm) past the point at which the TP was contacted

Question 11

It is best to avoid medial and lateral angulation of the needle to minimize the risk of

Answer 11

It is best to avoid medial
angulation of the needle to minimize the risk of local
anesthetic injection into a dural sleeve. It is also prudent to
avoid lateral angulation given that the PV space is narrower
laterally increasing the risk of pleural puncture

Question 12

Three US-guided approaches have been described.
The first approach utilizes US primarily to identify
the TP.

Answer 12

Once the TP is contacted under US guidance, the conventional loss-of-resistance technique is utilized. To visualize the TP, the US probe is placed in a longitudinal
parasagittal plane 2.5 cm from the midline. Generally, a 5- to 10-degree tilt laterally is needed to best visualize the TP, which appears as concave hyperechoic structure
approximately 1 cm wide with anechoic space deep to
it. This is commonly referred to as a “thumbprint sign.”
The parietal pleura can be visualized approximately 1 cm
deep to the TP on either side as a sharp hyperechoic line. Initial contact with the TP should be made with a 22-gauge finder needle that can serve to infiltrate local anesthetic. Generous local anesthetic infiltration is recommended to minimize paraspinal muscle discomfort and can serve to echolocate the needle tip. Once the TP is contacted with the finder needle, the depth is noted and a Tuohy needle or blunt-bevel block needle is introduced. Using an out-of-plane needle approach and similar to the
conventional technique, the TP process is contacted and
then redirected caudad 1 cm (and no more than 1.5 cm)
past the TP. Loss of resistance to saline is confirmed and
local anesthetic injection is performed

Question 13

The first approach utilizes US primarily to identify the TP. To minimize the risk of pleural puncture and development of pneumothorax,

Answer 13

it is useful to have a needle with centimeter markings and a closed needle-syringe system relative to atmospheric pressure.

Question 14

The second approach is a slight variation of the first and
utilizes an in-plane or out-of-plane approach to the PV
space

Answer 14

The probe is in the identical longitudinal parasagittal
plane and the PV space is approached directly without first contacting the TP process. a “pop” may be felt when the posterior costotransverse ligament is traversed with corresponding loss of resistance

Question 15

In the third approach, the TP is initially imaged with

Answer 15

a similar longitudinal parasagittal view, and the probe is then rotated obliquely to allow for the best view of the posterior costotransverse ligament and the PV wedge. The needle is advanced carefully utilizing an in-plane needle approach

Question 16

PV Block DOSING

Answer 16

A single injection of 15 ml can be expected to provide analgesia over 3 to 4.6 dermatomes in the thoracic region. Spread is initially at the level of injection and
along the intercostal nerve, and progresses in the PV “gutter” to cover one dermatome above and two dermatomes
below.

Question 17

PV Block Analgesia last for

Answer 17

typically ranges from 6 to 12 hr for a single injection. If a catheter is placed, infusion
of ropivacaine 0.2% to 0.5% at rates of 4 to 8 ml/hr may
be used

Question 18

PV Block COMPLICATIONS

Answer 18

Pneumothorax is estimated to occur in up to 0.5% of
patients, yet most are not clinically significant and can be
managed conservatively. most
patients will present with a sudden irritating cough or
sharp pain in the chest. Vascular puncture

Question 19

If the parietal pleura is violated, the

block can be converted

Answer 19

to an intrapleural block

Question 20

Life-threatening complications from PV blocks

Answer 20

have occurred as a result of bolus dosing. A bolus dose can accidentally be injected into the intrathecal or epidural
space, or into a blood vessel. bolus dosing with subsequent intrathecal or intravascular
spread—and not pneumothorax

Question 21

intercostal blocks can be used to provide chest

wall analgesia In patients with

Answer 21

spinal anomalies, trauma, or previous spine surgery

Question 22

INTERCOSTAL NERVE BLOCK

ANATOMY

Answer 22

As nerves leave the PV space, they enter the intercostal
space and lie between the innermost intercostal muscle
and the pleura

Question 23

primary landmark for intercostal nerve block

Answer 23

Lateral to the paravertebral muscles, the prominent angles of the ribs are palpable

Question 24

At the angle of the

rib, the nerve lies between

Answer 24

the innermost intercostal muscle

and the inner intercostal muscle

Question 25

Classically the intercostal nerves | have been thought to lie

Answer 25

caudad to the intercostal vein and artery, on the inferior portion of the rib.

Question 26

Most of the T1 nerve fibers combine with

Answer 26

C8 to form the lower trunk of the brachial plexus.

Question 27

form the intercostobrachial nerve that supplies the upper chest wall along with cervical fibers from the brachial plexus.

Answer 27

Fibers from T2 and T3

Question 28

Intercostal nerves T4–T11 supply | the

Answer 28

thoracoabdominal wall from the nipple line to below the umbilicus.

Question 29

The T12 nerve is actually a subcostal nerve that contributes branches to the

Answer 29

iliohypogastric and | ilioinguinal nerves

Question 30

INTERCOSTAL NERVE BLOCK TECHNIQUE (Patient's position)

Answer 30

The ideal patient position is prone, with a pillow under the abdomen and both upper extremities hanging over the sides of the table, which maximizes retraction of the scapulae away from the upper ribs. This allows for bilateral blockade and posterior access to the angles of the ribs to enhance safety and success of the procedure. The lateral decubitus position is also quite satisfactory for unilateral blockade after rib fractures and lateral thoracotomy as well as for chest tube placement. The supine position may also be utilized for bilateral block at the level of the midaxillary line; however, the rib and intercostal space are narrower here

Question 31

INTERCOSTAL NERVE BLOCK | Classic TECHNIQUE

Answer 31

locating the angle of the rib (approximately 8 cm lateral to the midline) and using a 22-gauge, short-bevel needle to walk off 3 mm deep to the lower costal margin, and repeating this at the desired levels.

Question 32

INTERCOSTAL NERVE BLOCK TECHNIQUE US

Answer 32

US imaging is used to identify the space between the internal and innermost intercostal muscles 8 cm lateral to the spinous process, and D5W or saline can be injected to confirm needle tip position in the fascial plane and anterior pleural displacement.

Question 33

INTERCOSTAL NERVE BLOCK | DOSING

Answer 33

A single-shot intercostal block can be expected to provide | analgesia for only 6 to 8 hours.

Question 34

INTERCOSTAL NERVE BLOCK | COMPLICATIONS

Answer 34

Total spinal anesthesia by injection into a dural sleeve is a rare but dangerous complication. Local anesthesia toxicity as a result of bolus dosing may occur due to rapid uptake from the well vascularized intercostal space. Also, pneumothorax and liver subcapsular hematoma formation are potential complications.

Question 35

Intrapleural block may be used to provide

Answer 35

unilateral chest wall analgesia during and after cholecystectomy, renal, breast, or thoracic surgery, as well for treatment of upper extremity ischemic and neuropathic pain, thoracic herpes zoster, pancreatitis, and thoracic cancer pain.

Question 36

When compared to intercostal blockade, intrapleural block produces analgesia that is

Answer 36

less intense and of shorter duration

Question 37

The visceral layer of pleura

Answer 37

surrounds the lung and reflects back on the chest wall and diaphragm to form the parietal pleura.

Question 38

The intrapleural space

Answer 38

a potential site for local anesthetic administration. Local anesthetics may block free nerve endings in the pleura and diffuse across the pleura to act on adjacent nerves

Question 39

Nerves around the pleura

Answer 39

The intercostal nerves are present posteriorly and laterally, while the splanchnic nerves, sympathetic chain, phrenic and vagus nerves are medial to the pleura. The lowest roots of the brachial plexus pass superiorly, over the cupola of the lung.

Question 40

INTRAPLEURAL BLOCK | POSITIONING

Answer 40

The ipsilateral arm should hang across the body or off the table to retract the scapula anteriorly.

Question 41

The endpoint for entry | into the intrapleural space is

Answer 41

detection of negative intrapleural pressure, which is present during spontaneous ventilation. Placement should be avoided during controlled ventilation to prevent catheter misplacement, lung injury, and pneumothorax.

Question 42

The site for catheter insertion is selected

Answer 42

from the fifth through eighth intercostal spaces

Question 43

INTRAPLEURAL BLOCK TECHNIQUE

Answer 43

a skin wheal is raised immediately superior to the selected rib, approximately 8 to 10 cm lateral to the midline. A 17- or 18-gauge epidural needle is then inserted at the same site, with its bevel aimed in the direction of intended catheter insertion. The epidural needle is placed perpendicular to the skin, over the rib, and walked cephalad until contact with the superior edge of the rib is lost. Before slowly advancing the needle further, the needle stylet is removed, and a glass syringe containing approximately 2 ml of saline is attached. The entry into the pleural space is identified using passive loss-of-resistance technique. When the needle tip is in the pleural space, the negative intrapleural pressure pulls down the syringe plunger and contained saline, and injection will be easy. The intrapleural catheter should be threaded approximately 5 to 10 cm into the pleural space, taking care to reduce air entrained through the needle.

Question 44

Injection with | the operative side uppermost favors

Answer 44

medial spread of solution | and unilateral sympathetic block.

Question 45

Injection in the supine position favors blockade of

Answer 45

the intercostal nerves with less sympathetic block.

Question 46

The block is then | performed on the left side for

Answer 46

pancreatic, gastric, or splenic | pain and on the right side for hepatic or gallbladder pain

Question 47

INTRAPLEURAL BLOCK | DOSING

Answer 47

A therapeutic dose of 20 to 30 ml of 0.25% to 0.5% bupivacaine is delivered over 2 to 3 min, and patient position is subsequently maintained for 20 to 30 min during which time a chest tube should be clamped if present. Repeated bolus doses may be given every 6 hours, or as needed. A continuous infusion of 0.25% bupivacaine at 0.125 ml/kg/hr produced better analgesia after cholecystectomy, with lower blood levels, than intermittent bolus dosing

Question 48

INTRAPLEURAL BLOCK COMPLICATIONS Complications from this procedure can be divided into two categories

Answer 48

those produced by traumatic injuries of either the needle or the catheter and those produced by systemic absorption of local anesthetic solution injected in the intrapleural space. Pneumothorax may occur. Systemic effects from drug absorption may occur, particularly with inflammation of pleural membranes. Local anesthetic toxicity. Pleural effusion, Phrenic nerve palsy, bronchopleural fistula formation, empyema, and injury to the neurovascular bundle may also occur following this block.

Question 49

neumothorax or catheter malposition | appear to be more likely with use of

Answer 49

sharper needles, stiffer epidural catheters, and positive-pressure ventilation during needle and catheter placement.

Question 50

INTRAPLEURAL BLOCK The following steps may minimize catheter-related risks:

Answer 50

slow introduction of a soft, flexible tip catheter; use of a blunt epidural needle; and use of a heavy glass syringe barrel to better detect entry into the intrapleural space

Question 51

occurs often after successful | intrapleural block.

Answer 51

Horner’s syndrome

Question 52

Suprascapular nerve block (SSNB) is indicated for

Answer 52

elief of acute and chronic pain in the shoulder, which may be due to bursitis, capsular tear, periarthritis, or arthritis

Question 53

The suprascapular nerve originates from

Answer 53

the superior trunk of the brachial plexus (C4–C6), crosses the posterior triangle of the neck, and passes deep to the trapezius muscle.

Question 54

suprascapular nerve traverses the

Answer 54

suprascapular notch and descends deep to the supraspinatus and the infraspinatus muscles, supplying the two muscles and about 70% of the shoulder joint.

Question 55

suprascapular nerve Sensory innervation includes the

Answer 55

posterior and posterosuperior regions of the shoulder joint and capsule, and the acromioclavicular joint

Question 56

SUPRASCAPULAR NERVE BLOCK | POSITIONING

Answer 56

The patient is positioned sitting, preferably with the arms folded across the abdomen. A line is drawn along the spine of the scapula from the tip of the acromion to the scapular border. The midpoint of this line is noted, and a vertical line, parallel to the vertebral spine, is drawn through it. The angle of the upper outer quadrant is bisected with a line; the site of insertion of the needle is 2.5 cm from the apex of the angle

Question 57

SUPRASCAPULAR NERVE BLOCK | TECHNIQUE

Answer 57

A 3-inch (7.5 cm), 22-gauge needle is inserted perpendicular to the skin in all planes. After contacting bone (i.e., the area surrounding the suprascapular notch) at approximately 5 to 6.5 cm, the needle is slightly withdrawn and redirected as needed until it slides into the notch. Up to 10 ml of local anesthetic is injected

Question 58

SUPRASCAPULAR NERVE BLOCK confirms successful block

Answer 58

No skin analgesia results from the block. Weakness of external shoulder rotation

Question 59

SUPRASCAPULAR NERVE BLOCK Complications

Answer 59

Pneumothorax may occur in less than 1% of cases

Question 60

SUPRASCAPULAR NERVE BLOCK | ULTRASOUND GUIDANCE

Answer 60

The patient is positioned sitting. A high-frequency US probe is placed over the scapular spine in transverse orientation, and the suprascapular fossa with the supraspinatus muscle above it are scanned. Slight lateral movement will bring into view the suprascapular notch. The SSN is visualized as a hyperechoic structure beneath the transverse scapular ligament, in the suprascapular notch

Question 61

Ilioinguinal and iliohypogastric nerve blocks may be used

Answer 61

in the diagnosis and treatment of chronic suprapubic and inguinal pain after lower abdominal surgery or hernia repair. They may be combined with genitofemoral nerve block. These blocks may be applied in the management of patients with neuralgias and nerve entrapment syndromes

Question 62

typically performed for inguinal herniorrhaphy.

Answer 62

Iliohypogastric and ilioinguinal nerve blocks are also important components of regional anesthesia of the inguinal region

Question 63

Bilateral ilioinguinal nerve block with 0.5% | bupivacaine

Answer 63

decreased analgesic requirements and pain scores for 24 hr after cesarean section performed under general anesthesia

Question 64

``` The iliohypogastric (T12–L1) and ilioinguinal (L1) nerves emerge from ```

Answer 64

the lateral border of the psoas major muscle, travel around the abdominal wall, and penetrate the transverse abdominal and the internal oblique muscles to innervate the hypogastric and inguinal areas

Question 65

The anterior | cutaneous branch of the iliohypogastric nerve passes

Answer 65

through the internal oblique muscle just medial to the anterior superior iliac spine (ASIS), to lie next to the external oblique muscle. It then passes through the external oblique above the superficial inguinal ring, and supplies the suprapubic area.

Question 66

The ilioinguinal nerve course

Answer 66

remains between the deeper two muscle layers, it travels through the inguinal canal and supplies the upper medial thigh and superior inguinal region

Question 67

An effective block of both nerves, ilioinguinal nerve and iliohypogastric nerve

Answer 67

performed medial to the ASIS must be made at multiple | depths, in various fascial planes.

Question 68

The genitofemoral | (L1–L2) nerve

Answer 68

passes through and along the anterior surface of the psoas major muscle, and it divides into genital and femoral branches above the inguinal ligament. Its genital branch travels with the spermatic cord and innervates the genitalia inferior to the area supplied by the ilioinguinal nerve.

Question 69

ILIOINGUINAL AND ILIOHYPOGASTRIC NERVE BLOCKS positioning

Answer 69

The patient is positioned supine, with a pillow under knees. The primary anatomic landmark is the ASIS, identified by palpation.

Question 70

ILIOINGUINAL AND ILIOHYPOGASTRIC NERVE BLOCKS TECHNIQUE

Answer 70

The injection site is about 2 inches medial and 2 inches cephalad to the ASIS. A 25-gauge, 1.5-inch needle is inserted perpendicular to the skin, noting the double pop feeling when each layer of fascia is penetrated. Infiltration with about 10 ml of local anesthetic is performed at each depth and, subsequently, fanned in the area.

Question 71

The genital branch of the genitofemoral nerve | block can be blocked by infiltration

Answer 71

of 5 to 10 ml of local anesthetic, using a 25-gauge, 1.5-inch needle inserted just lateral to the pubic tubercle and below the inguinal ligament. Infiltration around the spermatic cord at its exit from the inguinal canal is also an effective technique

Question 72

ILIOINGUINAL AND ILIOHYPOGASTRIC NERVE BLOCKS Ultrasound Guidance

Answer 72

The patient is positioned supine, and a high-frequency US probe is placed superior and medial to the ASIS, on an imaginary line uniting the ASIS and the umbilicus. The nerves are usually visualized between the internal oblique and transversus muscles. An in-plane technique provides optimal access to the ilioinguinal and iliohypogastric nerves; hydrodissection may be useful to better delineate the narrow fascial plane. Small vessels, including the deep circumflex iliac artery, identified with color Doppler, may be present in the fascial plane. Deep to the transversus muscle the parietal peritoneum and bowel can be identified

Question 73

ILIOINGUINAL AND ILIOHYPOGASTRIC NERVE BLOCKS COMPLICATIONS

Answer 73

ecchymosis, hematoma, visceral perforation, systemic toxicity, and infection. Accidental block of the lateral femoral cutaneous nerve and partial block of the femoral nerve may also occur.

Question 74

The transversus abdominis plane (TAP) block

Answer 74

uses anatomic landmarks | to approach the plane through the triangle of Petit

Question 75

The triangle of Petit

Answer 75

bordered by latissimus dorsi posteriorly, the external oblique muscle anteriorly, and the ASIS as base of the triangle.

Question 76

The innervation of the anterior | abdominal wall is provided by

Answer 76

the anterior rami of the T7–T12 and L1 nerves, whose terminal branches are coursing in the fascial plane between the internal oblique and the transversus abdominis muscle, the transversus abdominis plane.

Question 77

TRANSVERSUS ABDOMINIS PLANE BLOCK anatomic landmarks TECHNIQUE

Answer 77

the TAP is accessed through the triangle of Petit. A “double-pop” technique is used to confirm the needle passage through the external oblique fascia, followed by the passage through the fascial plane between the internal oblique and the transversus abdominis muscles.

Question 78

TRANSVERSUS ABDOMINIS PLANE | BLOCK Ultrasound Guidance

Answer 78

The three muscle layers, the external oblique, internal oblique, and transversus abdominis, and needle insertion plane, between the internal oblique and transversus abdominis muscles, can be easily vizualized when the probe is placed above the ASIS.60 An inplane or out-of-plane technique can be used. Hydrodissection of the plane may facilitate accurate placement of the needle. Fifteen to 20 ml of local anesthetic are typically used on each side

Question 79

Ultrasound-guided TAP blocks have been used to provide | postoperative analgesia for

Answer 79

lower abdominal surgeries, including inguinal hernia repair, cesarean section and retropubic prostatectomy. A subcostal approach has been described for laparoscopic cholecystectomy. It has also been used to provide postoperative analgesia for other upper abdominal surgeries, including laparoscopic surgeries such as appendectomy and incisional hernia repair