Truncal Nerve Blocks

Question 1

target of truncal blocks

Answer 1

• fascial planes and NOT individual nerves

- looking for fascial planes between muscles

Question 2

rectus sheath block

Answer 2

• indications - useful for umbilical surgery (esp in peds)
• least common bc usually surgeon will just inject local
• US allows safe placement of LA in close proximity to the epigastric arteries in and peritoneum

Question 3

rectus sheath block technique

Answer 3

• patient supine
• high frequency linear array transducer placed lateral to the umbilicus in transverse orientation
• needle is inserted using an in-plane technique
• up to 10 mL of LA injected bilaterally between rectus abdominus muscle and the posterior fascial plane

Question 4

rectus sheath block pearls

Answer 4

• peritoneum is just below the posterior fascia

- injections along the lateral wall have been shown to be more efficacious

Question 5

TAP block

Answer 5

• indications = alternative for low to mid abdominal wall surgery when an epidural and/or intrathecal opioids are contraindicated or refused
• block success depends on correct identification of transversus abdominus plane
• provides somatic anesthesia to the abomdinal wall from T7-L1 however is highly dependent on interfascial spread

Question 6

TAP block technique

Answer 6

• patient supine
• high frequency transducer placed between costal margin and iliac crest midaxillary line in transverse orientation
• transducer slid medially and laterally until the three muscle layers (external oblique, internal oblique, and transversus abdominis) are identified
• needle inserted using in plane technique until tip penetrates fascia between internal oblique and transversus abdominis
• up to 20 mL of dilute LA per side

Question 7

TAP Block pearls

Answer 7

• reports of LAST events following TAP blocks

- theory that because it is in such a tight fascial plane that it is absorbed faster

Question 8

erector spinae block (ESB)

Answer 8

• fasical plane block deep to the spinae muscle group
• sensory block
• minimal hemodynamic effects
• primarily targets dorsal rami and potentially ventral rami (depends on appraoch)
• easy to identify with ultrasound
• reduced incidence of complications

Question 9

how do you cover the ventral rami with an ESB?

Answer 9

if you inject by the lateral aspect of the transverse process

Question 10

ESB anatomy

Answer 10

• erector spinae is a group of three muscles (epaxial muscles) that provide support to the spinal column
• spinalis
• longisimus
• iliocostalis

Question 11

ESB technique

Answer 11

• use parasagittal plane to determine optimal block level
• volume dependent
• four dermatomal level of distribution (two above and below the injection site
• once the desired level is achieved, slide transducer laterally to identify the transverse process
• needle cephalad to caudal
• following negative aspiration, incremental injections of 5mL for a total of 20 mL
• repeat on opposite side

Question 12

ESB pearls

Answer 12

• unilateral block - will require bilateral block for most surgical procedures
• volume dependent block - as a sensory block, low concentration allows for increased volume

Question 13

ESB complications

Answer 13

• hematoma
• infection at needle insertion site
• tissue trauma
• pneumo
• hemodynamic instability
• LAST
• lumbar plexus block
• block failure

Question 14

quadratus lumborum indications

Answer 14

• large bowel resections, appy, chole
• C-section, total abdominal hysterectomy
• prostatectomy, renal transplant, nephrectomy, abdominoplasty
• iliac crest bone graft
• ex lap

Question 15

quadratus lumborum block

Answer 15

• targets iliohypogastric, ilioinguinal, and subcostal nerves that cross the psoas muscle and transversalis fascia
• lateral wall and some hip coverage

Question 16

what are the attachments of the quadratus lumborum muscle?

Answer 16

superior = T12
inferior = iliac crest
medial = transverse processes

Question 17

quadratus lumborum block technique

Answer 17

• most technically difficult
• patient lateral decubitus position with hips and knees flexed
• curvilinear transducer placed midaxillary line cephalad to iliac crest
• transducer slid posteriorly and tilted caudad until “shamrock sign” is visualized

Question 18

components of shamrock sign

Answer 18

• stem = L4 transverse process

- leaves = erector spinae, quadratus lumborum, and psoas major

Question 19

QL3

Answer 19

shamrock sign

Question 20

QL1

Answer 20

• find the TAP block
• slide until transverse abdominis and internal oblique join together
• go to thoraco-lumbar fascial plane

Question 21

QLB pearls

Answer 21

-the lower pole of the kidney lies anterior to the QL muscle and can reach L4 with deep inspiration

Question 22

PECs block indications

Answer 22

• analgesia following breast surgery
• biospy
• MAJOR breast reconstruction
• alternative to paravertebral block or thoracic epidural (reduces risk of pneumo and spinal)

Question 23

PECs I block

Answer 23

designed to anesthetized the medial and lateral pectoral nerves

Question 24

PECs II block

Answer 24

extension of PECs I and provides additional blockade of the upper intercostal nerves

Question 25

PECs I technique

Answer 25

- patient supine with arm abducted - high frequency transducer placed in cephalad medial and caudal lateral orientation at the level of the coracoid process - costal margins, pectoris major (PM), pectoris minor (Pmi), and serratus muscles are identified - needle inserted in plane, cephalad to caudad, until the tip penetrates the fascia between the PM and Pmi

Question 26

PECs II technique

Answer 26

- transducer slid caudad to the level of the 2nd rib and angled inferolaterally until the Pmi and serratus anterior muscles identified - further lateral movement will identify the 3rd and 4th rib - LA injected in two areas --> between the PM and Pmi AND between the Pmi and serratus anterior muscles

Question 27

paravertebral indications

Answer 27

- preioperative analgesia for thoracic, chest wall or breast surgery - pain management of rib fractures

Question 28

paravertebral block

Answer 28

targets the paravertebral space (PVS) which contains spinal nerves and their branches as well as the sympathetic trunk

Question 29

paravertebral anatomy

Answer 29

-wedge shaped area formed medially by the vertebral body, inferiorly by the parietal pleura, and anteriorly by the costotransverse ligament

Question 30

paravertebral technique

Answer 30

- transverse, in-plane - patient in lateral decubitus position - high frequency transducer placed in transverse orientation at the desired level just lateral to the spinous process - once the hyperechoic transverse process (TP) and ribs are identified, slide the transducer slightly caudad into the intercostal space

Question 31

paravertebral pearls

Answer 31

- downward displacement of pleura indicates correct spread of LA - bilateral epidural anesthesia is possible - constant visualization of needle tip is ESSENTIAL

Question 32

intercostal nerve block indications

Answer 32

- analgesia following breast, thoracic, and upper abdominal surgery - pain management of rib fractures

Question 33

intercostal nerve block

Answer 33

targets intercostal nerves resulting in ipsilateral anesthesia of specific levels; single dermatome level block

Question 34

intercostal nerve block technique

Answer 34

- patient in sitting, lateral decubitus or prone position with arms hanging freely - high-frequency transducer placed in a sagittal plane over the costae approximately 6-8 cm from midline - ID the 7th and 12th ribs to estimate the position of relative ribs - needle inserted in plane until the tip is observed between the internal and innermost intercostal muscles

Question 35

intercostal nerve block pearls

Answer 35

- difficult to perform above T7 due to the scapula | - excellent for analgesia, but inadequate surgical anesthesia