Advanced Techniques (pt 1)

Question 1

What are the indications for a Paravertebral Block?

Answer 1

-Breast Surgery
-Thoracotomy
-Rib Fractures
-Liver surgery
-Also flail chest and esophagectomies

Provides profound analgesia unilaterally or bilaterally.
Blocking nerves as they come out of the spinal column, in the paravertebral space. Lateral border. Runs continuous with epidural space.

Question 2

What are the advantages of a Thoracic Paravertebral Block (TPVB)?

Answer 2

-Excellent anesthesia/analgesia (Reduces opioid requirements)
-Unilateral or Bilateral
-Single shot or continuous catheter
-Can be placed in anti-coagulated pts
-Minimal hemodynamic disturbance (Prolonged orthostatic hypotension is very rare)
-Preserved postoperative lung function
-Inhibition of metastasis with breast malignancy (controversial - preemptive analgesia prior to breast surgery can have fewer metastasis after)
-Promotes early ambulation
-Preserves bladder sensation; Minimal risk of urinary retention
-Less cost to patient compared to continuous epidural
-Intact sensory and motor function DISTAL to target levels

Question 3

What are the absolute contraindications to a Paravertebral Block?

Answer 3

Infection at site
Empyema
Tumor occupying the paravertebral space
LA allergy

Question 4

What are the relative contraindications to a Paravertebral Block?

Answer 4

-Kyphoscoliosis (distorts image, impossible to due via landmark, very difficult with US. Higher block failure rate)
-Previous thoracotomy (TPVS may be obliterated due to scar tissue)
-Coagulopathy

Question 5

What are complications associated with PV Block?

Answer 5

Block failure 2-10%
Pneumothorax 0.5-2%
Hypotension 2-6%
Vascular puncture 1-5%
Horner’s syndrome 5-10%
Central neuraxial block
Sensory changes in arm from high thoracic block

Question 6

What makes up the Paravertebral Triangle?

Answer 6

Medial:
-posteriolateral aspect of the vertebral bodies, intervertebral discs, articular processes

Anterior:
-Parietal pleura

Posterior:
-SCL – Superior Costotransverse ligament (extends from the inferior aspect of transverse process above to rib below). Needs to be pierced to enter into the triangle/space when doing the block.

The PVS is contiguous with the epidural space medially. The sympathetic ganglia lie close to the somatic nerves, and both are frequently blocked when local anesthesia is injected into this space.

Question 7

Where is the Internal Intercostal Membrane (IIM) located?

Answer 7

Lateral to the superior costotransverse ligament (SCL), and continuous with it, is the Internal Intercostal Membrane (IIM).
-The IIM is the aponeurotic continuation of the internal intercostal muscle
-The SCL must be pierced to enter the TPVS

Question 8

Why would you use a Tuohy needle with a PV Block?

Answer 8

Can aim needle away from pleura and decrease risk of PTX with Tuohy

Question 9

What are the landmarks associated with a PV Block?

Answer 9

-Spinous processes (C7 most prominent)
-Scapula lower border (T7)
-Transverse Processes: 2.5cm lateral from midline, 2-6cm deep usually

Question 10

Describe the Transverse In-plane technique to a PV Block?

Answer 10

-Probe is oriented perpendicular to spine and in between ribs themselves.
-Needle travels lateral to medial (tuohy bevel away from pleura)
-Must pierce IIM (continuous with Superior costotransverse ligament)
-Goal: inject LA up and underneath IIM, will notice pleural line shimmering more and will actually push down and away from paravertebral space.

Question 11

Describe the Parasagittal In-plane technique to a PV Block?

Answer 11

-Needle angle may be steep and difficult to visualize with US
-Hydro-disect to locate needle
-Use transverse process to walk off as landmark
-Must pierce CTL to enter space
-Goal is depression of the pleura with LA.
-Fill space with fluid.

Question 12

What are the indications for Intercostal Blocks?

Answer 12

-Thoracic or upper ABD surgery
-Rib fractures
-Breast surgery

Very low volumes - only get intercostal nerves themselves (nerve runs with vascular bundle on rib’s inferior border)

Question 13

How do you perform an Intercostal Block?

Answer 13

-Needle is inserted at the angle of the rib, 6-8 cm lateral to spinous process
-Advance needle up and underneath rib in slight cephalad tilt, up underneath angle of rib
-Needle to pass 0.25 - 0.5 cm past rib (Don’t advance too far - PTX)
-Once needle passes underneath rib, inject fluid into space

US: Needle tip disappears up and underneath costal margin. Watch for appropriate LA spread.

Question 14

What are the indications for a Cervical Plexus Block?

Answer 14

-Carotid Endarterectomy
-Clavicle fractures
-Skin lesions

Superficial vs Deep method

Question 15

What is the difference between the Superficial and Deep approaches to Cervical Plexus blocks?

Answer 15

-Sensory blockade is similar in both (Anteriolateral neck and Anti/retro Auricular)

Motor blockade occurs with Deep:
-strap muscles
-Geniohyoid
-SCM
-Levator scapulae
-Scalene
-Diaphragm

Question 16

What is the anatomy relevant to a Cervical Plexus Block?

Answer 16

Plexus just emerges from posterior border right along C6. Same orientation as interscalene groove. Lays above interscalene muscles.

Question 17

What are the risks associated with a Cervical Plexus Block?

Answer 17

-Infection (low risk)
-Hematoma
-Phrenic nerve blockade (occurs with Deep approach)
-LA toxicity (CNS toxicity most common)
-Nerve injury
-Spinal Anesthesia

Question 18

How do you perform a Deep Cervical Plexus Block?

Answer 18

-Essentially a paravertebral block
-Find Mastoid process and Chassaignac’s Tubercle (TP of C6)

SCM – Posterior border
C2 2 cm below mastoid
C3 4 cm below mastoid
C4 6 cm below mastoid

-Needle is inserted at desired level (C6), perpendicular to skin, slightly caudal angle
-Inserted until contact with TP
-withdraw slightly, inject 5 mL LA

Question 19

How do you perform a Superficial Cervical Plexus Block?

Answer 19

-Needle insertion is halfway between mastoid and C6 TP
-SubQ Fan injection: Perpendicular, Cephalad, and Caudal
-Carotid surgery requires glossopharygeal branches blocked, can be done by surgeon
-Field block form cricoid to sternal notch can block any cross over fibers (subcut wheal can be done)
-Avoid depositing LA on Anterior Scalene to avoid phrenic nerve block

Question 20

When are airway blocks typically done?

Answer 20

Typically done for awake fiber optic intubations
-Oral or Nasal

Question 21

What do you need to address before performing an airway block?

Answer 21

-Anxiety: Midazolam, fentanyl, remifentanyl, Precedex
-Antisialogogue: Glycopyrolate, Atropine
-Anesthetize Airway: Topical, Inhilation, or Infiltration
-Vasoconstriction: EPI or Phenyleprine

Question 22

What is the innervation to the Nasal Cavity?

Answer 22

-Greater/Lesser Palatine: from pterygopalatine ganglion, innervates turbinates & septum. Can be blocked with LA soaked swab to upper border of middle turbinate at posterior wall of nasopharynx
-Anterior Ethmoid: from CN1, LA soaked swab to cribiform plate.

Question 23

What nerves provide Sensory to posterior 1/3 tongue, vallecula, anterior surface of Epiglottis, walls of pharynx, and Tonsils?

Answer 23

Facial
Glossopharyngeal
Vagus

Question 24

What nerve provides sensory to the Anterior 2/3 of tongue?

Answer 24

Trigeminal
Not part of gag reflex

Question 25

What nerve provides sensory to the Post Epiglottis, base of tongue, aryepiglottic folds, arytenoids?

Answer 25

Superior Laryngeal (CN10)
-Also does the Cricothyroid muscle

Question 26

What nerve provides sensory to the Vocal cords, trachea below cords?

Answer 26

Recurrent laryngeal
-Also does the rest of the intrinsic laryngeal muscles

Question 27

Why do you give Afrin or Neo?

Answer 27

To prevent airway from getting bloody.
-Vasoconstriction

Question 28

How can you use inhalation for topical anesthesia?

Answer 28

-Lidocaine 2-4% Neb
-15-30 minutes
-Not very dense
-Can be patchy (Certain areas that are mucus covered will prevent lidocaine from getting on the tissue itself)

Question 29

Blocking the Glossopharyngeal Nerve blocks sensory innervation to what? How is this done?

Answer 29

-Posterior 1/3 tongue
-Vallecula
-Ant surface of the epiglottis (lingual branch)
-Walls of the pharynx (pharyngeal branch)
-Tonsils (tonsillar branch).

Inject 5ml of LA
-caudal aspect of the posterior tonsillar pillar (palatopharyngeal fold)

Question 30

Blocking the Superior Laryngeal Nerve blocks sensory innervation to what? How is this done?

Answer 30

-base of the tongue
-Post surface Epiglottis
-Aryepiglottic fold
-Arytenoids

-Identify Hyoid Cornu
-Contact cornu
-Internal Branch: Walk off inferior edge pierce thyrohyoid membrane and Inject 2ml of LA.
-Both internal/External: Contact Cornu, Withdraw 1-2mm, and Inject 2ml of LA.

Question 31

Blocking the Recurrent Laryngeal Nerve blocks sensory innervation to what? How is this done?

Answer 31

-Vocal folds
-Trachea

Transtracheal Block:
-Identify Cricoid cartilage
-Lidocaine skin wheel
-Use 22/20ga needle or angiocath (angiocath reduces risk of tracheal laceration with needle tip as patient coughs)
-Pierce while aspirating
-Rapidly inject into lumen
-Manage cough (sprays vocal cords and trachea)