ITE CA-2 Anatomy (TL)

Question 1

Patients with biggest risk for injury from spinal anesthetic

Answer 1

Patients with space-occupying extradural lesions or those that reduce the cross-sectional area of the spinal cord, such as spinal stenosis, are most at risk for new or worsening neurologic injury from a neuraxial anesthetic.

Question 2

Landmark for stellate ganglion block

Answer 2

The major landmark for performing a stellate ganglion block is Chassaignac tubercle, which is the transverse process of C6

Question 3

Stellate ganglion block. Signs it’s working and risks of

Answer 3

Development of Horner syndrome in the patient generally designates a successful block, but is not the most useful sign as cephalad spread of the local anesthetic can cause this syndrome. Ipsilateral temperature changes is the most reliable for block success. Other potential side effects associated with this block include pneumothorax, phrenic nerve paralysis, accidental vertebral artery injection leading to seizures, brachial plexus injury, and intrathecal injection. The patient should therefore be closely monitored during and immediately after performing the block.

Question 4

Sensory point for C2

Answer 4

At least 1cm lateral to occipital protuberance at base of skull Or 3 cm behind the ear.

Question 5

Sensory point for C3

Answer 5

In the supraclavicular fossa at midclavicular line

Question 6

Sensory point for C4

Answer 6

Over the AC joint

Question 7

Sensory point for C5

Answer 7

Lateral (radial) side of antecubital fossa just proximal to the elbow

Question 8

Sensory point for C6

Answer 8

Dorsal prox phalanx thumb

Question 9

Sensory point for C7

Answer 9

Dorsal prox phalanx middle finger

Question 10

Sensory point for C8

Answer 10

Dorsal proximal phalanx small finger

Question 11

Sensory point for L1

Answer 11

Midway between T12 and L2

Question 12

Sensory point for L2

Answer 12

On anteromedial thigh, midway between inguinal ligament and med fem condyle

Question 13

Sensory point for L3

Answer 13

Med fem condyle above the knee

Question 14

Sensory point for L4

Answer 14

Medial malleolus

Question 15

Sensory point for L5

Answer 15

Dorsum of foot at third metatarsal phalangeal joint

Question 16

Supraclavicular block used for

Answer 16

The supraclavicular block (SCB) is known as a “do-it-all” block or the “spinal of the arm” since the nerves are closely packed and readily blocked (see attachment 2). It can be used for shoulder, elbow, and wrist surgery but most practitioners use it for surgery below the mid-humerus level. It is not commonly utilized due to the needle’s close proximity to the subclavian artery and pleura. The SCB is growing in popularity due to the increasing use of ultrasound-guidance which allows for direct visualization of the needle tip.

Question 17

Risk of pneumothorax with what block

Answer 17

supraclavicular block classically has been considered to carry a 1-6% risk of pneumothorax (PTX), but this rate decreases with experience, and possibly with the use of ultrasound.

Question 18

Complications of supraclavicular block

Answer 18

Complications of the SCB also include ScA puncture, spread of local anesthetic to the stellate ganglion, phrenic nerve blockade (50% of procedures), and recurrent laryngeal nerve blockade. While the most serious complication of a SCB is PTX, the most common complication is phrenic nerve blockade. Infraclavicular brachial plexus block is associated with axillary artery puncture and pectoral discomfort due to the needle transgressing the pectoral fascia. Interscalene brachial plexus block is associated with ipsilateral phrenic nerve and recurrent laryngeal nerve blockade, ulnar nerve (C8-T1) sparing, vertebral artery puncture, and Horner’s syndrome (ptosis, miosis, anhidrosis, hyperemia of the ipsilateral conjunctiva, and nasal congestion). Axillary blockade is associated with intravascular injection, terminal nerve injury from needle trauma, intraneural injection, and hematoma formation. These neural blocks are rarely complicated by PTX.

Question 19

Complications of infraclavicular block

Answer 19

Infraclavicular brachial plexus block is associated with axillary artery puncture and pectoral discomfort due to the needle transgressing the pectoral fascia.

Question 20

Interscalene block complications

Answer 20

Interscalene brachial plexus block is associated with ipsilateral phrenic nerve and recurrent laryngeal nerve blockade, ulnar nerve (C8-T1) sparing, vertebral artery puncture, and Horner’s syndrome (ptosis, miosis, anhidrosis, hyperemia of the ipsilateral conjunctiva, and nasal congestion).

Question 21

Axillary block complications

Answer 21

Axillary blockade is associated with intravascular injection, terminal nerve injury from needle trauma, intraneural injection, and hematoma formation.

Question 22

Where is brachial plexus relative to subclavian artery

Answer 22

The trunks and divisions of the brachial plexus are typically located just lateral, posterior, and superior to the ScA

Question 23

Where are scalene muscles relative to brachial plexus

Answer 23

The scalenus anterior muscle (SAM) is medial and anterior to the brachial plexus and ScA. The scalenus medius muscle (SMM) lies lateral and posterior to the brachial plexus and ScA

Question 24

Where is the subclavian vein

Answer 24

The subclavian vein (ScV) is usually found medial to the SAM when firm pressure is released (since veins are compressible and arteries are not on ultrasound).

Question 25

How do different mediums reflect ultrasound

Answer 25

Structures such as blood, which have a high water content, reflect little of an ultrasound’s beam and thus appear hypoechoic. Structures with low water content such as bone and tendon, reflect more of an ultrasound’s beam and appear hyperechoic. Air reflects a significant amount of the beam back, making the use of ultrasound gel important.

Question 26

How block RLN

Answer 26

Transtracheal injection of local anesthetic will block the recurrent laryngeal nerve.

Question 27

Femoral triangle

Answer 27

The femoral triangle is bordered by the inguinal ligament superiorly, the adductor longus muscle medially, and sartorius muscle laterally.

Question 28

What’s inside femoral triangle

Answer 28

The femoral triangle includes the femoral nerve, femoral artery, femoral vein, lymphatics, and pubic symphysis.

Question 29

How do you do femoral n block

Answer 29

When a femoral nerve block is performed, the injectate needle is inserted inferior to the inguinal ligament approximately one to two centimeters lateral to the femoral artery with the needle advanced in a medial to lateral manner.

Question 30

Transforaminal epidural injections

Answer 30

Transforaminal epidural injections are best suited for unilateral radiculopathies as compared to interlaminar epidural injections, which are better suited for bilateral neuraxial pain symptoms.

Question 31

What nerve block for FESS and where and why

Answer 31

The sphenopalatine ganglion derives the bulk of its innervation from the maxillary branch (V2) of the trigeminal nerve and provides innervation to the nasal cavity mucosa, hard palate, and lacrimal gland. Infiltration of local anesthetic via the greater palatine foramen can be used to produce a sensory block of the sphenopalatine ganglion and reduce the response to stimulation of the nasal mucosa during FESS.

Question 32

What innervates lateral aspect of the skin overlying the nose, cheek, and upper lip?

Answer 32

The infraorbital nerve is also derived from the maxillary branch of the trigeminal nerve, but it is mainly responsible for innervation of the lateral aspect of the skin overlying the nose, cheek, and upper lip. This nerve can also be blocked to aid analgesia in patients undergoing FESS.

Question 33

What does submandibular ganglion do

Answer 33

The submandibular ganglion provides secretory innervation to the sublingual and submandibular glands along with sensory innervation to the oral mucosa.

Question 34

What innervates the cheek

Answer 34

The zygomaticofacial nerve is primarily responsible for the innervation of the cheek.

Question 35

Differential blockade with local anesthetics results in what order of blocks

Answer 35

Differential blockade with local anesthetics results in sympathetic blockade first, followed by pain/sensory blockade, then motor blockade last. This is (at least in part) explained by differential susceptibility of nerve fibers to local anesthetics being A-delta, A-gamma > lA-alpha, A-beta > C.

Question 36

Differential blockade with local anesthetics results in what order of fiber blocks

Answer 36

Differential blockade with local anesthetics results in sympathetic blockade first, followed by pain/sensory blockade, then motor blockade last. This is (at least in part) explained by differential susceptibility of nerve fibers to local anesthetics being A-delta, A-gamma > lA-alpha, A-beta > C.

Question 37

A-alpha fibers

Answer 37

The following chart describes some qualities of various nerves: Fiber type Conduction type Diameter (mcm) Myelin Conduction Velocity (m/sec) A-alpha motor and proprioception 12-20 Yes 30-120 A-beta pressure and touch 5-12 Yes 30-120 A-delta pain and temperature 2-5 Yes 5-25 B preganglionic autonomic < 3 Yes 3-15 C dull pain, touch, sympathetics 0.3 - 1.3 No 0.7 - 2.0

Question 38

A-beta fibers

Answer 38

The following chart describes some qualities of various nerves: Fiber type Conduction type Diameter (mcm) Myelin Conduction Velocity (m/sec) A-alpha motor and proprioception 12-20 Yes 30-120 A-beta pressure and touch 5-12 Yes 30-120 A-delta pain and temperature 2-5 Yes 5-25 B preganglionic autonomic < 3 Yes 3-15 C dull pain, touch, sympathetics 0.3 - 1.3 No 0.7 - 2.0

Question 39

A-delta fibers

Answer 39

The following chart describes some qualities of various nerves:

Fiber type Conduction type Diameter (mcm) Myelin Conduction Velocity (m/sec)

A-alpha motor and proprioception 12-20 Yes 30-120

A-beta pressure and touch 5-12 Yes 30-120

A-delta pain and temperature 2-5 Yes 5-25

B preganglionic autonomic < 3 Yes 3-15

C dull pain, touch, sympathetics 0.3 - 1.3 No 0.7 - 2.0

Question 40

C fibers

Answer 40

The following chart describes some qualities of various nerves: Fiber type Conduction type Diameter (mcm) Myelin Conduction Velocity (m/sec) A-alpha motor and proprioception 12-20 Yes 30-120 A-beta pressure and touch 5-12 Yes 30-120 A-delta pain and temperature 2-5 Yes 5-25 B preganglionic autonomic < 3 Yes 3-15 C dull pain, touch, sympathetics 0.3 - 1.3 No 0.7 - 2.0

Question 41

B fibers

Answer 41

The following chart describes some qualities of various nerves: Fiber type Conduction type Diameter (mcm) Myelin Conduction Velocity (m/sec) A-alpha motor and proprioception 12-20 Yes 30-120 A-beta pressure and touch 5-12 Yes 30-120 A-delta pain and temperature 2-5 Yes 5-25 B preganglionic autonomic < 3 Yes 3-15 C dull pain, touch, sympathetics 0.3 - 1.3 No 0.7 - 2.0

Question 42

Medial calf innervation

Answer 42

medial lower leg is innervated by the saphenous nerve, which is a branch of the femoral nerve.

Question 43

Innervation of heel and plantar foot

Answer 43

tibial nerve is a branch of the sciatic nerve. Its sensory innervation includes the heel and plantar regions of the foot.

Question 44

Innervates lateral posterior leg

Answer 44

The sural nerve provides sensory innervation to the lateral posterior portion of the leg.

Question 45

Femoral nerve cutaneous innervation

Answer 45

The femoral nerve supplies cutaneous innervation via its branches to the anteromedial thigh (anterior cutaneous branches of the femoral nerve) and the medial side of the lower leg and foot (saphenous nerve).

Question 46

Sciatic nerve in pop fossa

Answer 46

The sciatic nerve divides into the common peroneal (lateral location) and tibial nerve (medial location) in the popliteal fossa at a point approximately 7 cm above the posterior knee crease midway between the biceps femoris (lateral) and semimembranosus (medial) muscle tendons

Question 47

Hemodynamics changes in CEA

Answer 47

Hemodynamic changes during CEA are common and are related to surgical manipulation, denervation, and impaired sensitivity of the carotid sinus baroreceptors. Stimulation of baroreceptors results in increased parasympathetic discharge with decreased sympathetic discharge. This leads to hypotension and bradycardia, which can potentially be prevented by local anesthetic infiltration. Lidocaine infiltration causes inhibition of baroreceptor output from the carotid sinus and would result in hypertension and tachycardia.

Question 48

Carotid body

Answer 48

carotid body is a chemoreceptor, not a mechanoreceptor, and does not control blood pressure.

Question 49

Risks for partiurients with ankylosis great spondylitis

Answer 49

Patients with ankylosing spondylitis have an increased risk of difficult airway and an increased risk of epidural hematoma during neuraxial anesthesial Decreased range of motion of the cervical spine due to intervertebral disc ossification can lead to difficult endotracheal intubation. AS is associated with atlantoaxial instability. Answer B: Temporomandibular joint hypomobility can lead to ill-sealing facemasks. This, in conjunction with constrictive lung disease from pulmonary fibrosis, can lead to difficulty with ventilation. Answer C: The increased risk of epidural hematoma in AS has been well-documented in numerous case reports. Patients with AS are frequently on NSAID pain medication leading to platelet dysfunction and increased bleeding risk. Lumbar spine fusion from ossification of ligaments and reduced interlaminar spaces can make neuraxial placement more difficult, increasing the incidence of epidural hematoma with increased attempts. Additionally, violation of the dura during multiple attempts at neuraxial anesthetic placement may lead to total spinal anesthesia. Caudal anesthesia may be a reasonable alternative.

Question 50

What factors affect spread of local in epidural

Answer 50

Local anesthetic spread during epidural injection is affected by several patient- and procedure-related factors. Increased volume of the injectate, positive airway pressure, lateral/Trendelenburg position, and increased age all generally increase the epidural spread of local anesthetics. Of these, the volume of injection has the most significant impact.

Question 51

Interscalene block

Answer 51

Interscalene brachial plexus blocks occur at the level of the upper trunks of the brachial plexus as they emerge between the two scalene muscles. It provides excellent anesthesia for surgeries of the shoulder, upper arm, and elbow. Interscalene blocks, as opposed to blocks at other levels of the brachial plexus, should be utilized for shoulder surgery because the suprascapular nerve is also anesthetized at this location. The supraclavicular nerve may also be anesthetized with this block and supplies sensation to the skin of the shoulder above the clavicle (arthroscope insertion site). The interscalene block is generally not recommended for hand surgery due to potential sparing of the inferior trunk, which includes the ulnar nerve.

Question 52

Where is phrenic nerve relative to brachial plexus at level of interscalene block?

Answer 52

The phrenic nerve passes anteriorly in the more cephalad portion of the brachial plexus and, if stimulated, can produce diaphragmatic responses that resemble hiccups. The needle must be redirected posteriorly to locate the brachial plexus.

Question 53

origin of great radicular artery

Answer 53

The great radicular artery (aka arteria radicularis magna or artery of Adamkiewicz) originates from the aorta between the T9 and T12 vertebral segments in 75% of the population

Question 54

anterior spinal cord blood supply and what tracts are there

Answer 54

Blood supply to the anterior two-thirds of the spinal cord (wherein the motor tracts are located) is provided by the SINGLE anterior spinal artery (ASA). The vertebral arteries supply branches to the upper cervical spinal cord segments while also forming the ASA. The ASA in the thoracic region is supplemented by radicular arteries from the intercostal branches and the aorta.

Question 55

blood supply to posterior spinal cord and what tracts are there

Answer 55

Blood supply to the posterior one-third of the spinal cord is provided by the TWO posterior spinal arteries (PSA). This portion is responsible for sensation and proprioception in the dorsal columns. Radicular arteries also supplement the posterior spinal arteries. Unlike the single ASA, compromise of one PSA will not typically lead to significant ischemia as there should still be overlapping blood flow from the second PSA. Following a TAAA repair, patients may present postoperatively with paraplegia due to anterior spinal cord ischemia but may have intact sensation due to the collateral posterior blood supply.

Question 56

Interruption of the great radicular artery may result in…..

Answer 56

Interruption of the great radicular artery may result in ASA syndrome, which includes bilateral lower extremity paraplegia as well as bowel and bladder dysfunction.

Question 57

Transurethral surgery of the bladder If the tumor is along the lateral aspect of the bladder what additional nerve to block?

Answer 57

Transurethral surgery of the bladder usually can be performed with spinal anesthesia without further consideration. If the tumor is along the lateral aspect of the bladder then the obturator nerve may be stimulated and the jerk reflex initiated even under spinal anesthesia. An obturator nerve block should be performed to help prevent this. Alternatively, general anesthesia with muscle relaxation can also be performed to prevent the reflex. If neuromuscular blocking agents are not used during general anesthesia, the obturator nerve block will still need to be performed.

Question 58

Block what nerves to prevent coughing during awake intubation

Answer 58

Coughing during awake intubation can be prevented by blockade of the superior laryngeal nerve and recurrent laryngeal nerve. The glossopharyngeal nerve also provides airway innervation but is involved in the gag, not the cough reflex.

Question 59

How long should pulse duration be for placing blocks

Answer 59

A pulse duration of approximately 0.1-0.3 ms is optimal for stimulation of motor nerves in most patients. Sensory nerves require a longer pulse duration time to elicit a response; a duration of 0.3-1.0 ms is generally recommended. Patients with peripheral neuropathy often require longer pulse durations to elicit a response; a duration of 0.3-1.0 ms may be required to stimulate motor nerves in these patients.

Question 60

An ilioinguinal block is performed in what plane between what muscles

Answer 60

An ilioinguinal block is performed in the transversus abdominis plane between the internal oblique muscle and the transversus abdominis muscle.

The transversus abdominis plane (TAP) block is performed at the same intermuscular plane as the ilioinguinal block, which can also anesthetize the ilioinguinal nerve.

Question 61

Best treatment for N/V after high spinal

Answer 61

Nausea and vomiting may be associated with neuraxial block in up to 20% of patients and atropine is almost universally effective in treating the nausea associated with high (T5) neuraxial anesthesia.

Question 62

How perform paravertebral block?

Answer 62

A paravertebral block is conducted with the patient in a seated position with the neck flexed forward. The spinous process of each level is identified, and a mark is placed at the most superior aspect. From the midpoint of these marks, a needle-entry site is marked 2.5 cm laterally. In the thoracic area, these marks should overlie the transverse process of the immediately caudal vertebra because of the extreme angulation of the thoracic spinous process. In the lumbar area, the transverse process is at the same level as the spinous process or even one level above the spinous process.

For the parasagittal ultrasound-guided technique, the transverse process (TP), the costotransverse ligament (CTL), and the pleura (P) are identified with the probe being parallel to the spinous process. Using an in-plane technique, the needle is directed towards the CTL then through the CTL which may result in a tactile change in resistance. Local anesthetic is then injected into the paravertebral space. For nearly all paravertebral block techniques, anatomic or ultrasound-guided, the transverse process serves as the key landmark.

Question 63

Supraclav block, pain with tourniquet, what else do you need

Answer 63

The intercostobrachial nerve supplies sensory innervation to the inner aspect of the upper arm. It may be anesthetized to prevent tourniquet-induced pain of the medial upper arm following otherwise adequate regional anesthesia to the upper extremity.

Question 64

The intercostobrachial nerve block is performed by _________

Answer 64

The intercostobrachial nerve block is performed by subcutaneous injection of 3-5 mL of local anesthetic along the axillary crease

Question 65

The cricothyroid muscle is innervated by …

Answer 65

The cricothyroid muscle is innervated by the external branch of the SLN

Question 66

Where does dural sac and conus medullaris end

in newborns?

in adults?

Answer 66

In newborns, the dural sac typically ends at S3 and the conus medullaris at L3.

In adults, the dural sac typically ends at S1-S2 and the conus medullaris at L1-L2.

Question 67

Ax block misses which nerve which travels where

Answer 67

The musculocutaneous nerve travels within the belly of the coracobrachialis muscle. The nerve may therefore be neglected during an axillary brachial plexus block for distal upper extremity surgery since it is not contained within the axillary sheath. The median, ulnar, and radial nerves (as well as the axillary artery) are contained within the sheath.

Question 68

Patients who aspirate when supine are most likely to collect secretions in the

Answer 68

Patients who aspirate when supine are most likely to collect secretions in the posterior segment of the right lower lobe.

Question 69

Complications of left IJ central line

Answer 69

Placement of a left-sided central line is associated with increased complications. There is an increased incidence of arterial puncture because the left internal jugular vein is often smaller and overlays the internal carotid artery more often than the right. Additionally, the more tortuous course increases the incidence of malposition.

Question 70

Efferent limb of laryngospasm reflex

Answer 70

Recurrent laryngeal nerve

Question 71

muscles involved in laryngospasm

Answer 71

lateral cricoarytenoid and transverse arytenoid

Question 72

nerve innervates cricothyroid muscles

Answer 72

external branch of superior laryngeal nerve

Question 73

nerve for sensory of posterior 1/3 of tongue

Answer 73

The glossopharyngeal nerve is responsible for the sensory innervation of the posterior 1/3 of the tongue

Question 74

afferent limb of laryngospasm reflex

Answer 74

The internal branch of the superior laryngeal nerve is responsible for sensory innervation of the trachea at and above the level of the vocal cords. This means that the internal branch of the superior laryngeal nerve functions as the afferent limb of the laryngospasm reflex.

Question 75

Anatomic landmarks for the infra-gluteal sciatic nerve block include

Answer 75

Anatomic landmarks for the infra-gluteal sciatic nerve block include the greater trochanter of the femur, ischial tuberosity, and the sciatic groove.

Question 76

Blood supply to cerebellum

Answer 76

Blood to the cerebellum is provided by the superior, anterior inferior, and posterior inferior cerebellar arteries which are branches from the vertebral and basilar arteries.

Question 77

nasopharynx, oropharynx, hypopharynx, larynx

Answer 77