Neuraxial blocks section 2

Question 1

Transection of the C6 posterior nerve root will cause:
A. diaphragmatic paralysis
B. impaired sympathetic outflow to the C6 distribution
C. Sensory block of the thumb
D. Motor deficit of the middle finger

Answer 1

C. sensory block of the thumb

Question 2

Posterior nerve roots are

Answer 2

sensory

Question 3

Anterior nerve roots are

Answer 3

motor and autonomic

Question 4

_______ is an area of skin that’s innervated by a dorsal nerve root (sensory) from the spinal cord

Answer 4

A dermatome

Question 5

Key dermatome: C6

Answer 5

thumb

Question 6

Key dermatome: C7

Answer 6

2nd and 3rd digits

Question 7

Key dermatome: C8

Answer 7

4th and 5th digits

Question 8

Key dermatomes: T4

Answer 8

nipple line

Question 9

Key dermatomes: T6

Answer 9

Xiphoid process

Question 10

Key dermatomes: T10

Answer 10

umbilicus

Question 11

Key dermatomes: L4

Answer 11

anterior knee

Question 12

The spinal cord has ____ paired spinal nerves

Answer 12

31

Question 13

A sensory level of T4 is needed for the following surgical procedures:

Answer 13

upper abdominal surgery
C-section
cystectomy

Question 14

A sensory level of T6-T7 is needed for the following surgical procedures:

Answer 14

lower abdominal surgery
appendectomy

Question 15

A sensory level of T10 is needed for the following surgical procedures:

Answer 15

Total hip arthroplasty, vaginal delivery, TURP

Question 16

A sensory level of L1-L3 (inguinal ligament) is needed for the following surgical procedures:

Answer 16

lower extremity surgery

Question 17

A sensory level of L2-L3 is needed for the following surgical procedures:

Answer 17

foot surgery

Question 18

A sensory level of S2-S5 is needed for the following surgical procedures:

Answer 18

hemorrhoidectomy

Question 19

Describe the dosing guidelines for a epidural catheter placed at T2-T6 (upper thoracic).

Answer 19

5-10 mL local anesthetic

Question 20

Describe the dosing guidelines for an epidural catheter placed at T6-L1 (lower thoracic)

Answer 20

10-20 mL

Question 21

Describe the dosing guidelines for an epidural catheter placed at L2-L5

Answer 21

20 mL local

Question 22

Key benefits of a well-executed thoracic epidural technique (compared to a lumbar epidural) include:

Answer 22

superior analgesia
minimizes the surgical stress response
reduces the incidence of postoperative pulmonary complications
can spare the nerves that innervate the legs, which will allow for postoperative ambulation

Question 23

When a thoracic epidural is combined with GA, cardiopulmonary considerations include a higher risk of:

Answer 23

bradycardia (blockade of cardioaccelerator nerves T1-T4)
Hypotension (decreased cardiac output & vasodilation)
changes in airway resistance (increased vagal influence on airways)

Question 24

In the subarachnoid space, the primary site of local anesthetic action is on the

Answer 24

myelinated preganglionic fibers of the spinal nerve roots

Question 25

Describe the order in which fibers are blocked.

Answer 25

Autonomic, then sensory, then motor neurons last

Question 26

Autonomic blockade is __________ than sensory blockade, and sensory blockade is _______ than motor blockade

Answer 26

2-6 dermatomes higher than sensory and sensory is 2 dermatomes higher than motor blockade

Question 27

Controllable factors that meaningfully affect spread of local anesthetic include

Answer 27

the dose and baricity of the local anesthetic, site of injection, and patient position

Question 28

Factors that don't meaningfully affect the spread include

Answer 28

barbotage, speed of injection, bevel orientation, body habitus, and gender

Question 29

Local anesthetics in the epidural space must first diffuse through _________ before they can block the nerve roots

Answer 29

dural cuff

Question 30

The primary determinants of spread for epidural anesthesia are

Answer 30

volume and level of injection

Question 31

Describe the autonomic, sensory, and motor block with epidural anesthesia

Answer 31

Sensory blockade is 2-4 dermatomes higher than the motor block; there's no autonomic differential blockade with epidural anesthesia

Question 32

__________ is the most reliable determinant of intrathecal spread when using a hypo- or isobaric solution

Answer 32

Dose

Question 33

______ is the most reliable determinant of intrathecal spread when using a hyperbaric solution

Answer 33

Baricity

Question 34

Describe how the level of injection affects spread in the epidural space of the lumbar region

Answer 34

spread is mostly cephalad

Question 35

Describe how the level of injection affects spread in the epidural space of the midthoracic region

Answer 35

spread is equally cephalad and caudad

Question 36

Describe how the level of injection affects spread in the epidural space of the cervical region

Answer 36

spread is mostly caudad

Question 37

Describe the order in which we can test a differential blockade

Answer 37

first- sense of temperature second- pain third- sense of light touch or pressure

Question 38

The _______ can be used to assess the degree of motor block

Answer 38

Modified Bromage Scale

Question 39

The Modified Bromage Scale can only evaluate the

Answer 39

lumbosacral nerves (nothing more cephalad)

Question 40

Describe the degrees (0-3) of the Modified Bromage Scale

Answer 40

0= no motor block 1= patient cannot raise an extended leg but can move the knees and feet 2= patient cannot raise an extended leg or move the knee but can move the feet 3= complete motor block

Question 41

Describe the block onset for peripheral nerves

Answer 41

B- first C- second A gamma & delta- third A alpha & beta- fourth

Question 42

What is the MOST appropriate spinal dose of 3% 2-chloroprocaine to achieve for a T10 level? a. 5 mg b. 20 mg c. 30 mg d. 50 mg

Answer 42

c. 30 mg the dose range needed to achieve a T10 level is 30-40 mg

Question 43

When dosing a spinal anesthetic, the most important controllable factors affecting block height include

Answer 43

dose, baricity, and patient postion

Question 44

When dosing an epidural anesthetic, the primary drug-related determinant of block height is

Answer 44

LA volume

Question 45

When dosing an epidural anesthetic, the primary procedure-related determinant of block height is

Answer 45

the level of injection

Question 46

When dosing an epidural anesthetic, the primary determinant of block density is

Answer 46

local anesthetic concentration

Question 47

Describe the necessary dosing for spinal anesthesia using Bupivacaine 0.5-0.75% for a T10 and T4 level to be achieved

Answer 47

T10: 10-15 mg T4: 12-20 mg

Question 48

Describe the onset of action of spinal anesthesia for bupivacaine 0.5-0.75%

Answer 48

4-8 min

Question 49

Describe the dosing for a T10 & T4 level of levobupivacaine 0.5% for spinal anesthesia

Answer 49

T10- 10-15 mg T4- 12-20 mg

Question 50

Describe the onset of action for spinal anesthesia of levobupivacaine 0.5%

Answer 50

4-8 min.

Question 51

Describe the duration of action of bupivacaine 0.5-0.75%

Answer 51

130-220 min.

Question 52

Describe the dosing needed to achieve spinal anesthesia of T10 & T4 using ropivacaine 0.5-1%

Answer 52

T10- 12 -18 mg T4- 18-25 mg

Question 53

Describe the onset of action of ropivacaine 0.5-1%

Answer 53

3-8 min

Question 54

Describe the duration of action of 0.5-1% ropivacaine

Answer 54

80-210 min.

Question 55

Describe the needed dosing for T10 & T4 spinal anesthesia using 2-chloroprocaine 3%

Answer 55

T10- 30-40 mg T4- 40-60 mg

Question 56

Describe the onset of action of 2-chloroprocaine 3%.

Answer 56

2-4 min.

Question 57

Describe the duration of action of 2-chloroprocaine 3%.

Answer 57

40-90 min.

Question 58

Describe the dosing of 0.5-1% tetracaine for T10 and T4 spinal anesthesia

Answer 58

T10- 6-10 mg T4- 12- 16 mg

Question 59

Describe the onset of action for tetracaine 0.5-1%

Answer 59

3-5 minutes