Exam 1

Question 1

What dermatome does the clavicle correlate with?

Answer 1

C4

Question 2

What dermatomes correlate with the nipples?

Answer 2

T4-T5

Question 3

What dermatomes correlate with the xiphoid?

Answer 3

T6-T8

Question 4

What dermatomes correlate with the inferior border of the scapula?

Answer 4

T7

Question 5

What dermatomes correlate with the umbilicus?

Answer 5

T10

Question 6

What dermatomes correlate with the Superior border of the iliac crest?

Answer 6

L4

Question 7

What dermatomes correlate with the perineum?

Answer 7

S2-S5

Question 8

What are the 3 classes of nerves?

Answer 8

motor, sensory and autonomic.

Question 9

What class of nerves transmit sensations such as touch and pain to the spinal cord and from there to the brain.

Answer 9

sensory

Question 10

What class of nerves Controls the caliber of blood vessels, heart rate, gut contraction and other functions not under conscious control.

Answer 10

autonomic - the PNS and SNS

Question 11

What class of nerves convey messages for muscles to contract and when they are blocked muscle paralysis results.

Answer 11

motor

Question 12

What is the goal of every regional anesthetic

Answer 12

Sensory anesthesia (or analgesia)

Question 13

What is local anesthetics Mechanism of action

Answer 13

Local anesthetics bind to sodium channels, in the inactivated-closed state, thus preventing them from converting to activated-open or rested-closed.

Question 14

When are Sodium channels not permeable to sodium and can not propagate an action potential.

Answer 14

in the inactivated-closed state

Question 15

LAs diffuse through What

Answer 15

the lipid bilayer of the cell [the uncharged portion)

Question 16

What does the charged portion of LA’s do once the uncharged portion diffuses through the lipid bilayer?

Answer 16

the charged portion accesses the Na+ channel and prevents an action potential from forming by blocking Na+ entry into the cell (the cell remains non depolarized)

Question 17

Though local anesthetics bind to sodium channels in the inactivated- closed state, they only gain access during?

Answer 17

the activated-open state

Question 18

What is Differential Blockade

Answer 18

Local anesthetics act on nerves at a different (or “differential”) rate, depending on The thickness of the nerve. Thicker nerves need more LA (exception to the rule is B pre-ganglionic sympathetic fibers)

Question 19

Motor fibers are (blank) than sensory fibers and therefore it is possible to get sensory anesthesia, without getting muscle paralysis.

Answer 19

larger

Question 20

What fibers are the most susceptible to conduction blockade

Answer 20

Preganglionic type B (despite being larger than type C fibers.)

Question 21

Myelin makes the nerve fiber more or less susceptible to conduction blockade?

Answer 21

more

Question 22

How many nodes of Ranvier does it take to block conduction?

Answer 22

approx 3

Question 23

As nerve size increases what happen to the nodes of Ranvier?

Answer 23

the nodes are more spread out and it’s harder to block them

Question 24

What is Nerve Fiber TypeA Alpha”s Function

Answer 24

Proprioception, large motor

Question 25

What is Nerve Fiber TypeA Beta"s Function

Answer 25

Touch, pressure, small motor

Question 26

What is Nerve Fiber TypeA Gamma"s Function

Answer 26

Muscle spindles

Question 27

What is Nerve Fiber TypeA Delta "s Function

Answer 27

Pain, temperature (fast pain, touch, cold temperature)

Question 28

What is Nerve Fiber Type B's function

Answer 28

Preganglionic autonomic

Question 29

What is Nerve Fiber Type C dorsal root's function

Answer 29

Pain ("slow" pain and temperature)

Question 30

What is Nerve Fiber Type C sympathetic's function

Answer 30

Postganglionic

Question 31

Which nerve fibers have heavy myelination

Answer 31

All Type A's (alpha, beta, gamma, delta)

Question 32

Which nerve fibers have light myelinaiton?

Answer 32

Type B

Question 33

Which nerve fibers do not have myelination?

Answer 33

Type C

Question 34

Which never fibers diameter is 12-20 (um)

Answer 34

Type A Alpha

Question 35

Which never fibers diameter is 5-12 [um)

Answer 35

Type A Beta

Question 36

Which never fibers diameter is 15-30 um

Answer 36

Type A Gamma

Question 37

Which never fibers diameter is 2-5 (um)

Answer 37

Type A Delta

Question 38

Which never fibers diameter is <3 (um)

Answer 38

TypeB

Question 39

Which never fibers diameter is 0.4-1.2 um

Answer 39

TypeC Dorsal root

Question 40

Which never fibers diameter is 0.7 - 2.3 um

Answer 40

TypeC Sympathetic

Question 41

What are some factors that affect nerve blockade

Answer 41

Tissue pH, C02 tension, local ion gradients, frequency of nerve stimulation

Question 42

What group of LAs are metabolized mostly by the liver

Answer 42

Amides

Question 43

What group of LAs are metabolized by plasma cholinesterase and the byproduct is PABA

Answer 43

Esters

Question 44

Which LAs are Amides;

Answer 44

Lidocaine, Mepivacaine, Bupivacaine, Etidcoaine, Prilocaine

Question 45

Which LA's are esters?

Answer 45

Cocaine, Procaine, Chloroprocaine, Tetracaine

Question 46

LAs that are more protein bound have less What

Answer 46

ability to cause toxicity

Question 47

The more lipid soluble an LA is the more (blank) it is?

Answer 47

potent

Question 48

pKa- agents that have a pKa that is closest to the body's pH
 will

Answer 48

have the fastest onset (because more will be unionized)

Question 49

What would cause a faster onset and longer duration of blockade of an LA

Answer 49

larger volume and concentration: the more injected (larger volume),

Question 50

What can limit systemic absorption and maintain the drug concentration in the vicinity of the nerve fibers.

Answer 50

use of vasoconstrictors (epi)

Question 51

Which LA would adding epi have less of an effect on and why? Bupivacaine or Lidocaine?

Answer 51

less of an effect on bupivacaine than lidocaine, presumably because of the greater lipid solubility of bupivacaine compared to lidocaine).

Question 52

Absorption is influenced by:

Answer 52

dose and pharmacologic properties of the individual drug (lipid solubility, protein binding).

Question 53

Which has a faster onset Subarachnoid blocks or epidurals?

Answer 53

subarachnoid blocks

Question 54

Does the addition of epi to LA's change rate of onset?

Answer 54

No

Question 55

What does addition of sodium bicarbonate to the LA do?

Answer 55

Speeds the onset and spread of the block by increasing pH of the LA so more is in the unionized form

Question 56

At what temperature would a LA work faster?

Answer 56

Body temp

Question 57

List (High to low) what injection sites from the notes would have greater peak plasma concentrations and shorter DOA. (Also greater risk for toxicity)

Answer 57

Intercostal space>Caudal>Epidural>Brachial plexus>sciatic/femoral nerves

Question 58

What is order of their “typical” presentation, of local anesthetic toxicity?

Answer 58

1. Circumoral numbness (numbness ot the tongue or lips) 2. Metalic taste 3. tinnitus 4. Lightheaded, Slurred speech, Visual Disturbances 5. Muscle twitching 6. Vertigo 7. Seizures soon afterwards and unconsciousness 8. CNS depression and Coma 9. Respiratory Arrest 10. Cardiovascular collapse

Question 59

How long is the pt monitored after initial insertion of a block?

Answer 59

Monitoring during the block (and for 30 minutes after)

Question 60

State monitoring modalities required during administration of a regional anesthetic

Answer 60

Airway, Oxygenation via pulse ox, Heart Rate (via pulse ox and/or ekg) and Blood Pressure

Question 61

Describe the equipment which must be available during the administration of a regional anesthetic, especially when “off site.”

Answer 61

- Source of oxygen, suction apparatus, airway equipment and positive-pressure ventilation. - Additional equipment if indicated (nerve stimulator, c-arm, ultrasound)