Regional anesthesia

Question 1

Where is the distal terminus of the subarachnoid space?

Answer 1

S2

Question 2

What accounts for most of the variability in the spread and regression of neuraxial anesthesia?

Answer 2

CSF volume

Question 3

What is the primary barrier to drug diffusion from the epidural space to the intrathecal space?

Answer 3

arachnoid mater

Question 4

What is the mechanism of respiratory arrest in a high/total spinal?

Answer 4

hypoperfusion to central ventilatory centers

Question 5

Which Rexed lamina layers in the gray matter of the spinal cord are involved in transmission of nociception?

Answer 5

I, II, and V “keep the pain alive”

Question 6

What agent gives you the longest duration single-shot spinal?

Answer 6

tetracaine (+/- epinephrine or phenylephrine)

Question 7

What are the mechanisms of spinal anticholinesterases?

Answer 7

increased cholinergic neurotransmission

NO release

Question 8

Which patient factor has the greatest influence on peak block height of a spinal anesthetic?

Answer 8

patient height

Question 9

How much does epinephrine extend the duration of epidural lidocaine?

Answer 9

50%

Question 10

Besides cocaine, which local anesthetic has vasoconstrictive properties?

Answer 10

ropivicaine

Question 11

How far above the sensory level does the sympathectomy extend in spinal anesthesia? Epidural anesthesia?

Answer 11

2-6 levels above for spinal

same level for epidural

Question 12

Does neuraxial anesthesia cause primarily arterial vasodilation or venodilation?

Answer 12

venodilation

Question 13

What factors lead to bradycardia after neuraxial anesthesia?

Answer 13

RA stretch receptors detecting loss of preload from venodilation (Bezold–Jarisch reflex)

Loss of T1-T4 cardiac accelerator fibers

Question 14

What are the mechanisms of action of intralipid?

Answer 14

lipid sink for local anesthetics

stabilization of mitochondria

Question 15

What can cause diplopia with a post-dural puncture headache?

Answer 15

traction on the 6th cranial nerve

Question 16

What is the most common causative organism of an epidural abscess after epidural anesthesia?

Answer 16

staph aureus

Question 17

What is the relative dosing of epidural vs. spinal medications?

Answer 17

10-fold higher dosing for epidural vs. spinal

Question 18

Where is the distal terminus of the spinal cord?

Answer 18

varies from L1 in adults to L3 in infants

Question 19

What are the 3 factors associated with transient neurologic syndrome after neuraxial anesthesia?

Answer 19

lidocaine (concentration-independent)
lithotomy
ambulatory surgery

Question 20

How do you treat TNS?

Answer 20

NSAIDs and time

Question 21

What are ASRA guidelines for timing neuraxial anesthesia and low-molecular weight heparin?

Answer 21

Placement > 12 h after prophylactic dose, > 24 h after therapeutic dose.

Resumption > 4 h after catheter removal AND > 12 h (prophylactic) or > 24 h (therapeutic) after placement

Question 22

How long should Plavix be held prior to neuraxial anesthesia?

Answer 22

7 days

Question 23

Why is Mg contraindicated in patients with myasthenia gravis?

Answer 23

It causes muscle weakness by blocking ACh release

Question 24

Which nerve has a characteristic bifurcation used to identify it on ultrasound?

Answer 24

Sciatic nerve popliteal approach (bifurcates into common peroneal and tibial)

Question 25

What vascular structure is immediately to the left of the celiac plexus?

Answer 25

Aorta

Question 26

Which nerve can be spared by an infraclavicular block?

Answer 26

Ulnar

Question 27

What nerves can be spared by an interscalene block?

Answer 27

Ulnar nerve

2nd intercostal brachial nerve (medial aspect of upper arm)