Regional- epidural neural blockade

Question 1

in adults you need ___ to __ mL of LA per segment being blocked

Answer 1

1-2 mLs per segment

Question 2

Name 2 curved needles

Answer 2

Touhy (30 degree curve)

Husteab (15 degree curve)

Question 3

Name a cutting needle

Answer 3

crawford (straight)

Question 4

the use of catheters w/ epidurals have a lower incidence of what?

Answer 4

inadequate analgesia

Question 5

place the Following in order of onset (fast to slowest)

Prilocaine

Mepivacaine

Bupivacaine

Chloroprocaine

Ropivacaine

Lidocaine

Answer 5

Chloroprocaine fast

Prilocaine Fast

Lidocaine Intermediate

Mepivacaine Intermediate

Bupivacaine slow

Ropivacaine Slow

Question 6

place the following in order of duration from shortest to longest (for a bonus name how long about each last)

Prilocaine

Mepivacaine

Bupivacaine

Chloroprocaine

Ropivacaine

Lidocaine

Answer 6

Chloroprocaine 50-90 min

Prilocaine 90-130 min

Lidocaine 90-150 min

Mepivacaine 120-160 min

Bupivacaine 200-260 min

Ropivacaine 300-600 min

The faster the onset the shorter the duration

Question 7

epidural relies on _____, thats why it is dependent on Volume

Answer 7

Diffusion

Question 8

For intrathecal or epidural anesthesia LA’s work on what 3 things

Answer 8

nerve rootlets

Nerve roots

Spinal cord

Question 9

name the nerve fibers 6 total

Answer 9

• B fibers
• C fibers
• A-delta
• A- Gamma
• A- beta
• A- alpha

Question 10

place the nerve fibers in order of blockade following epidural (also state if they are mylinated or unmylinated)

Answer 10

1. B fibers (small mylinated)
2. C and A-delta fibers (c-unmylinated)
3. A- gamma (Large Mylinated)
4. A-beta (Large Mylinated)
5. A-alpha (Large Mylinated)

remember is by

S M

U M

L M

Question 11

see picture to clearify the last slide on which nerves are blocked first and why

Surrounding thr outside of the root are B fibers (SM), immediatly interior to the B fibers (SM) are the C and A-delta fibers. The larger fibers A-gamma, A-beta, A-alpha (LM) are located at the core of the nerve bundle, Thus the LA first encounters the B fibers (SM), then the C and A-Delta fibers then the Large mylinated A fibers (A-delta, A-beta, A-alpha).

Answer 11

Question 12

what is the order of SENSITIVITY of the nerve fibers from most to least sensitive

Answer 12

• LM (A-delta, A-beta, A-aplha)
• Small mylinated (B-fibers)
• Unmylinated (C-fibers)

Remember

L M

S M

U M

Question 13

Name the structures the needle passes through for an epidural block

Answer 13

1. Skin
2. Subcutaneous
3. Supraspinous ligament
4. Intraspinous ligament
5. Ligamentum flavum
6. epidural space

Question 14

what is the most sensitive indicator of initial onset of sensory block

Answer 14

loss of temp sensation

Question 15

what is the most accurate assessment of overall sensory block

Answer 15

Pinprick

Question 16

why do you perform a test dose after satisfatory placement of the epidural catheter?

Answer 16

a test dose is designed to detect both SA and IV injection