EPIDURAL

Question 1

Epidural space anatomy

Answer 1

surrounds dura

nerve roots
fatty connective tissue
lymphatics
rich venous plexus (Batson plexus)

Question 2

What is significant about an epidural in pregnant patients?

Answer 2

PREGNANT women have engorged vessels
Increased risk of injection into intravascular space

Question 3

Why are epidurals more versatile than spinal?

Answer 3

1. It allows for continuous or repeated dosing
2. Can be used to block nerve signals at different levels of the spine, providing a range of anesthesia from mild to dense, depending on the drug and dosage
3. It allows for the insertion of a catheter. The duration of anesthesia can be extended as needed by administering additional doses
4. Generally associated with fewer complications like severe hypotension, as the onset is slower and more controlled.

Question 4

What does segmental block mean?

Answer 4

Confined at the level of injection because it is not spread by CSF

Certain nerve roots are blocked, sparing those roots above and below.

Used in a thoracic epidural, where cervical and lumbar roots are spared

Question 5

why not epidural

Answer 5

slower onset
the block may be less “dense.”
blocks smaller sensory fibers and spare motor fibers.

Question 6

Thoracic epidural

Answer 6

Spinal processes more cephalad angle, making insertion more challenging
More steep angle
done for thoracic procedures

Question 7

most common types of locals used for epidurals

Answer 7

Marcaine (amide)
Lidocaine (amide)
Chloroprocaine (ester)

Bolus to convert to c/s
3% concentration rapid onset
Fast acting: 10-15 min onset
High pH 8.9

Question 8

What will the needle pass through for the epidural?

Answer 8

Skin
Subcutaneous tissue
Supraspinous
Interspinous
Ligamentum flavum

Question 9

loss of resistance technique

Answer 9

Injecting saline for loss of resistance
Saline or is it a wet tap

Question 10

How many cm is the distance from the skin to the epidural space?

Answer 10

4-6 cm in 90% of the population
Thread catheter 3-5 cm
Check position
Presence of paresthesias?

Question 11

test dose for epidural catheter placement

Answer 11

3cc of 1.5% lidocaine = 45mg lidocaine
1:200,000 epinephrine 5 mcg x 3 = 15 mcg

not done in spinals

Question 12

What are you worried about with a test dose?

Answer 12

In a vessel
Hemodynamics
HR & BP >20% in intravascular
Circumoral numbness, ringing in ears, bradycardia

Question 13

Epidural catheter issues

Answer 13

Catheter tip is radiopaque
If it shears off within epidural space, may leave it and observe
If a portion is external, may need to be removed surgically
When d/c catheter, use firm continuous pressure. Dont jerk it. Always document tip intact.

Question 14

Epidural dosing

Answer 14

much larger dosing

1-2 ml of local per dermatomal level to be blocked
Height affects cephalad spread
Dose requirements decrease with age

Question 15

SAB injection

Answer 15

circumoral numbness, tinnitus, bradycardia- supportive care

Question 16

Epidural Hematoma

Answer 16

Sudden onset

sharp back pain/leg pain –> numbess to motor weakness
sphincter dysfunction
diagnosed by imaging
rapid decompression within 8-12 h to avoid permanent neurologic impairment

Question 17

clinical uses of CSE

Answer 17

General Surgery
Laboring analgesia & Cesarean Section
High risk patients