Neuraxial blocks 4

Question 1

Relative or absolute contraindications to neuraxial anesthesia include

Answer 1

coagulopathy
increased ICP
sepsis
infection at the puncture site
severe hypovolemia
valve lesions with fixed stroke volume
scoliosis, arthritis, spinal fusion, and osteoporosis
difficult airway
full stomach
peripheral neuropathy
multiple sclerosis

Question 2

Describe lab values which would preclude spinal anesthesia.

Answer 2

platelet count <100,000
PT, aPTT, or bleeding time twice the normal value

Question 3

Coagulopathy increases the risk of

Answer 3

spinal or epidural hematoma

Question 4

In terms of spinal anesthesia, increased intracranial pressure increases the risk of

Answer 4

brain herniation with a sudden change in CSF pressure

Question 5

Examples of valve lesions with fixed stroke volume that may preclude spinal anesthesia include

Answer 5

severe aortic stenosis, severe mitral stenosis, or hypertrophic cardiomyopathy

Question 6

Things that are not contraindications to spinal anesthesia include:

Answer 6

pre-existing back pain
previous back surgery
lower back tattoo

Question 7

Depending on the extent of the defect, patients with spina bifida are at increased risk for ______ with neuraxial anesthesia

Answer 7

traumatic injury during needle placement

Question 8

Patients that are at greatest risk for traumatic injury from neuraxial technique with spina bifida include those with

Answer 8

severe neural tube defects or a tethered cord

Question 9

If you perform spinal anesthesia on a patient with multiple sclerosis, it is important to understand that demyelinated fibers may be

Answer 9

more susceptible to local anesthetic-induced neurotoxicity- it’s best to use a lower dose and concentration of LA

Question 10

A full stomach may be a contraindication to neuraxial anesthesia because

Answer 10

hypotension (and brainstem hypoperfusion) related to the sympathectomy can cause nausea and vomiting which could lead to pulmonary aspiration

Question 11

Peripheral neuropathy may be a contraindication to neuraxial technique because

Answer 11

there is theory that these patients are more susceptible to injury and they are also slower to recover from it

Question 12

Cutting tip spinal needles include

Answer 12

Quincke or the Pitkin

Question 13

What is a benefit of a cutting tip spinal needle?

Answer 13

requires less force

Question 14

A concern with using a cutting spinal needle includes

Answer 14

higher incidence of post-dural puncture headache

Question 15

Non-cutting pencil point tips include

Answer 15

Sprotte or Whitacre
(lower incidence of PDPH but require more force to insert)

Question 16

If you’re using a spinal needle that is 22g or smaller, the risk of needle deflection is minimized by

Answer 16

placing an introducer needle into the interspinous ligament

Question 17

Types of epidural needles include

Answer 17

Crawford, Hustead, and Tuohy (most common)

Question 18

The ___________ of the Tuohy needle minimizes the risk of dural puncture

Answer 18

30-degree curvature and the blunt tip

Question 19

The optimal depth of catheter insertion into the epidural space is

Answer 19

3-5 cm inside

Question 20

An epidural catheter that is too shallow results in

Answer 20

higher incidence of inadequate analgesia (epidural failure)

Question 21

An epidural catheter that is too deep results in

Answer 21

the catheter may enter an epidural vein or exit through an intervertebral foramen

Question 22

Describe why you should never withdraw the catheter through the needle

Answer 22

the needle could sheer the catheter and leave fragments inside the patient

Question 23

The Green needle is considered to be a

Answer 23

non-cutting, rounded bevel tip needle

Question 24

Pros of using the pencil point tip spinal needle include

Answer 24

lower risk of PDPH, more tactile feel, needle less likely to deflect, less likely to injure the cauda equina

Question 25

Epidural needles differ by the amount of

Answer 25

curvature at the needle tip

Question 26

A Crawford epidural needle has a _____ degree tip

Answer 26

0

Question 27

A Hustead epidural needle has a ______ degree tip

Answer 27

15 degree

Question 28

A Tuohy epidural needle has a __________ degree tip

Answer 28

30 degrees notice the needle angle increases in alphabetical order

Question 29

A 22 pound child requires a caudal anesthetic. How many milliliters of 0.2% ropivacaine should be administered to achieve a T10 sensory blockade?

Answer 29

10 mL For a T10 sensory block you should administer 1 mL/kg

Question 30

The caudal approach is most commonly used in the

Answer 30

pediatric patients

Question 31

The caudal approach is useful for procedures requiring up to a

Answer 31

T10 sensory block

Question 32

Absolute contraindications to caudal anesthesia include

Answer 32

spina bifida, meningomyelocele of the sacrum, and meningitis

Question 33

The ________ of the local anesthetic solution determines the height of a caudal block.

Answer 33

volume

Question 34

Correct needle placement of caudal anesthesia is confirmed by

Answer 34

feeling a pop as the needle passes through the sacrococcygeal ligament to enter the epidural space.

Question 35

You should not use _________ for loss of resistance in children because of

Answer 35

air; risk of air embolism

Question 36

Why is caudal anesthesia infrequently used in adolescence and adulthood?

Answer 36

sacral anatomy is more difficult to identify a lumbar approach to the epidural space is easier to perform and equally effective

Question 37

Relative contraindications to caudal anesthesia include

Answer 37

pilonidal cyst, abnormal superficial landmarks, hydrocephalus, intracranial tumor, progressive degenerative neuropathy

Question 38

Describe the positioning for performing caudal anesthesia

Answer 38

prone- small roll placed under the iliac crests with the legs in the frog position lateral- flex the hips and make sure the top leg is flexed more than the bottom leg (Simm's position)

Question 39

Describe the landmarks needed for caudal anesthesia

Answer 39

use the posterior superior iliac spines and the sacral hiatus as landmarks envision an equilateral triangle with the apex of the triangle at the sacral hiatus

Question 40

Describe needle type and degree of insertion for caudal anesthesia.

Answer 40

22 or 25 gauge needle or 20 gauge IV catheter with bevel up at a 45 degree angle

Question 41

Resistance to injection with caudal anesthesia suggests that the needle tip is in

Answer 41

the subperiosteal area

Question 42

The patient may experience ______________ with caudal anesthesia

Answer 42

a feeling of fullness in the sacrum before the block sets up - this is normal

Question 43

________ provides analgesia that is equal to epidural opioids when administered with caudal anesthesia

Answer 43

clonidine 1 mcg/kg

Question 44

Describe the pediatric and adult dosing of a caudal block with the desired height block at the sacral level

Answer 44

peds: 0.5 mL/kg adult: 12-15 mL

Question 45

Describe the pediatric and adult dosing of caudal anesthesia with the desired height of the block to be sacral to low thoracic (~T10)

Answer 45

peds: 1 mL/kg adult: 20-30 mL

Question 46

Describe the pediatric and adult dosing of caudal anesthesia with the desired height of the block to be sacral to mid thoracic

Answer 46

peds: 1.25 mL/kg adult: N/A

Question 47

Common pediatric procedures where caudal anesthesia is useful include:

Answer 47

circumcision, hypospadias repair, anal surgery, inguinal herniorrhaphy, low thoracic surgery