Neuraxial

Question 1

Boundaries of epidural space

Answer 1

• cranial border: foramen magnum
• caudal border: sacrococcygeal ligament
• anterior border: posterior longitudinal ligament
• lateral border: vertebral pedicles
• posterior border: ligamentum flavum
  vertebral lamina

Question 2

Epidural space contains…

Answer 2

• nerve roots
• fat pads
• blood vessels

Question 3

Baxton’s Plexus

Answer 3

• drain venous blood from spinal cord
• valveless veins - pass through anterior and lateral regions of epidural space
• obesity & pregnancy inc. intra-abdominal pressure causing engorgement

Question 4

Epidural hematoma

Answer 4

• blood accumulates btw dura and bone
• accumulation of blood epidural space compresses the dura
• can compress spinal cord - causing spinal cord ischemia & permanent neurologic dysfunction
• surgical decompression w/in 8 hrs provides the best chances of recovery

Question 5

Subarachnoid space

Answer 5

• contains: CSF, nerve roots, rootlets, & spinal cord
• target for spinal anesthesia
• terminal end is dural sac (S2:adults, S3:infant)

Question 6

Dural sac landmark

Answer 6

• superior iliac spines

- S2

Question 7

Sacral hiatus

Answer 7

• S5
• incomplete fusion of laminae @ S5
• entry point to the epidural space

Question 8

Sacral Cornu

Answer 8

• bony nodules that flank the sacral hiatus

Question 9

Factors that affect spread of spinal anesthesia

Answer 9

• Baricity of LA
• pt position during & after block
• dose
• site of injection
• volume of CSF
• density of CSF

Question 10

Factors that effect epidural spread

Answer 10

volume

Question 11

Caudal Block Height Peds doses

• sacral
• sacral - T10
• sacral to mid thoracic

Answer 11

• 0.5 ml/kg
• 1 ml/kg
• 1.25 ml/kg

Question 12

Spinal cord ends at conus medularis

Answer 12

• Adult: L1-L2

- Infant: L3

Question 13

Cauda Equina

Answer 13

bundle of spinal nerves extending from conus medullaris to dural sac

Question 14

Dural Sac

Answer 14

• subarachnoid space terminates at dural sac
• Adult: S2
• Infant: S3

Question 15

Cauda Equina Syndrome

Answer 15

• Cause: neurotoxicity form inc. concentrations of LA
• Factors that inc risk: 5% lido & microcatheters
• S&S: bowel & bladder dysfxn, sensory deficits, weakness and/or paralysis
• Treatment: supportive

Question 16

Transient Neurologic Symptoms

Answer 16

• Cause: Pt positioning, stretching of the sciatic nerve, myofascial strain & muscle spasm
• inc risk: lidocaine, lithotomy, lithotomy, ambulation surgery & knee arthroscopy
• factors the don’t inc risk: early ambulation, LA concentration, baricity, glucose concentration
• S/Sx: severe back and butt pain that radiates to both legs, develops w/in 6-36 hr and persists for 1-7 days
• Treatment: NSAIDS, opioid analgesics & trigger point injections