Neuraxial blocks Flashcards
Vertebral column is formed by __ vertebrae?
33
Describe how many cervical, thoracic, lumbar, sacral, & coccygeal vertebrae there are.
Cervical= 7 Thoracic= 12 Lumbar= 5 Sacral= 5-fused Coccygeal= 4-fused
Describe the types of curves that exist in the spine.
Cervical & lumbar= lordosis
Thoracic & sacral= kyphosis
_____ & _______ join the anterior and posterior segments of the vertebra to form the vertebral foramen
Lamina & pedicles
The vertebral foramen contains the
spinal cord, nerve roots, and epidural space
Cervical and thoracic spinous processes angle in a ______ direction which requires more _________ approach with the needle
caudal; cephalad
The lumbar spinous processes project in a posterior direction which is beneficial because
it increases ease of access for placement of neuraxial anesthesia
The intervertebral disc separate ______ and act
each vertebra and act as shock absorbers
Spinal nerves exit the vertebral column through
the intervertebral foramina
_________ reduces the size of the intervertebral foramina
disc degeneration
Disc degeneration can lead to
nerve compression and manifest as pain, parathesias, and/or motor deficits
Surface landmark: vertebra prominens
C7
Surface landmarks: spine of scapula
T3
Surface landmarks: inferior angle of scapula
T7
Surface landmarks: rib margin 10 cm from midline
L1
Surface landmarks: superior aspect of iliac crest
L4
Surface landmarks: posterior superior iliac spine
S2
Tuffier’s line correlates with
L4
in infants up to 1 year it is L5-S1 interspace
The facet joints are responsible for
guiding and restricting the movement of the vertebral column
Injury to facet joint can
compress nerves leading to pain and muscle spasms
What spinal level coincides with the conus medullaris in adults?
L1-L2
What spinal level coincides to the conus medullaris in the infant?
L3
What spinal level coincides with the dural sac in the adult?
S2
What spinal level coincides with the dural sac in the infant?
S3
What is the bundle of spinal nerves that extend from the conus medullaris to the dural sac?
cauda equina
The filum terminale is fixated at which two points?
conus medullaris
coccyx
Describe the significance of the sacral hiatus
provides an entry point to the epidural space- useful in pediatrics
The sacral hiatus coincides with
S5
The sacral hiatus is covered by the
sacroccocygeal ligament
Bony nodules that flank the sacral hiatus are known as
sacral cornua
they are used as landmarks for caudal anesthesia
Order the spinal ligaments from superficial to deep: anterior longitudinal ligament, posterior longitudinal ligament, interspinous ligament, ligamentum flavum, supraspinous ligament
- supraspinous ligament
- interspinous ligament
- ligamentum flavum
- posterior longitudinal ligament
- anterior longitudinal ligament
With either the midline or paramedian approach, the needle should NEVER pass through
the anterior longitudinal ligament and the posterior longitudinal ligament
Ligaments transversed in the midline approach:
supraspinous ligament
interspinous ligament
ligamentum flavum
Ligaments transversed in the paramedian or Taylor approach
ligamentum flavum
The cranial border of the epidural space is
the foramen magnum
The caudal border of the epidural space is the
sacrococcxygeal ligament
The anterior border of the epidural space is the
posterior longitudinal ligament
The lateral border of the epidural space is the
vertebral pedicles
The posterior borders of the epidural space is the
ligamentum flavum and vertebral lamina
The epidural space communicates with the _____ space by way of the
paravertebral space by way of the intervertebral foramina
The epidural space contains
nerve roots, fat pads, and blood vessels
Epidural fact acts as a sink for
liphophilic drugs, reducing their bioavailability
bupivacaine> lidocaine & fentanyl> morphine
Epidural veins or Batson’s plexus work to drain
venous blood from the spinal cord
Obesity & pregnancy increase intraabdominal pressure leading to
engorgement of the plexus
associated with increased risk of needle injury or cannulation during neuraxial anesthesia
Describe the 3 meningeal layers from outside to inside
dura mater subdural space arachnoid mater subarachnoid space pia mater
This mater should never be punctured during spinal anesthesia
Pia mater
The pia mater is the external covering of
the spinal cord
The subarachnoid space contains
CSF, nerve roots, rootlets, and the spinal cord
The target of spinal anesthesia is the
subarachnoid space
Inadvertent local anesthetic injection into the subdural space will cause
a high spinal (if using epidural dosing) or a failed spinal (if using spinal dosing)
