Regional Anesthesia Flashcards
What 3 types of blocks are considered to be central blocks?
spinal, epidural, and caudal blocks
What is the site of action for central blocks?
the nerve root within the spinal cord
Where are the local anesthetics injected for a spinal block?
into the CSF
Where are the local anesthetics injected for an epidural block?
into the epidural space (at any level of the spinal column)
How many cervical vertebrae are there?
7
How many thoracic vertebrae are there?
12
How many lumbar vertebrae are there?
5
How many sacral vertebrae are there?
5 (fused)
What are 4 absolute contraindications to regional anesthesia?
- patient refusal
- sepsis or infection at injection site
- coagulopathy or anticoagulation
- elevated ICP or cerebral edema
What are a few relative contraindications to regional anesthesia?
- patient appropriateness
- local infection near injection site
- hypovolemia
- CNS disease
- chronic back pain or prior laminectomy
- prior SAB with difficulty
The spinal cord extends from the ______ ______ to ____.
foramen magnum to L1
The spinal canal extends from the ______ ______ to the ______ ______.
foramen magnum to the sacral hiatus
What part of the spinal cord continues past L1?
the cauda equina
How many pairs of spinal nerves carry motor and sensory information?
31 pairs
cervical (8), thoracic (12), lumbar (5), sacral (5), and coccygeal (1)
The dorsal root carries what type of nerve signals?
afferent
signals heading into the spinal cord and brain
The ventral root carries what types of nerve signals?
efferent
signals heading into the periphery
The sympathetic nerves originate where?
the thoracic and lumbar spine
The parasympathetic nerves originate where?
the cranial nerves and the sacral spine
Spinal anesthesia interrupts ______, ______, and _______ nervous system innervation.
sensory, motor, and sympathetic
If T6 is the target sensory blockade level, then usually two dermatomes up (T4) would be the ______ blockade level, and usually two dermatomes down (T8) would be the _____ blockade level.
T4 - sympathetic
T6 - sensory
T8 - motor
What two anatomic landmarks assist in identifying the location of L4?
spinous processes and the iliac crests
