Card Set Information
BC NU 591
With a spinal what is the principle site of action?
The nerve root
How many vertebrae total?
How many cervical?
5 fused sacral
What vertebral level do the scapula correspond to?
What vertebral level does the iliac crest correspond to?
Where does the spinal cord end in adults? In kids?
Kids L2 or L3
At what levels are spinals usually performed at?
Below L1 (below the level of the spinal cord)
Free flowing nerve fibers in CSF
Begin after spinal cord ends
Where does the CSF extend to?
3 levels of vertebral ligaments from superficial to deep
supraspinous, interspinous, ligamentum flavum
Where is spinal anesthesia performed?
Subarachnoid space, AKA intrathecal space
Between what membranes is a spinal located?
Arachnoid and pia mater
T or F, free flowing CSF is indicative of epidural placement?
F, this is indicative of spinal placement
What are the 3 membranes surrounding the spinal cord from superficial to deep?
Dura mater, arachnoid mater, pia mater
Between what two membranes is a epidural placed?
ligamentum flavum and dura mater
What artery and how many arteries supply the dorsal portion of the spinal cord?
Posterior spinal arteries
Is the dorsal portion of the spinal cord sensory or motor?
What artery and how many arteries supply the ventral portion of the spinal cord?
artery of Adamkiewicz
Is the ventral portion of the spinal cord sensory or motor?
2 types of spinal needles
cutting (cuts thru the dura) and non cutting (spreads the dura)
What size and type of spinal needle is least likely to cause a post dural puncture headache?
smaller non cutting needle
What 2 approaches are used to perform a spinal
midline (straight in) or paramedian (enter laterally)
Type of block produced with a spinal
-dense blockade (high concentration of LA at the nerve root)
-complete blockade (sympathetic and motor)
What is the principle site of action of neuraxial blockade?
smaller sympathetic nerves (pain and temperature) are more easily blocked than larger motor nerves
CV effects of a spinal
sudden hypotension and bradycardia (sympathectomy)
GI effects of a spinal
increased peristalsis, decreased sphincter tone (due to sympathectomy)
Where do the sympathetic nerves exit the spinal cord from? How does this affect hypotension?
The higher the sympathetic block, the more hypotensive the pt will be
Urinary tract effects of a spinal
urinary retention and loss of bladder control
endocrine effects of a spinal
blocks stress response of surgery
section of skin innervated by that spinal nerve
spinal level / sympathetic level
boundary of where the pt is able to feel sensation
T or F, a spinal uses a small amount of LA injected directly into the CSF to produce high levels of sensory and motor blockade
Does an epidural usually produce a sympathectomy?
No, only if it's a thoracic epidural
What is the most important factor affecting the level of spinal anesthesia?
-Baricity (heaviness of the solution in relation to CSF)
-Pt position is also important and is related to baricity
If a pt is supine where will a hyperbaric solution accumulate?
thoracic and sacral spine as both are convex
Is a higher dose of a LA needed to achieve a T4 or T10 blockade?
For what types of surgeries is a T4 level of spinal desired?
For what types of surgeries is a T10 level of spinal desired?
TURP, vaginal delivery, hip surgery
Are spinal needles larger or smaller than epidural needles?
Smaller as with a spinal you are not inserting a catheter
2 techniques to verify that you are in the epidural space
1) loss of rx
2) hanging drop
Is a spinal inserted with the pt awake or asleep?
Is an epidural inserted with the pt awake or asleep?
Either, however awake is preferred so the pt can communicate pain or paresthesias
Absolute contraindications to neuraxial blockade
-infection at injection site
-severe AS or MS
Recommendations re: neuraxial blockade with ASA and NSAIDs
Are pts taking NSAIDs or SQ heparin at increased risk for spinal hematoma?
Are pts taking plavix, fibrinolytic therapy, LMWH, or fully anticoagulated on heparin at increased risk for spinal hematoma?
Yes! Insertion and removal both pose a risk for spinal hematoma
Is PDPH related to timing of ambulation?
What factors lead to increased incidence of PDPH?
younger age, female, larger needle size, pregnant, multiple punctures
What 4 factors influence the affect of LA on nerve fibers?
1) myelinated or not
2) size of nerve fibers
3) concentration of LA at nerve fiber
4) duration of LA at nerve fiber