Flashcards in Regional Anesthesia Deck (138)
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1
How long does it take for the spinal cord to go from L3 in the newborn to L1?
20-24mos
2
Which ligament binds the epidural space posteriorly?
ligamentum flavum
3
Where is the epidural space the widest?
L2
4
Where is the epidural space the narrowest?
C5
5
What are the two high points of the vertebral column when the patient is lying supine?
L3 and C3
6
What are the two low points of the vertebral column when the patient is lying supine?
S2 and T6
7
What is ALWAYS going to be the principle site of action for spinals or epidurals?
the nerve root
8
Name the 3 main structures you pass through to get to the epidural space.
1) supraspinous ligament
2) interspinous ligament
3) ligamentum flavum
9
What are the 3 primary layers of the spinal meninges before reaching the cord?
1) dura mater (outermost--> toughest--> extends from foramen magnum to S2-3)
2) arachnoid mater (middle layer--> delicate, nonvascular--> ends at S2--> almost like spiderweb)
3) pia mater (closely adheres to spinal cord--> delicate, highly vascular)
10
Where is the subarachnoid space and CSF found?
between the arachnoid and pia mater
11
What is the easy way to remember the 3 outer layers and location of the subarachnoid space before the spinal cord?
DASP
Dura
Arachnoid
Subarachnoid space
Pia
12
Where is the epidural space located?
it is a potential space bound by the dura mater and the ligamentum flavum
13
Describe the blood supply to the spinal cord and nerve roots.
blood supply to the spinal cord and nerve roots is derived from a single anterior spinal artery and paired posterior spinal arteries
14
The principal site of action for neuraxial blockade is the ______.
nerve root
15
How much CSF do we have at any time? in the subarachnoid space?
100-150ml; 25-35ml
16
How much CSF do we produce per day?
500mL
17
How do vasoconstrictors prolong a spinal block?
decrease absorption
18
When administering a spinal, where is the concentration the greatest?
at the site of injection
19
What is the normal specific gravity of CSF?
1.004-1.009
James Bond 1.007 is in the middle
20
Label in relation to CSF: SAME, GREATER, LESS
Isobaric
same
21
Label in relation to CSF: SAME, GREATER, LESS
hyperbaric
greater
22
Label in relation to CSF: SAME, GREATER, LESS
hypobaric
less
23
Is sterile water hypo, hyper, or iso baric?
hypobaric
24
Is dextrose 5-8% hypo, hyper, or iso baric?
hyperbaric
25
What direction will a hyperbaric spinal given at L2 while the patient was sitting go if the patient is immediately laid supine?
cephalad. Think of the high and low points
26
What determines the duration of spinal anesthesia?
rate of elimination
27
What is the predominant action of a sympathetic blockade d\t local anesthetics?
venodilation
venodilation--> reduces venous return, SV, CO, and BP
28
What are the two causes for bradycardia following local anesthetic administration?
1) blockade of cardiac accelerator fibers
2) decreased venous return (from venodilation)
*Bainbridge reflex (unopposed vagal stimulation)
29
What is the BEST means for treating hypotension during spinal anesthesia?
physiologic not pharmacologic
*give fluids if not normovolemic, if normovolemic give ephedrine
30