Neuraxial Blocks Flashcards
1
Q
A
Superior articular process
2
Q
The vertebral column is formed by ____ vertebrae?
A
33
Cervical = 7
Thoracic = 12
Lumbar = 5
Sacral = 5-fused
Coccygeal = 4-fused
3
Q
What does letter D represent?
A
Spinous process
4
Q
What does A represent?
A
Transverse process
5
Q
What does C represent?
A
Lamina
6
Q
Cervical and thoracic spinous processes angle in a ____ direction. This requires a more ____ approach with the needle.
A
Caudal; cephalad
7
Q
A
Vertebra prominent C7
8
Q
A
Spine of scapula T3
9
Q
A
Inferior angle of scapula T7
10
Q
A
Rib margin 10cm from midline L1
11
Q
A
Superior aspect of iliac crest L4
12
Q
A
Posterior superior iliac spine S2
13
Q
The intercristal line (aka ________) is a horizontal line drawn across the superior aspects of the iliac crests that correlates with the ____ vertebra.
A
Tuffier’s line; L4
14
Q
In infants up to 1 year, the intercristal line (Tuffier’s line) correlates with the ____ interspace.
A
L5-S1
15
Q
A
Pedicle
16
Q
What does A represent?
A
Superior articular process
17
Q
What does B represent?
A
Transverse process
18
Q
What does C represent?
A
Lamina
19
Q
What does D represent?
A
Inferior articular process
20
Q
What does E represent?
A
Spinous process
21
Q
In the adult, which anatomic structure correlates with the termination of the dural sac?
A
Superior iliac spines (S2)
22
Q
Conus medullaris is at which vertebral level?
A
L1
23
Q
The sacral hiatus and sacrococcygeal ligament is at which level?
A
S5
24
Q
Cauda equina is comprised of nerves and nerve roots from the ____ nerve pairs and the ____ nerve.
A
L2-S5;
Coccygeal
25
The subarachnoid space terminates at the ______ in an adult _____ & infant ____
Dural sac
S2
S3
26
Anchors the spinal cord to the coccyx
Filum terminale
27
The filum terminale is fixated at which two points?
1. Conus medullaris
2. Coccyx
28
Order the spinal ligaments from superficial to deep
1.Supraspinous ligament
2. Interspinous ligament
3. Ligamentum flavum
4. Posterior longitudinal ligament
5. Anterior longitudinal ligament
29
What does A represent?
Supraspinatus ligament
30
What does B represent?
Interspinous ligament
31
What does C represent?
Ligamentum flavum
32
What does D represent?
Posterior longitudinal ligament
33
What does E represent?
Anterior longitudinal ligament
34
What does A represent?
Supraspinous ligament
35
What does B represent?
Interspinous ligament
36
What does C represent?
Ligamentum flavum
37
What does D represent?
Posterior longitudinal ligament
38
What does E represent?
Anterior longitudinal ligament
39
Piercing the ______ contributes to the loss of resistance when the needle enters the epidural space.
Ligamentum flavum
40
The needle passes through what 3 ligaments during the midline approach?
1. Supraspinous ligament
2. Interspinous ligament
3. Ligamentum flavum
41
What ligament does the needle pass through during the paramedian or Taylor approach?
Ligamentum flavum
42
The paramedian approach involves inserting the needle ____ degrees off the midline or _________ to the interspace
15 degrees;
1cm lateral and 1cm inferior
43
Which statements about the epidural space are true?
A. Batson’s plexus passes through the lateral region.
B. Its volume is increased during the third stage of pregnancy
C. It neighbors the pia mater
D. It ends at the sacrococcygeal ligament
A & D
44
_______ is the network of epidural veins that drain the spinal cord and the meninges. It typically passes through the lateral and anterior regions of the epidural space
Batson’s plexus
45
Transection of the C6 posterior nerve root will cause?
Sensory block of the thumb
46
The ____ roots are sensory, and the _____ roots are motor and autonomic.
Posterior (dorsal); anterior (ventral)
47
Diaphragmatic paralysis occurs with injury to ______
C3-5
48
What dermatome block height level is required for upper abdominal surgery, cesarean section, & cystectomy?
T4 nipple line
49
What dermatome block height level is required for lower abdominal surgery and appendectomy?
T6-T7 (xiphoid process)
50
What dermatome block height level is required for total hip arthroplasty, vaginal delivery, & TURP?
T10 (umbilicus)
51
What dermatome block height level is required for lower extremity surgery?
L1-L3 (inguinal ligament)
52
What dermatome block height level is required for foot surgery?
L2-L3
53
What dermatome block level is required for Hemorrhoidectomy?
S2-S5
54
Blockade of cardio accelerator nerves occurs at which levels?
T1-T4
55
In the ______ space, the primary site of local anesthetic action is not eh myelinated preganglionic fibers of the spinal nerve roots
Subarachnoid
56
What is the most reliable determinant of intrathecal spread when using hypo- or isotonic solution?
Dose
57
What is the most reliable determinant of intrathecal spread when using a hyperbaric solution?
Baricity
58
Sensory blockade is ___ dermatomes above the motor block. (Spinal)
2
59
Autonomic blockage is ___ dermatomes above the sensory block. (Spinal)
2-6
60
What are the primary determinants of spread in epidural anesthesia?
Volume and level of injection
61
What structure must be traversed by epidural LAs and what is their primary target?
LA in the epidural space must first diffuse through the dural cuff before they can anesthetize the nerve roots
62
What type of fiber is blocked first after a spinal anesthetic?
Type B- preganglionic ANS fibers
63
Skeletal muscle- motor
Proprioception
A alpha
64
Touch
Pressure
A beta
65
Skeletal muscle- tone
A Gamma
66
Fast pain
Temperature
Touch
A delta
67
Preganglionic ANS fibers
B
68
Postganglionic ANS fibers
C (sympathetic)
69
Slow pain
Temperature
Touch
C (dorsal root)
70
_____ is the determinant of epidural block height
Volume
71
____ is the primary determinant of epidural block density
Concentration
72
What are the 3 most important factors that determine local anesthetic spread in the subarachnoid space?
Baricity, patient position, & LA dose
73
In the supine position:
The greatest points of lordosis are ___ & ___
The greatest points of kyphosis are ___ & ___
C5 & L3;
T5-T7 & S2
74
In the supine position, how will a hypobaric solution spread in the intrathecal space?
It will concentrate in the lower lumbar region
75
After administering a hyperbaric solution, the block is not as high as expected. What can you do?
If the block hasn’t set, you can place the pt in the trendelenburg position
76
Define baricity
The ratio is the density of local anesthetic solution to the density of CSF
77
The gut receives parasympathetic innervation from ____ and sympathetic innervation from ____
Vagus nerve (CN 10);
Sympathetic chain (T5-L2)
78
What reflex contributes to asystole that occurs with spinal anesthesia?
Bezold-Jarisch reflex. The heart slows to allow it adequate time to fill
79
What is the most likely cause of apnea due to spinal anesthesia?
Brainstem hypoperfusion
80
Neuraxial opioids inhibit afferent pain transmission in the ______ (lamina _ of the dorsal horn)
Substantia gelatinosa; 2
81
List 3 valvular lesions that are generally regarded as contraindications for neuraxial anesthesia
AS, MS, hypertrophic cardiomyopathy
82
For a T10 sensory caudal block, how much LA should be administered?
1ml/kg
83
What are absolute C/I to caudal anesthesia?
Spina bifida
Meningomyelocele
Meningitis
84
What are the relative C/I to caudal anesthesia?
Pilonidal cyst
Abnormal superficial landmarks
Hydrocephalus
Intracranial tumor
Progressive degenerative neuropathy
85
What ligament is punctured when performing a caudal block?
Sacrococcygeal ligament
86
To remove an epidural catheter, hold lovenox for ___ and restart in ____
12 hrs; 4 hrs
87
Surgical decompression of epidural hematoma within ___ offers the best chance of recovery
8 hours
88
A patient presents with lower extremity weakness, numbness, low back pain, and bowel and bladder dysfunction after neuraxial anesthesia. What is the most likely cause?
Epidural hematoma
89
How long must clopidogrel be discontinued before doing a neuraxial block?
7 days
90
How long must Enoxaparin be discontinued before performing a neuraxial block
Prophylactic dosing = 12 hrs
Therapeutic dosing = 24 hrs
91
What are the most common side effects of an epidural blood patch?
Backache & radicular pain
92
Transient neurological symptoms respond to what?
NSAIDs, opioids, trigger point injection
93
______ is the most common cause of TNS
Lidocaine
94
What medication can be given to prevent the Bezold-Jarisch reflex during spinal anesthesia?
Ondansetron (5-HT3 receptor antagonists)
95
What factors increase risk of cauda equina syndrome? Why?
5% lidocaine & microcatheters.
Microcatheters focus LA on a small area of the cord, exposing this region to a high concentration of LA
96
Neurotoxicity is the result of exposure to high concentrations of LA leading to?
Cauda equina syndrome
97
Bowel and bladder dysfunction, sensory deficits, weakness, & paralysis are symptoms of what?
Cauda equina syndrome
98
Patient positioning, stretching of the sciatic nerve, myofascial strain, and muscle spasm can lead to what?
Transient neurologic symptoms
99
What factors increase the risk of TNS?
Lidocaine, lithotomy position, ambulatory surgery, & knee arthroscopy
100
Sever back & butt pain that radiates to both legs. Usually within 6 - 36 hrs of neuraxial anesthesia and persists for 1 - 7 days
TNS (transient neurologic symptoms)
101
What is the BEST course of action when an epidural catheter breaks during its removal?
Leave it inside the patient
102
How does neuronal anesthesia cause hypotension?
The primary mechanism is anesthetic blockade of the preganglionic B fibers in the sympathetic chain (sympathectomy)
