Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Advanced Anes. Spring 21 > Spinal & Epidural Anesthesia > Flashcards

Spinal & Epidural Anesthesia Flashcards

1
Q

Spinal Cord - general

A
  • cord is approx 25 cm shorter than vertebral canal
  • enlarged @ C5-7 (brachial plexus) & L2-3 (lumbar & sacral plexus)
  • extends from medulla oblongata to L2 (adult) or L3 (peds)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cauda Equina

A
  • long roots of lumbar and sacral nerves

- extends from L1-S5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Intervertebral Foramina

A
  • superiorly and inferiorly larger
  • lateral notches
  • allow for passage of nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What forms the facet joint?

A

superior and inferior articular surfaces and lateral notches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Regional Variation: Cervical & Thoracic

A

-spinous processes are more angled - need more cephalad angle for needle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Regional Variation: Lumar

A

-larger vertabra, less overlap and larger gaps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Regional Variation: Sacrum

A
  • fused section of vertebra

- sacral hiatus- lamina of last vertebra is incomplete, bridged by ligaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Caudal Block Landmarks

A

PSIS
SC
SH
TC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Abnormal Curvatures

A

scoliosis - lateral
kyphosis - posterior
lordosis - anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

3 Ligaments

A

Supraspinous (superficial)
Intraspinous
Ligamentum Flavum (deep)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ligamentum Flavum

A

-thickest, “V shaped”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Epidural Space: location, origination and end

A

lies between ligamentum flavum and dura mater

-contiguous from base of cranium to sacral sulcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Epidural Space: distance from skin

A
  • varies with level, loosely correlated with weight

- midline, lumbar approach = 2.5-8cm, average 5 cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Epidural Space: Contents

A
  • veins (valveless, engorge during pregnancy), fat, lymph, segmental arteries and nerve roots
  • potential space is largest lumbar >thoracic>cervical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Spinal Cord: Layers

A

Dura Mater
Arachnoid Mater (holds CSF)
Pia Mater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Spinal Nerves

A 
31 pairs 
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Thoracic nerves & CT placement

A

-thoracic nerves run along inferior margin of rib, so place a chest tube at superior aspect of rib

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Level and vertebra

A

-cervical correlate with vertebra below, after T1, correlates with vertebrae above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Dorsal

A

entering sensory root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Ventral

A

outgoing motor root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

H-shaped central gray region…

A

neuronal cell bodies and unmyelinated fibers, surrounded by white matter (fiber tracts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Grey Matter

A

subdivided into 12 laminae of rexed
I-VI = afferent tracts (receive sensory info)
VII - IX = ventral tracts - motor neurons, interneurons involved in motor functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Lamina II

A

substanca gelatinosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

White Matter

A
  • organized
  • dorsal white - almost exclusively ascending sensory
  • lateral & ventral white - descending motor tracts, most cross over at some point
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What can the lateral and ventral white matter do?

A
  • ascend to the brain

- associate trat originate and terminate entirely within spinal cord (reflexes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sensory Pathways

A

afferent (ascend)

-transmit pain & temp (epidermis), pressure, touch, vibratory, proprioception (dermis)

27
Q

2 Classifications of receptors

A

1 - extroceptors (near surface of skin and oral mucosa)

2 - proprioceptors (deeper skin layers, joint capsules, ligaments, tendons, muscles and periostium)

28
Q

2 Main Sensory Tracts

A

Dorsal Column - Medial Lemniscus

Anterolateral Pathway

29
Q

Dorsal Column - Medial Lemniscus

A
  • carries signals upwards towards the medulla in dorsal column tract
  • crosses over at medulla
  • carried through brainstem to thalamus in medial lemniscus tract
30
Q

Anterolateral Pathway

A
  • originates in dorsal horn to laminae I, IV, V, VI where they synapse
  • immediately cross over in anterior commissure to anterior and lateral white columns
  • go to brainstem or thalamus
31
Q

Dorsal Column Medial Lemniscus - characteristics

A

fibers: large, myelinated
conduction speed: 30-110 m/sec
spatial orientation: high with respect to origin
-discrete types of mechanoreceptive sensations

32
Q

Anterolateral system

A

fibers: small, myelinated
conduction speed: few - 40 m/sec
spatial orientation: low with respect to origin
-broad spectrum of sensory modalities - pain, warmth, cold, crude touch

33
Q

SNS

A
  • preganglionic neurons (b fibers, small)
    originate: intermediolateral gray horn btwn T1-L2/3
  • exit spinal cord via ventral nerve root - white rami communicans
34
Q

Cervical Ganglia

A

-divided into superior, medial and inferior ganglia

35
Q

Cervical Ganglia: SNS stim of superior…

A

mydriasis (contract radial muscle of eye)
relaxation of ciliary muscle
constriction of blood vessels of head

36
Q

Damage to superior cervical ganglia, central SNS damage or injury to other paravertebral ganglia..

A

miosis (small pupil), ptosis (droopy lid), anhydrosis (no sweat)

aka horner’s syndrome

37
Q

Inferior cervical ganglia fuses with ___ to form the _____

A

inferior cervical ganglia fuses with the first thoracic to form the stellate ganglia (C5-6)

38
Q

Pain and temp pathway

A

some fibers in dorsal horn give off branches that synapse with internuncial neurons - synapse with ventral horn
-part of reflex response to pain

39
Q

Dermatomes

A

T4 - nipple line
T 6-7 - xiphoid process
T 10 - belly button

40
Q

Motor Pathways

A

motor/efferent (exit) - info from brain to voluntary muscles, smooth and cardiac muscles and some glands

41
Q

Corticospinal tract

A
  • supplies voluntary muscles of the trunk and extremities

- originates in large, upper motor neurons located in PREcentral gyrus

42
Q

Damage to corticospinal tract neurons

A

-located antrior to precentral gyrus

damage = lower motor neurons can overfire (hyperreflexia) or fire simultaneously (spasticity)

43
Q

Upper motor neuron paralysis

A

reflexes intact, suppressor fibers impeded, hyperreflexia occurs

44
Q

Damage to lower motor neurons

A

produce flaccid type paralysis

45
Q

Which two disease processes effect the corticospinal tract?

A

cerebral palsy and ALS

46
Q

Pro’s of spinal anesthesia

A

less adverse in-hospital outcomes, less NV, urinary retention, less opioids, less hospital length of stay
-more mental alertness, long term pain control (epidural)

47
Q

Uptake & Spread from subarachnoid space

A
  • concentration of LA in CSF
  • surface area of nerve tissue exposed
  • lipid content of nerve tissue
  • blood flow
48
Q

Distribution

A

baricity, position, dose

49
Q

Spinal Anesthesia Physiologic changes

A
  • liver - no change if MAP maintainted
  • CV - sympathectomy (block height)
  • hypotension and bradycardia
  • venodilation >arterial dilation

GI- SNS innervation from T6-12 - increased secretions, sphincters relax, bowel constricts

50
Q

Spinal - prone position

A
  • can use of pt in this position for surgery

- iso or hypobaric

51
Q

Process

A 
ID iliac crests (L4-5
clean skin
drape
ID level to block
local (use as finder)
approach - median, paramedian, taylor
52
Q

Parethesia

A
  • stop advancing

- remove stylet and check for CSF

53
Q

PDPH

A
  • up to 25% incidence
  • relief when supine
    tx: fluids, caffeine, bed rest, analgesics, sumatriptan
  • can take 1-6 wks to resolve

epidural blood patch 1-2 times

54
Q

1st sign of CV collapse following spinal…

A

bradycardia

55
Q

Epidural

A

level L2-4, can use adult levels after age 8

56
Q

Epidural below T4

A

vasomotor tone controlled by T5-L1

decreased venous return and subsequent decrease CO

57
Q

Epidural above T4

A

T1-4 cardiac sympathetic fibers

profound hypotension and brady

58
Q

Concentration

A

lower - sensory

higher - may get motor

59
Q

Key factor,,

A

volume
adults: 1-2 mL for each level to be blocked
lumbar gets more spread cephalad than caudal
thoracic even spread up and down
-position is not considered a factor

60
Q

Does age effect epidural dose?

A

yes, increased age = decreased dose

61
Q

Epidural height

A 
<5'2" = used 1 mL per level
>5'2" = increase by 0.1 mL for each 2"
62
Q

Epidural: Pregnancy and Obesity

A

decrease dose, epidural veins engorged

63
Q

Epidural: Subdural injection

A

-delayed high spinal

64
Q

Epidural: Subarachnoid injection

A

-immediate high spinal

Advanced Anes. Spring 21 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions