Brainscape's Knowledge GenomeTM

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


See full index

Basic Principles > 3 - Neuraxial Anesthesia > Flashcards

3 - Neuraxial Anesthesia Flashcards

1
Q

How many vertebrae are in the spinal column?

A

33

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

Number of vertebrae:

Cervical

Thoracic

Lumbar

Sacral

Coccygeal

A

7 cervical

12 thoracic

5 lumbar

5 sacral (fused)

5 coccygeal (fused)

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

The epidural space extends from ____ to ______

A

foramen magnum

sacral hiatus

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

Which vertebrae have no epidural fat?

A

Cervical

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

Dura Mater

A

Thickest, outermost meningeal layer

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

Arachnoid Mater

A

Laminar layer over the inner surface of the dura

Trabecular spider formations connect the laminar layer to the pia mater

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

Does the dura or arachnoid membrane most impede drug movement through the meninges?

A

Arachnoid

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

Is CSF primarily in the subdural or subarachnoid space?

Why?

A

Subarachnoid

low permeability of arachnoid mater keeps it from migrating out into the subdural space

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

What percentage of CSF is water?

A

99%

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

Adult total volume of CSF

A

100-160 ml

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

What is the main production site of CSF?

A

Parenchymal Capillaries of the brain and spinal cord

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

Which direction does CSF flow?

A

Not unidirectional

Transmitted cardiac oscillations produce local mixing

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

Where is CSF absorbed?

A

Parenchymal capillaries of the brain and spinal cord

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

Which grows faster in a fetus: the spinal cord or the vertebral cloumn?

A

The vertebral column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where does the spinal cord end in adults?

Newborns?

A

L1

L3

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

How are spinal nerves and dermatomes named in cervical regions?

All other regions?

A

Lower vertebrae of the foramen they pass through

Upper vertebrae of the foramen they pass through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the cauda equina?

A

the lumbar and sacral spinal nerves that extend beyond the tip of the spinal cord

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

When using hyperbaric drugs, you should position the operative side ________

A

down

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

When using isobaric or hypobaric drugs, you should position the operative side _______

A

UP

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

For C/S spinal lying down, which side should the patient lie on?

A

Right side

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

Which is usually larger: epidural or spinal needle?

A

Epidural

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

What length of catheter should be inserted into the epidural space?

A

5 cm

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

The two most important factors that determine the spread and duration of subarachnoid anesthesia are

A

Density and Dose

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

How is hyper/hypo/isobaric determined?

A

It’s the ratio of two densities:

Dnesity of the CSF

Density of the drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Hyperbaric solutions are ______ dense than CSF

A

More

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

How are local anesthetics made hyperbaric?

A

Mixed with dextrose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In a supine patient, hyperbaric anesthetics will flow to

A

The upper thoracic region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Vasopressors prolong the effect of _______ in intrathecal anesthesia, but not ________

A

tetracaine

lidocaine, bupivicaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How does intrathecal precedex effect duration?

A

Prolongs the duration of subarachnoid anesthesia and analgesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What amount of fentanyl is optimal as an adjuvant to spinal analgesia?

A

Smaller doses are just as effective and cause less itching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How is epidural spread effected by age?

A

Spreads further in older people

May worsen hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In epidurals, the large the dose, the _________ spread

A

larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the effect of using sodium bicarb as an adjuvant

A

Raises the pH, which increases non-ionized circulating amount

Decreases the speed on onset

Inreases the density of block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the effect of using A2 agonists as adjuvants?

A

Epinephrine decreases systemic absorption of the drug

Precedex/Epi/Clonidine improve speed of onset and duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Who do A2 agonists improve the analgesia of a block?

A

Stimulation of A2 receptors produces analgesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Most common complication in obstetric epidural management

A

Accidental injection of drugs into intrathecal space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What abnormal things are you looking for when test dosing an epidural with lidocaine?

A

Tingling in feet at 2-3 minutes

Motor loss at 3 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Unrecognized subdural injection would cause what?

A

Excessive epidural block

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Subarachnoid anesthesia occurs mostly in the ________

A

Spinal nerve roots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

How does neuraxial block effect MAC?

A

Decreases MAC of inhaled volatile gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What effect does neuraxial anesthesia have on sedatives?

A

Potentiates their action

Also causes sedation on its own

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Why do patients with neuraxial anesthesia lose sensation to a greater degree than motor use?

A

Sensory fibers are thinner than the large, thick motor fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

A patient with a sensory block at T10 may have a sympathetic block _______

A

Much higher

smaller fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Sensitivity of fibers to neuraxial anesthesia:

Motor

Sensory

Sympathetic

A

small

intermediate

large

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What happens to CO and SVR after intrathecal block?

A

Increases

Decreases

46
Q

What vertebral level is sympathetic stimulation of the heart?

What would happen if it was blocked?

A

T1-T4

Disproportionate vagal response —-> severe bradycardia

47
Q

What are the differing effects of using phenylephrine vs ephedrine for neuraxial hypotension?

A

Phenylephrine will not increase the heart rate, and in fact will decrease it

Ephedrine will increase the heart rate

48
Q

What are four ways to alleviate N/V with spinal anesthesia?

A

Fix hypotension

Administer oxygen

Fluids

Zofran

49
Q

Why does patients with neuraxial anesthesia get nauseated?

A

Increased vagal activity increases peristalsis

Hypotension causes hypoperfusion of the vomiting trigger chemoreceptor in the medulla

Opiates, when included in the injection

50
Q

A patient with a Thoracic block and normal respiratory function may still be prone to aspiration. Why?

A

The abdominal muscles are crucial in coughing

51
Q

Postdural puncture headaches usually effect the _____ and _____ regions of the head

A

front

occipital

52
Q

Which needles are pencil point?

A

Whitaker

Spratte

53
Q

What needle is a cutting needle?

A

Quincke

54
Q

How often is a blood patch effective in fixing PDPH?

A

95%

55
Q

When does PDPH usually develop

A

24-72 hours after dural puncture

56
Q

Why does hearing loss sometimes occur with spinal anesthesia?

A

Decreased CSF pressure reduces the function of the inner ear

57
Q

When does hearing reduction from spinal anesthesia usually resolve?

A

Within 1 month

58
Q

Cervical and thoracic vertebrae have spinous processes that _______________

A

angle acutely in a caudal direction

Very tight construction and angles, making needle insertion difficult

59
Q

Why is the lumbar area easier to cannulate?

A

spinous processes shorter and broader with posterior orientation

Relatively large gaps between processes

60
Q

What is the average distance from skin to lumbar epidural space?

A

5cm

61
Q

Where is the epidural space largest?

A

midline midlumbar region

62
Q

Why are midline epidural approaches preferred?

A

Epidural space is larger anterior to posterior than it is laterally

The plexus is most prominent in the lateral portion

63
Q

what happens to epidural veins in pregnant women?

A

Engorged d/t increased abdominal pressure

64
Q

What is a differential block?

A

Iterrupts autonomic transmission but not sensory or motor

65
Q

A sympathetic block can be as much as ______ above the sensory blockade

A

six dermatomes

66
Q

Do patients with neuraxial anesthesia have a higher or lower incidence of urine retention that general anesthesia?

A

Lower

67
Q

What is selective anesthesia?

A

small doses of local injected into only the nerve roots inolved in the surgical field

Usually CSE

68
Q

What type of local anesthetic is used in prone cases?

A

Hypobaric

69
Q

Conducting a spinal in a patient with increased ICP may cause

A

Brain herniation

70
Q

Which musculoskeletal deformity is a risk factor for CNB complications?

A

Osteoporosis

71
Q

What is a double crush phenomenon?

A

CNB peripheral neuropathy on top of Pre-existing neuropathy

72
Q

Why is garlic a concerning herbal medication?

How long should it be d/c’d prior to sx?

A

Inhibits platelet aggregation

Increases fibrinolysis

7 days

73
Q

Why is ginkgo a concerning herbal medication?

How long should it be d/c’d prior to sx?

A

inhibits platelet activation

36 hours

74
Q

Why is ginseng a concerning herbal medication?

How long should it be d/c’d prior to sx?

A

lowers blood glucose

increases PT/PTT

34 hours

75
Q

What is the most common pathogen associated with epidural abscesses?

A

S. aureus

76
Q

What is the best test for suspected epidural hemorrhage or abscess?

A

MRI

77
Q

Which type of heart failure is a relative contraindication to CNB?

A

preload dependent (hypertrophic, severe Ao Stenosis)

These patients can’t tolerate even short periods of bradycardia or decreased preload from vasodilation

78
Q

What is specific gravity

A

density of a substance compared to water

79
Q

What factors can increases the specific gravity of CSF?

A

Hyperglycemia

Uremia

Age

80
Q

What factors can decrease the specific gravity of CSF?

A

temperature (increased temp)

Bilirubin in the CSF (from jaundice/liver fx)

81
Q

What is the ratio of specific gravity of an isobaric anesthetic to CSF

A

1

82
Q

What is the baricity of a hypobaric solution?

Hyperbaric?

A

< 0.999

> 1.0015

83
Q

Name three highly protein bound drugs.

Do they have a long or short duration?

A

Tetracaine

Bupivicaine

Ropivicaine

Long

84
Q

Name two low protein-bound drugs.

Do they have a long or short duration?

A

lidcocaine

mepivicaine

Short

85
Q

To minimize the risk of PDPH, the epidural needle should be turned _________

A

with the bevel parallel to dural fibers

86
Q

How far should a CSE catheter be threaded?

A

2-3 cm

87
Q

To avoid PDPH with CSE, how long should the catheter be left in place if possible?

A

40 hours

88
Q

Cauda Equina Syndrome

A

persistent paralysis of the cauda equina nn

lower extremity weakness

bowel and bladder dysfunction

89
Q

Transient Neurologic Syndrome

A

pain originating in the gluteal region radiating to both lower extremities

spontaneously resolved within 10 days

90
Q

Use of spinal lidocaine in CSEs is associated with which two syndromes?

A

cauda equina

transient neurologic

91
Q

The sympathetic nerve fibers that innervate the heart are called the _______

A

cardiac accelerators

92
Q

What is a 5-HT3 drug?

Why are they used to prevent SIH?

A

ondansetron

given prophylactically

thought to block the reflexive bradycardia and hypotension caused by sympathetic blockade

93
Q

In managin SIH when should ephedrine be used?

Phenylephrine?

A

bradycardia

normal or tachycardia

94
Q

Ephedrine effects _______ receptors

phenylephrine effects _______ receptors

A

A and B

A

95
Q

Bezold-Jarisch Reflex

A

stimulation of mechanoreceptors in the left ventricle causes bradycardia

96
Q

What is the largest interlaminar space?

A

L5

97
Q

What effect does neuraxial anesthesia have on the bowel?

A

Unopposed parasympathetic innervation:

Constriction

Increased peristalsis

98
Q

Sympathetic innervation of the gut originates at

A

T5-L2

99
Q

The cauda equina extends from ____ to ______

A

L1 to S5

100
Q

To what degre will epinephrien extend the action of lidocaine?

Tetracaine?

Bupivicaine?

A

A little

A lot

hardly at all

101
Q

In the supine position, the most dependent level of the spine is at

A

T4

102
Q

What is normal CSF pressure?

A

10-20

103
Q

Where are the two enlargements of the spinal cord?

Why?

A

cervical enlargement: C4 to T1 - Brachial Plexus

Lumbosacral: L2 to S3 - Lumbar and sacral plexus

104
Q

When is a caudal epidural block frequently used?

A

Neonatal abdominal surgery

105
Q

What is the preload crystalloid dose?

A

15ml/kg

106
Q

The classic epidural test dose is

A

3ml, 15mg lidocaine

107
Q

How can CSF be distinguished from saline?

A

Warm

+ for glucose

108
Q

Which drugs are associated with increased incidence of POUR?

A

Opiods, anitcholinergics, sympathomimetics

109
Q

When performing CSE, _______ should be used for loss of resistance while placing the epidural

A

Air

Prevents confusion of saline with CSF

110
Q

A patient who received duramorph intraop develops pruritis, nausea, and ventilatory depression. What may be helpful?

A

Antiemetics

Narcan for ventilatory depression and pruritis

Basic Principles (15 decks)

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