Neuraxial 5/29 Flashcards
Test 1 (136 cards)
1
Q
The _________ is a connective tissue that divides the ___________ space from R & L. What can this cause?
A
Plica Mediana Dorsalis
Epidural space
A pronounced plica mediana dorsalis can cause a unilateral block
2
Q
We put LA in the ______ (2) when doing a spinal. What is in this area?
A
SA space
intrathecal space
CSF
nerve roots
spinal cord
3
Q
During a spinal, the “pop” sensation if often felt when going through the _______
A
Dura Mater (outer layer)
4
Q
T/F: temperature follows a different pathway in pain
A
F
They follow the same pathway
5
Q
Where is the subdural space located? Describe this area?
A
Between Dura mater (outer layer) & arachonoid mater (middle layer)
“Potential space” similar to epidural space but without veins
6
Q
What happens if you give an epidural dose in the subdural space? spinal dose?
A
Epidural: “high spinal” effect dt volume & smaller area –> affects larger area than intended
Spinal: failed spinal block dt very small volume
7
Q
What is the order is the meninges from outer to inner? Briefly describe each layer.
A
- Dura mater: Tough/fibrous
- Arachnoid mater: thin layer directly under dura
- Pia mater: Highly vascular & attached to spinal cord
8
Q
The ______ mater should never be punctured. What is signigicant regarding this layer?
A
Pia
Significant for LA reabsorption went in SA space
9
Q
anterior cord = ________ & posterior cord = ________
A
motor
sensory
10
Q
The spinal cord has ____ pairs of spinal nerves. Where are they corresponded to?
A
31 PAIRS (62 total)
Cervical = 8
Thoracic = 12
Lumbar = 5
Sacral = 5
Coccycx = 1
11
Q
Nerves C1 to C7 exit the spine ________ the corresponding vertebrae & C8 nerve exits _____ vertebrae
A
above
below C7
This is why there is an additional cervical nerve
7 C-vertebrae vs 8 nerves
12
Q
C-section sensory needs to block to _____ which is the ____
A
T4
Nipples
13
Q
Dermatome levels: Anterior & inner surface of lower limbs
A
L1, 2, 3, 4
14
Q
Dermatome levels: foot
A
L4, L5
S1
15
Q
Dermatome levels: medial side of great toe
A
L4
16
Q
Dermatome levels: posterior & outer surface of lower limbs
A
S1, S2
L5
17
Q
Dermatome levels: lateral margin of foot & little toe
A
S1
18
Q
Dermatome levels: perineum
A
S2, 3, 4
19
Q
Dermatome levels: umbilical
A
T10
20
Q
Dermatome levels: Inguinal/ groin regions
A
T12
21
Q
Dermatome levels: clavicles
A
C5
22
Q
Dermatome levels: lateral parts of upper limbs
A
C5, 6, 7
23
Q
Dermatome levels: medial side of the upper limbs
A
C8
T1
24
Q
Dermatome levels: thumb
A
C6
25
Dermatome levels: hand
C6, 7, 8
26
Dermatome levels: ring & little fingers
C8
27
Dermatome levels: nipples
T4
28
T/F: there is no dermatome level in the face
T
29
sensory innovation in the face is controlled by _______ nerve which is cranial nerve ___
Trigeminal nerve
CN V (5)
30
What are the three divisions of the trigeminal nerve? What do they cover?
V1: Ophthalmic
-forehead, scalp, upper eyelids
V2: maxillary
-lower eyelids, cheeks, nostrils, upper lip, upper teeth
V3: mandibular
-lower jaw, lower teeth, lower lip, part of the tongue
31
_________ nerve is irrelevant with airway blocks and determine how we do awake fiber optics
Trigeminal nerve
32
How do we induce pediatrics?
Inhaled agents --> Sevo
33
Dermatome level for Sx: C-section/Upper abd
T4
Nipples
34
Dermatome level for Sx: Hysterectomy/Lower abd, gynecologic, urologic
T6
2 segments under nipple
35
Dermatome level for Sx: testicular procedure
T8
2 levels above umbilicus
36
Dermatome level for Sx: penis
S2
Perineum
37
Dermatome level for Sx: scrotum
S3
Perineum
38
Dermatome level for Sx: vaginal delivery, Hip procedure, TURP, uterine, tourniquet
T10
umbilicus
39
TURP =
Transurethral resection of the prostate
40
Dermatome level for Sx: thigh, lower leg, knee
L1
Anterior & inner surface of lower limbs
41
Dermatome level for Sx: Foot, Ankle
L2
Anterior & inner surface of lower limb
42
Dermatome level for Sx: Peri-anal, anal (saddle block)
S2 - S5
perineum
43
If the pt is bucking the vent, what are the 1st things we should do? Why?
1. Turn gas up - fastest & doesnt mess up wake up
2. Give propofol
3. Give NMB - will mess up wake up
44
What are the **controllable factors** that affect the spread w/ SAB? (4)
1. Baricity
2. Pt position
3. Dose
4. Site of action
45
What are the **noncontrollable factors** that affect the spread w/ SAB? (3)
1. Volume of CSF
2. Increased Intra-abd pressure (obesity, pregnancy)
3. Age
46
What does NOT affect the spread w/ SAB? (5)
1. Barbotage
2. Speed of injection
3. Orientation of bevel
4. addition of vasoconstrictor
5. gender
47
L3 - L4 has a ______ gap than L4 - L5. Which is the safest place for SAB?
bigger
L4 - L5
48
Spinal needle is _____g & epidural is _____g _____
22-25g
18-19g blunt
49
Less CSF = ________ spread & more CSF = ______ spread
higher
Less
50
How does increased age affect SAB?
Neural nerves are more vulnerable to LA
Decreased CSF = higher spread
51
Increasing intra-abd pressure causes CSF to ______ & this ______ the spread
decrease
increases
52
What is the definition of barbotage?
Aspirating CSF & mixing it w/ LA
Then giving the mixture
53
With epidural, what controllable factors significantly affects the spread? (3) non-controllable factors? (2)
Controllable:
1. LA volume (most important drug-related)
2. Level of injection (most important procedure-related)
3. LA dose
Non-controllable:
1. Pregnancy
2. Old age
54
With epidural, what controllable factors have a small affect on the spread? (2) non-controllable factors? (1)
Controllable:
1. LA concentration
2. Pt postion
Nonconotrollable:
1. Height
55
With epidural, what controllable factors does not affects the spread? (3)
1. Additives
2. Direction of bevel
3. Speed of injection
56
What guides the direction of the catheter w/ epidurals?
The direction of the bevel
57
Chloroprocaine is faster despite its pKa being ____ dt it's _________
8.7
higher concentration
58
What is the dose for fentanyl with epidural?
25 mcgs
59
With epidurals, if you inject in the lumbar region the LA will spread ________
cephalad (up)
60
With epidurals, if you inject in the mid-thoracic region the LA will spread ________
balanced
both cephalad and caudad
61
With epidurals, if you inject in the cervical region the LA will spread ________
caudad (down)
62
Describe A-alpha fibers
Myelination: heavy
Function: skeletal muscle - motor
63
Describe A-Beta fibers
Myelination: Heavy
Function: Touch/pressure
64
Describe A-gamma fibers
Myelination: medium
Function: Skeletal muscle - tone
65
Describe A-delta fibers
Myelination: medium
Function: Fast/sharp pain, temperature, touch
66
Describe B fibers
Myelination: light
Function: Preganglionic ANS fibers
67
Describe C-sympathetic fibers
Myelination: 0
Function: Postganglionic ANS fibers
68
Describe C-Dorsal root fibers
Myelination: 0
Function: Slow pain, temperature, touch
69
_________ blockade requires a ________ concentration of LA than motor & results in a higher block
sensory
lower
69
________ blockade requires the ________ concentration of LA & has the HIGHEST level of blockade
Autonomic
lowest
70
What is the definition of Differential Blockade?
Different types of nerve fibers having varying sensitivities to LAs, affecting the level of block achieved.
Ex) Autonomic block being highest w/ lower concentrations, but at a lower concentration sensory nor motor may not even be affected.
70
What is the arrangement of the nerves affected by LA? What is affected?
1. B fiber: autonomic preganglionic fibers --> venodilation/hypotension
2. C fibers: pain/temperature
3. A-delta fibers: Pain/temperature
4. A-gamma: skeletal muscle - tone
-A-beta: touch/pressure
-A-alpha: skeletal muscle - motor
71
Pain is blocked ______ motor
before
72
73
What is last to be blocked?
Motor
A- alpha fibers
74
Sensory blockade is ____ levels ______ motor level
2
higher
75
Sympathetic blockade is ____ levels ______ sensory level
2-6
higher
76
Motor blockade is ____ levels ______ sensory level
2
below
77
If sensory block is at T8, where is SNS block? Motor block?
SNS: T2 - T6
Motor: T10
78
You should take vitals every ______ for the 1st _______ while initiating a block.
3 mins
30 mins
79
What is the order of nerve recovery from a neuraxial block? (Reverse)
1. A-alpha: skeletal muscle - motor
2. A-beta: touch/pressure
3. A-gamma: skeletal muscle - tone
4. A-delta fibers: Pain/temperature
5. C fibers: pain/temperature
6. B fiber: autonomic preganglionic fibers --> venodilation/hypotension
80
Which fiber is blocked the longest?
B fiber: autonomic preganglionic fibers --> venodilation/hypotension
81
What is the order of senses to be blocked?
1. temperature (first)
2. pain
3. touch/pressure (last)
82
We use the ________ to monitor blocks. It is from ___ to ____. Describe it.
Bromage Scale
0 - 3
0 = No motor block
3 = complete motor block
(Specifically assesses lumbosacral region only)
83
What are the CV SE of neuraxial LA?
1. Decrease preload (venous return) = dilate veins dt sympathetecomy
2. Decrease afterload (SVR) = dilate arteries (more in elderly/cardiac)
3. Decreased CO: decrease in venous return & SVR --> decrease SV --> HR x SV = CO --> decrease in CO
4. Decreased HR dt:
-Blockade of cardiac accelerators
-activation of Bezold-Jarisch reflex
-activation of REVERSE Bainbridge reflex
84
T/F: With neuraxial, CO will initially decrease.
F
May increase and then decrease over time
85
What is the Bezold-Jarisch reflex? What does it mediated by? How do we treat it?
Protective mechanism by ventricles --> causes bradycardia
Mediated by 5-HT3 receptors in the vegus nerve
Tx w/ Zofran
86
________ inhibits the Bezold-Jarisch reflex
Ondansetron (zofran)
87
The Bainbridge reflex causes _______
Tachycardia
88
What causes sudden cardiac arrest w/ neuraxial LA? Who/what is it more common in? (3) When does this normally happen?
Unopposed parasympathetic tone to cardiac accelerators --> profound bradycardia, hypotension --> cardiac arrest
Young adults w/ high parasympathetic tone
-large blood loss
-orthopedic cement placement
20-60 mins after onset of spinal
89
It is ________ common to have sudden cardiac arrest with epidurals than spinals. What are the stats?
less
Spinal 7:10,000
Epidural 1:10,000
90
T/F: Ephedrine does not have tachyphylaxis
F
It does, you need to increase the dose to get the same response as before
91
How do you PREVENT spinal-anesthesia induced hypotension? (4)
1. Vasopressors - phenylphrine (neo)
2. 5-HT3 antogonist (serotonin) - ondansetron (zofran)
3. Fluid management - coloading
(avoid preloading & excessive fluids)
4. Positioning - usually related to pregnancy --> tilt pt to L relieves pressures of inferior vena cava
5. Anticholinergic - Gylcopyrrolate (rubinol)
92
Compare coloading vs preloading
All crystalloids are warmed
Coloading: 15ml/kg fluids given, maybe n a pressure bag, at the same time as block being placed
preloading: 500 cc fluids given within 30mins before block
-not recommended dt min impact
93
Turning pt to the _____ relieves pressure to what what of the heart? What does this help with?
Left
Inferior vena cava
Helps improve hypotension
94
What Is the TREATMENT for spinal-anesthesia induced hypotension?
1. Vasopressors - Ephedrine & epinephrine (Ephedrine preferred for symptomatic Brady)
2. Anticholinergics - atropine, glycopyrrolate
3. Fluids - crystalloids or colloids
4. Position trendelenburg
**Caution w/ position!!**
T-burg after admin of block --> reduce cerebral perfusion, reduce brain drainage (increase ICP) , and heighten block
95
What are the effects of neuraxial on pulmonary?
1. Decreased ERV (expiratory reserve volume)
2. Small decrease VC (vital capacity)
3. COPD, Asthma, Pickwickian syndrome -- feelings of dyspnea after admin of LA --> lose ability to take big breath/strong coughs
96
What is Pickwickian syndrome?
Morbidly obese
97
If pt starts to get dyspnea after admin of LA, what should we do?
put in semi-fowlers
98
What spinals nerves innervate the phrenic nerve?
C3, 4, 5
99
A constipated termite ______ pass the board
CANNOT
100
Describe the innervation of the GI system
1. Parasympathetic innovation via vagus nerve which causes:
-Afferent: sensations of society, distention, nausea
-Efferent: tonic contractions, sphincter relaxation, peristalsis, secretion
2. Sympathetic innovation from T5 – L2
-Afferent: visceral pain
-Efferent: inhibits peristalsis in gastric secretions, and cause sphincter contractions and vasoconstriction (opposite of parasympathetic)
101
Sympathetic innovation of GI tract comes from _____
T5 – L2
102
Parasympathetic innovation of GI tract comes from _____
Vagus nerve
103
sympathetic innervation: diaphragm
C4
104
sympathetic innervation: esophagus
T4 & T5
105
sympathetic innervation: heart
T3 & T4
106
sympathetic innervation: liver & bladder
T8 – T 11
107
sympathetic innervation: stomach
T8
108
sympathetic innervation: Colon
T 11
109
sympathetic innervation: small intestine
T10
110
sympathetic innervation: bladder
T 11 – L1
111
sympathetic innervation: kidney & testes
T10 - L1
112
What are the impacts of neuraxial onf GI? (2-5)
-Increases parasympathetic activity
-Reduces sympathetic time
1. Relax sphincter
2. Increases peristalsis
3. Small contracted gut --> N/V
4. Increased GI blood flow
5. Reduced postop incident of ileus in abd Sx
113
What are the GU effects with neuraxial LA?
**no change in RBF when MAP is maintained**
1. Sympathetic block above T10 affects bladder control
-urinary sphincter relaxed
2. W/ addition of opioids:
-decrease in detrusor contractions (decreased sensation of urination)
-increase bladder capacitance (full bladder)
**Need foley catheter w/ neuraxial & scan before going home**
114
What are the metabolic/endocrine effects of neuraxial LA?
Can partially/totally block Neuro endocrine response which includes: elevated cortisol, epinephrine, NE, vasopressin, activation of RAAS
115
Quantenary amines are ________ (2)
Anticholinergics
NMB
116
What are LA composed of? (3)
1. Benzene ring (lipophilic/aromatic ring)
2. intermediate chain
3. Tertiary amine/hydrophilic
117
The ________ is responsible for the drug class. What else is it responsible for?
Intermediate chain
metabolism
allergic response
(both related to drug class)
118
How many i's do Ester's have? What is its identifying chain? How are they metabolized? What preservative does it produce?
1
-COO-
Plasma
para-aminobenzoic acid (PABA)
119
How many i's do Amide's have? What is its identifying chain? How are they metabolized? What preservative does it produce?
2
-NHCO-
Liver
Methylparaben
120
What type of LA is least common for an allergic reaction?
Amides
Esters have Para-Aminobenzoic acid which is more likely to cause an allergic reaction
121
Onset of action =
pKa
**Exception is chloroprocaine**
122
Potency =
Lipid solubility
123
Duration of action =
Protein binding (A1-acid glycoprotein)
124
What does A1-acid glycoprotein do?
Keeps LA in place
125
How does LAs work?
Nonionized La go into Acidic cytoplasm --> acidic cytoplasm turns LA ionized --> blocks receptor from inside cell
126
What are the factors influencing vascular uptake & plasma concentrations of LA? (5)
1. Side of injection
2. Tissue blood flow
3. Physiochemical properties
4. Metabolism
5. Addition of vasoconstrictor
127
What is the order of blood concentration of LA from highest to lowest?
1. IV
2. Tracheal
3. Intercostal
4. Caudal
5. Paracervical
6. Epidural
7. Brachial
8. Sciatic
9. Subcutaneous
128
Hypobaric LAs are _______ dense than CSF so they _____. They are made with _____
Less
Float
water
129
Isobaric LA are made with _____
saline
130
Hyperbaric LAs are _______ dense than CSF so they _____.They are made with ______. What is the exception?
More
Sink
dextrose
Procaine is in water
131
What is the baricity of isobaric, hyperbaric, and hypobaric LA?
iso = 1
hyper >1
hypo < 1
132
What LA's are hyperbaric? (4)
1. Bupivacaine 0.75% -- in 8.25% dextrose
2. Lidocaine 5% -- in 7.5% dextrose
3. Tetracaine 0.5% -- in 5% dextrose
4. Procaine 10% -- in water
133
What LA's are isobaric? (4)
1. Bupivacaine 0.5% -- in saline
2. Bupivacaine 0.75% -- in saline
3. Lidocaine 2% -- in saline
4. Tetracaine 0.5% -- in saline
134
What LA's are hypobaric? (3)
1. Bupivacaine 0.3% -- in water
2. Lidocaine 0.5% -- in water
3. Tetracaine 0.2% -- in water
