U8-APEX REGIONAL Anesthesia-NEURAXIAL COMPLETE Flashcards
(439 cards)
1
Q
Layers to the Spinal cord from SKIN to Spinal Cord
SS-SIFEDAsPs
A
Skin
Subcutaneous
Supraspinous Ligament
Interspinous Ligament
Ligamentum Flavum
Epidural Space
Dura Matter
Arachnoid Mater
Subarachnoid
Pia mater
Spinal cord
2
Q
What is the cranial border of the epidural space?
A
Foramen Magnum
3
Q
What is the caudal border of the epidural space?
A
Sacrococcygeal Ligament
4
Q
What is the anterior border of the epidural space?
A
Posterior Longitudinal ligament
5
Q
What is the lateral border of the epidural space?
A
Vertebral pedicles
6
Q
What is the posterior border of the epidural space
A
Ligamentum Flavum
Vertebral lamina
7
Q
The epidural space contains
A
nerve roots, fat pads and blood vessels
8
Q
Where does the epidural veins drain? what Plexus
A
Batson’s plexus, drains venous blood from the spinal cord
9
Q
What things can affect the Barton plexus and cause engorgement of the epidural veins?
A
Obesity
Pregnancy
Anything that increase intra-abdominal pressure
10
Q
What can Act as a sink for lipophillic drugs in the epidural space?
A
Epidural fat act as a sink for lipophillic drugs, reducing their bioavailability.
11
Q
Culprit for difficult epidural catheter insertion as well as unilateral epidural blocks
A
Plica Mediana Dorsalis
12
Q
What is an epidural hematoma? and explain its significance?
A
Blood that accumulates between the dura and theb one. Since bone is hard, accumulation of blood in the epidural space compresses the dura. Which can com press spinal cord causing spinal cord ischemia, and permanent neurological dysfunction.
13
Q
For epidural what is the timeline for best chances of recovery?
A
Surgical decompression within 8 hours
14
Q
Describe the Dura mater
A
Tough fibrous protective shield that pro
15
Q
Dura begins where and end where?
A
Begins at foramen magnum
Ends at the dural sac
16
Q
The subdural space is
A
potential space between the dura mater and the arachnoid mater.
17
Q
Potential space between the dura mater and the arachnoid mater is the
A
Subdural space
18
Q
Inadvertent injection of Local anesthetic in the subdural space will cause
A
a high spinal if using epidural dosing or a failed spinal if using spinal dosing.
19
Q
What is the first, second and third meningeal layer?
A
First –> Dura mater
Second –> Arachonid mater
Third –> Pia mater
20
Q
What is the thin layer of connective tissue that neighbors the dura mater?
A
Arachnoid mater
21
Q
What is the target space when performing a spinal anesthetic?
A
Subarachnoid space
22
Q
The terminal end of the subarachnoid space is called
A
dural sac
23
Q
Where is the dural sace in adult? infant?
A
S2, S3 (Infant)
24
Q
External covering of the spinal cord?
A
PIA
25
Shoulder NEVER be punctured during spinal anesthesia?
PIA
26
Anchors spinal cord to the coccyx
Filum terminale
27
Where is CSF contained?
Subarachnoid space.
28
In the Adult, which anatomic structure correlates with the termination of the dural sac?
Superior Iliac spines
29
Conus medullaris land mark
L1
30
Tuffier's lines landmark
L4-L5 interspace
31
L4-L5 interspace corresponds to the
illiac crests
32
Dural sac ends where
S2
33
Dural sac correspons to the
Superior iliac spines S2
34
S5 landmarks
Sacral hiatus and sacrococcygeal ligament
35
The sacrum has how many vertebrae
five
36
The sacral hiatus is covered by the
Sacrococcygeal ligament
37
Posterior roots are (sensory or motor)
Sensory (sensor to the back door)
38
Anterior roots are (sensory or motor)
Motor (motorcycle to the front)
39
Diaphragmatic paralysis occurs with injury to what levels?
C3-C5
40
The spinal cord contains how many spinal nerve?
31 paired spinal nerves
41
What is a spinal nerve consists of ?
posterior (dorsal nerve) root or anterior (ventral) nerve root.
42
Posterior nerve roots carry sensory or motor information ?
Sensory information
43
Anterior nerve roots carry sensory or motor information ?
Motor and s\autonomic information
44
What is a dermatome ?
Is an area of the skin innervated by a dorsal root from the spinal cord
45
What is a MYOTOME?
Muscles innervated by the ventral root from the spinal cord.
46
Spinal nerve root C6 cutaneous innervation
1st digit (thumb)
47
Spinal nerve root C7 cutaneous innervation
2nd and 3rd digits
48
Spinal nerve root C8 cutaneous innervation
4th and 5th digits
49
Spinal nerve root T4 cutaneous innervation
Nipples line
50
Spinal nerve root T6 cutaneous innervation
Xiphoid Process
51
Spinal nerve root T10 cutaneous innervation
Umbilicus
52
Spinal nerve root T12 cutaneous innervation
Pubic symphysis
53
Spinal nerve root L4cutaneous innervation
Anterior knee
54
Unmyelinated fibers are the
C fibers
55
The epidural space contains. Epidural fat acts as a sink for lipophilic drugs, reducing their bioavailability (bupivacaine > lidocaine and fentanyl > morphine).
nerve roots, fat pads, and blood vessels
56
An epidural hematoma is blood that accumulates between
the dura and the bone. Since the bone is hard, accumulation of blood in the epidural space compresses the dura.
57
Epidural hematoma--> Surgical decompression within.
eight hours provides the best chances of recovery
58
Has long been considered the culprit for difficult epidural catheter insertion as well as unilateral epidural blocks.
The plica mediana dorsalis
59
The epidural veins (Batson’s plexus) drain
venous blood from the spinal cord.
60
Obesity and pregnancy increase intra-abdominal pressure, causing engorgement of the plexus. This is associated with an increased risk of
needle injury or cannulation during neuraxial techniques.
61
Acts as a sink for lipophilic drugs, reducing their bioavailability (bupivacaine > lidocaine and fentanyl > morphine).
Epidural fat
62
Anterior border of the epidural space is
Posterior Longitudinal ligament
63
Caudal border of the epidural space is the
Sacrococcygeal ligament
64
Cranial border of the epidural space is
foramen magnum
65
It anchors the spinal cord to the coccyx.
The filum terminale is a continuation of the pia mater caudal to the conus medullaris.
66
Conus medullaris levl
L1
67
After the needle advance through the epidural space it comes in contact with the
Dura mater,
68
Tough layer that protects the spinal cord
Dura.
69
Where does the dura begins and ends?
Begins at foramen magnum and ends a a dural sac.
70
Potential space between the dura mater and arachnoid mater is
the subdural space
71
Inadvertent injection of LA in this location will cause a
HIGH SPINAL if using epidural dosing or a failed spinal if using spinal dosing.
72
What is the target space when performing a spinal anesthetic?
Subarachnoid
73
The terminal end of the subarachnoid is called the
Dural sace.
74
Dural sac ends at _____in the adult
S2
75
Dural sac ends at _____in the infant
S3
76
Sacral Hiatus Coincides with space.
S5
77
Sacral hiatus and sacrococcygeal ligament
S5
78
Is covered by the
acrococcygeal ligament.
79
Results from the incomplete fusion of the laminae at
S5 and sometimes S4.
80
Is covered by the
sacrococcygeal ligament.
81
Motor and autonomic roots are
Anterior
82
DAS VEM
Dorsal Afferent Sensory
Ventral Efferent Motor
83
Sensory roots are
Posterior
84
Spinal cord how many paired spinal nerves?
31
85
Each spinal nerve is formed by
Posterior (dorsal nerve root) and anterior(ventral) nerve root.
86
What is a dermatome?
Area of the skin innervated by a dorsal nerve root from the spinal cord.
87
What is a myotome?
Muscles innervated by the ventral root from the spinal cord.
88
Cutaneous innervation: 2nd and 3rd digit (thumb)
C7
89
Cutaneous innervation: 2nd and 3rd digit (thumb)
C7
90
Cutaneous innervation: 4th and 5th digit (thumb)
C8
91
Cutaneous innervation: Nipple line
T4
92
Cutaneous innervation: Xiphoid process
T6
93
Cutaneous innervation: Umbilicus
T10
94
Cutaneous innervation: Pubic Symphisis`
T12
95
Cutaneous innervation:Anterior knee
L4
96
Not innervated by a spinal nerve, what part of the body
Face
97
Face is innervated by the
Trigeminal Nerve (CN V)
98
C fibers : degree of myelination
None
99
A Alpha : degree of myelination
Heavy
100
A Gamma: degree of myelination
Moderate
101
Primarily determinant of EPIDURAL ANETHESIA SPREAD is
Volume
102
The primary site of local anesthetic in the subarachnoid space is on th
Myelinated pre-ganglionic fibers of the spinal NERVE ROOTS
103
The primary site of local anesthetic in the subarachnoid space is on th
Myelinated preganglionic fibers of the spinal NERVE ROOTS
104
LA of the spinal anesthesia inhbiits
Neural transmission in the superficial layers of the spinal cord.
105
Epidural anesthesia: LA in the epidural space must first
Diffuse through the DURAL CUFF before the can block the nerve roots.
106
Epidural anesthesia: LA also leak through the
Intervertebral foramen to enter the paravertebral area.
107
Spinal anesthesia : Factors that DO significantly affect spread: NONControllable factors
Volume of CSF
Density of CSF
108
Spinal anesthesia : Factors that significantly affect spread: NONControllable factors
Volume of CSF
Density of CSF
109
Spinal anesthesia : Factors that DO NOT significantly affect spread:
Barbotage
Increase intra-abdominal pressure
Speed of injection
Orientation of bevel
Addition of vasoconstrictor
weight
Gender
110
Epidural Anesthesia : PRIMARY determinant of spread
VOLUME
111
Spinal anesthesia: Fibers Blocked first, second, and last (ASM)
Autonomic fibers are blocked first,
Sensory fibers are blocked seconds
Motor neurons are blocked last
112
SPINAL ANESTHESA: Autonomic VS SENSORY Block; MOtor Vs sensory block
Autonomic blockade is 2 - 6 dermatomes higher than sensory block.
Sensory block is two dermatomes higher than motor block.
113
Epidural Anesthesia: is there an autonomic differential blockade with epidural anesthesia?
NO
114
Epidural anesthesia sensory block height vs motor block ?
Sensory block is 2 - 4 dermatomes higher than motor block.
115
Since autonomic fibers are blocked by LA concentrations that do not affect sensory or motor neurons, the level of autonomic blockade is
higher than sensory and motor block.
116
Since sensory fibers are blocked by LA concentrations that do not affect______neurons, the level of sensory block is _____ than motor block.
motor neurons; higher
117
Touch and pressure fibers
B(beta)
118
Preganglionic ANS fibers
B fibers
119
Postganglionic ANS fibers
C fibers Unmyelinated
120
Fast pain temperature and touch
A-Delta fibers
121
Skeletal muscle and proprioception fibers
A-Alpha
122
Skeletal muscle tone fibers
A-Gamma
123
Block onset (BC DGBA)
B first
C second
DG third
BA Fourth
124
Neuraxial blockade reduces what respiratory mechanics?
Accessory muscle function is reduced
125
Accessory muscle function is reduced by
Neuraxial blockade
126
2 respiratory mechanics changes by neuraxial anesthesia? What patient population is more at risk?
Impairment of the intercostal muscles (inspiratory and expiratory) and abdominal muscles (ability to cough and secretions) will decrease pulmonary reserve. COPD patients
127
Systemic Effects of Neuraxial Anesthesia: Cardiovascular
vasodilates the arterial and venous circulations, although it predominantly affects the venous capacitance vessels.
128
Sympathectomy on CO, VR, and BP
Sympathectomy does what? Consequently, there is a reduction in venous return, cardiac output, and blood pressure.
129
How do you minimize hypotension post sympathectomy?
Volume loading with ~ 15 mL/kg and vasopressors will minimize hypotension.
130
Systemic Effects of Neuraxial Anesthesia:
Respiratory--> In healthy patients, neuraxial anesthesia has
Apnea is usually NOT the result of phrenic nerve paralysis or high concentrations of local anesthetic in the CSF.
negligible effects on minute ventilation, tidal volume, respiratory rate, dead space, and arterial blood gas tensions.
131
Systemic Effects of Neuraxial Anesthesia:
Respiratory--> In healthy patients, neuraxial anesthesia has
Apnea is usually the result of cerebral hypoperfusion.
Apnea is usually NOT the result of phrenic nerve paralysis or high concentrations of local anesthetic in the CSF.
negligible effects on minute ventilation, tidal volume, respiratory rate, dead space, and arterial blood gas tensions.
132
Why does the patient complain of dyspnea after a sympathectomy?
Loss of proprioceptive input from the chest may cause the patient to complain of dyspnea.
133
After sympathectomy: Apnea is usually the result of
cerebral hypoperfusion.
134
With neuraxial anesthesia, Apnea is usually NOT the result of what?
NOT the result of phrenic nerve paralysis or high concentrations of local anesthetic in the CSF.
135
Neuraxial anesthesia and CNS
Spinal anesthesia reduces sensory input to the reticular activating system. This can cause drowsiness.
136
Neuraxial anesthesia and Neuroendocrine
By inhibiting afferent traffic originating from the surgical site, neuraxial anesthesia diminishes the surgical stress response.
137
Neuraxial anesthesia and hormonal levels.
This reduces circulating levels of catecholamines, renin, angiotensin, glucose, thyroid stimulating hormone, and growth hormon
138
Inhibition of the sympathetic chain between what levels leave parasympathetic action unopposed?
T5 – L2 allows parasympathetic output to the gut to function unopposed.
139
Inhibition of the sympathetic chain between what levels leave parasympathetic action unopposed/
T5 – L2 allows parasympathetic output to the gut to function unopposed.
140
Inhibition of sympathetic outflow IN GUT causes
sphincters to relax and increases peristalsis.
141
Neuraxial and kidneys and liver:
So long as systemic blood pressure is maintained, hepatic and renal blood flow and function are unchanged
142
Absolute contraindication to spinal
Patient refusal
143
Neuraxial blocks are contraindicated in significant pathologic or therapeutic coagulopathic states: If Platelet count is
< 100,000.
144
Neuraxial blocks are contraindicated in significant pathologic or therapeutic coagulopathic states: if PT, aPTT, and/or bleeding time
twice the normal value.
145
Neuraxial blocks are contraindicated in significant pathologic or therapeutic coagulopathic states: - PT, aPTT, and/or bleeding time
twice the normal value.
146
ICP and Neuraxial
Increased Intracranial Pressure
Increase chance of brain herniation with sudden change in CSF pressure.
147
Neuraxial and Infection at the Puncture Site
Needle introduces pathogen beyond the BBB.
148
Infection at the Puncture Site
Needle introduces pathogen beyond the BBB.
149
Neuraxial and Hypovolemia
Worsening of hypotension due to sympathectomy.
150
Valve Lesions with Fixed Stroke Volume
Examples include:
Scoliosis, Arthritis, Spinal Fusion and Osteoporosis
severe aortic stenosis, severe mitral stenosis, or hypertrophic cardiomyopathy.
151
Neuraxial technically more difficult in
Scoliosis, Arthritis, Spinal Fusion and Osteoporosis
152
Difficult Airway and neuraxial
Neuraxial anesthesia isn't always the answer to the patient with a difficult airway. Block failure may require rapid conversion to general anesthesia.
153
Neuraxial and reticular activating system
Depression of the reticular activating system is common, and this may contribute to sedation. Supplementation with IV sedatives may lead to airway obstruction or collapse.
154
Full stomach and neuraxial
Hypotension related to the sympathectomy may cause nausea and vomiting
155
Peripheral Neuropathy and NEURAXIAL:
More susceptible to what? What about from a legal standpoint?
The theory is that these patients are more susceptible to injury. They are also slower to recover from it. Although data in this area is lacking, the legal world has a strong opinion. For this reason, many practitioners will not perform a neuraxial block in a patient with peripheral neuropath
156
Neuraxial anesthesia AND Multiple Sclerosis
Epidural is safe
Intrathecal MAY EXACERBATE SYMPTOMS
157
Although a spinal anesthesia may exacerbate_______If a spinal anesthetic would benefit the patient then patient should be informed that there may be a small risk of symptom exacerbation.
MS
158
Lidocaine 5% in 7.5% in dextrose is -(hypo, hyper or isobaric)
Hyperbaric
159
If you use hypobaric solution in the sitting position what happens
LA will rise in a cephalad (rostral) direction and will fail to adequately anesthesize the sacral nerve roots .
160
If we use hyperbaric solution in the jackknife position?
the LA will rise in a cephalad direction and will fail to anesthesize the sacral nerve roots
161
CSF specific gravity is
1.002 - 1.009
162
Condition that increase specific gravity?
Hyperglycemia
Uremia
High protein
Advanced age
Colder temperature
163
Condition that decrease specific gravity
Liver disease
Jaundice
Warmer temperature
164
Baricity describes what
The density of LA in relation to CSF
165
Describes a local anesthetic solution whose baricity is similar to CSF.
A higher density solution is hyperbaric, and a lesser density solution is hypobaric.
These are important concepts because a hyperbaric solution will sink, a hypobaric solution will rise, and an isobaric solution will remain in place.
Procaine 10 percent in water is an exception. A 10 percent solution contains a lot of molecules, which explains why it's hyperbaric.
An isobaric solution
166
Added to increase baricity is _______
Dextrose
167
Added to reduce baricity is _____
Water
168
As a general rule, solutions in dextrose _______are, in saline are ______and in water are
hyperbaric; isobaric; hypobaric.
169
A hyperbaric solution will settle to where in the spinal canal?
lowest point of the spinal canal
170
A hyperbaric solution will settle to where in the spinal canal?If we lay the patient supine after the block, a hyperbaric solution will slide down the lumbar lordosis and eventually pool in the sacrum and the thoracic kyphosis.
lowest point of the spinal canal
171
If we lay the patient supine after the block with a hyperbaric solution, a hyperbaric solution will
Slide down the lumbar lordosis and eventually pool in the sacrum and the thoracic kyphosis.
172
If we lay the patient supine after the block with a hyperbaric solution, a hyperbaric solution will s
lide down the lumbar lordosis and eventually pool in the sacrum and the thoracic kyphosis.
173
A spinal anesthetic tends to level off at
T4.
174
If the patient becomes hypotensive immediately following the SAB, you may be tempted to place her in the Trendelenburg position. This shifts the highest point of kyphosis to T1 and creates the
real possibility of a high spinal.
175
A hypobaric solution will settle to what part of the spinal canal?
highest point of the spinal canal
176
A hypobaric solution will settle to what part of the spinal canal? If we inject a hypobaric solution and then place the patient supine, the solution will float toward the lower lumbar region. It does not float towards the cervical region, because this would first require the local anesthetic to sink into the thoracic kyphosis
highest point of the spinal canal
177
If we keep the patient in the sitting position after the block with a hypobaric solution, what will happen? Is it safe?
A hypobaric solution will rise towards the brain - this isn't a good idea.
178
If we inject a hypobaric solution and then place the patient supine, the solution will float toward the
lower lumbar region, It does not float towards the cervical region, because this would first require the local anesthetic to sink into the thoracic kyphosis
179
Whitacre needle anatomy:
Non cutting, square
180
Sprotte needle anatomy:
Noncutting, long circle
181
2 cutting tip needles are
Quicke
Pitkin
182
Higher riskof PDPH with
Cutting tip needle
183
Lower risk of PDPH with
Pencil point tip
184
Non cutting tip 2 types
Pencil point tip
Rounded bevel tip
185
Needle less likely to deflect with
Pencil point
186
Name 3 pencil point
Spotte
Whitacre
Pencan
187
Less likely to injure the cauda equina: Cutting or noncutting
Noncutting tip
188
Rounded bevel, non-cutting is the _____Needle
Greene
189
Epidural needles differ by the amount of
curvature at the needle tip.
190
Notice that the EPIDURAL needle angle increases in alphabetical order: CHT
Crawford = 0 degrees
Hustead = 15 degrees
Tuohy = 30 degrees
191
Which needed and how does it minimize the risk of dural puncture?
The 30 degree curvature + the blunt tip of the Tuohy needle
192
How Far to Advance the Epidural Catheter?
The optimal depth of catheter insertion is 3-5 cm inside the epidural space.
193
Epidural Too shallow →
higher incidence of inadequate analgesia (epidural failure)
194
Epidural Too deep →
Catheter may enter an epidural vein or exit through an intervertebral foramen
195
For T10 sensory block you ned to administer _____For a caudal block
1ml/kg
196
Caudal Anesthesia
sacral, lumbar, and lower thoracic dermatomes.
197
Caudal block is used for
procedures requiring up to a T10 sensory block.
198
While this approach is commonly used in pediatric anesthesia, it is infrequently used in adolescence and adulthood because:
Sacral anatomy is more difficult to identify.
A lumbar approach to the epidural space is easier to perform and equally effective.
199
Contraindications Absolute
Spina bifida
Meningomyelocele of the sacrum
Meningitis
200
Relative Contraindications to caudal
Pilonidal cyst
Abnormal superficial landmarks
Hydrocephalus
Intracranial tumor
Progressive degenerative neuropathy
201
Technique: The caudal approach to the epidural space is performed in what 2 positions?
lateral or prone position.
202
Caudal technique: In the lateral position, flex the hips and make sure the top leg
is flexed more than the bottom leg (Simm’s position).
203
Caudal technique In the prone position, a
small roll should be placed under the iliac crests and the legs in the frog position.
204
Landmarks for the caudal block
Using the superior iliac spines and the sacral hiatus as landmarks, envision an equilateral triangle with the apex of the triangle at the sacral hiatus.
205
After sterile preparation, place a 22 or 25 gauge needle or 20 gauge IV catheter bevel up through the
sacral hiatus at a 45 degree angle aiming cephalad.This is why the superior iliac spines are useful landmarks.
Advance until you feel a pop. This signifies entry into the epidural space. From here, drop the angle and advance into the epidural space.
Placing the needle tip beyond S2-S3 increases the risk of dural puncture.
Palpate the skin during injection to rule out subcutaneous infiltration.
Resistance to injection suggests the needle tip is in the subperiosteal area.
206
During caudal block, Before injection,
aspirate for blood or CSF.
207
During caudal block In children, what should not be used?
air should not be used for loss of resistance. This can cause air embolism.
208
Epinephrine 1:200,000 (5 mcg/mL) will
reduce vascular uptake of the local anesthetic. This extends block duration.
209
Clonidine and experience
1 mcg/kg provides analgesia that is equal to epidural opioids.
210
Caudal block patient may experience this?
The patient may experience a feeling of fullness in the sacrum before the block sets up. This is a normal response.
211
Caudal just like an epidural, what determines the height of a caudal block.
volume
212
CAUDAL BLOCK: Pediatric sacral block dose
0.5ml/kg
213
CAUDAL BLOCK:ADULT sacral block dose
12-15 ml
214
CAUDAL BLOCK: Pediatric sacral to LOW THORACIC ( ~ T10) block dose
1ml/kg
215
CAUDAL BLOCK: Adult sacral to LOW THORACIC ( ~ T10) block dose
20-30ml
216
CAUDAL BLOCK: Pediatric sacral to MID THORACIC( ~ T10) block dose
1.25 ml miller says avoid this dose range
217
Any concentration of bupivacaine, levobupivacaine, or ropivacaine may be used so long as the total dose does not exceed
2.5 mg/kg - 3 mg/kg (Davis).
218
Intrathecal opioids associated with LATE RESPIRATORY DEPRESSIOn
MORPHINE
219
Provider a wider band of anesthesia fentanyl or morphine
Fentanyl
220
Neuraxial opioids have_______relationships when compared to IV, IM, or PO administration
different PK/PD
221
Neuraxial opioids Mechanism of Action
work by inhibit afferent pain transmission in the substantia gelatinosa in LAMINA II of the dorsal horn.
222
Opioids decrease afferent pain transmission. Neurotransmission is reduced by: DCIK
Decreased cAMP, decreased Ca+ conductance, and increased K+ conductance.
223
When combined with local anesthetics, neuraxial opioids create a
denser block.
224
Neuraxial opioids to systemic circulation
systemic circulation, where the blood delivers them to opioid receptors throughout the body.
225
Neuraxial opioids do NOT cause:
- sympathectomy
- skeletal muscle weakness
- changes in proprioception
226
Intrathecal vs. Epidural Administration
An opioid deposited into the intrathecal (Subarachnoid/spinal) space can
easily diffuse into the spinal cord.
227
An opioid deposited into the epidural space will
diffuse within the epidural tissue.
228
Opioids can diffuse within the epidural tissue. From the epidural space, it diffuses across the
dural cuff and into the CSF to reach the spinal cord. It also diffuses into the bloodstream. Since only a fraction of the dose reaches the subarachnoid space, a higher dose is required.
229
Fentanyl intrathecal vs epidural dose
10-20 mcg vs 50-100mcg
230
Fentanyl EPIDURAL INFUSION DOSE
25-100 mcg/hr
231
HYDROMORPHONE EPIDURAL DOSE
0.5 - 1 mg
232
Hydromorphone EPIDURAL INFUSION dose
0.1 - 0.2 mg/hr
233
Meperidine INTRATHECAL vs EPIDURAL DOSE
10 mg vs 25-50 mg
234
Meperidine EPIDURAL INFUSION dose
10-60 mg/hr
235
Morphine INTRATHECAL dose
0.25 - 0.30 mg
236
Morpine EPIDURAL INFUSION dose
0.1 - 1 mg/hr
237
Morphine EPIDURAL dose
2-5 mg
238
Lipophillic drugs when injected to the intrathecal space
Get absorbed into the EPIDURAL SPACE then into the systemic circulation : MOST OF IT GO TO SYSTEMIC CIRCULATION
239
Hydrophillic drugs when injected to the intrathecal space
Get absorbed into the EPIDURAL SPACE then into the systemic circulation : Less go to systemic circulation, MORE TO BRAINSTEM
240
Hydrophillic opioids are
Meperidine
Morphine
Hydromorphone
241
Lipophillic opioids are
Sufentanil
Fentanyl
242
Hydrophillic vs Lipophillic which stays longer in the CSF?
Hydrophillic Longer
Lipophillic shorter
243
Spread of CSF hydrophillic vs lipophillic
Hydrophillic --> Extensive
Lipophillic--> minimal
244
Wider band of anesthesia with
Hydrophillic
245
More rostral (TOWARD BRAIN) spread with
Hydrophillic
246
LESS rostral (TOWARD BRAIN) spread with
Lipophillic
247
Site of Action: Hydrophillic
Substantia Gelatinosa in REXED Lamina II and III
248
Site of Action: LIPOphillic
Substantia Gelatinosa in REXED Lamina II and III (SYSTEMIC)
249
Onset of HYDROPHILLIC OPIOIDS
Delayed 30 -60 min
250
Onset of LIPOPHILLIC OPIOIDS
Fast 5-10 min
251
Duration of HYDROPHILLIC OPIOIDS
Longer 6-24 h
252
Duration of LIPOPHILLIC OPIOIDS
Faster 2-4
253
Systemic absorption of HYDROphilic opioids
Less (thats why their duration of action is longer)
254
Systemic absorption of LIPOphilic opioids
More
255
Respiratory depression of Hydrophillic opioids
Early < 6 hr
Late > 6 hr
256
Respiratory depression of LIPOphillic opioids
Early only
257
N/V of HYDROPHILLIC
HIGHER INCIDENCE
258
N/V of LIPOPHILLIC
Lower INCIDENCE
259
PRURITUS of HYDROPHILLIC
HIGHER INCIDENCE
260
PRURITUS OF LIPOPHILLIC
Lower incidence
261
Most common side effect of neuraxial opioids are
Pruritus (MOST COMMON)
Respirator depression
Urinary retention
N/V
262
There are four key side effects of neuraxial opioids that you should understand:
.
Is caused by stimulation of opioid receptors in the trigeminal nucleus and not by mast cell degranulation. Indeed, non-histamine releasing drugs, such as fentanyl and sufentanil, cause pruritus.
Can be treated with an opioid antagonist, such as naloxone. Diphenhydramine doesn't fix the cause, but its sedative effects may be beneficial.
pruritus, respiratory depression, urinary retention, and nausea and vomiting.
263
There are four key side effects of neuraxial opioids that you should understand:
pruritus, respiratory depression, urinary retention, and nausea and vomiting.
264
Pruritus more common in
Is the most common side effect of neuraxial opioids. It is more common in obstetric patients
265
What causes the neuraxial pruritus --> Is caused by
stimulation of opioid receptors in the trigeminal nucleus and not by mast cell degranulation. Indeed, non-histamine releasing drugs, such as fentanyl and sufentanil, cause pruritus.
266
What should neuraxial pruritus be treated with ?
Can be treated with an opioid antagonist, such as naloxone.
267
Doesn't fix neuraxial pruritus but may help?
Diphenhydramine doesn't fix the cause, but its sedative effects may be beneficial.
268
Respiratory Depression --> _______-can cause a biphasic respiratory depression. The early phase results from systemic absorption.
Hydrophilic drugs
269
Late phase respiratory depression results from the tendency of hydrophilic opioids to
ascend towards the brain where they can inhibit the respiratory center. The early phase is < 6 hours, and the late phase occurs between 6 and 12 hours.
270
Lipophilic drugs are more quickly absorbed by the spinal tissue, which limits the amount of spread. In the epidural space, diluting a lipophilic drug in 10 cc of preservative free of _______
sodium chloride will enhance spread. Early phase respiratory depression results from systemic absorption. There is no late phase of respiratory depression with these drugs
271
Respiratory depression is more common with:
- high opioid doses
- co-administered sedatives
- low lipid solubility
- advanced age
- opioid naivety
- increased intrathoracic pressure
272
Urinary Retention for opioids is most common with which population>?
Is most common in young males.
273
Urinary retention: Neuraxial vs IV or IM
Is more common with neuraxial opioids when compared to IV or IM administration.
274
Why do people get urinary retention with neuraxial opioids?
Results from inhibition of sacral parasympathetic tone.
275
Neuraxial bladder detrusor muscle
This causes bladder detrusor muscle relaxation and urinary sphincter contraction.
276
Used for urinary retention reversal
Can be reversed with naloxone.
277
Nausea and vomiting with neuraxial anesthesia Is caused by
-
- activation of opioid receptors in the area postrema of the medulla
- vestibular apparatus
278
What reduces the efficacy of epidural opioids?
2-Chloroprocaine
279
Epidural morphine may reactivate what viral disease? Why?
herpes simplex labialis. This is best explained by cephalad spread of morphine to the trigeminal nucleus. It usually presents 2 – 5 days after epidural morphine administration.
280
Opioids from epidural space to breast milk?
Transfer of opioids from the epidural space to the breast milk is minimal.
281
Sedation is dose dependent, but it is most common with
sufentanil.
282
Opioids and vasopressin
have an antidiuretic effect by increasing vasopressin release.
283
Peristalsis slows, increasing
gastric transit time.
284
Any opioid that enters the systemic circulation becomes available to
cross the placenta and enter the fetus.
285
PDPH and orientation of the needle
Perpendicular is worst than parallel
286
Using air or saline for
Epidural placement does not affect the risk of incurring a dural puncture.
287
PDPH include
Early ambulation
Old age
Use a continuous spinal catheter
288
Puncturing the dura causes As CSF pressure is lost, the cerebral vessels dilate. In addition, the brainstem sags into the foramen magnum, which stretches the meninges and pulls on the tentorium. These factors contribute to PDPH
CSF to leak from the subarachnoid space.
289
The classic presentation includes a fronto-occipital headache, which may be accompanied by
Nausea
Emesis
Photophobia
Diplopia, and tinnitus.
290
In the upright position
gravity makes the headache worse, while the supine position brings relief.
291
As CSF pressure is lost,
the cerebral vessels dilate.
292
In addition, the brainstem sags into the foramen magnum?
the brainstem sags into the foramen magnum, which stretches the meninges and pulls on the tentorium. These factors contribute to PDPH.
293
Higher risk of PDPH
Younger age
Female
Pregnancy
294
Lower risk of PDPH
Older age
Male
NonPregnant
295
No effect on risk of PDPH
Early ambulation
296
Treatment of PDPH:
Bed rest
Hydration
NSAIDs
Caffeine (cerebral vasoconstriction)
Epidural blood patch
Sphenopalatine ganglion block
297
Epidural Blood Patch
An epidural blood patch is the definitive treatment for PDPH, and each patch is associated with a 90 percent success rate. If the headache does not improve after two blood patches, other etiologies should be sought.
298
The most common side effects of Epidural blood patch are
backache and radicular pain
299
Explain epidural blood patch?
Using sterile technique, 10 – 20 mL of venous blood is withdrawn from the patient and then reintroduced into the epidural space. When the patient senses pressure in her legs, buttocks, or back, the injection is complete.
300
A blood patch is useful for two reasons.
First, it compresses the epidural and subarachnoid spaces, which increases CSF pressure.
Second, it acts as a plug that prevents further leaks.
301
Sphenopalatine Ganglion Block
The SPG block is an alternative to the epidural blood patch in the treatment of PDPH. It’s simple to perform with a very low risk of side effects.
302
Explain Sphenopalatine ganglion block
-Soak a long cotton-tipped applicator in a local anesthetic solution (1 - 2 percent lidocaine or 0.5 percent bupivacaine).
-Place the patient in the sniffing position.
Insert the applicator into each nare towards the middle turbinate.
Continue insertion until you encounter the posterior wall of the nasopharynx. This is in the vicinity of the sphenopalatine ganglion.
Leave the applicator in place for 5 - 10 minutes.
The patient should notice symptom improvement at this time.
303
Post-Spinal Bacterial Meningitis
When placing a neuraxial block, there are two routes by which an infectious organism can reach the CSF.
304
Failure of aseptic technique/Bacteria in the patient’s blood at the time of SAB
Post-spinal Bacterial Meningitis
305
What is the one of the most common culprits responsible for post-spinal bacterial meningitis?
Streptococcus viridans
306
Why is it important to wear a mask when during neuraxial?
Streptococcus viridans It is commonly found in the mouth, and this is why it's so critical to wear a mask while performing a neuraxial block. It’s also found on the hands and forearms, so hand washing is essential.
307
How do we prepare the patients’ back?
-Chlorhexidine (is neurotoxic, so it must be allowed to dry before puncturing the skin with the needle)
- Iodine
- Alcohol
308
Most effective prep for neuraxial
Combination of alcohol and chlorhexidine is
309
Needle diameter and PDPH
Larger diameter make PDPH risk higher
310
The risk of epidural hematoma is similar during
block placement and catheter removal.
311
Why do patients with cardiac stents present a difficult situation.
Discontinuation of anticoagulants and antiplatelet drugs can increase the risk of while stent thrombosis, failure to discontinue many of these drugs puts the patient at risk for epidural hematoma
312
Epidural hematoma can cause what?
cause paralysis.
313
Presenting symptoms of epidural Hematoma
include lower extremity weakness, numbness, low back pain, and bowel and bladder dysfunction.
314
Epidural hematoma :best chance of recovery.
Surgical decompression within eight hours offers the best chance of recovery.
315
COX-1 inhibitors MOA
Inhibits cyclooxygenase
316
COX-1 inhibitors Examples
ASA
NSAIDs
317
Anesthetic management with proceed with neuraxial anesthesia if:
Pt has normal clotting mechanism
Pt is on NO other blood thinners
318
Glycoprotein IIb/IIIa Antagonists : MOA
Inhibits platelet aggregation via surface receptors
319
Examples of GP IIb/IIIA antagonists
Tirotiban
Eptifibatide
Abciximab
320
GIIB/IIIA Antagonist: Tirotiban : Before placement hold for how long?
Hold 8 hours
321
GIIB/IIIA Antagonist: Eptifibatide : Before placement hold for how long?
Hold 8 hours
322
GIIB/IIIA Antagonist:Abciximab : Before placement hold for how long?
Hold 1-2 days
323
Thienopyridine Derivaties: MOA
Inhibits platelet aggregation by blocking ADP transferase.
324
Thienopyridine Derivaties: Examples
Clopidogrel
Ticlodipine
325
How long do you hold CLOPIDOGREL for block placement?
Hold for 7 days
326
How long do you hold TICLODIPINE for block placement?
Hold for 14 days
327
MOA of unfractionated heparin
Potentiates antithrombin
328
Factors that unfractionated heparin inhibits
Factor 2 (Thrombin)
7, 9, 10 , 11, 12
329
Heparin IV: before block placement hold for how long?
2-4 hours
330
Heparin IV: After block placement hold for how long?
1 hour
331
Heparin IV: After indwellling catheter removed hold for how long?
2-4 hours
332
LMWH MOA
Irreversibly inhibits Xa
333
LMWH names ends with
-parin
334
LMWH prophylactic dosing is ____daily ; Hold catheter for ___hrs, before block placement
once; 12 hours
335
LMWH Therapeutic dosing is ____daily ; Hold catheter for ___hrs, before block placement
twice daily; 24 hrs
336
Before removing indwelling catheters hold LMWH for
12 hours
337
After removing indwelling catheters hold LMWH for
2 hours
338
If prescribed after a single shot block, hold LMWH prophylactic dose for
6-8 hours
339
If prescribed after a single shot block, hold LMWH Therapeutic dose for
24 hours
340
Anti-vitamin K drugs are
Warfarin
341
Warfarin MOA
Inhibits vitamin K dependent factors 2, 7, 9 , 10
342
How long do you hold warfarin before block placement?
5 days
343
When can you remove catheter (INR)?
INR < 1.5
344
Absolute contraindications to NEURAXIAL ANESTHESIA, medication class
TPA
Streptokinase
ANY meds with -ase
345
Herbals that inhibits platelet aggregation( GGG)
Ginseng
Ginkgo
Garlic
346
If patient on herbals that inhibit platelet aggregation, you should
Proceed if no other blood thinning drugs.
347
Pain that radiates to lower back and legs after a SAB is most likely
TNS
348
TNS is associated with which LA?
Lidocaine
349
Conus Medullaris: The spinal cord ends in a taper as the conus medullaris. In the adult: _______and in the
In the infant:
L1-L2; L3
350
Cauda Equina is a bundle of _______that extends from ______to where ?
Bundle of spinal nerves extending from conus medullaris to dural sac.
351
Dural Sac: Where does The subarachnoid space terminates
In the adult: ____
In the infant: ____
at the dural sac. S2 adult, S3 infant
352
Filum Terminale: Extends from
This extends from the conus medullaris to the coccyx.
353
Cauda Equina Syndrome Cause:
Neurotoxicity is the result of exposure to high concentrations of local anesthetic.
354
Factors that Increase Risk of Cauda Equina syndrome
5% lidocaine
Spinal micro catheters
355
Cauda Equina and spinal catheters
Micro catheters focus local anesthetic on a small area of the cord, exposing this region to a high concentration of LA.
356
Cauda Equina Signs and Symptoms:
Bowel and bladder dysfunction, sensory deficits, weakness, and/or paralysis.
357
Treatment of Cauda Equina
Supportive
358
Transient Neurologic Symptoms
Cause:
Patient positioning
Stretching of the sciatic nerve
Myofascial strain
Muscle spasm.
359
It is highly unlikely that neurotoxicity causes
TNS.
360
Factors that Increase Risk of TNS
Lidocaine
lithotomy position
ambulatory surgery, and knee arthroscopy.
361
Does local anesthetic concentration increase the risk of TNS?
NO
362
Does early ambulation increase the risk of TNS?
NO
363
Does baricity increase the risk of TNS
NO
364
Does glucose concentration increase the risk of TNS
NO
365
Signs and Symptoms of TNS
Severe back and butt pain that radiates to both legs.
366
Treatment of TNS
NSAIDs, opioid analgesics, and trigger point injections
367
When does TNS develops?
It generally develops within 6 – 36 hours and persists for 1 – 7 days.
368
If patient is on SQ heparin for DVT prophylaxis, how do you determine when to proceed with neuraxial>
Proceed if normal clotting mechanisms AND is not on any other blood thinning
369
What is the first ligament that the needle encounters while performing a subarachnoid block via the paramedian approach?
Ligamentum flavum
370
The layers encountered during the paramedian approach from superficial to deep:
Skin → subcutaneous tissue → ligamentum flavum → dura mater → subdural space → arachnoid mater → subarachnoid space
371
When placing the needle in the subarachnoid space, you want the tip to ente
below the conus medullaris and above the lower border of the intrathecal space (dural sac).
372
The only real benefit of a cutting tip needle is that it requires
less force during insertion.
373
Which factors have the GREATEST influence on the spread of local anesthetic in the intrathecal space? (Select 2.)
Baricity and dose
374
Most Important Factors That Determine Spinal Block Height: DRUG FACTORS
Pt and procedures factors
Drug Factors = dose, baricity
Patient Factors = CSF volume, pregnancy, old age
Procedure Factors = patient position
375
Other Factors That Determine Spinal Block Height:
Drug Factors = volume, concentration, temperature, viscosity
Patient Factors = height, weight, intraabdominal pressure
Procedure Factors = needle type, needle orifice orientation, level of injection
376
Which factors have the GREATEST influence on the spread of local anesthetic in the epidural space?
Volume
Dose
Pregnancy
377
Most Important Factors That Determine Spinal Block Height: Pt factors
CSF volume, pregnancy, old age
378
As a general rule, you can predict the relative baricity of the LA solution based on its diluent: which one is hyperbaric, isobaric, and hypobaric
Dextrose = Hyperbaric (sinks)
Saline = Isobaric (remains in place)
Water = Hypobaric (floats)
379
Procaine 10 percent in water is the exception - it is a
hyperbaric solution! This is due to the fact that there are so many molecules in the solution (it makes it heavy).
380
hen injected into the intrathecal space, which opioids undergo the GREATEST degree of rostral spread?
Morphine
Hydromorphone
381
Neuraxial opioids inhibit
neurotransmitter release (substance P) in substantia gelatinosa (Rexed lamina II) in the dorsal horn of the spinal cord.
382
The relative lipophilicity of an opioid determines its
tendency to stay inside the intrathecal space vs. its tendency to diffuse into the systemic circulation.
383
Which nerve roots are the MOST resistant to the effects of local anesthetics?
L5
S1
384
A few key points about L5 and S1:
They are the largest spinal nerves.
They are the most resistant to the effects of local anesthetics.
The L5-S1 interspace is the largest interspace in the vertebral column.
385
In what order does regression of spinal anesthesia occur?
1 + Motor function
2 + Touch
3 + Pinprick
4 + Temperature
386
To assess the adequacy of your spinal anesthetic, you need to know a thing or two about differential blockade. Spinal nerves are anesthetized in the following order:
Pre-ganglionic sympathetic
Temperature
Pin prick (fast pain)
Touch
Motor
387
Spinal nerves recover in the opposite order in which they were anesthetized.
Motor
Touch
Pinprick (fast pain)
Temperature
Pre-ganglionic sympathetic
388
A patient with severe COPD received a spinal anesthetic. Impairment of which of the following muscles is MOST likely to contribute to respiratory compromise? (Select 2.)
Intercostals
Abdominal
389
Neuraxial anesthesia impairs accessory muscle function;WHat changes occur to lung volumes?
vital capacity and expiratory respiratory volume are decreased.
390
reduction in which of the following is the primary mechanism for hypotension after a T4 spinal anesthetic?
Preload
391
Vascular SNS innervation =
T1 - L2
392
Cardiac SNS innervation
= T1 - T4
393
All effects CV of Sympathectomy
↓ Preload (venodilation)
↓ Stroke volume (↓ preload)
↓ Afterload (arterial dilation)
↓ Heart rate (↓ cardiac accelerator function & ↓ preload)
394
It's important to understand that sympathectomy with spinal anesthesia can be as high as
2 - 6 levels above the level of sensory blockade! By contrast, sympathectomy is the same as the sensory level during epidural anesthesia.
395
Because___ of the blood volume resides in the
75% venous circulation, dilation of the venous capacitance vessels (↓ preload) is the primary mechanism of hypotension with a high spinal.%. The body compensates with vasoconstriction above the level of sympathectomy, however a higher block limits the effectiveness of this compensatory mechanism.
396
Which of the following BEST explains why spinal anesthesia can cause cardiac arrest in the patient with severe aortic stenosis?
Decreased aortic diastolic blood pressure
397
Explains why spinal can cause cardiac arrest in patient with severe aortic stenosis?
Patients with severe aortic stenosis have a fixed afterload. This is best explained by a tight aortic valve that limits the volume of blood the heart can eject during each beat. Because of this, cardiac output is highly dependent on preload.
398
Spinal anesthesia decreases preload as well as
SVR. This sets the stage for hypotension in the patient with a fixed afterload.
399
Hypotension reduces ____________
Aortic diastolic blood pressure, and this in turn impairs coronary perfusion pressure (CPP = AoDBP - LVEDP).
400
Patients with AS tend to have an
increased LVEDV and LVEDP, further reducing CPP.
401
Placing the epidural catheter in the region of the incisional dermatome provides the best analgesia with the lowest risk of side effects. Simply put, we can give less drug.Where to place the catheter based on the location of the incision:
Thoracic =
Upper abdominal =
Middle abdominal =
Lower abdominal =
Lower extremity =
Thoracic = T4-T8
Upper abdominal = T6-T8
Middle abdominal = T7-T10
Lower abdominal = T8-T11
Lower extremity = L1-L4
402
After placement of an epidural, a patient complains of a fronto-occipital headache, diplopia, and tinnitus. What is the BEST intervention to treat this patient's symptoms?
Caffeine
403
Explain how PDPH occur
When a hole is created in the dura, CSF leaks through it. This reduces CSF volume and pressure. Traction on the meninges and cerebral vasodilation cause the headache.
404
The definitive treatment of PDPH is
Epidural blood patch.
405
Conservative treatment measures include:
Intravenous hydration (increases CSF production)
Supine position (maintains a higher CSF pressure in the brain)
Caffeine (reverses cerebral vasodilation)
Theophylline (reverses cerebral vasodilation)
NSAIDs
406
Injection during an epidural blood patch should stop when the patient:
notes pressure in her back.
407
Explain how a Blood patch is done
Using sterile technique, 10 - 20 mL of venous blood is withdrawn from the patient and then reintroduced into the epidural space. You should stop injecting when the patient senses pressure in her legs, buttocks, or back.
408
A blood patch is useful for 2 what reasons.
First, it compresses the epidural and subarachnoid spaces, which increases CSF pressure. Second, it acts as a plug that prevents further leakage.
409
What is the MOST common consequence of an epidural blood patch?
Backache
410
Are the most common side effects of an epidural blood patch..
Backache and radicular pain.Less common side effects include cranial nerve palsies and transient bradycardia.
411
Treatment of backache and radicular pain after epidural blood patch
Treatment consists of NSAIDs and antispasmodic medications
412
When compared to an epidural technique, which of the following complications are more likely with spinal anesthesia? (Select 2.)
Cauda Equina syndrome
Meningitis
413
Complications more likely to occur after epidural anesthesia include:
Epidural abscess (direct contamination of epidural space)
Spinal hematoma (large needle = larger hole)
Traumatic spinal cord injury (larger needle = larger injury)
414
Select the organism that is MOST likely to cause post-spinal bacterial meningitis.
Streptococcus viridans
415
When placing a neuraxial block, there are two routes by which an infectious organism can reach the CSF.
Failure of aseptic technique
Bacteria in the patient’s blood at the time of SA
416
Streptococcus viridans is one of the most common culprits responsible for post-spinal bacterial meningitis. It is commonly found in the
mouth, and this is why it's so critical to wear a mask while performing a neuraxial block.
417
What is the MOST efficacious skin preparation method for neuraxial anesthesia?
Chlorhexidine + Isopropyl alcohol
418
Suitable methods to prepare the skin for neuraxial anesthesia include
chlorhexidine, isopropyl alcohol, and iodine solutions.
419
A patient with an epidural catheter at the L4-5 interspace received 20 mL of 0.25% bupivacaine. After 25 minutes, the patient loses consciousness. What is the MOST likely explanation for this complication?
Subdural injection
420
A potential space is an
The subdural space is a potential space. It is located between the dura and the arachnoid. It is deep to the epidural space and superficial to the subarachnoid space. Be able to identify all of these spaces in an image.
While the epidural space extends to the foramen magnum, the subdural space extends intracranially. The hallmark of a subdural injection is high but patchy block that usually develops after a 15-30 minute delay. If local anesthetic reaches the brain, unconsciousness can occur. Treatment is supportive.
area between two membranes. It is usually empty, but it can expand to a much larger size if fluid accumulates between the membranes.
421
The subdural space is a potential space. It is located between the
dura and the arachnoid. It is deep to the epidural space and superficial to the subarachnoid space. Be able to identify all of these spaces in an image.
422
If local anesthetic was injected into the
vasculature or intrathecal space, the patient would’ve experienced symptoms within several minutes (not 25).
423
While the epidural space extends to the
foramen magnum, the subdural space extends intracranially.
424
The hallmark of a subdural injection is
high but patchy block that usually develops after a 15-30 minute delay. If local anesthetic reaches the brain, unconsciousness can occur. Treatment is supportive.
425
A patient requests an epidural for an open gastric bypass procedure. She continued all of her home medications through the day of surgery. Which of the following preclude the placement of an epidural catheter in this patient? (Select 2.)
Clopidogrel
Enoxaparin
426
The most significant risk factor for epidural hematoma is the
presence of a coagulation defect
427
Laboratory cutoffs (these differ from book to book): Plt, PT, PTT
Platelets < 100,000/mcL
PT > 2x normal
PTT > 2x normal
428
Drugs that increase risk of hematoma:
Thienopyridine derivatives (clopidogrel, ticlopidine)
Glycoprotein IIb/IIIa antagonists (abciximab, eptifibatide, tirofiban)
Low molecular weight heparin (enoxaparin, dalteparin, tinzaparin)
Intravenous heparin
Oral anticoagulants (warfarin)
429
Drugs that do NOT increase the risk of hematoma:
NSAIDs
Mini-dose unfractionated heparin for DVT prophylaxis
Herbal medications (garlic, ginkgo, ginseng)
430
Diagnostic features of epidural hematoma include all of the following EXCEPT:
fever
431
Bleeding in the spinal canal issue
in the spinal canal can compress the spinal cord, impairing its perfusion
432
Epidural hematoma signs and symptoms
Patients will present with radicular back pain, lower extremity weakness, and bowel and bladder dysfunction
433
Suspicion of an epidural hematoma warrants an
emergent MRI.
434
Definitive treatment of Epidural Hematoma
Surgical decompression is the definitive treatment, yielding the best results if performed within 8 hours of symptom onset.
435
An epidural abscess is more likely to present with
fever and anterior spinal artery syndrome presents as painless lower extremity motor impairment with bowel and bladder dysfunction.
436
A caudal anesthetic is suitable for all of the following procedures EXCEPT:
pilonidal cystectomy.
437
Caudal anesthesia is useful for procedures that require
sensory block at or below T10
438
Absolute contraindications to caudal anesthesia include
spina bifida, meningitis, and meningomyelocele of the sacrum.
439
Relative contraindications to caudal anesthesia include
Pilonidal cyst
Abnormal landmarks
Hydrocephalus
Intracranial tumor, and progressive degenerative neuropathy.
