Exam 1 Spinal & Epidural Neuraxial Anesthesia [5/28/24] Flashcards
1
Q
List the 3 major anesthesia techniques
A
- General Anesthesia
- MAC
- Regional Anesthesia
S1
2
Q
Regional anesthesia has 2 classifications. What are they and its subclasses?
A
Central neuraxial
1.Spinal
2.Epidural
3.Combined spinal and epidural [CSE]
4.Caudal: this is peds specific.
Peripheral blocks
1.upper extremity blocks
2.lower extremity blocks
3.trunchal: top block, interfascial block, perivertibral, pectoral nerve block 1 and 2.
S1
3
Q
What cannot be given through the spinal?
A
Reglan and Zofran `
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4
Q
What are the clinical Indications for neuroaxial anesthesia?
A
- Surgical procedures involving the lower abdomen, perineum, and lower extremities
- Orthopaedic surgery [alot of spinals]
- Vascular surgery on the legs
- Thoracic surgery (adjunct to GETA) [usually epidurals]
S5
5
Q
What are the 6 benefits for neuraxial anesthesia?
A
Reduces the following:
1. Postoperative ileus
2. thromboembolic events
3. PONV
4. Respiratory Complications
5. Bleeding
6. Narcotic Usage
Reduces PIT RBN (say it like Pit rubbin’)
S6
6
Q
What causes PONV?
What are the risk factors?
A
- PONV occurs due to induction medication like anesthetic gasses & opioids.
- Factors for increased PONV:
1.Females
2.NON-Smokers
4.Age 40 and higher
S6
7
Q
List the other benefits of neuraxial anesthesia.
A
- Great mental alertness
- Less urinary retention*
- Quicker to eat, void, and ambulate
- Avoid unexpected overnight admission from complications of general anesthesia
- Quicker PACU discharge times*
- Preemptive anesthesia
- Blunts stress response from surgery
BM QUAP
S7
8
Q
If using neuraxial anesthesia, and the pt needs to be put to sleep but needs to maintain respiratory drive what can be administed?
A
- Propofol
- 100-300 mcg/kg
S7
9
Q
What are the relative contraindication for neuroaxial anesthesia
A
- Deformities of spinal column [issues w/positioning]
- Spinal stenosis, kyphoscoliosis, ankylosing spondylitis
- scoliosis, lordosis, kyphosis
- Preexisting disease of the spinal cord [residual weakness]
- Exacerbate a progressive, degenerating disease
- Multiple Sclerosis, post polio syndrome
- Chronic headache/backache
- Inability to perform SAB/Epidural after 3 attempts
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10
Q
Why are chronic headaches/backaches a relative CI for neuroaxial anesthesia?
A
- A complication of neuroaxial anesthesia is post-dural puncture heacache.
- if pt has backpain, and we are sticking needes in the back it might worsen the pain
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11
Q
What are the absolute CI for neuroaxial anesthesia?
A
- Coagulopathy
- Patient refusal
- Evidence of dermal site infection
- known coag disoder or on anticoagulants
- Severe or critical valvular heart disease
- HSS [idiopathic hypertrophic subaortic stenosis]
- Operation >duration of LA
- Increased ICP
- Severe CHF
S9-10
12
Q
What are the coagulation problems that are absoulte contraindications for neuroaxial anesthesia
A
- INR > 1.5
- PLT < 100,000
- PT: 24-28 seconds
- PTT: 50-64 seconds
- BT: 6-14 min
- Known coag disorder or taking anticoags.
PT, PTT, BT 2X THE NORMAL
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13
Q
Normal PT
A
12 - 14 seconds
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14
Q
Normal INR
A
0.8 - 1.1
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15
Q
Normal aPTT
A
25 - 32 seconds
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16
Q
Normal Bleeding Time [BT]
A
3 - 7 minutes
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17
Q
Normal Platelets
A
150,000 - 300,000 mm3
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18
Q
List the factors involved in the coagulation cascade
* Intrinsic
* Extrinsic
* Common
A
- Intrinsic: 12→ 11→9 →8
- Extrinsic: 3→7
- Common: 10 + 5 →2 →1←13
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19
Q
PT/INR measures?
PTT measures?
A
- PT/INR = extrinsic
- PTT = intrinsic
S9
PT = PLAY TENNIS OUTSIDE = EXTRINSIC
PTT = PLAY TABLE TENNIS INSIDE = INTRINSIC
20
Q
What happens when we get injured?
A
Hemostasis:
1.Vascular effect - Body has vascular constriction.
2.Primary mechanism: where PLT is activated.
* PLT activation occurs by extrinsic methods.
* VWF (Factor VIII) pulls platelets to come closer and work together. This makes the PLT sticky. This forms a PLT plug [not strong].
3.Secondary mechanism: intrinsic/extrinsic/common pathway.
S9
21
Q
What does the bleeding time look at?
A
- Examines PLT activation and adhesion.
- longer BT = problem with PLTs.
S9
22
Q
What severe valvular heart diseases are absolute CI for neuroaxia anesthesia?
A
- Aortic stenosis <1cm2
- Mitral stenosis <1cm2
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23
Q
List the valve area for AS for the following:
* Mild
* Moderate
* Severe
* Critical
A
- Mild: ≥1.5
- Moderate: 1.0 - 1.5
- Severe: 0.7 - 1.0
- Critical: < 0.7
cm2
24
Q
What is the average course of valvular aortic stenosis in adults
A
- Age 35-40: increasing obstuction, myocardial overload
- Age 60: onset of severe symptoms **
- Age 63: average age of death.
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25
What are the s/sx of severe or critical AS? What are its survival rates?
* Angina - 5yrs
* Syncope - 3yrs
* Heart failure - 2 yrs, the worst [NYHF 3 or 4]
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Why is aortic stenosis a contraindication?
* Main issue for anesthesia is loss of afterload, SVR, and HR.
* W/general anesthesia, SVR is dropped.
* W/regional anesthesia esp spinal = Death Spiral
DEATH SPIRAL: decrease SVR →hypotension → ischemia → decrease CO →worsened BP →angina.
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27
What is the death spiral that occurs due to AS?
1. hypotension causes myocardial ischemia
2. ischemia contractile dysfunction
3. decreases CO
4. worsening hypotension
5. increased ischemia
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28
Compare & Contrast the following characteristics of spinals and epidural:
* Onset
* Spread
* Nature of block
* Motor block
* Hypotension
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29
Compare & Contrast the following characteristics of spinals and epidural:
* Onset
* Duration
* Placement level
* Difficulty of placement
* Dosing
* Concentration
* LA toxicity
* Gravity influence
* Manipulation of dermatome spread after dosing
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What is the placement and needle size for spinals?
* Placement: L3-L4, L4-L5, L5-S1 but we as SRNAs do L4-L5
* Smaller needle: 25-27g
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31
What is the placement and needle size for epidurals?
* Placement: anywhere there is epidural space
* bigger needle: 18-19 g
* can do epidurals by thoracic but draw back is accidentally hitting the spinal cord.
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Baracity affects epidurals or spinals?
What does hyper, hypo, and iso -baric mean?
* Affects spinals
* hyperbaric: sinks
* hypobaric: floats
* isobaric: stays in place
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Positioning affects epidurals or spinals?
How would you postion a pt with right hip pain?
* Affects epidurals
* pain in right buttock - turn to right side to have LA stay on that side.
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34
How many total vertebras do we have?
* Total:
* Cervicle:
* Thoracic:
* Lumbar:
* Sacrum:
* Coccyxs:
* Total: 33
* Cervicle: 7
* Thoracic: 12
* Lumbar: 5
* Sacrum: 5
* Coccyx: 4
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What are the 4 curvatures of the spine?
1. Normal
2. Scoliosis
3. Kyphosis
4. Lordosis
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36
Each vertebra, except for ____, is divided into two main parts:
* The____ segment, known as the body.
* The ____ segment, called the vertebral arch.
* C1
* anterior
* posterior
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37
what 2 structures link the anterior [body] and posterior [vertebral arch] segments?
the lamina and pedicle
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38
The connection of the anterior [body] and posterior [vertebral arch] segments form the ____ ____.
* verterbral foramen
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39
The vertebral foramen is a crucial space within the vertebra why?
houses the spinal cord, nerve roots, and the epidural space, which is a protective cushioning area around the spinal cord.
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40
The ____ processes stick out to the sides (lateral), while the ____ processes stick out towards the back (posterior).
* transverse
* spinous
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what attach to the spinous and transverse processes to help stabilize and support the spine?
muscles
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42
The spionus process is used as a landmark for what?
to find the middle line of the back
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43
How are lumbar vertebrae different from thoracic and cervical vertebrae?
the orientation of the spious process is different
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44
Cervical and thoracic spinous processes tilt ____, requiring a needle approach from ____.
* downward (caudal direction)
* above (cephalad approach)
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Lumbar spinous processes stick out directly ____, which makes it easier to reach the spaces around the spinal cord, such as the ____ & ____ spaces.
* backwards (posterior)
* epidural and intrathecal spaces.
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These are the soft pads between each vertebra that act as shock absorbers.
intervertebral disc
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These are the openings between the vertebrae where spinal nerves exit the spine.
intervertebral foamina
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48
how is the intervertebral formaina formed?
* The anterior side of the foramen is formed by the vertebral body and the intervertebral disc.
* The posterior side of each foramen is formed by the facet joints, which are part of the vertebrae.
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how is each facet joint made?
* Each facet joint is made by two parts:
* The inferior articular process of one vertebra connects with the superior articular process of the vertebra right below it.
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whati s the function of the facet joints?
They help guide and limit the spine's movement, keeping the back's motions controlled.
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* what happens if a facet joint gets injured?
* what are the symptoms of this?
* it can press on nearby spinal nerves
* pain and muscle spasms in the area of skin served by that nerve (dermatome).
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# surface landmarks
where is the superior aspect of the iliac crest?
L4
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where is the posterior superior iliac spine?
S2
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54
what is tuffier's line [intercristal line]?
This horizontal line runs across the top edges of the hip bones (iliac crests) and matches the L4 vertebra
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Tuffier's Line helps identify the correct spaces between vertebrae for inserting spinal anesthesia needels.
* The space above this line aligns with the ____ vertebrae.
* The space below this line aligns with the ____ vertebrae.
* L3 - L4
* L4-L5
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56
in infants up to one year the intercristal line corresponds with the ____ intervertebral space
L5-S1
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57
The sacrum is a triangular-shape section of fused vertebra (5). The lamina of ____ is incomplete and bridged only by ligaments.
S5
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Sacral Hiatus
* location?
* covered by?
* purpose?
* Located at the base of the sacrum and aligns with the S5 vertebra.
* Covered by the sacrococcygeal ligament.
* Acts as an access point to caudal anesthesia
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Sacral Cornua
* The projections of the articular processes are known as cornu
* The sacral cornu are the “horns” or bony protuberances that guard the area of the ____
* Landmark for ____ anesthesia
* sacral hiatus
* caudal
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60
Components of the spinal cord?
* starts at the medulla oblongata
* conus medullaris
* caurda equina
* dural sac
* filum terminale
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61
the spinal cord has a ____ origin, starting in the ____.
* rostral origin
* medulla oblongata
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* What is the conus medullaris?
* where does it end in adults?
* where does it end in infants?
* where the spinal cord tapers off at the end
* In adults, it ends between the L1 and L2 vertebrae. (L1 in most textbooks)
* In infants, it ends at L3.
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* what is the cauda equina?
* what does it consist of?
* A bundle of spinal nerves extending from conus medullaris to the dural sac.
* Consists of nerve roots from L2 to S5 vertebrae and the coccygeal nerve.
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* what is the dural sac?
* where does it end in adults?
* where does it end in infants?
* The subarachnoid spaces ends at the dural sac.
* Ends at S2 in adults.
* Ends at S3 in infants.
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* what is the filum terminale?
* what is its main function?
* The filum terminale is a structure that continues downward from the end of the spinal cord.
* It is a continuation of the pia mater.
* It extends from the conus medullaris to the tailbone (coccyx).
* Its main function is to anchor the spinal cord to the coccyx.
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66
what are the parts of the filum terminale?
* Internal Filum Terminale:
* Begins at the conus medullaris, extending to the dural sac.
* L1-S2
* External Filum Terminale:
* Starts from the dural sac and extends into the sacrum.
* S2-S5
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67
how does the spinal cord receive blood supply?
* one anterior spinal artery
* two posterior spinal arteries
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Anterior spinal artery
* origination?
* supplies what part of the cord?
* how much does it supply?
* Originates from the vertebral artery.
* Supplies the front (motor) portion of the spinal cord.
* Supplies the anterior 2/3 of the spinal cord
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Two posterior spinal arteries
* Emerge from the ____.
* Originates from the ____ artery.
* Supply the ____ portion of the spinal cord.
* cranial vault
* vertebral
* posterior (sensory
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70
what part of the cord has better protection from ischemia the posterior or anterior?
* The posterior spinal arteries are paired and have many connections (collateral anastomotic links) from the subclavian and intercostal arteries.
* These connections help protect the sensory part of the spinal cord from ischemia.
* The anterior spinal artery, being a single artery, does not have as many protective links, making the motor part more vulnerable to ischemia.
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what are symptoms of anterior spinal artery syndrome?
If the anterior spinal artery is affected by ischemia, it can lead to:
* Motor paralysis.
* Loss of pain and temperature sensation below the affected area.
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what are causes of ischemia that can lead to anterior spinal artery syndrome?
* Low blood pressure (profound hypotension).
* Mechanical blockage.
* Blood vessel disease (vasculopathy).
* Bleeding (hemorrhage).
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the anterior spinal artery receives additional blood slupply through what branches?
The anterior spinal artery receives additional branches from the **intercostal and iliac arteries**, though these are variable.
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Artery of Adamkiewicz:
* what is it?
* where does it arise?
* damage to this can cause what?
* A crucial connection that supplies blood to the lower two-thirds of the spinal cord.
* It usually arises from the aorta between the T9and L2 regions
* Damage to this artery can also lead to anterior spinal artery syndrome.
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75
what are the spinous ligaments [posterior to anterior]?
* Supraspinous Ligament
* Interspinous Ligament
* Ligamentum Flavum
* Posterior Longitudinal Ligament
* Anterior Longitudinal Ligament
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Runs along the back, connecting the tips of the spinous processes from the upper back down to the lower back.
Supraspinous Ligament
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Located between the spinous processes, providing stability by joining adjacent vertebrae.
interspinous ligament
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* They are particularly thick in the lower back and form the sidewalls of the space outside the spinal cord (epidural space).
* Piercing this ligament indicates entry into the epidural space during procedures.
ligamentum flavum
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Runs along the back side of the vertebral bodies inside the spinal column.
posterior longitudinal ligament
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* Attached to the front of the vertebral bodies, running the length of the spinal column.
* Also connects to the outer fibers of the intervertebral discs, helping to bind the vertebrae together.
anterior longitudinal ligament
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81
what layers are transvered during a midline spinal?
* Skin
* Subcutaneous fat
* Supraspinous ligament
* Interspinous ligament
* Ligamentum flavum
* Dura Mater
* Subdural space
* Arachnoid Mater
* Subarachnoid space
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82
what layers are transvered during a paramedian approach?
* Skin
* Subcutaneous fat
* Ligamentum flavum
* Dura Mater
* Subdural space
* Arachnoid Mater
* Subarachnoid space
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paramedian approach
* Used when?
* Positioning:
* Use: When the interspinous ligament is calcified or the patient cannot flex their spine.
* Positioning: Can be performed while the patient is sitting, lying on their side, or face down.
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Paramedian Approach Procedure:
* Insert the needle 15 degrees off the spine’s midline.
* Position the needle 1 cm to the side (lateral) and 1 cm below (inferior) the space between the vertebrae (interspace).
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