Spinal & Epidural Lecture 1 Flashcards
(97 cards)
1
Q
What types of anesthesia are included in the tern neuraxial anesthesia?
A
- Spinal
- Epidural
- Combined spinal and epidural (CSE)
- Caudal
2
Q
When is caudal anesthesia used?
A
In pediatrics
3
Q
What are common surgical procedures when neuraxial anesthesia is used?
A
- Lower abd, perineum, lower extremities
- Orthopedic surgery (knee/hip)
- Vascular surgery on legs
- Thoracic surgery (adjunct with GETA)
4
Q
How is epidural used as an adjunct to GETA with thoracic surgeries?
A
Allows pt to perform exercises (breathing and ambulation) by optimizing post op pain management
5
Q
What common issues with surgery does neuraxial anesthesia reduce?
A
- Post op ileus
- Thrombotic events
- PONV (by reducing opioid use and volatiles)
- Respiratory complications
- Bleeding
- Narcotic usage
6
Q
Patients with spinal anesthesia can sometimes take longer to ________ because the bladder is distended
A
Urinate (still less urinary retention than GA)
7
Q
List other benefits of neuraxial anesthesia:
A
- Mental alertness
- Less urinary retention (spinal more of an issue)
- Quicker to eat/void/ambulate
- Avoid unexpected overnight admission from complicated GA
- Quicker PACU discharge times (depending on if spinal causes urinary retention)
- Preemptive anesthesia
- Blunts stress response from surgery (sympathectomy)
8
Q
What constitutes a relative contraindication?
A
Depends on situation→ can create extra work
9
Q
What is the most common absolute contraindication for neuraxial anesthesia?
A
Patient refusal
10
Q
What are some relative contraindication for neuraxial anesthesia?
A
- Spinal column deformities (spinal stenosis, kyphoscoliosis, ankylosing spondylitis)
- Preexisting diseases of the spinal cord (MS, Post polio syndrome)
- Chronic headache/backache (informed consent of potential CSF leak complication)
- Unable to perform SAB/epidural after 3 tries
11
Q
How many attempts does each provider get to perform SAB/epidural?
A
3
12
Q
How does length of time for each of these anesthetics compare: Spinal, GETA, Epidural
A
- GETA takes the longest
- Epidural longer than spinal
- Spinal shortest
13
Q
What is the American Society of Regional Anesthesia and Pain Medicine (ASRA) in range PT? What AC is it measuring?
A
- 12-14 seconds
- Coumadin
14
Q
What is the ASRA in range value for INR? What anticoagulant is it measuring?
A
- 0.8 - 1.1
- Coumadin (intrinsic)
15
Q
What is the ASRA in range value for aPTT? What anticoagulant is it measuring?
A
- 25-32 seconds
- Heparin
16
Q
What is the ASRA in range value for bleeding time? What is bleeding time looking at?
A
- 3-7 min
- Platelet function
17
Q
What is the ASRA normal platelet count?
A
150,000 - 300,000 mm3
18
Q
Why is it important to know the patients clotting levels before neuraxial anesthesia?
A
Need to know what they are and need to know the hospital policy for administering neuraxial and lab parameters
19
Q
What are absolute contraindications for neuraxial anesthesia?
A
- Coagulopathy (risk epidural hemotoma)
- INR >1.5
- Plt <100,000 (look at trends)
- Nagelhout x2 (PT, aPTT, BT)
- Known coagulation disorder or taking AC
- Pt refusal (opt for GETA)
- Evidence of dermal site infection
- Severe of critical aortic or mitral stenosis (<1.0cm2)
- Hypertrophic subaortic stenosis
- Length of procedure (longer surgeries cant use spinal)
- Increased ICP
- Severe CHF (EF <30-40% preload dependence)
20
Q
What are clinical symptoms of aortic stenosis?
A
- Angina
- Syncope
- Heart failure
21
Q
What is the survival rate for aortic stenosis with heart failure?
A
2 years
22
Q
What factors are involves in the intrinsic and extrinsic pathways?
A
23
Q
What is the survival rate for someone with aortic stenosis with syncope?
A
3 years
24
Q
What is the survival rate for pt with aortic stenosis and angina?
A
5 years
25
How does hypotension (potential complication for neuraxial) cause harm to the patient?
26
Explain how SAB is only "one attempt"?
Once the needle is out you cant put it back and there is no catheter like an epidural
27
What type of neuraxial can be used in a case that is around 4 hours?
Epidural→ Can give additional LA through the catheter if the local is wearing off
28
What is the onset, spread, nature, motor and chance of hypotension associated with spinal blocks?
- Rapid onset
- Put the patient flat and it may spread higher than expected (upward)
- Numbs and creates dense motor block
- Common to have hypotension
- T1-T4 cardiac accelerators (spinal travels there when the patient is laying down= sympathectomy)
- instant responses with spinal when in right place
29
What is an indicator that the spinal anesthetics is working/ in the right place?
Hypotension and bradycardia (sympathectomy)→ Cardiac accelerators T1-T4
30
What is the onset, spread, nature of block, motor block, and risk of hypotension associated with epidural anesthesia?
- Slow onset
- More controlled spread→ controlled with volume of LA
- Segmental block (go up segments by giving more mL)
- Minimal motor block
- Less hypotension than spinal
31
If you are giving and epidural at L4 but want to block up to T10 how do you accomplish this?
Epidural= segmental block→ so give more mL
32
What is the onset of spinal block?
Rapid (5 min)
33
What is the onset of epidural block?
Slow (10-15 min)
34
How does the duration of a spinal block compare to duration of epidural block?
- Spinal block duration is limited and fixed
- Epidural block duration is unlimited (catheter to add more La if needed)
35
What are the placement level for spinal (SAB)?
- L3-L4
- L4-L5
- L5-S1
36
What is the placement level for epidurals?
Any level
37
What is an important factor to consider when using spinal block for a procedure?
Want to know the length of procedure to decide which LA to use (can only give once)
38
How does placement difficulty compare with spinal and epidural?
Spinal placement is easier that epidural
*More skill required for epidural placement*
39
How is dose/concentration of local anesthetic for spinal anesthetic determined?
- Dose based local anesthetic→ small amount of LA
- Usually use 3cc max for spinal
- Higher concentration of LA for spinal
40
Which type of neuraxial is LA systemic toxicity a concern?
- Epidurals→ veins in the space where systemic absorption can happen (aspirate first and test dose before injecting full LA)
- Spinal→ no veins in subarachnoid space= no risk of LAST
41
How is the dose/concentration of LA for epidural determined?
Volume based (segmental)→ concentration of epidural LA is lower than spinal concentration
42
How can we manipulate dermatome spread after dosing an epidural?
Incremental spread based on volume (1-2 mL per segment)
43
How many mL would you give via epidural if trying to block T4-L4?
12mL incrementally (1-2mL per segment and we are trying to block 12 segments)
44
Which type of neuraxial technique does baracity of the LA matter?
- Spinal→ subarachnoid space has CSF so the baracity matters because there is fluid in the space for the med to potentially travel
- Epidural→ no CSF in the epidural space, only potential space so baracity doesnt matter
45
What is included in the epidural space?
- Fats
- Veins
46
If you give a hyperbaric spinal anesthetic in the subarachnoid space, but want LA to move higher...what should you do?
- Hyperbaric= sinks
- To move LA up trendelenburg and start checking sensory perception of patient
47
What is a good technique to test if the patients sensory function is present or not?
*Sensory travels with pain and TEMP*
Use something cold like alcohol swap or cold metal spool to check sensory function within 1st 5 min of spinals anesthetic
48
What happens if your needle goes too far and punctures the dura?
- "Wet tap"→ causes headache
- If it happens it usually occurs in skinny patients
49
How does gravity influence spinal and epidural anesthesia?
- Spinal: Gravity with baracity
- Epidural: Gravity with position
50
How many vertebra do adults have?
33
51
List number of cervical, thoracic, lumbar, sacral and coccyx vertebra:
Cervical: 7
Thoracic: 12
Lumbar: 5
Sacral: 5
Coccyx: 4
52
A) Normal (4 curves in the spine)
B) Scoliosis
C) Kyphosis
D) Lordosis
53
What is the landmark to palpate the center/median aspect of the spine?
Spinous process
54
What is a common issue why students miss spinal/epidurals?
They arent centered
55
What is the portion of the vertebra that houses the spinal cord, nerve roots, and epidural space?
Vertebral foramen
56
Why is the site for spinal anesthesia in the lumbar region of the spine?
Spinal cord doesnt extent to lumbar region
57
What 2 parts of the vertebra connect the anterior and posterior segments?
- Lamina
- Pedicle
58
What are the 2 main parts of each vertebra (aside from C1)?
- Anterior segment (body)
- Posterior segment (vertebral arch)
59
What is a protective cushioning around the spinal cord?
Epidural space
60
How does the spinous process differ higher up in the spine (thoracic) compared to lower in the spine (lumbar)?
- Thoracic spinous process more caudal
- Lumbar spinous process more horizontal
61
What are 2 important positions to obtain neuraxial access? How does needle angle differ when accessing thoracic vs lumbar areas?
- Patient position
- Needle angle
- Thoracic access increased needle angle or access above (cephalad)
- Lumbar access less needle angle more horizontal
62
Openings between vertebra where spinal nerves exit the spine:
Intervertebral foramina
63
What forms the anterior side of the intervertebral foramen?
- Vertebral body
- Intervertebral disc
64
What forms the posterior side of the intervertebral foramen?
Facet joints (part of the vertebra)
65
How does disc degeneration impact potential neuraxial access?
- Creates smaller cushion between the vertebra and foramina becomes smaller and can press on spinal nerves causing pain, numbness, weakness
- Will be harder for patient to get in right position for access
66
What is each facet joint made by?
Inferior articular process of one vertebra and the superior articular process of vertebra below it
67
What is the function of facets joints?
- Guide and limit the spines movement
- If injured can press on nearby spinal nerves
- Symptoms: this pressure can cause pain and muscle spasm in area of skin served by that nerve
68
What vertebra corresponds to the superior aspect of iliac crest?
L4
69
What vertebra corresponds to the posterior superior iliac spine?
S2
70
What is the name for the horizontal line that runs across the top edge of the hip bones and matches L4 vertebra?
Intercristal line/ Tuffier's line
71
Where is the safest place for a subarachnoid block (spinal)?
Tuffier's line (L4)
72
What vertebra corresponds with the vertebral prominens?
C7
73
What vertebra corresponds with the root of spine of the scapula?
T3
74
Which vertebra does the sacral hiatus align with?
- At the base of sacrum and aligns with S5 vertebra
- Covered by sacrococcygeal ligaments
75
What is the landmark for caudal anesthesia?
Sacral cornu (like a horn at the bottom of babies spine)
76
Where is the needle/LA inserted for caudal anesthesia?
Sacral hiatus→ center of sacral cornu
77
Is caudal anesthesia spinal or epidural?
Epidural→ no CSF and the LA is put into a potential space
78
What vertebra does CSF stop at?
End of dural sac
- S1/S2 in adults
- S3 in infants
79
What is rostral origin of the spinal cord?
Medulla oblongata
80
What is the place where the spinal cord ends called and at what vertebra level for adults and infants?
- Conus Medullaris
- Adults: L1/L2
- Infants: L3
81
What is the cauda equina and how far does it extend?
- Cauda Equina= Bundle of nerves extending from conus medullaris to dural sac
- Nerve roots from L2- S5 and coccygeal nerves (2 nerves at each SC level)
82
What is the filum terminale and how far does it extend? What is its main function?
- Filum Terminale: continues down from the end of the SC→ continuation of the pia mater
- Extends from conus medularis to coccyx (tailbone)
- Function is to anchor SC to the coccyx
83
Where does the internal filum terminale start and end?
Begins at conus medularis extending to dural sac
84
Where does external filum terminale start and end?
Starts at dural sac and extends into sacrum
85
What is the primary function of the anterior spinal artery (1)?
Motor (comes from vertebral artery)
86
What is the primary function of the posterior spinal arteries (2)?
Sensory (comes from vertebral artery)
87
What happens if anterior spinal artery is affected by ischemia (Anterior spinal artery syndrome)?
- Motor paralysis
- Loss of pain/temp sensation below affected area
88
Where does the Artery of Adamkiewicz arise from?
T7-T9 and L2 regions
89
IF approaching midline for spinal anesthesia, what order of layers you do trasverse?
90
If approaching paramedian for spinal anesthesia access what layers do you traverse?
91
When is paramedian approach indicated for spinal anesthesia?
- Interspinous ligament is calcified
- Patient cannot flex spine
92
What is the process for paramedian approach and how does the needle angle change?
- Insert needle 15 degrees off the spine midline
- Position needle 1cm to the side and 1cm below the space between the vertebra
93
Which space do you hit first when performing neuraxial anesthesia?
Epidural first the subarachnoid space
94
What happens if you inject LA into subdural space?
- LA will not work→ patient will still have sensation and movement
- Subdural space= potential space between dura mater and arachnoid mater
95
Where are the veins in the epidural space located?
Lateral side of the epidural space
96
Order of meningeal layers from outer to inner:
- Dura mater
- Arachnoid mater
- Pia mater (covers spinal cord)
97
What are the boundaries of the epidural space?
- Cranial border: Foramen magnum
- Caudal border: Sacrococcygeal ligament
- Anterior border: Posterior longitudinal ligament
- Lateral borders: Vertebral pedicles
- Posterior borders: ligamentum flavum and vertebral lamina
