Spinal & Epidural Anesthesia Flashcards
0
Q
_______ not completely fused in pediatric patient, can do caudal anesthesia (only on pediatric patient).
A
Sacral vertebrae
1
Q
- Lower angle of scapula = ____
- Top of iliac crest = _____
- Place when feeling patient’s back (on hips come across to medial section of back)
A
- L1
- L4-L5
- Tuffier’s Line
2
Q
When you have herniations, usually from?
*Want to get the widest space for the widest access for needle placement.
A
Intervertebral disk
3
Q
Vertebral Curves in Supine Position:
- High?
- Low?
A
- C5 & L3
* T5 & S2
4
Q
The building blocks of the spine are the individual bones called?
A
Vertebrae
5
Q
Purpose is to stabilize vertebral body?
A
Ligaments
6
Q
Ligaments:
1) Most anterior ligament that connects the apices of the spinous process.
2) Connects spinous process to spinous process, put needle through ligament here. Positioning very important.
3) Very thick ligament, just before epidural space.
A
1) Supraspinous
2) Interspinous
3) Ligamentum Flavum
7
Q
Ligaments:
1) Located behind vertebral body.
2) Typically ligaments that sit above C7, occasionally inject steroids for neck pain.
A
1) Longitudinal
2) Ligamentum nuchae
8
Q
Ligamentum Flavum:
- Extends from foramen magnum to?
- Tough, wedge shaped ligament, composed of?
- Thickest in _____ (3-5 mm @ ___ in adult).
- The so called yellow ligament
A
- Sacral hiatus
- Elastin
- Midline (L3)
9
Q
Protective membranes?
A
Meninges (continuous with cranial meninges)
10
Q
Spinal Meninges:
Thickest meningeal tissue. Begins at foramen magnum and ends caudally at S2.
*Abuts the ____ (subdural space)
A
Dura mater
*Arachnoid mater
11
Q
Spinal Meninges:
Principal physiologic barrier for drugs moving btw the epidural space and the spinal cord?
*Abuts the ____, giving rise to the subarachnoid space.
A
Arachnoid Mater
*Pia mater
12
Q
Spinal Meninges:
Contains CSF. Continuous with the cranial CSF and provides vehicle for drugs in the spinal CSF to reach the brain?
*Houses the spinal nerve _____ & _____.
A
Subarachnoid space
*roots and rootlets
13
Q
Spinal Meninges:
Adheres to the spinal cord?
A
Pia mater
14
Q
- In spinal we are depositing local anesthetic directly into ____ where nerve roots and rootlets are, onset is faster, will not need as much medication.
- In epidual anesthesia, giving med behind ______ in epidural space, has to go through dura, subdura and arachnoid space, onset much slower when compared to spinal (dosage will also have to be a little bit higher).
A
- CSF
* Ligamentum flavum
15
Q
Spinal Cord: Foramen magnum to ______ (terminates at _____).
Termination of the _____ @ S2.
A
Conus medullaris
L1-L2
Dural sac
16
Q
Dermatomes:
Portion of the spinal cord that gives rise to all the rootlets of a single spinal nerve is called a?
A
Segment
17
Q
Is the skin area innervated by a spinal nerve and its segment
A
Dermatone
18
Q
_____ is the skin area innervated.
Need to assess patient’s dermatomes to make sure level is blocked where it needs to be.
If _____ does not work, may need to go to plan B general anesthesia (would not do another spinal due to risk of local anesthetic toxicity)
A
Dermatome
Spinal block
19
Q
Example of test question: Pinky is innervated by?
Patient starts losing sensation in pinky, we were trying to block at level of T4.
*At ____ patient will start losing feeling of respiration.
(Start wondering if block is migrating up, place patient sitting up/arm up. Make sure patient does not lose airway.)
A
C8
C4
20
Q
CSF:
Volume - ____ in the subarachnoid space.
CSF volume replaced 3-4x/day.
Produce ____ cc/hr by the?
A
- 150 cc
- 21
- choroid plexus
21
Q
CSF:
-Specific Gravity?
A
1.004-1.008
22
Q
CSF replaces itself daily.
We think of specific gravity when we want to change the?
A
Baricity of local anesthetic
23
Q
Blood supply of the spinal cord: (3)
1) Responsible for 2/3 of flow?
A
1) Anterior spinal artery
2) Posterior spinal arteries
3) Radicular artery
24
Physiology of Neural Blockade:
Local anesthetic bathes the ______ in that space.
Nerve roots
25
Physiology of Neural Blockade:
1) Local anesthetic is injected into CSF?
2) Local anesthetic is injected into epidural or caudal space?
1) Sub-arachnoid Block (Spinal Anesthesia)
| 2) Epidural Anesthesia
26
Physiology of Neural Blockade:
*Overall Goal
1) _____ - interrupts transmission of painful stimuli
2) _____ - skeletal muscle tone
1) Sensory blockade
| 2) Motor Blockade
27
In pediatric patient's a ________ is like an epidural block, block sensory but get some motor.
Caudal Block
28
Neural Blockade of Subarachnoid Block (SAB) and Epidural Block:
1) Principal site is the?
2) _____ can occur at any point AND all points along the ______ extending from the site of drug administration to the interior of the cord.
1) Nerve root
2) Blockade
neural pathways
29
Subarachnoid block (spinal block) more profound response from _______ than epidural block.
Autonomic Nervous System
*If aiming for T10 block (umbilicus). At T10 will get autonomic block up to about T4.
30
Not just getting block at L4, getting some below and some above.
Will lose some of autonomic response - _____ or ____ (this is expected, this is not a complication). Make sure patient gets good ____, may want ____, phenylephrine or ephedrine at bedside.
- bradycardia or hypotension
- pre-hydration
- fluid
31
Physiology of Centroneuraxial Blockade:
Blocks all impulses regardless of fiber type: (4)
Nociceptive
Motor
Proprioceptive
Autonomic
32
Physiology of Centroneuraxial Blockade:
*The Purpose is blockade of ____ impulses.
(this impulse is a stimulus that causes pain or injury)
*However, ____ and ____ are also blocked!
* Nociceptive impulses
| * Autonomic and Motor
33
Autonomic and motor is an ______, we don't mean for this to happen, but can't prevent it.
Ancillary Block
34
Benefits of Neuroaxial Anesthesia:
1) Decreased _______ response to surgery and anesthesia when compared with general anesthesia.
2) Avoids?
3) Decreased incidence of post-op ______.
1) metabolic stress
2) airway instrumentation
3) nausea (as long as they are well hydrated)
35
Benefits of Neuroaxial Anesthesia (continued):
1) Less intra-operative _____ (good thing for patients with lots of coexisting diseases).
2) Post-op?
3) Allows patient to remain awake during?
1) sedation
2) pain relief
3) C-section
36
Disadvantages of Neuroaxial Anesthesia:
1) _____
2) Slower case start if challenging placement
3) _____ depends on experience
4) _____
(Patients talk about BP issues, what happened to their mother, etc.)
1) Hypotension
3) Failure rate
4) Urban legends
37
Considerations for choosing a regional technique: (4)
1) Anatomy
2) Age
3) Pregnancy
4) Pathophysiology
38
Considerations for choosing a regional technique:
1) Anatomy: do they have scoliosis, contractures, ____ - may make impossible to do
2) Age: ____ at extreme ages
3) Pregnancy: reduced volume in _____, compression of vena cava (problems with CO, decreased venous return. Never let them _____, lye on ____ so uterus is tipped, no compression of vena cava.
4) Physiology: _____ - may not want to do spinal
(consider epidural due to slower onset, will tolerate anesthesia better)
1) BMI of 45
2) dose requirements diminish
3) epidural space
lye flat
hip
4) Valvular disorders
39
Indications of SAB/Epidural:
*Sensory level of anesthesia required vs. adverse physiological effects of regional anesthesia
*Need to consider: (3)
1) Length of procedure
2) Post-op analgesia needs
3) Co-existing diseases
40
Indications of SAB/Epidural:
*Sensory level of anesthesia required vs. adverse physiological effects of regional anesthesia
____ using thoracic muscles to help push air out (leaning forward to breathe), if blocking T4, think your blocking T6 will not spontaneously ventilate very well. Using those accessory muscles to breathe.
COPD patient
41
You can ____ an epidural because your leaving the catheter in (can not do this with spinal, taking needle out). Patient needs _____ need to insert at the same time with spinal, can add later with epidural.
- Re-dose
| - Post-op pain relief
42
Indications for SAB/Epidural Block:
* Anesthesia
1) Sole anesthetic
2) Combined?
3) Combined?
* Do this with major abdominal procedures, lower extremity vascular cases.
2) Combined Subarachnoid Block (SAB) with Continuous Lumbar Epidural (CLE)
3) Combined General Anesthesia and Regional
* Put epidural in, do test dose to make sure it is working then put patient to sleep
43
Indications for SAB/Epidural Block:
*_____ - Postoperative, Labor and delivery
Analgesia
44
Absolute Contraindications for SAB/Epidural Block:
1) PATIENT REFUSAL!
2) Infection at injection site
3) Increased ____
4) Clotting defects/anticoagulant therapy (can be absolute and relative - depends on where you are, check levels)
5) Severe ____ or ____
6) ____ disease or ____
7) ____, inability to remain still for block placement
8) Bacteremia, Septicemia
3) ICP
4) hemorrhage or hypovolemia
5) CNS disease or meningitis
6) Hysteria
45
Physiologic Changes & Effects of Neuroaxial Blocks:
*Cardiac - Effects depend on ____ & ____ of the ANS
- Make sure patient is very well hydrated.
- Remember change in CO is due to ____ & ____. Make sure giving preload to make up for this.
* SPREAD AND BLOCKADE
| - Preload decrease and venous pooling
46
Physiologic Changes & Effects of Neuroaxial Blocks:
*Cardiac
~____ dilation > ____ dilation
~____ = decreases 15-25%, age dependent
~____ = decreases 10-15%
~HR decreases ___-____ (cardioaccelerators), unopposed vagal & decreased stimulation of right atrial baroreceptors
~____ = what is a safe "acceptable"level? HTN vs Normal patient
(can go a lot less low with HTN patient)
```
~Venous dilation > arterial dilation
~SVR
~CO
~T1-T4
~MAP decreases
```
47
In order for patient to be sensory free for C-section, block needs to be at ____ (nipple line). Assess ____ to make sure patient has this block.
____ is fast in onset, injecting medication directly into CSF.
- T4
- Dermatone
- Spinal
48
Physiologic Changes and Effects of Neuroaxial Blocks:
*Pulmonary
~Low levels of blockade will have a minimal effect
~As block ascends, ____ paralysis occurs, a perception of ineffective breathing and decrease ability to cough develops/protect airway.
~No direct respiratory effects except those r/t ____ unless high block
(___ - ___ = ____ nerve) = Patient will first say pinkies are tingling, get bed in?
- Accessory Muscle
- Positioning
- C3-C5 = phrenic nerve
- Reverse trendelenberg
49
*With ____ may see ischemia of the central respiratory centers causes respiratory arrest.
Profound hypotension
50
Physiologic Changes & Effects of Neuroaxial Blocks:
* Gastrointestinal
1) ____ (20%) goes along with low BP
* Cardiac is the major system affected, keep BP up, fluids
2) ____ - due to unopposed parasympathetic activity
3) Flow to ____ - BP dependent
4) Renal blood flow is autoregulated, not really affected.
5) Bladder dysfunction = ____ (common, not sure why). If no catheter is present avoid excessive IV fluids.
1) Nausea and Vomiting
2) Hyperperistalsis
3) Liver
4) Urinary retention
51
Physiologic Changes & Effects of Neuroaxial Blocks:
*Metabolic/Endocrine
1) Blocks the _____ to surgery
2) ______ may be blocked from the adrenal medulla
3) ______ is delayed
4) ______ - altered thermoregulation with vasodilation
1) Stress response
2) Catecholamine release
3) Cortisol secretion
4) Shivering
52
Techniques for SAB/Epidural Block:
_____ is CRUCIAL!
Position
53
Positioning: (need to have someone help you with positioning)
* _____ = forehead to the knees, thighs flexed up to abdomen
* _____ = Good for low lumbar/sacral block, improved midline anatomy
* Lateral decubitus
| * Sitting
54
SAB/Epidural Pre-procedure:
- Appropriate monitors
- _______
- Equipment for airway management and resuscitation is available
- Emergency drugs drawn and available
- Consider ____ prior to procedure (if necessary)
-Fluid bolus (minimum of 500-1000 cc prior to starting)
-Sedation
(never give to woman in labor, won't remember baby being born and what she gets the baby will get)
55
SAB Needles:
* Designed to spread the dural fibers and help reduce the occurrence of post dural puncture headache.
* Yields a distinct pop as pencil point penetrates the dura.
* Offers increased "tip strength" to minimize bending or breakage.
* Precision-formed side hole enables directional flow of anesthetic and reduces the possibility of straddling the dura.
* Tracks straight when advancing through ligaments toward the dura.
Pencil Point Needles (Sprotte)
56
SAB-Needles:
* Dural "pop" is less likely to be appreciated due to the sharper tip.
* Increased risk of postdural puncture headache due to increased trauma to the dura.
* Introducer may not be necessary depending on patient's size.
Cutting Needle (Quincke)
57
*Will hear dural pop with this needle? Less like with other.
*Pencil Point Needles (Sprotte)
58
This needle has an increased risk of postdural puncture headache due to increased trauma to the dura. (Other needle is decreased risk because it is designed to spread the dural fibers).
Cutting Needle (Quincke)
59
If patient is lateral want ____ to push fibers aside
Bevel up
60
Techniques of SAB/Epidural Blocks:
1) ____ = The most common approach, the needle or introducer is placed midline, perpendicular to spinous processes, aiming slightly ____.
2) Paramedian Approach (not tested on this)
Median Approach
| cephalad
61
Midline Approach - Tissue layers transversed for Epidural Block
1) Skin
2) SQ tissue
3) ?
4) ?
5) ?
6) ?
3) Supraspinous ligament
4) Intraspinous ligament
5) Ligamentum flavum
6) Epidural Space - Inject here!
62
Midline Approach - Tissue layers transversed for SAB
1) Skin > SQ tissue > Supraspinous ligament > Intraspinous ligament >
3) ?
4) ?
5) ?
6) ?
7) ?
8) ?
3) Ligamentum Flavum
4) Epidural Space
5) Dura mater
6) Subdural space
7) Arachnoid mater
8) Subarachnoid space - Inject here!
63
After Subarachnoid space will have ___ and ____ should not be in these spaces!
Pia mater and spinal cord
64
Placement of Spinal Anesthesia (SAB):
*Anatomic Landmarks identified: _____ & _____
(palpate transverse process of upper vertebrae, ensure midline)
*Sterile field>prep site>drape, sterile gauze wipe iodine>skin wheel
*_____ passed through, angled 10-15 degrees, slightly _____. Stop at?
- Superior Iliac crests & L4-5
- Introducer, 17 G
- Cephalad
- Ligamentum Flavum
65
Placement of Spinal Anesthesia (SAB): (continued)
* _____ inserted into introducer. Go from ligamentum flavum to?
* STOP when presence of ____ is determined (remove stylet and rotate 90 degrees x4).
* _____ CSF > inject dose slowly and after instillation ____.
* Needles removed intact and patient positioned.
- 25 G choice needle
- Subarachnoid space
- CSF
- Aspirate
- Aspirate CSF again
66
SAB & Epidural Block:
Want needle bevel ____ to longitudinal fibers.
Parallel
67
SAB:
Increased resistance as pass through? And then loss of resistance (pop) as pass through _____ to _____
* After this remove ____, confirm free flow of CSF (rotate 90 degrees x4)
* ____ before and after medication injection
- Ligamentum flavum
- dura to subarachnoid space
- Stylet
- Aspirate CSF
68
Epidural Block:
If puncture CSF high risk of post epidural headache, hole is so big patient will have continuous leak of CSF (headache gets worse and worse). If headache occurs, place patient ____ & ____.
Flat and hydrate
69
Epidural Placement:
This technique uses an air-filled glass syringe?
*Other technique known as the Continuous Catheter Technique
Loss of Resistance Technique
70
Epidural Insertion Sites? (3)
1) Thoracic
2) Caudal
3) Lumbar
71
Epidural Space:
Widest point is? (5 mm)
*Contains fat and blood vessels, closed space, medication and catheter deposited into _____ _____.
*Before you inject need to ____ - make sure you are not getting CSF, do not want to inject large amount of epidural medication into CSF.
- L2
- Potential Space
- Aspirate
72
Epidural Block:
* Spinal needle inserted (L2) _____ through layers to _____ (this is very thick, often a pop as needle pierces this). Once here, start bouncing through with glass air-filled syringe the final 2 cm. When _____ entered resistance is gone and fluid is easily injected (need to aspirate before injecting, make sure no CSF).
* This technique is known as?
- Perpendicular
- Ligamentum flavum
- epidural space
- Loss of resistance technique
73
Epidural Block:
Distance from skin to ligamentum flavum roughly?
At _____ should start feeling tough ligament, start bouncing here the final 2 cm until you feel loss of resistance.
* Epidural Catheter Placement:
* Advance catheter another _____ into the epidural space. For PARTURIENTS advance _____ into epidural space.
~ 4-6 cm
~ 4 cm
~ 2-3 cm
~ 4-6 cm
74
```
Spinal Anesthesia (SAB) - What affects spread:
1) the weight in grams of 1 cc of solution at a specified temperature?
```
2) the ratio of the density of a solution to the density of water (temp constant)?
3) the density of a solution to the density of another substance?
1) Density
2) Specific Gravity
3) Baricity
75
Spinal Anesthesia (SAB) - What affects spread:
*CSF specific gravity?
Local Anesthetic (LA) vs. CSF
1) LA is heavier than the CSF?
2) LA is lighter than the CSF?
3) LA is equal to CSF?
*1.004-1.008
1) Hyperbaric
2) Hypobaric
3) Isobaric
76
Spinal Anesthesia (SAB) - What affects spread:
* The ______ of the local anesthetic solution can be altered by the addition of dextrose/water or local anesthetic.
* These both produce reliable blocks?
* specific gravity
| * isobaric and hyperbaric solutions
77
Spinal Anesthesia (SAB) - What affects spread:
~Mix the local anesthetic with dextrose allows LA to settle in dependent areas? What is the SG?
- Hyperbaric
| - SG >1.11
78
Spinal Anesthesia (SAB) - What affects spread:
~Mix the local anesthetic with sterile water? SG?
- Hypobaric
| - SG <1.005
79
Spinal Anesthesia (SAB) - What affects spread:
~Mix the local anesthetic with CSF? SG?
- Isobaric
| - SG <1.006
80
Use with thoracic epidurals - saying your giving a block at this level, do not want it to go up or down?
Isobaric solution
81
Factors Affecting the Spread of the Local Anesthetic in SAB:
(and the ultimate extent of the block obtained)
* 3 most important?
4) Level of injection
5) Barbotage/Rate of injection
6) Direction of needle and bevel
1) Baricity of the LA solution
2) Position of the patient
3) concentration and volume injected
82
Factors influencing block height? (4)
1) Dose
2) Site of injection
3) Baricity
4) Position of patient
83
Decisions to consider when dosing SAB? (4)
1) Surgical site
2) Length of procedure
3) Body size (height/weight)
4) Physiology
84
When can the patient be discharged?
- Spinal: Can go from PACU to floor after _____ <____, stable and comfortable.
- Spinal: Can go from SDS to home after ____ & ____.
- 4 dermatome regression
-
85
Spread of Epidural Block:
*ALWAYS ____ and give a _____ prior to injection/use _____.
- aspirate
- test dose
- incremental dosing
86
Spread of Epidural Block:
Volume and Concentration of Local Anesthetic:
*____ volume of a ____ solution.
~Decreased sensory and motor blockade with wide segmental spread
~The quality and extent of the _____ is dependent upon volume and concentration of the local anesthetic
- Large
- dilute
- epidural block
87
For induction of Epidural Blockade: ____ to ____ of LA per segment.
*Repeat doses
1.25-1.6 ml
88
Involves the delivery of local anesthetic to the epidural space via injection through the sacral hiatus?
Caudal Block
89
Caudal Anesthesia:
1) ____ component of epidural space
2) Access via _____ and _____
3) Equipment ___ or ____ gauge needle and syringe
1) Sacral
2) sacrococcygeal ligament
sacral hiatus
3) 22 G or 23 G needle and syringe
90
Caudal Anesthesia - Uses:
1) ____ post-op pain
2) ____ (birth defect)
3) ____ repair
4) Procedures of the ____ & ____ regions
1) Pediatric
2) Hypospadias
3) Inguinal hernia
4) perineal & sacral areas
91
Caudal Anesthesia - Disadvantages:
1) Variably anatomy in _____ (often fused, difficult to hit epidural space)
2) High risk of injection into a?
3) Difficulty maintaining sterility should a ____ be used.
1) adults
2) venous plexus
3) catheter
92
* 1-4% incidence, due to decreased intracranial pressure with compensatory cerebral vasodilatation?
* Occurs within one day to one week of spinal or epidural anesthesia
Post-dural Puncture Headache
94
Complications and Management Spinal/Epidural/Caudal:
1) ____*
- Bradycardia, sudden cardia arrest, nausea/vomiting
2) Unintentional _____
3) Catheter ____
4) Really big complication!
1) Hypotension
2) Intravascular injections
3) Catheter shearing
4) Post-dural Puncture Headache
95
Complications and Management Spinal/Epidural/Caudal:
1) High blockade or inadequate blockade?
2) Neurologic complications = backache, infections (?), ____
3) This is a life threatening event! Patient's need to go to OR immediately! Can become paralyzed with this.
1) Post-dural puncture headache
2) Septic meningitis
Urinary retention
3) Epidural hematoma
96
Post-dural puncture headache - Treatment:
*Bedrest, hydration, oral analgesics, abdominal binder, ____ injection ____ or ____ patch.
epidural saline
| caffeine or epidural blood patch
97
Treatment of Post-dural Puncture Headache:
~If headache unresponsive to fluids, tylenol, bedrest need to do epidural blood/caffeine patch or epidural saline injection.
*This forms a clot over the meningeal hole preventing further leak?
1) Aseptic blood draw of 10-20 cc
2) Aseptic epidural injection of blood into epidural level (at same level or more ____ site (LOR or hanging drop technique).
*Epidural blood patch
| caudad
98
90% effective in relieving post-dural puncture HA?
-Side effects backache, ____ pain
Epidural blood patch
-radicular
99
Primary cause is coagulation defect?
Epidural hematoma
100
1) Patient presents with numbness or lower extremity weakness?
2) Consult neurosurgery immediately if this is suspected ____ before permanent injury.
3) Greater than ____ makes the odds of decompression less successful.
1) Epidural hematoma
2) 6-8 hours
3) 8 hours
101
Epidural Hematoma & LMWH:
1) Hold ____ pre-placement of epidural
2) Hold ____ post surgical procedure
1) 10-12 hours
| 2) 10-12 hours
102
* Symptoms of this will include: Neurologic, circum-oral numbness, tinnitus, vision changes, dizziness, slurred speech, restlessness, muscle twitching, and more symptoms
1) ____ followed by CNS depression, apnea, hypotension
2) Transient _____
3) ______ = continuous injection of local anesthetic can cause this, do not see much today (rare)
*Local Anesthetic Toxicity
1) Seizure
2) Transient radicular irritation
3) Cauda equina syndrome
103
```
Post-dural Puncture Headache:
Increased incidence with -
1) ____ patients
2) ____ more affected
3) ____ needle size
*Caucasian, pregnancy, dehydration, cutting tipped needles, multiple puncture attempts
```
1) Younger
2) Females
3) Larger
104
Use Tuohy needle with?
Epidural block
105
- With SAB usually insert needle at?
| - With epidural block usually insert needle at?
- L4-5
| - L2
