Neuraxial Analgesia
The Tuohy needles, and catheters have calibrated markers to determine
depth of insertion from skin
Tx for Post Dural Puncture HA
fluids, analgesics, caffeine, blood patch
T4 innervation must be blocked during epidurals for pain control
for abdominal procedures
Epidural space ends at the ________ ________
foramen magnum
Where do spinal nerves emerge?
intervertebral foramen
Two pedicles together and notches from what?
intervertebral foramina
Lordotic curvature
inward
How are dural fibers oriented?
longitudinally
When using cutting spinal needles you should align bevel
longitudinally, it may reduce incidence of PDPH
Anterior Artery syndrome results in
loss of motor loss
Indictions for epidural anesthesia are the same anatomic sites as spinal except for areas covered by _______ ______ _________
lower sacral roots
Where do spinous Processes project?
posteriorly
When performing neuraxial anesthesia it is important that you stay in the
midline
The Ventral half is
motor
Tetrocaine is more
motor block
Sensory,Motor are Larger and blocked when?
myelinated more slowly
Positioning for spinal rarely done in
prone position Perineal procedures doen in "jackknife position"
With epidural we generally put a _______ in
needle
Common complications of neuraxial anesthesia
nerve damage,bleeding, infection (rare)
Local anesthetics effect requires transfer across
nerve membrane
How do vasoconstrictors increase duration of LA?
reduce spinal chord blood flow, affect absorption of LA
The Vertebral Canal contains the spinal chord and it's
nerve roots
Demyelination disorders put patient at higher risk for
nerve toxicity with the use of LA
Also called conduction anesthesia or regional anesthesia
neuraxial anesthesia
Both spinal and epidural anesthesia are
neuraxial anesthesia
Using vasoconstrictors to La's associated with increased risk for transient __________ symptoms
neurologic
Kyphotic curvature
outward
What provides 25% of blood flow to the spinal chord?
paired posterior spinal arteries
When you enter the dura with a spinal you will encounter
resistance
In isobaric LA where does the drug stay after injection
right where you leave it
Consider _________/________ prior to administration of neuraxial anesthesia
sedation/analgesia
A Clot in a paired posterior spinal artery will result in _______ loss
sensory
Bupivicaine more
sensory block
Sensory anesthesia is assessed by ability to discriminate
sharpness (needle)
How are spinal needles classified?
size, tip design
Spinal needles are much _____ than epidural needles
smaller
Discussion for neuraxial anesthesia should include
specific benefits, and potential complications
When we talk about barcicity, we talk about?
specific gravity
Baricity and specific gravity of LA is compared in relation to
spinal fluid
Major site of action for an epidural
spinal nerve roots where dura is relatively thin to a lesser extent transfer across dura into SAS
Beyond Dorsal root ganglion are classified as
spinal nerves
If you leave a patient with head down after inserting a hyperbaric spinal you risk
spread to the phrenic nerve which innervates the diaphragm
When prepping for neuraxial anesthesia, In chloraprepping
start at the center and circle out
Caudal Anesthesia demands attention to
sterile technique
How are pedicles notched?
superiorly, inferiorly
other interspaces are counted up and down from
surface landmarks
Onset of spinal anesthesia order
sympathetic-sensory-motor
Epinephrine can be used to vasoconstriction vessels to decrease
systemic absorption
If the HR doesn't go up after the test dose of LA with epinephrine
then you know you are not in the intrathecal, and you know you are not in the vasculature You still don't know if you're in the epidural
Kyphotic curves
thoracic and sacral
There is more flexibility with respect to ________ in epidurals Epidurals can be extended into _________ ______ period
time Post-op
The supraspinous ligament runs from
tip of spinous process to tip of spinous process
Epidurals can take up to 10-15 minutes
to take effect compared to spinals which only take 5 minutes
Where do hyperbaric LA migrate when you lay a patient down supine?
toward the thoracic kyphotic curve
Anatomy of the spine includes anterior ______ _______ and Posterior ______
-Vertebral Body -Arch
High spinal can paralyze ________,_________ muscles impacting ability to cough and clear secretions
-abdominal -intercostal
Always ______ catheter prior to epidural injection for evidence of ______ or ________
-aspirate -CSF -blood
LA are weak _______ they exist largely in _______ form in commercial preparations
-bases -ionic
Morphine can cause _______ ________ depression due to circulation in spinal fluid up to the midbrain
-central respiratory
What does neuraxial analgesia require?
-complete understanding of anatomy for placement -physiology for appropriate conduct
Preganglionic Sympathetic Nerve fibers originate in the _______ and travel with _______ nerve roots
-cord -ventral
LA has to _______ _______ in the epidural space
-create voids
Baricity is ________ of LA relative to ________ of ________
-density -density -CSF
The Pia lateral forms ______ ligament which provides lateral suspension of the chord; at the end of the chord forms ______ _______ that attaches to posterior wall of _______ (longitudinal suspension)
-denticulate -filum terminale -coccyx
Lidocaine is good for ________ use and not ______ use
-epidural -spinal
Nerves give rise to ________, _________, ________
-epineurium -perinerium -endoneurium
The Epidural space is an irregular column of _______,_________ and _______
-fat -lymphatics -vessels
Continous spinal anesthesia allows for -Increased ________ for repeat _______ -Lower ______ -not used __________
-flexibility -dosing -doses -frequently
The Vertebral (Spinal) Canal extends from ________ _______ to ______ ______
-foramen magnum -sacral hiatus
3 different types of LA, that are injected with respect to baricity
-hyperbaric -hypobaric -isobaric
Sense of _________ to _______ due to proprioceptive loss of ________ muscles
-inability -breath -thoracic
Vasoconstrictors - _________ duration of ____ Epinephrine - (0.1-0.2 mg, 0.1-0.2 ml of 1:1000 solution) Phenylephrine (not as common) 2-5 mg, 0.2-0.5 ml of 1% solution
-increase -LA
Below the 8th cervical nerve, each spinal nerve passes through the _____ ______ of the corresponding __________
-inferior notch -corresponding vertebrae
Pia- _______ layer; Highly ________; closely applied to cord
-innermost -vascular
Myelin prevents LA from reaching the
Axon
Tx for a failed epidural: ______________ can be added on top Érapidly hydrolyzed in plasma, may provide adequate anesthesia for surgery to continue
Chloroprocaine
Curves _______ impact LA spread in epidural
DON'T
__________ __________ - during certain types of surgery (hips, trans-urethral resection of prostate) - associated with decrease in systemic blood pressure, peripheral venous pressure
Decreased bleeding
The area of skin innervated by each spinal nerve
Dermatomes
Postoperative problem with caudal anesthesia?
Infection
If the patient has strong hand grip
They are not in cervical distribution of the block
________ epidural injections - produce symmetric/greater dermatomal spread
Thoracic
-Downward angular spinous processes -Tight interlaminar spaces (Lumbar or thoracic?)
Thoracic Spine
associated with pain or sensory abnormalities in the lower back, buttock, or lower extremities. The symptoms of burning pain and paresthesiain the L5 and S1 dermatomes usually start after the effects of spinal anesthesia have concluded and may last up to hours to four days. Not associated with sensory or motor deficits.
Transient Neurologic Symptoms
Modest head down (5-10 degrees, does not significantly effectcephaladspread of LA) Volume Sympathomimeticswith inotropic, vasoconstrictor effects :Ephedrine, Phenylephrine
Treatment for hypotension of Sympathetic Blockade
What can you do to further accentuate cephalic spread in a hyperbaric solution?
Trendelenburg position
Specialized needle of epidural anesthesia
Tuohy needle
How many dermatomes higher is sympathetic blockade compared to sensory blockade?
Two dermatomes
Complications of Spinal Anesthesia ________ ________- Spinal impacts neural activity to and from bladder - large amts of IV fluids can cause bladder distention Avoid overhydratingin outpatients, minor surgery
Urinary retention
What engorges epidural veins? Increases likelihood of IV cannulation during attempted epidural placement? Reduces epidural effective volume?
Vena Cava Compression
When you attach your LA to your spinal needle , and withdraw to a degree you will see
a swirl of the CSF into syringe of LA
The sacral hiatus is _______ in 8% of adults
absent
You don't get creep with epidurals, so the only way to increase the level is to
add volume
Epi has __________ ____ adrenergic effect analgesia activity also
alpha 2
Spinal Anesthesia has little if any effect on resting ____________ ventilation
alveolar
Spinal catheters are very dangerous because they can be mistaken for
an epidural catheter
Prolonged sensory blockade after an epidural may be the result of
an epidural hematoma
Sympathetic C fibers
are blocked first during spinal anesthetics
BE careful injecting large does of Bupivicaine/Rocaine
because it's cardiotoxic
Spinal anesthesia is restricted to lumbar
below level of chord
Where does the epidural space lie?
between dura and wall of vertebral canal
Where does the first cervical nerve pass?
between occipital bone and first cervical vertebrae
Lordotic curves
cervical and lumbar
Where do posterior spinal arteries emerge from?
cranial vault
Which block is first occur?
Sympathetic block
You should use the smallest possible needle size (with introducer) for _________ _________ because they are highest risk for PDPH
-young patients
What is the most commonly used hyperbaric LA?
0.75% bupivacaine with 8.25% glucose
Assessment for level of anesthesia performed
1 minute after injection
Barcity does not come into place when the LA is injected into the
epidural space
In epidurals the catheter should be threaded 3-5 cm into the
epidural space
Epidurals take more ______ compared to Spinal Anesthetics
volume
What effects distribution of LA in CSF?
-Baricity of LA -Contour of Spinal Canal -Position of patient within first few minutes of injection
When you need long duration of spinal anesthesia consider
-Bupivicaine -Tetracaine
Duration of epidural Anesthesia: Affected by: Choice of local anesthetic Vasoconstrictor Use Most common LAs used: _______________- rapid onset and short duration ________________- intermediate onset/duration ______________.__________- slow onset, prolonged duration of action
-Chloroprocaine -Lidocaine -Bupivicaine/Rocaine
The Dura mater also covers the ______ and _____ nerve roots
-Dorsal -Ventral
Factors affecting spread of epidural are mostly _______ dependent, ______ dependent to a lesser extent
-Dose -Site
Side/Effects Complications from an epidural: ________ _______ - from vascular trauma during placement; If suspected, MRI urgent as recovery of motor function less likely as time passes ______ ______ - inadvertent penetration of dura with large Tuohy needle - PDPH highly likely ________ _________ - not as dramatic as with SAB, treat similarly
-Epidural Hematoma -Wet Tap -Systemic Hypotension
Test dose of local anesthetic - 3cc 1.5% __________ with __________ 1:200,000
-Lidocaine -Epinephrine
Before a neuraxial procedure, infiltration of ______ _______ to anesthetize skin and ________ tissue at site of entry (allow time to effect)
-Local Anesthetic -Subcutaneous
What does duration of LA depend on?
-Local anesthetic selected -Precense of vasoconstrictor
Epidural Insertion involves identification of epidural space via two methods
-Loss of Resistance -Hanging Drop
Most popular epidural technique ______ also used
-Midline -Paramedian
Epidurals are _______ instant onset, volumes have to be administered _______
-NOT -SLOWLY
Does baricity influence spread of epidural anesthesia? _________ is less of a factor in spread in epidural anesthesia
-No -Positioning
The Posterior Arch consists of: -Lateral cylindrical _________ -Posterior ________ -Transverse _______ -____________ Processes
-Pedical -Laminae -Processes -Spinous
Lines across posterior superior iliac spines represent
-S2 landmark caudal limit of dural sac in most adults
GI Impact- level above ______ - inhibition of sympathetic flow to GI tract (unopposed parasympathetic tone)- contracted ______, relaxed ________
-T5 -intestines -sphincters
The for curvatures of the spine are either _______ or _______
-lordotic -kyphotic
Increased blood flow to _________ _________- likely associated with decreased incidence of ________________ events.
-lower extremeties -thromboembolic
Damage to the artery of Adam results in bilateral _____ loss but preservation of _____ function
-motor -sensory
Injection of anesthetic into epidural can be through ______ or _______threaded into epidural space
-needle -catheter
-The touhy needle has single ______ tip or _________ tip (associated with better LA spread)
-open -multiorifice
Dura- ________ layer- extends from_______ _______ to ______-_____ ; tough fibre elastic membrane
-outermost -foramen magnum -S1,S4
Where do preganglionic sympathetic neurons project?
-paravertebral sympathetic ganglia -and more distant sites (adrenal medulla, mesenteric, and celiac plexi)
First 5-10 minutes after injection critical for adjusting level with _____________, _________, for cardiovascular responses (extreme vigilance)
-positioning -assessing
Modifications for Lidocaine include reducing dose from 100mg to 60-70mg and dilution of commercial formulation with equal volume of _______ or ______ before injection
-saline -CSF
In Epidurals ________ injection thru needle or catheter- simple, distribution of LA more uniform incremental dosing (5cc) over 1-3 min prudent
-single
Spinal anesthesia is generally a _________ shot technique
-single
Pt may be pretreted with IV fluid prior to ______ _________ to prevent __________
-spinal anesthetic -hypotension
Epidural Anesthesia is also used to __________ GA
-supplement
The spine provides structural _______ and critical protection of ______ ________
-support -neural structures
Structures passed through with spinal needle skin-________ ligament-interspinous ligament-__________ __________-________ space-________-Subarachnoid space
-supraspinous -ligamentum flavum -epidural -dura
You will get ________ effect at a higher level than __________ with a spinal,________ blockade is the lowest
-sympathetic -sensory -motor
Failure of spinals could be due to _______ or ________ of ______
-technique -maldistribution -LA
Lidocaine has issues with ________ _________ _________ and rare but permanent neurologic deficits (largely related to continuous spinal techniques but also with single dose)
-transient neurologic symptoms
The Artery of Adam enters vertebral canal in a ______ pattern On the ______ (80% of the time), commonly T9-L1 (T5-L4)
-variant -left
Nerves emerge from the _____ _____ and ________
-vertebral foramina -meninges
The total volume in a spinal is
2-3 cc MAX
How many true vertebrae are there?
24
How many pairs of spinal nerves are there?
31
Intravenous preload amount for neuraxial anesthesia
500-1000 ml
Duration of LA Lidocaine
60-90 min
There are _____ cervical vertebrae
7
True Vertebrae: Cervical- Thoracic- Lumbar- Sacral-
7 12 5 5
There are _____ cervical spinal nerves
8
What cervical nerve passes between C-7 and T-1?
8th cervical nerve
ÒPatient refusal ÒInfection at site of insertion ÒElevated intracranial pressure ÒBleeding/coagulopathy ÒSevere AS or MS ÒSeverehypovolemia ÒLA allergy ÒSevere uncorrected anemia
Absolute Contraindications for Neuraxial Anesthesia
-Mepivacaine, Procaine (less risk of transient neurologic syndrome, but risk none the less) -Chloroprocaine (preservative free) - 40-60 mg can produce excellent anesthesia with little/no risk of TNS (use of vasoconstrictors not recommended due to increase in side effects)
Alternatives to Lidocaine for short duration
What is the major pharmacologic barrier preventing movement of drugs from the epidural to subarachnoid space?
Arachnoid
The largest Anastomotic supply to the single Anterior Artery comes from the
Artery of Adamkiewicz (radicularis magna)
Complications of Spinal Anesthesia _________- usually assoc. with multiple attempts, surgical position, loss of curvature
Backache
7th cervical nerve passes above the
C-7 vertebrae
Until _____-______ impacted, spinal has no effects on respiratory impact
C3-C5
Is Spinal Anesthesia LA is injected into
CSF
You know you are in the subarachnoid space, when you see what?
CSF leak out of the hub
-Mitral Stenosis -Aortic Stenosis -Idiopathic hypertrophic aortic stenosis
Cardiac Disease contraindications to neuraxial anesthesia
_________interspaces are more prone to failure
Caudad
The Sacral Hiatus is an insertion site for
Caudal Anesthesia
-Local not delivered into epidural space -Spread of LA solution inadequate to cover relevant dermatomes -Local not delivered into epidural space -Spread of LA solution inadequate to cover relevant dermatomes
Causes for failed Epidural Anesthesia
If you were doing a thoracic epidural, you would have to angle your needle
Cephalad
_______________ not as effective as opioids, augments hypotension, sympatholyticeffects of LAs
Clonidine
alpha 2agonist located presynaptically to inhibit further release of epinephrine and norepinephrine.
Clonidine
-SpecializedTuohyinserted into epidural space -Spinal needle through hub into SAS -Epidural catheter inserted -Provides rapid onset and intense sensory anesthesia of a spinal with ability to supplement and extend duration unique to epidural
Combined Epidural
-0.75%bupivacainewith 8.25% glucose -5% lidocaine with 7.5% glucose -Tetracaine1% (make into 0.5% with equal vol. of 10% glucose)
Commercially Available LA solutions
-Large doses required for epidural anesthesia -Numerous venous plexuses in epidural space -Risk of substantial systemic absorption of LA -Rarely a problem, especially if vasoconstrictors are used
Considerations for Epidural Anesthesia
-Contour of vertebral canal is critical to distribution - consider supine (horizontal) -Thoracic/sacral kyphosis are dependent areas relative to lordoticpeak of lumbar area -Anesthetic delivered cephalad to peak will move toward dependent thorax
Considerations with hyperbaric solutions
DPS
Dorsal-Posterior-Sensory
There is increased risk for systemic absorption, due to higher vascularity in an
Epidural
Slower onset and less hypotension is
Epidurals
-Decreases vascular absorption -Maintains effective concentrations at nerve roots for longer periods -Limits systemic uptake -Lowers risk for systemic toxicity -Pronounced effects on duration of chloroprocaineor lidocaine
Epinephrine (1:200,000)
__________ -lipophilic, rapidly absorbed in systemic circulation, exhibits little rostralspread, site of action is dorsal horn a few segments above lumbar insertion site
Fentanyl
____________ (up to 25 mcg) - used for short surgical procedures (does not preclude discharge the same day)
Fentanyl
What is the baricity of most LA?
Hyperbaric
What baricity of solutions has: -limited use clinically -used for Prone procedures perineally -hip procedures (affected side up)
Hypobaric Solutions
Decreases venous return Decreases Systemic Vascular Resistance Directly related to level of anesthesia, intravascular volume status (exaggerated by hypovolemia)
Hypotension from Sympathetic Blockade
What Drains vertebral canal? Is Prominent in lateral epidural space? Empties into azygous vein?
Internal Vertebral Venous Plexus
What baricity of solutions has: -limited spread -can achieve more profound motor block and prolonged DOA compared to equivalent hyperbaric LA
Isobaric Solutions
Where does the spinal chord end?
L1-L2
The spinal chord in adults ends somewhere between
L2-L3
Three interspaces where we inject spina fluid
L3-4 L4-5 L5-S1
Do not intentionally perform spinal cephalic to
L3-L4
Paramedian approach is done at
L4-L5
Taylor approach gives you access to what interspace?
L5-S1
What position effectively eliminates influence on curvature of the spine on distribution of LA?
Lateral position
What has been the most popular choice of LA
Lidocaine
Requires use of 3-4 cc of air or fluid attached to needle. If bevel of needle is in a ligament, the resistance is high. As needle traverses ligamentum flavum and enters epidural space, resistance disappears and is easy to inject.
Loss of Resistance Technique
Loss of lordotic curvature during neuromuscular blockade can result in
Lower back pain
__________ epidural injections - produce preferential cephalad spread (negative intrathoracicpressure transmitted to epidural space)
Lumbar
-Nearly Perpendicular spinous processes -wide inter laminar space (Lumbar or thoracic?)
Lumbar Spine
The spinal cord is protected by 3 layers of connective tissue known as the
Meninges
This approach is: -Technically easier -Passes thru less sensitive structures -palpations of surface landmarks more and more difficult due to obesity
Midline
___________- hydrophilic, spreads rostrally within CSF, can produce analgesia for thoracic surgery when administered in lumbar region
Morphine
_______________ (0.1-0.5 mg) - can last up to 24 hours (admitted and monitored for respiratory depression)
Morphine
Spinal Anesthesia is _________ uniformly successful
NOT
You are ________ as likely to get a total spinal from an epidural as you are a spinal
NOT
Is the vasoconstrictor effect equivalent for all LA's?
No
-To enhance surgical anesthesia -Provide postoperative pain control -Lipid solubility is major factor in selection/use
Opiod adjuncts to epidural anesthesia
when added to LAs enhance surgical anesthesia and provide postopanalgesia (mediated at dorsal horn of cord)
Opiods
Common but relatively minor consequence of spinal anesthesia
PDPH
Use of the Whitacre,Sprotte designs associated with lowest incidence of
PDPH
Which spinal arteries have rich collateral anastomotic connections with subclavian and intercostal arteries?
Paired Posterior Spinal Arteries
This approach is generally: Typically 1cm lateral to the midline Variability in rostral/caudal plane Angled cephalad and medial Needle bypasses supraspinous and interspinous ligaments
Paramedial approach
What epidural approach is better suited for thoracic insertions due to angulation of spinous processes?
Paramedian approach
Spinals may migrate more cephalic in women because they have a larger
Pelvis
____________ is good choice for maintaining BP after a spinal block
Phenylephrine
-Due to loss of CSF thru hole in dura into epidural space -Downward displacement of brain -Stretch of sensitive supporting structures -Incidence related to age, diameter of needle -Transient, variable onset (hours to days Sx: migraine type headache, postural impact on symptoms
Post Dural Puncture Headache
Epidural Anesthesia has less risk for
Postural Puncture Headache
Up to 10-15% of patients Increases with increasing level of anesthesia Associated with block of cardioaccelerators and decreased venous return (Bezold-JarishReflex) Moderate Severity - usually responsive to Atropine, Ephedrine (treat symptomatic bradycardia in aggressive stepwise escalation) Bradycardia unresponsive to atropine - move to epinephrine (up to 1.0 mg)
Profound Bradycardia with spinal anesthesia
Open ended (beveled, cutting)
Quincke design
ÒBacteremia(small risk for epidural abcess, meningitis) ÒPre-existing neurologic disease - (multiple sclerosis) ÒChronic Back Pain - may exacerbate, patients may associate with block when not causally related. ÒSevere spinal deformity ÒUncooperative patient
Relative Contraindications for Neuraxial Anesthesia
Sympathetic blockade with an epidural is ______ onset than SAB
SLOWER
Opening between the unfused lamina of S4-S5
Sacral hiatus
What kind of block is used for perineal procedures (anorectal, genital, cerclage)?
Saddle Block
-takes less time to perform -less painful on insertion -profound sensory, motor block
Seen in spinal anesthesia
-Persistent neurologic complications -From direct trauma (needle, catheter) -Indirect - by mass effect (hematoma, abcess) -Paresthesia on insertion of needle -Withdraw and reinsert (never inject in face of paresthesia)
Side Effects, complications of spinal anesthesia
What provides 75% of blood flow to the spinal chord?
Single Anterior Artery
What receives anastomotic supply from intercostal, iliac arteries?
Single Anterior Artery
What position should you consider for caudad spread of a hyperbaric solution?
Sitting position
Positioning for Epidural/Spinal
Sitting/Lateral/Prone
Why do we inject in these areas? (L3-L4)(L4-L5)(L5-S1)
So that we miss the spinal chord
-Raises pH and shifts equilibrium toward non-ionized form -Promotes rapid onset -Dose is 1 ml of 8.4% to 10 cc local anesthetic (lidocaine or chloroprocaine) -Not added to bupivicaine
Sodium Bicarbonate
What is a more reliable block, epidural or spinal?
Spinal
What uses less LA spinal or epidural anesthesia?
Spinal Anesthesia
Continous spinal anesthesia involves inserting a catheter into
Sub Arachnoid space
Contains CSF, continuous with the cranial arachnoid space
Subarachnoid Space
Epidural blocks nerves exiting the
Subarachnoid space
-Apnea, loss of consciousness (associated with profound hypotension, bradycardia) - can quickly become resuscitation (Intubation- IV induction if vital signs allow) -Nausea - associated with hypotension - usually resolves when BP restored - can be related to parasympathetic dominance (glycopyrolate)
Symptoms of high spinal anesthesia
Line at the inferior angle of the scapula represent
T7
Repeat does of spinal increases risk for
TNS
Which approach is? ÉParamedianto access L5-S1 interspace(generally the widest interspace) ÉOften inaccessible from midline due to downward angulationof L5 spinousprocess ÉInvolves palpating posterior superior iliac spine ÉThen 1cm to toward midline, then 1cm caudad, 55degree angle medially.
Taylor Approach
What supplies critical blood flow to the lower two thirds of the spinal chord?
The Artery of Adam
VAM
Ventral-Anterior-Motor
Closed, pencil tip with side port
Whitacre, Sprotte
Can patients be completely awake or sedated to a degree in neuraxial anesthesia?
Yes
Do you prepare for GA and Neuraxial Anesthesia the same?
Yes
Are epidurals titratable?
Yes, level of block, degree of sensory/motor block
If you block cardioaccelerator fibers you may suffer from
bradycardia
Neuraxis
brain and spinal chord
Dexmetomidine,opiods,clonidine,epinephrine
can all extend duration of LA
The epidural catheter should be pointing
cephalic
You get more _______ spread with hyperbaric solutions
cephalic
At rest relaxed breathing is
diaphragmatic
If you are looking at a patient's back you are looking at the _______ aspect of the spine
dorsal
Posterior spinal arteries supply ________ portion of spinal chord
dorsal (sensory)
Sensory neurons
dorsal root
The Tuohy needle may rest against or tent ______ without penetration
dura
Caudal is technically _____ to do in children
easy
With abnormal coagulation you have a high risk of _______ hematoma
epidural
With a total spinal you will see
hypotension, bradycardia,respiratory arrest, loss of consciousness
Lines across the ______ _______ - traverses the body of L4
iliac crest
Surgical Procedure involving the lower abdomen, perineum, and lower extremities
indications for spinal anesthesia
Sensory Nerves can regenerate but
it takes a long time
Where do the transverse processes project?
laterally
Sympathetic fibers are smaller and blocked when?
unmyelinated FIRST
Epidural techniques can be done
up and down the spine
The vertebral body is ______ to the spinal chord
ventral
The single anterior artery supplies the ______________ portion of the spinal chord
ventral (motor)
Motor neurons
ventral root
Where does the single anterior artery emerge from?
vertebral artery
If the CSF clears from blood after entering the subarachnoid space
you are clear to inject LA
If you get blood when you enter the subarachnoid space
you are likely not midline, off laterally
As you block the ANS higher and higher
you get more hypotension and vasodilation
Never withdraw the catheter back through the Tuohy needle why?
you will Shear it and leave the catheter inside the patient