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