How many vertebrae are there?

how many:

cervical

thoracic

lumbar

sacral

coccygeal

33 Vertebrae:

7 cervical

12 thoracic

5 lumbar

5 sacral (fused; S5 not fused posteriorly = caudal space/sacral hiatus)

4 coccygeal (fused)

angle of the spinous processes

natural curvatures of the spine

abnormal curvatures of the spine

effect of positioning of needle on above

What is the shape of the interlaminar foramen?

What enlarges it?

triangular shaped

base is formed by upper edge of the lower vertebra's lamina

flexing slides the articular processes upward enlarging the interlaminar foramen

(Pt flexion forward does this)

What are the curvatures of the spine at the cervical and lumbar curves?

What about the thoracic and sacral curves?

Spinal curves have significant impact on ____ of __________?

cervical & lumbar curves are convex anteriorly

thoracic & sacral curves are convex posteriorly

Spinal curves have significant impact on spread of Local Anesthetic.

Where are the high and low points of the spine in the supine position?

T/F Hyperbaric spinals rise to these high points?

high points of the cervical and lumbar curves are at C5 and L5

low points of the thoracic and sacral curves are at T5 and S2

F - hyperbaric spinal falls to low points 

Where is the ligamentum flavum the thickest?

How thick is it?

Where is it farthest from the spinal meninges?

thickest in the midline:

3-5mm at the L2-3 interspace of adults

farthest from the spinal meninges in the midline

In regards to the ligamentum flavum, why is midline insertion of an epidural needle optimal?

What are 2 spinal ligaments not penetrated during spinal or epidural anesthesia?

Where are they?

What do these ligaments provide?

anterior and posterior longitudinal ligaments

run along the anterior and posterior surfaces of the vertebral bodies

provide stabilization

What is the subdural space?

Where may you see subdural injections?

potential space between dura & arachnoid

may see subdural injection in:

 less than 1% of intended epidurals

up to 10% of intended subarachnoid blocks

Describe the arachnoid mater.

What is it the primary barrier to?

Describe the subarachnoid space.

delicate, avascular membrane

primary barrier to movement of drug from epidural space to Spinal cord

subarachnoid space between arachnoid and pia mater contains CSF - contiguous with cranial CSF

Which meninge is closely adherent to SC?

How is it connected to the adjacent meninge?

pia mater

connected to arachnoid mater by trabeculae

What kind of intercellular spaces does the pia mater have?

What happens to it at the tip of the SC; what is its job there?

The pia mater is fenestrated.

at tip of SC, becomes the filum terminale, anchoring the cord to the sacrum

Where does the SC extend in the developing fetus?

In a term newborn where does the SC end?

1st trimester-spinal cord extends entire length of vertebral column

term newborn-SC ends at L3

Where does the SC end in the adult?

What does flexion of the vertebral column produce?

Adult

60% end at L1

30% end at L2

10% end at L3

flexion of the vertebral column produces slight cephalad movement of the distal end of cord

How many pairs of spinal nerves are there?

Where are the motor and sensory roots?

31 pairs of spinal nerves

anterior = motor root

posterior = sensory root

What is a dermatome?

T4 is where?

T6?

T10?

a skin area innervated by a given spinal N

T4 = nipple

T6 = xyphoid

T10 = umbilicus

How many posterior spinal arteries?

The posterior spinal arteries supply blood to the ________ portion of the SC?

2 posterior spinal arteries

dorsal, sensory portion of cord

(have extensive collateral supply from subclavian and intercostals)

2 posterior spinal arteries

1 anterior spinal artery

Where does the anterior spinal artery originate from?

What does it supply?

originates from the vertebral artery

supplies the ventral, motor portion of cord

What is the Artery of Adamkiweicz?

Where does it come from?

Where does it supply crucial blood supply?

largest anastomotic link of anterior spinal artery

comes from the aorta, typically entering on the left at the L1 vertebral foramen

crucial blood supply of lower 2/3 of anterior cord

What is Anterior Spinal Artery Syndrome?

What causes it?

T/F Posterior spinal artery syndrome is common as well and affects the sensory part of SC.

bilateral lower extremity motor weakness; also with loss of bowel and urinary control

(not sensory)

Damage to the artery of Adamkiewicz

F - since there are 2 posterior arteries even if one is damaged the other will supply blood to the posterior SC.

Where is the extensive venous plexus for the spinal cord located?

Where does it drain into?

extensive venous plexus located primarily in the lateral epidural space

drains into the azygous vein & then the vena cava

What may dilate the venous plexus in the lateral epidural space?

What problems can this cause with anesthesia?

increased abdominal pressure or a mass compressing the vena cava may dilate the venous plexus in the epidural space

this increases:

-probablility of puncturing a vein during epidural placement

-spread of LA d/t decreased effective volume of epidural space

(the block may be higher than anticipated b/c dilated veins take up a lot more space = less epidural space for drug to distribute in)

Increasing concentrations of LA will produce blockade in what sequence?

What is the significance of this?

Autonomic - Preganglionic sympathetics - B fibers

Sensory - Pain, Temperature - Small A fibers

Motor - Large motor - Large A fibers, C fibers

Useful in performance of differential block for diagnosis in pain management

SNS, sensory, & motor block will reach different levels following central neuraxis anesthesia

Where is the sympathetic block in relation to the sensory block?

Motor block?

Where is site of action for central neuraxis?

sympathetic block

2-6 levels above sensory block

motor block (& sometimes proprioception)

2-3 levels below sensory block

Not completely certain but the current idea is that it is at nerve root, not cord itself per lec

What is the difference in magnitude of a block d/t?

What are 2 potential problems with a differential block?

likely d/t decr concns of LA in CSF as a fcn of distance from the injection site

Problems:

-may be distressing to the pt

(ie if a pt can still move they may be afraid that they will feel too - reassurance & explanation is needed)

-sympathectomy

(blocks vasoconstriction etc in areas of block = more PNS tone and possible bradycardia and hypotension)

hypotension and bradycardia

primarily due to blockade of sympathetic efferents

related to block height

What are the risk factors for hypotension from a spinal? (4)

How can you help prevent this?

age >50 years

hypovolemia

concurrent GA

addition of phenylephrine to LA (decr BP more)

preop fluid loading

age <50 years (stronger PNS drive)

ASA 1 physical status classification

B-blockade

What are the HD changes from a spinal that cause hypotension?

Which makes the bigger impact?

d/t both arterial and venodilation

venodilation likely makes the bigger impact

What level of a spinal causes blockade of the cardioaccelerator fibers?

What does decreased preload cause?

blockade of cardioaccelerator fibers at T1-T4

decr preload causes cardiac stretch receptors to reflexively slow HR

spinal - better, faster, and less hemodynamic derangement

*epidural without epi is actually a bit more stable per lecture, but epidural with epi = much greater increase in HR and decrease in BP.

prehydration

vasopressors

What fluid regimen has been shown to reduce hypotension prior to doing a spinal?

Is this a reliable measure?

500-1500mL of crystalloid has been shown to reduce hypotension in some studies

no, does not reliably protect against hypotension

What vasopressor should be used to treat spinal-induced hypotension? Why?

When should you treat it?

Ephedrine 5-10mg boluses

alpha+beta preferable to pure alpha agonist

When to Treat - guidelines only:

25-30% drop from baseline BP

HR <50-60/min

(watch for a high block in a young person)

What respiratory effects can be seen with a high block?

What may patients complain of?

What can help them?

Respiratory effects are typically minimal but accessory muscles of respiration can be compromised by high block

-caution when used in patients dependent on accessory muscles (ie COPD)

-patients may complain of dyspnea due to lack of sensation of the chest wall moving

-typically responds to reassurance

What is respiratory arrest related to?

What does it respond to?

rare episode of respiratory arrest r/t hypoperfusion of brainstem resp centers, not phrenic paralysis

-responds to improvement in CO and/or BP

GI effects

What does a sympathectomy produce?

Effects seen? (4)

produces unopposed parasympathetic activity:

1. increased secretions

2. relaxation of sphincters

3. increased peristalsis

4. constriction of the bowel (this may improve

    surgical conditions)

What is N/V associated with from spinal? (4)

What is a common tx of N/V assoc. with spinal per lecture?

1. hypotension

2. block height greater than T5

3. opioids

4. hx of motion sickness

ephedrine

What renal effects may be seen with a spinal?

Probably not any more severe than with patients receiving ___________?

may see urinary retention following both spinal and epidural anesthetics

probably not any more severe than with patients receiving parenteral narcs

Endocrine/Metabolic

What may spinal and epidural anesthesia inhibit?

When is the greatest effect seen?

Unclear whether morbidity and mortality are ________ but evidence is accumulating

Inhibit the surgical stress response d/t blockade of efferent sensory input

greatest effect with LE & lower abd. surgery

Unclear whether morbidity and mortality are reduced but evidence is accumulating

What are the 2 basic styles of spinal needles?

What type of needle produces fewer PDPHAs?

Cutting (Tuohy, Quincke)

Pencil point (Whitacre, Sprotte)

a smaller gauge, pencil-point needle produces fewer PDPHAs than a larger gauge, cutting type needle

sharper, easier to get thru skin

no introducer needed unless very small needle used

What is the advantage of a pencil point needle? (2)

What is a CSE needle?

How does it work?

decreased PDPHA

"better" tactile feel

Combined spinal epidural needle

larger needle is used to get into epidural space and then a smaller spinal needle is put through epidural needle and then into subarachnoid space

see pic in packet

In preparation for a spinal, what should drug selection be appropriate to?

What are the considerations of selecting an appropriate drug?

-duration & unique features of procedure

-which LA?

-addition of:

vasoconstrictor

alpha-2 agonist

narc - Fentanyl vs Morpine

-hyperbaric vs hypobaric vs isobaric

POSITION!

POSITION!

POSITION!

Hyperbaric - operative side down

Hypobaric - operative side up

comfortable for the pt

easy position to maintain with sedated pt

knees flexed

shoulders rounded

(no need for neck flexion b/c that doesn't change back position)

lower back bowed out

(opens spaces, gets rid of lordosis)

lateral decubitis

sitting position

prone

useful in morbidly obese patients or those with difficult anatomy

useful when a low level is desired, as in perineal surgery

feet resting on stool

keep low back bowed out to minimize lumbar lordosis

Prone

What position is the patient usually in?

What does this allow for?

usually in the jackknife position when surgery will require this position

allows pt to position themselves

What procedures is the prone position useful for?

What maybe required when placing the spinal in the prone position?

useful for rectal, perineal procedures

may require gentle aspiration on needle as CSF won't flow uphill

prone (not jackknife) for caudal epidural placement in adults

(rare for surgery, more common in pain clinic)

Monitors On

Sedation as appropriate

Oxygen as needed

(usually NC adequate; use mask if give propofol per Anderson)

Do a good, WIDE prep with betadine, chlorhexidine, etc

-you may not be successful at your chosen interspace

When placing the drape for a spinal, what should you pay particular attention to?

Once the drape is on, don't...

What can you use for drape?

pay particular attention to maintaining a sterile field

once you lay the drape on, don't pick it back up and move it

clear plastic

paper

sterile towels

identify the L3-4 or L4-5 interspace

certainly no higher than L2-3

Where do you start for a skin wheal?

How far do you inject?

starting near bottom of the chosen interspace, create a skin wheal of 1% lidocaine with a 25ga or smaller needle

inject to a depth of 1-2" in direction of anticipated spinal needle travel

base depth of injection on pt's body habitus

How should the fitting of the needle be in the stylet?

What does the stylet prevent?

tight fighting

prevent plugging of needle and carrying tissue into epidural or subarachnoid space

What is the size of the introducer?

What does this prevent?

typically 18ga ~1.5 inches

prevents smaller needle and pencil points from bending or getting misdirected

Can the introducer reach the SAS?

If you need to redirect the needle, what must you do?

the introducer can reach the SAS in some people

if redirecting the needle, you must pull it back into the introducer and redirect introducer first (come back to sub q tissue)

Insert needle:

Midline

Nearer the bottom of the interspace

With a 10-15 deg cephalad angle

(angled up towards head)

Anchor introducer in interspinous ligament

How do you hold the needle?

What are the 2 goals of advancing the needle?

there are many ways to hold the needle-find what works for you

Goals:

absolute control of needle depth

tactile sensation of diff. tissues & perforation of dura

When advancing the needle, what does tactile sensation provide for?

What is the pop felt?

distinction between ligament and paraspinous muscle which is entered if you deviate from midline

distinct pop felt on puncturing the dura

What is the definitive confirmation of correct placement of a spinal needle?

What went wrong if you make contact with the bone? (3)

CSF not just the pop when going through dura

too steep an angle

directed caudad

started in the wrong place

What should you do if you hit the bone?

What can happen if you don't do this?

pull needle back to sub q tissue & redirect

 otherwise:

needle may bend

won't reliably redirect

When is a paramedian approach valuable?

List some examples: (4)

Why is this approach not utilized very much for epidurals?

valuable in patients who are unable to reduce their lumbar lordosis (bigger target)

some elderly males

fusion

you gave a bit too much sedation

pain (hip fracture)

more vasculature there

a paramedian approach at L5-S1

same merits as discussed w/ paramedian approach

What is a paresthesia?

How can this happen?

typically transient tingling ("pins and needles") pain shooting into buttocks or down leg

needle likely deviated from midline

or

 paramedian approach needs angle adjustment

What should you never do with a paresthesia?

What if a paresthesia develops, what do you need to do before injecting the LA?

NEVER INJECT INTO A PARESTHESIA

(b/c likely in or touching a nerve per Anderson)

pull the needle back to sub q & redirect in opposite direction of side which produced paresthesia

-advance the needle slightly (1-2mm)

-particularly important with pencil point needle where hole is not at end of needle

-remove the stylet

-CSF should flow freely

-if not rotate the hub 90 degrees

ANCHOR the needle on patients back

and

attach syringe with LA

aspirate gently -CSF should swirl in your local syringe (should be no blood)

When CSF aspirates gently or is free flowing then you can inject the LA; how fast should this be done?

When is re-aspiration done?

inject your local over 5-10 seconds

Re-aspiration

some never

some in the middle

some at the end

What is the key to injecting your local?

What are the subsequent steps after injecting?

the key is to securely anchor the needle against the patient's back so it doesn't move

remove syringe

replace stylet

remove needle

position patient!!!

Post-block, what should you immediately do?

What about within 1-2 minutes?

immediately position patient to achieve desired block height

within 1-2 minutes begin to assess development of block level

-Sympathetic

-Sensory

-motor

What can repositioning the patient modify?

After ____ min repositioning your pt will not modify the block height much.

What do you actively monitor post-block?

reposition as necessary to modify block height

after ~5 min

actively monitor patient's hemodynamic status

-frequent BPs

sympathetic block:

with the back of your hand, feel where the patient starts to sweat

 the sensory block is 2-6 levels below that point

adequate block height of analgesia for proposed surgery

adequate duration of block for anticipated length of surgery

Procaine

Lidocaine

Mepivicaine

Chloroprocaine

Tetracaine

Bupivacaine

Ropivacaine

Levobupivacaine

Procaine dose

Describe Procaine relative to Lidocaine.

Procaine (50-150mg)

more frequent nausea

higher failure rate

slower recovery

decreased incidence of TNS

Lidocaine dose?

When does TNS develop most commonly with Lidocaine?

Recommendations to prevent TNS:

limit dosage to______mg

reduce concentration from __% to __% or less

Lidocaine (60-70mg)

TNS develops most commonly following outpt surgery in the lithotomy & knee arthroscopy positions

Recommendations:

limit dosage to 60-70mg

reduce concentration from 5% to 2.5% or less

Mepivacaine dose?

How does Mepivacaine compare to Lidocaine?

Mepivacaine (30-60mg)

slightly longer acting than Lido

similar to slightly lower incidence of TNS

What does Chloroprocaine have a history of?

Dose?

Does it cause TNS?

Is it ok to add a vasoconstrictor?

hx of problems in past with preservatives and large epidural doses getting subarachnoid

excellent analgesia with 40-60mg

with little or no incidence of TNS

no, do not add epinephrine

What are the advantages of Ropivacaine & Levobupivacaine compared to bupivicaine for spinals?

other advantage?

no advantages over Bupivicaine in doses used for spinal anesthetics

may have protective value in epidural doses; less risk for cardio and neuro toxicity

(more $expensive$ so no particular advantage)

What is the longest acting LA when a vasoconstrictor is added?

Dose?

What may be the problem?

Tetracaine

12-25mg

addition of epi may increase the incidence of TNS which is otherwise low with tetracaine

How is Tetracaine packaged (2 ways)?

How do you mix it?

comes as 1% solution

 or

Niphanoid crystals 20mg

-reconstitute w/ 2 mL sterile H2O to give a 1% solution

-mix w/ equal volu. D10 producing a hyperbaric 5mg/ml solution

Bupivacaine dose?

When is Bupivacaine hyperbaric and isobaric?

Is it ever really isobaric?

Bupivicaine (12-15mg)

hyperbaric 0.5% & 0.75% solution prepackaged in dextrose

isobaric 0.5% & 0.75% plain solutions

-probably not bc everyone's CSF is different

levobupivacaine: 12-15 mg

ropivacaine: 15-25 mg

Vasoconstrictors

Clonidine

Narcotics

Neostigmine

When are vasoconstrictors useful?

Name 2 and the doses used

usefulness varies with LA used

-Epinephrine (0.1-0.2mg, max 0.5mg)

-Phenylephrine (2-5mg)

Lidocaine - addition of VC may increase neurotoxicity

Chloroprocaine - addition of epi may produce flu-like effects

Tetracaine - Epi or Phenylephrine may increase incidence of TNS

How does Clonidine affect a spinal? (3)

dose?

Clonidine (75-150mg)

increases duration and quality of block

inhibition of nocioceptive afferents

has been shown in some studies to exacerbate hypotension

What narcs can be added to a spinal?

doses?

how long can pain relief last?

may produce...

Fentanyl (12.5-25mcg)

Morphine (0.1-0.5mg)

-may produce some pain relief for up to 18-24 hrs

-may produce respiratory depression

dose (volume X concentration)

site of injection along the neuraxis

baricity of the LA solution

posture of the pt

volume of CSF - most variability

density of CSF

added VC

coughing, straining, or bearing down (labor)

barbotage

rate of injection (except hypobaric)

needle bevel (except Whitacre needles)

gender

weight

CSF volume

 - accounts for ~80% of variability in block height

Patient Position

Age

-but less imp than others

20+ minutes

(be aware that the surgery can begin in 5 minutes, BUT the block height may continue to rise for 20+ minutes)

What is the primary determinant of duration of a spinal block?

2-Dermatome Regression is an indicator that a block is _____ to recede.

Complete resolution may take 2-3X longer to occur and it means?

What is the most important aspect about choosing a drug for a spinal?

Drug Selection

beginning to recede (down 2 dermatomes from peak block level)

Block is Completely resolved =-)

How long will its duration be at surgical site!!

appropriate for planned surgery?

pt refusal

pt's inability to remain still

increased ICP

coagulopathy

infection at site/sepsis

severe hypovolemia

aortic outlet obstruction

pre-existing neurologic disease?

Is the anatomic location amenable to a spinal anesthetic?

Will the duration of surgery exceed that of your block?

Does the pt's mental status make them a candidate for RA?

pt's inability to remain still

-given an alternative, the risk is not worth it

With increased ICP, when is the potential for risk of herniation a possibility?

When may ICP increase further?

potential for risk of herniation if CSF is removed

may further increase ICP further if large volumes are injected into epidural space

NOT a contraindication since intracranial pressure is globally elevated

Idiopathic intracranial hypertension (IIH), sometimes called by the older names benign intracranial hypertension(BIH) or pseudotumor cerebri (PTC), is a neurological disorder that is characterized by increased intracranial pressure(pressure around the brain) in the absence of a tumor or other diseases. The main symptoms are headache, nauseaand vomiting, as well as pulsatile tinnitus (buzzing in the ears synchronous with the pulse), double vision and other visual symptoms. If untreated, it may lead to swelling of the optic disc in the eye, which can progress to vision loss.^[1]

IIH is diagnosed with a brain scan (to rule out other causes) and a lumbar puncture; lumbar puncture may also provide temporary and sometimes permanent relief from the symptoms

What is a big risk with coagulopathy and placement of a spinal block? Especially with?

Is thrombocytopenia a contraindication?

increased risk of epidural hematoma, particularly in association with LMWH

thrombocytopenia is not a contraindication, but facility may have policy about placing a spinal

Why is an aortic outlet obstruction (ie ______) a contraindication?

Titrated ______ better than spinal b/c spinal decreases _________ more.

ie. severe aortic stenosis 

acute reduction in afterload compromises aortic pressure & subsequently coronary perfusion pressure

Titrated epidural better than spinal b/c spinal decreases afterload more.

What pre-existing neurologic disease has been considered a contraindication to a spinal?

Why has it incorrectly been considered a contraindication?

Is RA impossible with a neuro disease?

MS and other disease that have intermittent exacerbations

 due to legal concerns

does not preclude RA, but warrants a more thorough discussion with the pt

PDPHA

Backache

Hearing Loss

Total Spinal

Neurologic Injury

What is a PDPHA?

What is the location and nature of a PDPHA?

Post Dural Puncture Headache

Location - frontal, occipital, or both

Nature - dull or throbbing

POSTURAL

stand up or sit down the HA gets worse, but improves if pt lies down

typically 12-48 hrs following puncture

may rarely occur immediately

Cutting Needle (Quincke)

Needle Size - bigger needle, more problems

Pregnancy vs Female gender?

Previous Hx of PDPHA

Age

What have pencil point needles greatly reduced?

How have they reduced this? (2)

the incidence of PDPHA

less cutting of the fibers 

greater inflammatory response 

(more inflammation = quicker closure of site per Dr.Anderson)

nope, rare

(should not be accessing the CSF; no hole in dura)

low risk in children

increases in puberty

decreases again in elderly

List the factors that may increase the incidence of post-spinal puncture headaches. (6) (chart)

Age - younger more frequent

Gender - females>males

Needle Size - larger>smaller

Needle Bevel - less when the needle bevel is placed in the long (parallel) axis of the neuraxis

Pregnancy - more w/ pregnant (debatable per Anderson)

Dural Punctures - more with multiple punctures

continous spinals

timing of ambulation

From graph & rubber band demo in class:

Increasing age ______ risk for PDPHA.

Parallel bevel insertion ______ risk.

Perpendicular bevel insertion ______ risk.

The reason that the above is true is not b/c the dural fibers run _______ but rather because the _____ placed on the dura mater is longitudinal; thus perpendicular cuts get ____ w/ normal dural tension & parallel cuts are ______ ______.

Increasing age decreases risk for PDPHA.

Parallel bevel insertion decreases risk.

Perpendicular bevel insertion increases risk.

The reason that the above is true is not b/c the dural fibers run longitudinal but rather b/c the tension placed on the dura mater is longitudinal; thus perpendicular cuts get wider w/ normal dural tension & parallel cuts are pulled closed.

What is the definitive treatment of a PDPHA?

How is this done?

This tx is ____% effective?

Epidural Blood Patch

epidural needle placed

15-20mL of blood removed from pt sterilely

slow injection of blood into epidural space

~90% effective

When performing an epidural blood patch, where should you inject the blood?

What if you are unable to inject in the desired location?

try to go at same interspace as previous puncture

if unable, go lower

MRI studies show significantly more spread of blood in a cephalad direction than caudad

Is an epidural blood patch effective?

Must use strict _______ _________.

What is warranted prior to the procedure?

What 2 issues are you most concerned with detecting with your hx and physical?

remarkably effective treatment

Must use strict aseptic technique

a basic neurlogic hx & physical 

subdural hematoma

new onset of neurologic symptoms

(above may need further investigation like a MRI, not just a blood patch)

What are the post procedure instructions that you must document? (3)

Also should document and inform pt of normal side effects they should expect; such as _______ and _________.

bed rest, no lifting for 24 hrs

(have to continue to regenerate CSF and clot can be dislodged with lifting)

force po caffeine-containing fluids

reasons to return to ER

low grade fever and mild backache

high fever

severe backache

new neurologic symptoms

incontinence

numbness

worsening of HA

After a spinal, how does a backache present?

May occur in ___ % of ppl.

What is the etiology? (4)

usually minor and brief

may occur in ~10%

etiology uncertain

possible causes include:

needle trauma

LA irriation

ligamentous strain

surgical positioning

How long does hearing loss last?

Incidence is ___%?

What gender is it seen more in/ratio?

Etiology?

transient, mild decrease lasting 1-3 days

incidence up to 40%

3:1 female to male predominance

etiology unclear

What is a total spinal?

What results if a reg. spinal becomes a total spinal?

block of entire SC & possibly brainstem

results in:

profound hypotension & bradycardia from high sympathetic block

and

possible respiratory arrest

CV support

- vasopressors, fluids, atropine

Respiratory support

 - ventilation, oxygenation

serious injury is rare (0.03-0.1%)

spinal not proven to be causative in all these cases

limited motor weakness

persistent paresthesias

Etiologies:

direct needle trauma

SC ischemia

inadvertent injection of a neurotoxic substances or bacteria

epidural hematoma (can compress nerve)

yes

maldistribution can cause injury

ie. spinal microcatheters

appropriate for outpt anesthesia?

use of spinal microcatheters?

bzd's for sedation?

improved long-term outcome with RA?

combined spinal-epidural?

reimbursement of postop pain management?

PDPHA 

urinary retention 

Lidocaine and TNS

-alternative to Lidocaine

-length (cost) of extended PACU stay

probably not

is there a patient or procedure that can only be done with a continuous spinal? No per Dr. Anderson

good sedative drugs

may raise seizure threshold

resuscitation following cardiac collapse from LA toxicity more difficult with diazepam on board

may mask early symptoms, delaying appropriate therapy (ie CNS symptoms...cardiac collapse is late symptom)

Are bzd's an issue with spinal anesthesia?

What about with epidurals?

NO, d/t extremely small doses

warrants a reasonable discussion if talking about the large LA doses for epidurals

decreased surgical stress response

modification of surgical effects on fibrinolytic system

translation of findings to long-term morbidity and mortality

gives excellent spinal analgesia for surgery

allows postop epidural for pain control

may delay ambulation, or add risk/impact staffing (DVT)

systematic review shows little difference between CSE and epidural analgesia

CSE=combined spinal-epidural

used most frequently in obstetrics

useful in surgery which is of uncertain duration and amenable to central neuraxis block

useful for postop pain management

C7 - 1st prominent spinous process

T1 - most prominent

T7 - lower borders of scapula

L4 - illiac crest

S2 - posterior superior illiac spine

there are variations

Thoracic vertebrae have the steepest angle

Lumbar - flat spinous process

Cervical - not as flat as lumbar but flatter than thoracic

Supraspinous Ligament

Intraspinous Ligament

Ligamentum Flavum

Epidural Space

Dura Mater

Subdural Space

Arachnoid Mater

Subarchnoid Space

if you went too far:

Pia Mater

SC

Spinal - Subarachnoid space (free flowing CSF)

Epidural - sub nothing: want to be outside and in epidural space

T4 - Nipple

T6 - Xiphoid Process

T10 - Umbilicus

its not completely understood

prinicpal site of action is the nerve root, not SC

Hip surgery - less blood loss and less coagulopathies

most of time it doesn't really matter if you do a spinal or GA when considering morbidity and mortality

Each landmark below corresponds to a vertebrae; what are they:

C7

T7

L4

S2

Do these landmarks always correspond accurately?

C7 - cervical spine

T7 - inferior angle of scapula

L4 - Iliac crest

S2 - Posterior superior iliac spine

NO; they are not absolute b/c each pt varies some in there anatomy

When placing an epidural it is common to use the ________ approach because there is more ______ laterally in the epidural space. 

What are two ways we try to assure that we are not in a vein before injecting drug into an epidural space?

midline approach

vascular (big epidural veins)

Aspirate 

test dose

T/F Epinephrine or other vasoconstrictors added to a spinal will increase the height of the block.

F - it does not increase height but rather increases duration of block