Clinical Correlations Neuraxial Anesthesia

Front 1

How many spinal curves are there

Back 1

4
Cervical C7, thoracic T7, lumbar L3-4, sacral

Front 2

When pt is supine what is the highest and lowest point of the spine

Back 2

T5 is the lowest
L4 is the highest

Front 3

Ligaments of the vertebral column

Back 3

supraspinous
interspinous
lig flavum

Front 4

name the 3 maters

Back 4

dura, arachnoid, pia

Front 5

Where is the epidural space

Back 5

foramen magnum to caudal canal

Front 6

Epidural space (not really an open space) contains

Back 6

lymphatics, adipose tissue, veins

Front 7

Spinal cord ends at

Back 7

L2

Front 8

the dural sac ends at

Back 8

S2

Front 9

How many arteries supply the spinal cord & location

Back 9

3
one ant
two post

Front 10

What is the major art of the spinal cord

Back 10

artery of adamkiewcz)

Front 11

CSF Composition

Back 11

Clr colorless
Contains gluc, pro, elytes
SP grav = 1.003-1.009 (r/t baricity of spinal anesth)

Front 12

CSF volume

Back 12

120-150ml
20-80ml in spinal arach space (varies per person, obese<,)
Fluid ossilates vigorously w/ art pulsations

Front 13

CSF volume
Rate of formation/day

Back 13

150ml/day up to .35ml/min

Front 14

Dermatomes
Definition

Back 14

cutaneous area innerv. primarily by a single nerve root

Front 15

Dermatomes
Significance

Back 15

guide for required anesthetic
level for intended surg
estimates physio changes

Front 16

Deramtome Landmarks
L1

Back 16

immediately above genitalia

Front 17

Deramtome Landmarks
L1O

Back 17

Umbilicus

Front 18

Deramtome Landmarks
T8

Back 18

lower Costal margin

Front 19

Deramtome Landmarks
T6

Back 19

xiphoid

Front 20

Deramtome Landmarks
T4

Back 20

nipple line

Front 21

Deramtome Landmarks
C8

Back 21

little finger

Front 22

Deramtome Landmarks
C6

Back 22

thumb

Front 23

Spinal Anesthesia
Zones of differnetial blkade
T2 =

Back 23

Sympathectomy level (sm amt blk

Front 24

Spinal Anesthesia
Zones of differnetial blkade
T4 =

Back 24

Sensory level (alittle more blk)

Front 25

Spinal Anesthesia
Zones of differnetial blkade
T6=

Back 25

Sensory level (sufficient blk)

Front 26

Epidural Anesthesia
Zones of Differential Blkade
C8

Back 26

Sympathectomy level

Front 27

Epidural Anesthesia
Zones of Differential Blkade
T4

Back 27

Sensory level

Front 28

Epidural Anesthesia
Zones of Differential Blkade
T8

Back 28

Sensory level

Front 29

Differential Blkade
Clinical Signs

Back 29

Small fibers : B&C (pain 1st blk (feel warm, dec pain
-A-delta (pain) gamma,beta (loss sens pain, pressure, touch
-A-alpha loss of motor & propriocep
-Return of funct (motor, prop, press, touch, pain, sympathetics)

Front 30

Differential Blkade Reasons
Spinal

Back 30

-Cephalad spread diluts LA
-In Vivo diff sensitivity to local anesth
-sympathetics most sens
-sensory intermediate
-motor least sens

Front 31

Differential Blkade Reasons
Epidural
Wider spread of zones w/ epidural d/t diff

Back 31

-site of action
-how Local anesth (LA) reaches sites of actions

Front 32

Deramtomes
Estimating Physiologic Change
L1

Back 32

Minimal physio change

Front 33

Deramtomes
Estimating Physiologic Change
T10

Back 33

low ext venous pooling, mild dec in BP

Front 34

Deramtomes
Estimating Physiologic Change
T6

Back 34

splanchinic bed vasodilat, dec exp manuerveres

Front 35

Deramtomes
Estimating Physiologic Change
T4

Back 35

above plus frequent C-A blkade

Front 36

Deramtomes
Estimating Physiologic Change
C8 (phrenic nerve)

Back 36

above plus OCC phrenic nerve

Front 37

epiural blk at T1-T4 (Cardiac accelator) results in

Back 37

parasympathetic response

Front 38

Physiology: T5 Level of Spinal Anest Blk
Cardiovasc changes MAP

Back 38

MAP dec by 15-20%
-loss of symp tone, arteriole dilate, dec 15-20% SVR
-Intrinsic mus tone further dec
-dec sympath tone, some dec in cardiac contract

Front 39

Physiology: T5 Level of Spinal Anest Blk
Cardiovasc changes in C.O.

Back 39

C.O. = venous return dependent
-if maintained, little or no chng
-if not, mod to sev hypotension

Front 40

Physiology: T5 Level of Spinal Anest Blk
Cardiovasc chng HR
Stable or slight dec unless

Back 40

-t1-T4 cardioaccelerators blkd
-dec ven return -> non stretch of RA/Great Vein Stretch Recpt -> Brady

Front 41

Physiology: T5 Level of Spinal Anest Blk
Cardiovasc changes to myocardium

Back 41

dec coronary bld flow w/ dec mean aortic press
-dec HR + LV work contrib to lower cardiac O2 demand

Front 42

Physiology: T5 Level of Spinal Anest Blk
Cerebral Circulation changes

Back 42

-dec in MAP compensated by autoreguation -> no chng in CBF
-HTN PT autoreg shift to right -> tx aggressive, to maintain BP at 20-30% from baseline

Front 43

Physiology: T5 Level of Spinal Anest Blk
Pulmonary Changes

Back 43

Expiratory changes (dec FVC,FEV1 & cough d/t paralysis of IC/ABD musc
-Insp chng minimal: VT, MV unchg
-PaO2, PaCO2 nrml

Front 44

Physiology: T5 Level of Spinal Anest Blk
Few Pulmonary Changes

Back 44

-Phrenic nerves C3-5
-Zones of diff blkade
-Resist of motor nerves to locals

Front 45

Physiology: T5 Level of Spinal Anest Blk
Hepatic Circ

Back 45

-reduce in hepatic bld w/ dec MAP
-Post-op dysfunct check other causes, surg site, bld transfus, drugs

Front 46

Physiology: T5 Level of Spinal Anest Blk
Renal effects

Back 46

-slight reduc in GFR & renal funct.
-R/T dec MAP

Front 47

Physiology: T5 Level of Spinal Anest Blk
GI

Back 47

-T5-L1 symp fibers inhibit motility
-sympathectomy unopposed vagal tone -> inc peristalisis
-NV w/ nrml VS: tx w/ atropine or glycopyrrolate

Front 48

Physiology: T5 Level of Spinal Anest Blk
Endocrine effects

Back 48

-No increase in stess horomones (hi spinal)
-probably beneficial, outcomes controversial

Front 49

Physiology: T10 or lower

Back 49

Saddle blk or Low SAB (most previous effects of T5 don't occur)
-Low SAB very safe even in sick pts (hips, turp)
-Safer than gen anest agents less use of high SAB

Front 50

Physiology: T5 Epidural

Back 50

-all previous effects of SAB apply
-most difference r/t systemic effects of Locals

Front 51

Physiology: T5 Epidural
Cardiovasc changes

Back 51

-same as SAB as long as Locals serum levels are low
-toxic levels-> myocard dep
-use of EPI: lowers BP,SVR, Inc SV & CO

Front 52

Physiology: T5 Epidural
Pulmonary effects

Back 52

-Sim to SAB
-harder to obtain resp paralysis (wider band of zones of differential blk(

Front 53

Physiology: T5 Epidural
Other Physilogic effects

Back 53

-poss cardioproctective effects
-improve global cardiac funct
-reduce thromoembolic comp
-reduce bld loss
-thoracic epi more favorable that lumbar

Front 54

Physiology: Epidurals

Back 54

-slower onset
-easier to manage
-solid motor blk difficult
-fewer resp complaints