epidural, combined spinal/epidural Flashcards
what determines the level of anesthesia with an epidural?
VOLUME, no such thing as overdosing an epidural
diffusion dependent
LA spreads __ for epidural
cephalad
T/F - any procedure that can be done with a spinal can also be done with epidural
true
What’s special about a Touhy?
has the most curvature 30*, therefore less likely to pierce arachnoid and enter subarachnoid
What size catheter should you use in the epidural?
2 sizes SMALLER than the needle
the majority of the population have loss of resistance between __ - __ cm
4-6 cm
the paramedian/lateral approach does not have to pass through what two layers?
supraspinous ligament
intraspinous ligament
epidural insertion site for TAH and low abdominal surg
L2-L3
2-3 kids is just about right
epidural insertion site for upper abdominal surg
T8-T10
ribs 8-10 are the “false” ribs in humans
epidural insertion site for thoracic surg
T4-T5
“Thora” has five letters
epidural insertion site for chronic pain therapy or surgery of the arms, shoulders, or upper chest
C7-T1
__ affects the density of the block
concentration
__ affects the spread of LA throughout the epidural space
volume
do blocks occur faster in cephalad or caudad direction?
cephalad
what is the “take home” volume per dermatomal segment?
1-2 ml per dermatome
where are the opioid receptors in the spinal cord?
substantia gelatinosa
how much more opioid must you give epidural vs. IV?
spinal vs. Epidural
Epidural = IV dose
10x epidural compared to intrathecal
morphine 200 mcg spinal, but 2000 mcg epidural or IV
the time of maximum spread of LA for epidural?
10-25 minutes
when sensory regression of 1-2 dermatomes occurs, give a dose of __ - __ the initial dose
30-50%
number one complication of epidural
backache
when should you give epidural morphine?
AFTER BABY DELIVERED AND CORD CLAMPED due to resp depression
after age __, anatomy changes make caudal site identification difficult and spread of LA less reliable
12
slide 30
how much volume for caudal anesthesia for sacrum?
how much volume for caudal for T10?
10-15 ml
20-30 ml
what is in your test dose for an epidural?
3 ml’s of 1.5% lido and 1:200,000 epi
equals 45 mg lido and 15 mcg epi total
Epidural final site of action
Ventral and dorsal rootlets, cord
Protein binding gives you
Longer duration
In adults the dura ends around
In peds the dura ends around
L2 aduLts
S4 pedS
Why does the caudal approach have such a high failure rate?
False passages
