Regional Flashcards
what anesthetic agents can cause neuroapoptosis?
- GABAA agonists (propofol, benzos, volatile agents)
- NMDA antagonists (ketamine, N2O
what age kids are at risk of neuroapoptosis?
what increases the risk?
- kids < 3 yrs (occurs in utero during 3rd trimester too)
- increased risk with anesthesia time > 3 hrs and repeated exposure
why is use of neuraxial and regional techniques growing?
to avoid GA
T/F: regional techniques are safe and effective for intra-op and post-op analgesia in infants, children, but not in pre-term neonates
false - safe for infants, children, and neonates
advantages for using regional/spinals in peds
- opioid related adverse effects avoided
- promotes spontaneous ventilation and earlier extubation
- reduces risk of post-op apnea and respiratory dysfunction in high-risk infants
- airway instrumentation can be avoided
- enhances hemodynamic stability
advantage of continuous epidural analgesia in peds
- decreases time to extubation
- promotes return of bowel function
- decreases metabolic stress response
- may decrease postoperative sedation needs
- promotes shorter ICU length of stay
little fact: when combined with GA, regionals decrease intra-op volatiles, opioids and neuromuscular blocking agents
(reduces risk of negative cognitive outcomes)
yay
indications for spinals (5)
- lower abdominal procedures (urologic and hernias)
- lower extremity orthopedics
- omphalocele
- exploratory laparotomy
- myelomeningocele
T/F: there are frequent complications with spinal use in peds, mainly being permanent neurologic injury or death
false
“Complications infrequent; no reports of permanent neurological injury or death in children”
what can be added to a spinal to double the duration?
clonidine
complex procedures often benefit from a spinal combined with what other technique?
caudal catheter
agents commonly used for sedation with spinals?
precedex - infusion
fentanyl, midazolam - boluses
difference in conus medullaris in peds vs adults?
when is it the same as adults?
conus medullaris more caudal in neonates and infants (L3)
reaches adult level at 1 y/o
level of lumbar puncture in peds vs adults?
why?
at L4-L5 or L5-S1 to avoid spinal cord trauma
what approach to a spinal is preferred in peds?
midline
difference in sacrum in peds vs adults
- sacrum more narrow and flat
- access to subarachnoid space from caudal canal more direct (dural puncture more likely)
differnce in ligamentum flavum in peds vs adults?
consideration?
less dense in peds
harder to feel loss of resistance
duration of spinal in peds vs adults?
why the difference?
- peds have shorter block duration
- due to faster CSF turnover rate
in a pediatric patient, how much space is between the skin and the subarachnoid space?
1.5 cm
T/F: a spinal eliminates the incidence of post-op apnea in former premies
false - decreases but does not eliminate
what agent when given in addition to a spinal causes more apnea than a GA?
ketamine
what is deafferentation?
sedation due to decreased sensory input to RAS from periphery
(can be advantage or disadvantage of SAB)
what specific pediatric population is the most common to use spinal techniques on?
infants
uncommon past infancy
what age group is the most hemodynamically stable after a spinal or epidural anesthetic?
infants - more stable than older kids or adults
~and more responsive to hemodynamic meds vs those ppl too
who has a bigger impact on their respiratory function with a spinal - infants or children?
why?
infants - they rely more on diaphragm for their tidal volume
but most compensate and tolerate well
common technique for spinals in peds
- usually sitting position
- 1% lidocaine
- midline insertion at L4-L5 or L5-S1 (lower than adults)
- must remain horizontal to avoid high spinal - no leg raises, toe touches, somersaults, etc.
- avoid sedation if possible - esp ketamine
complications of SAB
- total spinal - apnea, bradycardia
- post-dural puncture headache
- spinal cord trauma
- epidermoid tumors
what usually causes epidermoid tumors?
when needle used without the stylet
effects of prolonged amide infusions in infants and young children
- variable pharmacokinetics
- increased risk of LAST
which LA is starting to have a resurgence for epidural anesthesia?
how is it metabolized?
2-chloroprocaine
metabolized by plasma esterases in seconds to minutes
*theoretically can epidurals in peds be the sole anesthetic?
yes - but usually combined with GA
most common regional technique in children — in some places
caudals
are caudal blocks used ase the sole anesthetic?
nope, always used with GA
landmarks for a caudal block
- posterior iliac spine
- sacral cornu
T/F: a caudal block requires sterile technique
false - aseptic*
is a caudal block a type of spinal or type of epidural?
epidural
technique for a caudal block
- after induction, turn lateral or prone
- palpate landmarks
- insert small gauge needle, angiocath, or Crawford needle at 45°angle
- after “pop”, drop to angle parallel to back and advance into caudal canal
- for continuous, insert catheter
- test dose while watching EKG & BP
- inject local over approx. 2 minutes - injection should be easy
- watch for sub-cu infiltration
how long to inject local over for a caudal block
over 2 minutes
for a continuous caudal epidural, how far does the catheter need to be advanced?
mid-level of surgical incision
fun facts on back side :)
- some ppl use ultrasound to confirm catheter placement of caudal epidural catheter
- these need “meticulous dressing for catheter placement”
the dose needed for a caudal block depends on what two factors?
- desired dermatome level
- volume
not concentration
common volume per kg and drug given for a T4-T6 sensory caudal block
0.5-1 mL/kg of 0.2% ropivacaine
(or can use 0.25% bupivacaine but its more toxic)
~~idk if saying we won’t dose on exam was we don’t need to know them, or if we just wont have to calculate
what is a common drug to administer with a caudal block to prolong the block?
what dose of this drug is associated with increased apnea?
common: clonidine 1 mcg/kg
2 mcg/kg increases apnea
~~idk if saying we won’t dose on exam was we don’t need to know them, or if we just wont have to calculate
dose that can be used for post-op pain control with a caudal epidural catheter?
considerations if little babe?
max: 0.4 mg/kg/hr (of what? unclear)
if < 6 months reduce by 30%
~~idk if saying we won’t dose on exam was we don’t need to know them, or if we just wont have to calculate
contraindications to a caudal block
- parents refuse consent
- surgeon preference
- allergy to local anesthetics
- skin infection/diaper rash in sacral area
- VP shunt in place
- history of spinal abnormality or surgery (relative)
- sacral “dimple” (relative)
when we look at our little baby patient’s booty, we see a cute lil booty dimple.
what can this indicate?
is this an absolute contraindication to a caudal block?
- can indicate spinal structures behind due to some malformation
- only a relative contraindication, not absolute
post caudal complications
which is most common?
- most common: catheter displacement/malfunction
- IV or IO injection → CV arrest
- epidural abscess (emergent)
- meningitis
- epidural hematoma
- urinary retention
- neuronal injury (rare)
what are some common fascial blocked used as an adjunct to GA?
*ones that we would do
- TAP block
- quadratus lumborum block (QLB)
- serratus anterior plane block (SAPB)
- erector spinae block (ESB)
what are some common blocks done by the surgeon as an adjunct to GA?
- rectus sheath
- inguinal
- penile
- intercostal
- paravertebral
is it safe to administer regional to an anesthetized child?
yep
here’s some obvious reasons why:
- maintains stillness
- avoids uncooperative and distressed patient
- immobility helps avoid accidental needle displacement/puncture of vital structures
negative - any advantages of patient feedback are lost with children who are unable to communicate usefully
