Exam 3 Part VI Flashcards
cause of cauda equina syndrome with chloroprocaine
- high dose 2. low pH 3. preservative sodium metabisulfite
what are the local tissue toxicities that LA can cause
- cauda equina syndrome 2. transient neurologic syndrome
transient neurologic syndrome is associated with which LA
5% single dose spinal lidocaine
sx with transient neurologic syndrome
- pain in back and lower extremities 2. burning and itching, cramp-like pain that radiates to the anterior posterior thigh 3. no permanent issues 4. only lasts up to 5 days post-spinal
tx of transient neurologic syndrome
supportive with NSAIDS
mixing lidocaine 1:1 with ______________ has been found to decrease irritation to the spinal cord decreasing risk of transient neurologic syndrome
CSF
lidocaine can be used in what type of blocks
all blocks
use of lidocaine in _______________ anesthesia has decreased 2/2 transient neurologic syndrome
spinals
Lido + Epi can prolong the DOA by as much as __________%
50
lido causes _________________ at most concentrations, but causes ____________ at low doses
vasodilation; vasoconstriction
what is the least systemically toxic amide
prilocaine
_________________ causes metHb 2/2 metabolite O-toluidine
prilocaine
why is epi not needed with prilocaine
does not significantly vasodilate
prilocaine is administered what routes
- infiltration 2. IV 3. regional 4. PNB 5. spinal 6. epidural
routes of lido
- all block routes 2. topical 3. neb
_________________ is very similar to lido but has a slightly longer DOA
mepivacaine
___________________ is c/i with OB bc metabolism is prolonged with fetus and newborn
mepivacaine
_________________ is an amide anesthetic can cause sudden cardiac arrest
bupivicaine
with bupivicaine the ________________ block lasts longer than the _________
sensory; motor
routes of bupivicaine
- regional 2. local 3. spinal 4. epidural
effects of PNB with bupivicaine last __________________ hours
24-Dec
intrathecal anesthesia with bupivicaine has an onset in _________________, with _______________hours of analgesia
2-3; 4-6
____________________ is an amide LA that is a racemic mixture used with epi
bupivicaine
_____________ is an s-enantiomer of bupivicaine
levobupivicaine
benefit of levobupivicaine compared to bupivicaine
decreased toxicity –> allows for larger doses
levobupivicaine & ropivacaine, at low doses will cause ______________________
vasoconstriction
____________________ is a single enantiomer of bupivacaine with less toxicity, less lipid soluble, less potent than bupiv
ropivacaine
epidural use of ropivacaine allows for _________________ > ______________ blockage
sensory; motor
____________________ was used in infiltration & spinal blocks before lidocaine became popular
procaine
___________________ is the ester LA that causes an allergic rxn 2/2 PABA metabolite the most
procaine
procaine has a ____________ potency and a _____________ duration
low; short
chloroprocaine has a _____________ potency and a ________________ toxicity
low; low
what LA is the LEAST toxic of all agents currently in use
chloroprocaine
______________________ can interfere with subsequent doses of epidural amides or opioids
chloroprocaine
_____________________ is an ester LA that is used in high concentrations, rapidly metabolized, has virtually no fetal transmission
chloroprocaine
__________________ is used in C/S with Bicarb for rapid onset of surgical block
chloroprocaine
tetracaine has a ____________ onset and a ______________ duration
slow; intermediate-long
T/F: tetracaine has a low potency
FALSE
current use of __________________ LA is mainly topical via mucous membranes or skin wounds, & sometimes for spinals
tetracaine
_________________ is VERY toxic and can cause cauda equina syndrome with repeated spinal dosing
tetracaine
what is the only natural LA
cocaine
____________________ is a LA that inhibits neuronal reuptake of catecholamines –> HTN, arrhythmias, tachycardia, and potentially cardiac arrest
cocaine
which LA is a secondary amine
benzocaine
which LA is permanently non-ionized
benzocaine
benzocaine has a _____________ onset and a ___________ DOA
slow; short
benzocaine is limited to _________________ anesthesia
topical
pKa of benzocaine
2.5-3.2 (why it is permanently non-ionized and has a high risk of toxicity/methoglobinemia)
dosage guideline of chloroprocaine w/o epi
11 mg/kg; max 800 mg total dose
dosage guideline of chloroprocaine with epi
14 mg/kg; max 1000 mg
dosage guideline of lidocaine without epi
4-5 mg/kg; max 300 mg
dosage guideline of lidocaine with epi
7 mg/kg
dosage guideline of bupivacaine without epi
2.0 mg/kg; max - 175 mg
dosage guideline of bupivacaine with epi
2.5 mg/kg ; max 225 mg
dosage of ropivacaine w/ or w/o epi
3 mg; max 200 mg
dosage guideline of procaine
7 mg/kg max 350-600 mg
dosage guideline of mepivacaine
7 mg/kg; max 400 mg
dosage guideline of prilocaine for body weight less than 70 kg
6 mg/kg; max = 500 mg
what other receptors other than the VG Na channels have LA been found to work on/effect (however, clinical significance is unclear)
- GCPR (inflammatory modulation) 2. suppression of polymorphonuclear leukocyte priming (iflammatory modulation) 3. K+ channels 4. Ca++ channels
LA binding to K+ or Ca++ channels leads to significantly _____________ potent LA effects
less
how does diameter & myelination influence sensitivity of LA
- larger the nerve - longer the onset time 2. greater myelination = greater diffusion barrier to LA
which nerve fibers are your largest and most heavily myleinated?
A-alpha
which nerve fibers have the fastest conduction velocity of ALL fibers
A-alpha
which fiber(s) have the second fastest conduction
A-beta; A-gamma
which fiber is responsible for reflexes
A-gamma
which has the slowest conduction velocity of all alpha fibers
A-delta
which fiber has the function of preganglionic autonomic vasomotor
B fibers
which fibers have the function of postganglionic autonomic vasomotor
sympathetic C fiber
which fibers are responsible for pain, temperature, and touch
DRG (C fibers) and A-delta fibers
which fibers are responsible for motor tone
A-gamma
which fibers are repsonsible for motor, touch, and pressure
A-beta
which fibers are responsible for proprioception and motor
A-alpha
order in which nerve fibers are affected by LA
sympathetic C and B fibers –> DRG C and A - delta –> A-beta –> A-gamma –> A-alpha