Exam 2 - Local Anesthetics Flashcards
mechanism of all local anesthetics
blocking Na influx through voltage gated Na channels
how are local anesthetics affected by low pH (acidity/inflammation)
less able to cross the membrane
increased risk of toxicity
can you mix local anesthetics?
no - no clinical benefit except bupivacaine + liposomal bupivacaine
common routes of administration of local anesthetics
PNB
spinal
epidural
tissue or infiltration with nocita only
what are adjuncts you can use with local anesthetics
epinephrine
dexmedetomidine
buprenorphine for maxillary/mandibular blocks
NSAIDs (meloxicam)
steroids
symptoms seen with local anesthetic systemic toxicity
CNS excitation
CNS depression
CVS depression
coma/death
what drug are CNS and CVS toxic doses very similar
bupivacaine
what is the primary risk factor for local anesthetic systemic toxicity
DOSE
how are local anesthetics affected by regional blood flow
want vasoconstriction to keep drug where you put it
what patients are at risk of LAST and require reduced doses
hepatic, renal, cardiac and pulmonary dysfunction patients
patients with high CO (CKD, systemic hypertension)
very old or very young
hypercapnia and acidosis put a patient more at risk for what
CNS toxicity
definitive treatment for LAST
IV intralipid
what species have a lower tolerance for local anesthetics
sheep < cats < equine/cattle < dogs
list the local anesthetics from shortest duration/onset time to the longest
lidocaine
mepivacaine
bupivacaine
ropivacaine
nocita
are longer or short acting local anesthetics more toxic
long acting
