Local Anesthetics Flashcards
what are properties for a good local anesthetic?
- not be irritating to tissues
- no permanent damage to nerves
- low systemic toxicity
- short onset
- long DOA
what are the 2 types of local anesthetics?
amides
esters
where are amides metabolized?
in the liver
where are esters metabolized?
in blood by pseudocholinesterase
what is the order of function in which sensations are blocked by anestehsia?
- pain- blocked first
- temp
- touch
- proprioception
- deep pressure
- movement
what is the MOA of local anesthetics?
increase threshold of depolarization & inhibits permeability of cell mb to Na+
what effect does pH have on the anesthetic?
increasing pH will dec. effectiveness of anesthetic
does vasoconstriction or vasodilation prolong action of local anesthetics?
vasoconstriction
what is the properties of epinephrine when it is added to LA?
increases DOA
decreases systemic toxicity
provides hemostasis
how much does 0.25% of anesthetic contain?
2.5mg/ml or cc
how much does 0.5% of anesthetic contain?
5mg/ml
how much does 1% of anesthetic contain?
10mg/ml
how much does 2% of anesthetic contain?
20mg/ml5
what is the toxic dose of plain lidocaine?
300mg
what is the toxic dose of marcaine?
175mg
