Term
| what does local anesthesia do> |
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Definition
| blocks pain by blocking sodium channels |
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Term
| what are the factors that can affect Local anesthesia? |
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Definition
potency
time of onset
duration of LA agent |
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Term
| what are ideal properties of L.A. |
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Definition
potent
reversible
abscence of local reactions
abscence of systemic reactions
rapid onset
satisfactory duration
adequate tissue penetration
low cost
stability in solution (long shelf life)
ease of metabolism and excretion |
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Term
| this form of anesthetic is known for high chance for allergic reactions. they are non injectible but they are topical. |
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Definition
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Term
| where are esters metabolized? |
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Definition
in blood plasma
(remember bloody ester lol) |
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Term
| where are amides metabolized |
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Definition
| amides metabolized in liver |
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Term
| amides may be contraindicated in what cases |
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Definition
alcohol abuse
liver issues (hep C)
the reason is that the liver may be compromised and may not be able to metabolize |
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Term
| what are the components of molecular structure. |
|
Definition
lipophilic aromatic ring(improves lipid solubility and penetration of L.A.
intermediate hydrocarbon (may be ester or amide)
hydrophilic terminal amine (on / off switch allowing L.A. to exist as lipid soluble or water soluble assisting with blocking conduction. |
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Term
| what are the routes of delivery for L.A. |
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Definition
topical (high risk of toxicity)
injectible (less toxic) |
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Term
| why are topicals a higher concentration that injectible |
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Definition
they help diffuse across membranes
but they have high risk for toxicity |
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Term
| what does the intermediate hydrocarbon do? |
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Definition
determines course of biotransformation
plasma or liver enzymes.
for ester or amide |
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Term
| what bonds are involved in hydrophilic terminal amine |
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Definition
tertiary-3 bonds lipid soluble
quarternary-4 bonds positively charged water soluble |
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Term
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Definition
| works well because placement is near nerve |
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Term
| ph of local always starts out more )acidic or basic)before injection. |
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Definition
| ph of local always starts out more acidic |
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Term
| adding vasoconstrictors is good because? |
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Definition
| limits toxicity and lowers ph (makes it more acidic) and acts as a preservative. |
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Term
| what must solution do to become more basic? why do this? |
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Definition
solution must conver to tertiary lipid soluble base structure.
it needs to be more basic to penetrate the nerve.
some attach to recepters and some end up free bases. |
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Term
|
Definition
| free base or dissociated ions |
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Term
| the higher the pka the (slower or faster?) it is to work. |
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Definition
| high pka indicates long uptake and longer time to work. |
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Term
| lidocaine has a pka of 7.7 and it is 29 % base will this have a slow or fast onset? |
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Definition
| onset will be faster for lidocaine. |
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Term
| does marcaine have slow or fast onset>? |
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Definition
| marcaine has the slowest onset and lasts the longest. |
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Term
| what can happen in area of infection and injection site? |
|
Definition
-tissue is more acidic
-slows release of free base
-stays quarternary (water soluble)
-difficult site for LA
-edema |
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|
Term
| what determines the onset of action? |
|
Definition
PKA determines the onset of action.
low pka is short onset
high pka is longer drawn out onset |
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|
Term
| what bundles receive la last? |
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Definition
| core bundles (center of nerve) |
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|
Term
| what bundles receice LA first? |
|
Definition
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Term
|
Definition
| time interval between initial deposition of anesthetic solution and complete conduction blockade. |
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Term
| what is important to do when re-injecting? |
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Definition
| re-inject before mantle fibers recover. |
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Term
|
Definition
| increased tolerance to drug administration repeatedly |
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|
Term
| absorption of LA depends on |
|
Definition
dose
route
vascularity
presence or abscence of vasoconstrictors |
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|
Term
| explain distribution of LA in body |
|
Definition
-in blood supply to systemic
-goes to vital organs
-crosses blood-brain barrier
-if alot ends up in tissues, toxicity can occur |
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Term
|
Definition
| time it takes to eliminate half of the drug |
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Term
| half life for lidocaine is? |
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Definition
| 90 min half life for lidocaine |
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|
Term
| bupivicaine/marcaine has half life of?? |
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Definition
| 3.5 hours LASTS long!!!!!! |
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Term
| in esters what is the major cause of allergic reactions? |
|
Definition
| PABA (paraaminobenzoic acid) |
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Term
| dental topicals commonly used? |
|
Definition
benzocaine
tetracaine
procaine (used by medical professionals also known as novacaine which is no longer used due to high chance for allergy) |
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|
Term
|
Definition
lidocaine/xylocaine
mepivicaine/carbocaine
bupivicaine/marcaine |
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Term
| what LA is partially biotransformed in liver and partially metabolized in lungs? |
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Definition
| Prilocaine is biotransformed in liver and lungs |
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|
Term
| what % of septicaine/articaine is biotransformed in liver. |
|
Definition
| 5-10% of articaine is biotransformed in liver |
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|
Term
| what is the major organ that excretes LA |
|
Definition
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|
Term
| what are some effects of CNS from local anesthesia? |
|
Definition
crosses blood brain barrier
muscle twitching, tremors
high blood levels, depressed, unconscious, convulsions, hypotension.
respiratory arrest |
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Term
| the affects local has on CVS and CNS depend apon? |
|
Definition
amount of vasodilation
concentration of drug
route
rate of injection
vascularity of area of injection |
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Term
|
Definition
increase in bp and respiration
moderate overdose can cause depression, mi, circulatory distress. |
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Term
| if symptoms arise within 5 minutes of injection is it more or less severe? |
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Definition
| more severe the faster the symptoms appear for CVS |
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