LA Flashcards
_______ to the tissues and produce no secondary local reaction
non-irritating
LA have a ______ of _______, ________ and be of ______ duration
LOW DEGREE of SYSTEMIC TOXICITY, RAPID ONSET and be of SUFFICIENT duration .
have a _____ _____ properties to be effective as a topical anesthesia
sufficient penetrating
LA must be ____ in solution and under go biotransformation readily within the body
stable
TRUE OR FALSE
LA is capable of being sterilized by heat with deterioration
FALSE, without deterioration
what is PABA means
para-aminobenzoicacid esters
what are the benzioc esters
cocaine and benzocaine
an ester group that is used in dentistry as topical anesthesia
benzocaine
A PABA group which in spray form and use when the patient need to undergo in general anesthesia
tetracaine (pontocaine)
ESTER OR AMIDE and its brand name
procaine
ester, novocaine
ESTER OR AMIDE and its brand name
2-chloroprocaine
ester, nesacaine
ESTER OR AMIDE and its brand name
propoxycaine
ester, ravocaine
ESTER OR AMIDE and its brand name
tetracaine
ester, pontocaine
ESTER OR AMIDE and its brand name
articaine
amide, primacaine
ESTER OR AMIDE, and its brand name
prilocaine
amide, citanest
ESTER OR AMIDE and its brand name
mepivacaine
amide, carbocaine
ESTER OR AMIDE and its brand name’
lidocaine
amide, xylocaine
ESTER OR AMIDE and its brand name
etidocaine
amide, duranest
ESTER OR AMIDE and its brand name
bupivacaine
amide, marcaine or sensorcaine
an ester group used in eye surgery
cocaine
an amide group that is known for paresthesia
articaine
what year did cocaine made
1884
what year did procaine made
1905
year of lidocaine made
1948
year of mepivacaine made
1956
year of prilocaine made
1960
year of bupivacaine made
1963
year of etidocaine made
1971
year of articaine made
1975
compare lidocaine and procaine
lidocaine has more than procaine
rapid onset of action
more profound anesthesia
longer durationand greater potency
charateristics of pure LA
weekly basic
poorly soluble in water
unstable when exposed to air
what acid addd to pure LA to be stable, acidic and soluble
hydrochloric acid
pH level of LA w/o epinephrine
5.5 or 6.5
pH level of LA w/ epi
3.3-4.4
what characteristics of LA with epi when deposit
burning sensation on injection
slightly slower onset of action
and mor post injection soreness
it is added to LA to make injection more comfortable
sodium bicarbonate or CO2
low concentration of H+ ( high pH)
free base
high concentration of H+ (low pH)
cation
what are the 2 factors involve in the nerve membrane
diffusion through nerve sheath (free base) and binding of the receptor sites (cation)
pH level of normal tissue
7.4 pH
pH level of inflamed tissue
5-6 pH
how many % did cation have if the tissue is inflamed
99%
why LA is not effective when the tissue is inflamed
because the pH level, it is acidic
LA is effectively stops the nerve impulse propagation
minimal blocking concentration
how many successive nodes of ranvier o blocked the nerve conduction to be stop
3
proportional to the diameter of the nerve and spans 3 nodes that must be blocked by LA
critical blocking length
it is longer in thicker muscle fibers and less smaller in pain fibers
internodal distance
a single nerve cell
nerve fiber
covers each nerve fiber
endoneurium
bundle of 100-500 nerve fibers
fasciculi
it covers the fasciculi
perineurium
innermost layer of perineurium
perilemma
it supports fasciculi and carrying nutrient vessels
epineurium
outer layer of epineurium
epineural sheath
what fiber anesthesize first and it covers the?
mantle fiber and it covers the proximal structures
what fiber anesthesize next and it covers the?
Core fiber and it covers the distal structures
in diffusion, greater the initial concentration of LA, the __________ and the _______
faster the diffusion of molecules and more rapid the onset of action
in blocking process, what are the factors that decrease the LA concentration outside the nerve
some of the drug is absorbed by non neural tissues
some is diluted by interstitial fluid
some is removed by capillaries and lympatics from injection site
some ester types are hydrolyzed
measure from time of deposition to profound anesthesia or to complete the conduction blockage
induction time or onset
factors of induction time
concentration of the drug
pH of local anesthetic solution
rate of diffusion
anatomical barries of the nerve
what are the factors affecting the LA action
pka
lipid solubility
protein binding
non nervous tissue diffusibility
vasodilator activity
what is the action affected of pka and its description
onset, low pka has more rapid onset
what action affected on lipid solubility and its descrip
potency, higher the lipid solubility, more potency
what action affected in protein binding and its descrip
Duration, higher the protein binding, longer the time of duration
action affected in vasodilator activity and its descrip
potency and duration, the higher the vasodilator property, higher the bloodflow and it decreases the potency and duration
what LA is not use that has high pka and longer time of onset
procaine
what LA has highest lipid solubility
Etidocaine
what LA has higher protein binding
bupivacaine
signs of recovery from anesthesia
follow the diffusion pattern, reversed order
concentration gradient is reversed
mantle fiber lose LA first than core fibers
what is the meaning of intraneural concentration exceeding the extraneural concentration?
anesthetic molecules diffuse out of the nerve
effects of plain LA
more blood flow
more absorption of LA in blood circulation
high chance of toxicity
shorter the duration of action
more bleeding
what are the effects of LA with vc
decreased the blood flow
decreased the absorption of LA
decreased the chance of toxicity
longer duration of action
less bleeding
causes of vasodilator
increased rate of absorption into the blood
decreased the duration of pain control
increased the ansthetic blood level and potential for over dose
it prevents the oxidation of the vasopessor by oxygen that can cause allergy and asthma attacks
sodium bisulfite
in derma that topical anesthesia used on intact skin
EMLA or eutectic mixture of LA
seen on the vial and possess bacteriostatic, fungistatic and antioxidant properties
methylparaben
what LA used on hypothyrodism patient
plain LA
least vasodilate type of LA
mepivacaine
what nerve has high risk of paresthesia
inferior alveolar nerve and lingual nerve
contraindication in the prilocaine
methemoglobinemia and anemia
to prolong the shelf life in a vial
methylparaben
What is the alternative LA if the patient is allergic to sodium bisulfate
plain LA
2% lidocaine in vial
3% mepivacaine and 4% prilocaine in dental cartridge
in the concentration of VC there is effect of its duration?
none, all concentration has longer duration
in the concentration of the vc, there is an effect in the bleeding?
yes, more concentrated less bleeding
why articaine is not used in blocking technique?
increased risk of nerve paresthesia in inferior alveolar and lingual nerve block that suggest a possible greater neurotoxicity
what can happen if the balance between the rate of absorption into the bloodstream and the rate of removal from the blood is not balance to metabolized?
possible of toxicity
ester is metabolized and excrete in?
metabolized in plasma and excrete in kidney
what are the contraindication of ester
plasma cholinesterase deficiency
renal impairment
how the amide metabolized and excrete?
metabolized in the liver and excrete in the kidney
what are the contraindication of amides
liver dysfunction
renal impairment
how to manage the patient if it is contraindicated and has allergic reaction but has no alternative?
the LA can be administered but in less dosage
the dosage of the LA is varies and depends the effectivity on what?
vascularity of the tissues
individual tolerance
techniques of anesthesia
according to american heart association the vasoconstrictor in LA is not contraindicated as long as?
preliminary aspiration is practiced
the agent is injected slowly
smallest effective dose is administered
why is bupivacaine is not used in pediatric patient?
greater risk of paresthesia
prolonged duration of action
potential self mutilation
what are the 5 selections of LA nd VC ?
duration of the procedure
need for post operative pain control’
physical condition of the patient
desire to produce hemostasis
whethe there is any contraindication exist
weighing the risk of using it to its potential benefit and if an acceptable alternative is not available
relative contraindication
under no circumstance should the drug be administered to the patient
absolute contraindication
how the duration of plain prilocaine is used?
when the technique is by infiltration , the duration is short
when the technique is by nerve block, the duration is intermediate
General order of loss of nerve function
Pain
Temperature
Touch and pressure
Propioception
Skeleton muscle tone
Clinical advantage of articaine
Duration of its anesthetic effect
Superior diffusion in bony tissue