Study sets, textbooks, questions
Upgrade to remove ads
Anesthesiology Exam One
Terms in this set (124)
What is the definition of a local anesthetic?
Loss of pain without the loss of consciousness, usually completely reversible
How does a LA prevent an action potential from firing?
Blocks voltage gated Na+ channels (blocks influx of Na+)
What is the primary determinant of intrinsic anesthetic potency?
What happens to the potency as the lipophilicity increases
What are the functions for large diameter nerve fibers
motor function, proprioception, touch, pressure
What are the functions for the thinnest nerve fibers
pain, temperature, signals tissue damage
What is the order of sensory function block?
Pain, Cold, Warmth, Touch, Deep Pressure, Motor
What is the responsibility of the amine end of a LA?
hydrophilic, it keeps the LA on either side of the nerve membrane
What is the responsibility of the aromatic end of a LA?
lipophilic, it penetrates the nerve membrane
When was lidocaine introduced?
1948 - Nils Lofren
How much volume is in one cartridge?
How much epi does 1:100,000 specify?
How much epi does 1:50,000 specify?
0.02mg/ml ...etc know how to determine this
What are the 4 LA techniques
Topical, Local Infiltration, Field Block, Nerve Block
What region does topical anesthetize
What region does local infiltration anesthetize
Terminal nerve endings
What region does field block anesthetize
Terminal nerve branches
What region does a nerve block anesthetize
Close to main nerve trunk
Where does V1 exit the skull?
Superior Orbital Fissure
Where does V2 exit the skull?
Where does V3 exit the skull?
What other part of CN V exits the skull through foramen ovale?
Motor Root (pons/medulla oblongata)
What are the three main branches off opthalmic?
Frontal, Nasociliary, Lacrimal
What are the branches off of Frontal?
Supraorbital and Supratemporal
What are the branches off of Nasociliary
Long Ciliary (Sympathetic)
Short Ciliary (Parasympathetic)
What are the main branches off of the maxillary nerve?
infraorbital, posterior superior alveolar, palatine, and nasopalatine
What are the branches off the infraorbital nerve?
zygomatic --> zygomaticotemporal and zygomaticofacial
What does the greater palatine nerve supply?
soft tissues of the hard palate
What does the lesser palatine nerve supply?
soft tissues of the soft palate, uvula
What does the anterior superior alveolar (off infraorbital) supply?
What are the lacrimal and communicating zygomatic responsible for?
What do you usually anesthetize when working with the maxilla?
Terminal branches (most are infiltrations NOT blocks)
Where do supraperiosteal injections affect?
Small areas/single tooth
Where do ASA nerve block affect?
Incisors and Canines
Where do MSA nerve blocks affect?
Bicuspids and MB root of maxillary 1st molar
Where do PSA nerve blocks affect?
All three molar minus MB root of maxillary 1st molar
Why do you aspirate? (negative pressure)
To determine if you are in a blood vessel
How long are short and long needles?
1'' and 1 5/8'' , respectively
What does a larger gauge indicate for diameter of a needle?
What are the advantages of a large gauge?
better accuracy, decreased needle breakage and tissue deflection, easier/more accurate aspiration
Can a patient tell the difference between larger or small gauge needles?
What are the parts of a LA cartridge
rubber septum/diaphram, aluminum cap, rubber plunger (LA are color coded)
What are the components of a LA cartridge
NaCl - isotonicity
Vasopressor (increases depth and duration, decreases absorption
Na (meta) bisulfite (antioxidant -preservation)
What does a true positive indicate?
Blood in syringe/ Needle in vessel
What does a true negative indicate?
No blood in syringe/ Needle not in vessel
What does a false positive indicate?
Blood in syringe / Needle not in vessel
What does a false negative indicate?
No blood in syringe/ Needle in vessel
What does C-CLAD stand for?
computer controlled LA delivery
What does TENS stand for?
Transcutaneous electronic nerve stimulation
TENS applies the gate theory of pain, what is this theory?
stimulation of peripheral nerves prevents transmission of painful stimuli
What are the percentage of LA and epi concentrations available for lidocaine/xylocaine?
2% w/ 1:100,000 and 2% w/ 1:50,000
What are the two LA that do not contain epi
Carbocaine (mepivacaine) and Citaneste plain (prilocaine)
What percentage of Carbocaine (mepivacaine) is available in clinic
What percent citaneste forte (prilocaine) and epi concentration is available in clinic
4% w/ 1:200,000
What percent marcaine (bupivacaine) and epi concentration is available in clinic
What percentage septocaine (articaine) and epi concentration is available in clinic
4% w/ 1:100,000
What are the two reasons epi is used in LA's?
vasoconstrictor (keeps LA at site of injection) and hemostasis
What is the percentage success rate of anestheisa upon the 1st injection
What is the differential blockage?
Refers to the order of sensory loss w/ LA
All LA are vasodilatory, except one...name it!
Why can we use carbocaine/prilocaine w/out epi?
They are less vasodilatory than lidocaine/articaine so you can get away with not having epi
How are lipid solubility and onset of action and extent of absorption related
What are the three factors that determine the duration of a LA?
Protein binding of LA, Extent of vasodilation, presence of vasoconstrictor
What are the primary factors affecting the onset of a LA?
Lipid Solubility, pH of tissue, and pKa of LA
How is pKa related to onset of LA?
The lower the pKa the greater proportion of drug in the teritary/diffusible/unionized form (faster onset)
What are the secondary factors affecting onset of LA
time of diffusion from needle to nerve, nerve morphology, and concentration of drug
Which LA is the longest acting?
0.5% Marcaine (Bupivacaine)
What is the most vasodilatory LA?
0.5% Marcaine (Bupivacaine)
How is bupivacaine the longest acting LA when it is the most vasodilatory?
It binds to tissue proteins extremely strongly and has epinephrine --> both counteract vasodilation
Where are amides metabolized
liver (long half lives)
How is the metabolism of LA's affected in pts with CHF or on beta blockers?
2-3 times higher blood lvls
What does lidocaine form that can cause toxicity
active metabolites (articaine does not have these)
Where are esters metabolized
blood (short half lives)
What is the pulpal duration for 3% Mepivacaine
What type of patients is mepivacaine useful for
Vasoconstrictor contraindicated and geriatric patients
What type of patients is mepivacine contraindicated
children- higher percentage so you can't use as many cartridges
What are two advatages of Prilocaine compared to Lidocaine
40% less systemic toxicity and less painful injection
What are the adverse side affects of Prilocaine
methemoglobinemia and parasthesia
What is the pulpal duration for Prilocaine w/out epi and with w/ epi?
60 min and 60-90min (longer than xylocaine)
What is the onset of action for Bepivacaine?
6-10 min (slow compared to lidocaine which is 3-6min)
What is the pulpal duration for Bepivacaine
90-180min (good for lengthly procedures)
What LA has the most pain upon injection?
0.5% Bepivacaine (low pH)
What is the onset for 4% Articaine
What are the structural differences between Articaine and lidocaine
Thiopene ring instead of a benzene ring (increases lipid solubility) and has an ester group (reduced half life to 20 min)
What are the two factors that determine systemic duration of a LA
time it stays in the area by nerve and metabolism (blood is faster)
What is the duration of a maxillary infiltration and nerve block when using articaine
2.25 hrs and 4 hrs respectively
What are the adverse side affects of Articaine
methomoglobinema and parathesia associated with mandibular blocks
What is the most commonly affected nerve in parasthesia? (most often during mandibular block)
What is an advantage of Articaine
excellent bone penetration
What are the maximum mg/kg and max cartridges for lidocaine
7mg/kg and 14 cartridges
What are the maximum mg/kg and max cartridges for mepivacaine
6.6mg/kg and 7 cartridges
What are the maximum mg/kg and max cartridges for prilocaine
8mg/kg and 8 cartridges
What are the maximum mg/kg and max cartridges for bupivacaine
1.3mg/kg and 10 cartridges
What are the maximum mg/kg and max cartridges for articaine
7mg/kg and 7 cartridges
How are allergy and toxicity related to dose
Allergy is NOT related to dose and toxicity is related to dose
If a pt is allergic to amide what is the protocol
Skin test for carbocaine and switch to a different amide structure (lidocaine and prilocaine are similar and mepivacaine and bupivacaine are similar)
What can you use if a pt is allergic to both esters and amides
What can you use if a pt is allergic to bisulfites
Carbocaine or Citaneste plain
If a pt is experiencing toxicity, what happens (in order)
Excitation --> Tonic Clonic Seizures --> CNS depression
Why does a pt experience seizures before generalized CNS depression during toxicity?
the inhibitory neurons are affected first (then excitatory)
What should you do if a pt has an epi overdose
Keep the pt calm, have the pt hyperventilate, should only last several min
How do you reduce the risk of toxicity of LA
do not use epi, use least amount of LA possible, infuse drug slowly, pay attention to maximum values
What are the Class B LA that are safe to use in pregos
Lidocaine and Prilocaine
What are the Class C LA that are NOT safe to use in pregos
Articaine, Mepivacaine, and Bupivacaine
What are the contraindications with epi
Uncontrolled hypertension,CHF, hyperthyroidism diabetes, unstable angina, refractory arrhythmeias, recent MI, sulfite sensitivity, steroid dependent asthma, and pts with pheochromocytoma
Rating for tricyclic antidepressants, beta blockers, general anesthesia or cocaine and epinephrine in LA?
1 - most likely a severe DDI
How does tricyclic antidepressants interact epinephrine in LA
block reuptake of NE and epi (more sympathetic stimulation 3 fold more)
How much LA would you use for ppl taking tricycling antidepressants
1/3 of maximal dose of 1:100,000 LA
How does beta blockers interact with epi
Make epi completely vasoconstrictors (alpha adrenergic)
Affects of beta blockers and epi in LA usage
PR and BP increase --> reflex is to slow the heart (bradycardia) and cardiac arrest after 2 cartridge injections
How much LA would you use for ppl taking beta blockers
1/2 max dose of 1:100,000 LA
How does cocaine interact with epi in LA
Blocks the reuptake and enhances the release of neurotransmitters --> intensifies the postsynaptic affect
How long after a person has used cocaine should you wait to provide dental care
How does general anesthesia interact with epi in LA
disrupts the dysrythmogenic action of epi (halothane is the worst)
What can alpha adrenergic blockers cause when used with epi?
Orthostatic hypotension (epi acts as completely vasodilatory)
Rating for alpha adrenergic blockers , adrenergic neuronal blockers and thyroid hormones
4 - avoid IV otherwise vasoconstrictors can be used without special precautions
Rating for monamine oxidase inhibitors (MOI)
5 - do not have to worry
How do MOI's work
They block the catabolism of NE
How does Oraverse work
It is a alpha one adrenergic inhibitor - makes epi completely vasodilatory
What is the active ingredient in Oraverse
What is the pulpal and soft tissue duration for lidocaine?
60 min and 3-5 hrs
What can prilocaine and lidocaine provide?
epidermal anesthesia to intact skin (everything except pulp)
What kind of injection can you use to avoid a mandibular block?
PDL injection (40-60 min pulpal anesthesia, but injecting under great pressure!)
What is the maximum amount of epi?
0.2mg (0.04 in sensitive pts)
Sets with similar terms
Anesthesiology exam 1
Local exam 3
Dental Hygiene Local Anesthesia Study Boards
Anesthesia Chapter 17
Other sets by this creator
Memorize #'s for Oral Exam
Guidelines Pediatric Dentsitry