Oral Surgery Test Review Flashcards
The following are associated with the extracellular space:
- Na+
- K+
- Cl-
Na+
Is there more?
Na+, Cl-, Bicarb
The following are associated with the Intracellular space:
- Na+
- Cl-
- K+
K+ and proteins
small amounts of Na+ Cl- and Bicarb
??????
_______ _______ is where local anesthesia exert their pharmacological actions
Nerve membrane
______ ______ ______: Local anesthesia bind to specific receptor on the
Na channel
SPECIFIC RECEPTOR theory
Nodes of Ranvier: Sodium channel is_______.
abundant
How Local Anesthesia Work?
• Decrease permeability of ion channels to Na
• Nerve block by local anesthesia is a
Non-depolarizing block
T/F: nerves have a quicker conduction than un-myelinated. AND….
Adelta and A Alpha (about 120 m/sec) are faster than C fibers (1.2 m/sec) .
true
Where does local anesthesia work at myelinated nerve?
the nodes of ranvier
Is local anesthesia hydrophilic or they like oily stuff?
Hydrophillic (injectable)
t/f: only the free base form of LA can diffuse through the wall of the nerve.
true
t/f:
↑ pKa translate to slow onset
true
t/f:
↓ pKa will have faster onset
true
t/f: Extracellular pH determines the ease for nerve blockade
true:
So, since: RNH = RN+H+
does the higher pH (more H+ shift the equation to RNH which cannot cross neerve membrane like free base can. This results in less effective LA?
t/f:
Greater lipid solubility relates to intrinsic potency
true – Nerve membrane is 90% lipid
t/f:
Increased protein binding will increase duration
true – Nerve membrane is 10% protein
Lipid Solubility influences: _______
potency
pKA influences: _______
onset
Protein Binding influences: ________
Duration
↑ Tolerance to drug after repeated administration
Tachyphylaxis
what are the Different classes of local anesthesia
Ester and Amide
______ most potent vasodilator
Procaine
_______ : the only local anesthetic with constrictor effect
Cocaine
_____ ______ has greatest % of anesthetics
Skeletal muscle
How do you calculate elimination half life?
Time needed for 50% reduction in blood level
- 1st t ½ 50%
- 2nd t ½ 75%
- 3rd t ½ 87.5%
- 4th t ½ 94 %
_______ local anesthetics cross blood-brain barrier, and placenta
ALL LA
How ______ metabolize in the body:
- Hydrolyzed in plasma by pseudocholinesterase into paraaminobenzoic acid (PABA)
Ester Metabolism
How ______ metabolize in the body:
- Primary biotransformation site is Liver
- Liver function/ hepatic perfusion influence
Pharmacology of Local Anesthesia Metabolism biotransformation
– Relative contraindication for
• ASA IV to V patient with liver dysfunction, heart failure
Amide Metabolism
Would CHF or Liver failure increase Ester availability, but decrease amide availability.
Please call or text me. I seriously have no clue.
_______ are primary excretory organ
Kidneys
Initial clinical signs/symptoms of CNS toxicity are________!
Excitatory
Further______ in toxicity leads to cessation of seizure activity:
respiratory depression
reparatory arrest
increase
What are the stages/ signs of local anesthesia over dose / toxicity?
– Numbness of tongue and circumoral region (symptoms)
– Slurred speech, shivering, A/V disturbances, Disorientation, tremor.. (signs)
– Luckily, lidocaine don’t have these s/s but mild sedation or drowsiness
the follow are examples of _____ _____:
Epinephrine
Norepinephrine
Dopamine
natural catecholamines
The following are examples of ______ ______:
Isoproterenol
Levonordefrin
synthetic catecholamines
the following are examples of ___-_____:
Amphetamine, Ephedrine, Methamphetamine
Non-catecholamines
All Cathecholamines work on adrenergic receptors with______ acting
direct
Adrenoceptors:
Vasoconstriction increased peripheral resistance increased BP mydriasis increased closure of internal sphincter of the bladder
Alpha 1
Adrenoceptors:
inhibition of norepinephrine release
inhibitiomn of insulin release
alpha 2
Adrenoceptors:
tachycardia
increased lipolysis
increased myocardial contractility
beta 1
Adrenoceptors:
vasodilatation
slightly decreased peripheral resistance
bronchodilation
increased muscle and liver glycogenolysis
increased release of glycogen
relaxed uterine smooth muscle
beta 2
In a ratio for epinephrine dilution, 1: 100,000
the 1= ______ mg
1000 mg
do the following question:
Epinephrine dilution:
a)
1: 300,000
vs.
b)
1: 200,000
Which one is more concentrated
a) 0.00333333333 mg/ml
b) 0.005mg/ml
B is more concentrated
_________:
Lack significant B2 actions • Intense vasoconstriction Almost exclusive alpha action • Dramatic elevation of blood pressure 9X higher than epinephrine
norepinephrine
1) Blood pressure in excess of 200 mmHg systolic or 115 mmHg
Contraindication of vasoconstrictor
2) Uncontrolled hyperthyroidism
Contraindication of vasoconstrictor
3) Severe cardiovascular disease
a) Less than 6 months after myocardial infarction
b) Less than 6 months after cerebrovascular accident
c) Daily episodes of angina pectoris or unstable angina
d) Cardiac dysrhythmias despite appropriate therapy
e) Postcoronary artery bypass surgery (CABG), less than 6 months
Contraindication of vasoconstrictor
4) Undergoing general anesthesia with halogenated agents
Contraindication of vasoconstrictor
5) Patient receiving nonspecific B-blocker, MAOi, Tricyclic antidepressants
Contraindication of vasoconstrictor
Using the categories provided, which patients are considered ASA 4 risks and are not normally considered candidates for elective or emergency dental treatment in the office.
1) Blood pressure in excess of 200 mmHg systolic or 115 mmHg
2) Uncontrolled hyperthyroidism
3) Severe cardiovascular disease
a) Less than 6 months after myocardial infarction
b) Less than 6 months after cerebrovascular accident
c) Daily episodes of angina pectoris or unstable angina
d) Cardiac dysrhythmias despite appropriate therapy
e) Postcoronary artery bypass surgery (CABG), less than 6 months
4) Undergoing general anesthesia with halogenated agents
5) Patient receiving nonspecific B-blocker, MAOi, Tricyclic antidepressants
1-3d
Do patient OD if your exceed MRD?
not always but the chances are definitely increased.
t/f: Maximum calculated drug dose should decrease in medically compromised, debilitated, or elderly persons
true
That’s correct. Disadvantaged people are slower in metabolizing these
drugs. So you need to decrease the MRD on them
Which drug?
Onset of action: rapid (2-3 mins)
Anesthetic t ½ : 1.6 hours
Maximum Recommended Dose (MRD)
4.4mg/kg (Council on Dental Therapeutics of the ADA and USP convention)
Absolute maximum 300mg
8 Cartridges will be the maximum # used on a patient
Healthy patient, maximum epinephrine is 0.2mg or 200mcg
Cardio patient , maximum epinephrine is 0.04mg or 40mcg
Lidocaine