Anek Flashcards
Guedel’s stages of general anesthesia
- amnesia and analgesia
- unconscious/delirium /unstable
- surgical anesthesia/ desirable stage/ stable
- respiratory depression
Anes has the capacity to oxidize but the most commonly cited anes related to methemoglobinemia is? it is converted into?
Prilocaine (Citanest) is converted into orthotuluidine (cause methemoglobinemia)
**Risk of methemoglobinemia is also increased in articaine above recommended dose
Maximum dosage of epi for normal patients
0.2mg (200 micrograms)
Maximum dosage of epi for cardiovascular-compromised patients
0.04mg (40 micrograms)
Only anesthesia that is a vasoconstrictor
Cocaine - not used in dentistry
Safest local anesthesia
Lidocaine (Xylocaine, Lignocaine)
Amide Local anesthesia usally without vasoconstrictor since it is a weak vasodilator, SHORTEST acting amide
Mepivacaine (Marcaine)
Metabolized both by liver and plasma, specially designed for dentists, increased risk of paresthesia
Articaine
amide local anesthetics combined to produce topical anesthesia
Lidocaine + prilocaine (Eutectic Mixture of L. A.)
1st synthetic LA
procaine (novocaine)
shortest acting LA
procaine (novocaine)
Preservatives of LA that can cause allergic reactions
Methyparaben - prevent microbial contamination
antioxidant of vasoconstrictors of LA (reducing agent)
Sodium bisulfites - prevent oxidation
Max dose of lidocaine with epi (adult)
7mg of lidocaine / kg
Pero max daily pa rin 500mg
total max daily dose (lidocaine w. epi)
500mg
Total max daily dose (lidocaine w/o epi)
300mg -lidocaine w/o epi is more toxic
needle used in Md block in pedo px
27 (short -20mm)
needle used for intraligamentary injection
30 gauge (ultra short <20mm)
bubble in the LA is primarily due to what molecule
nitrogen
Reference point for TRUE ASAN block
distal of canine, 1st PM
injection site for greater palatine nerve block
bet mx 1st and 2nd molar
Tissue that can be punctured during Classic Md block
buccinator
medial pterygoid muscle
sphenomandibular ligament
considered the TRUE md nerve block
Gow-gates technique - more accurate but technique sensitive
closed mouth md blocking
akinosi-vazirani
Max dosage for norepinephrine and usual concentration on anes
0.34mg (n), 0.14mg (cvd)
1:30 000
**Can cause local ischemic effect (4mL)
Levonordefrin (Neo-cobefrin)
Max Dosage, conc
Dosage: 1mg (n) 0.4mg (cvd)
1:20 000
Arteriolar constriction
Phenylephrine max dose and conc
1:2500
Dose: 4mg (n), 1.6mg (cvd)
Longer lasting effect
Most stable, weakest
Analog of vasopressin, NONsympathomimetic amine?? max dose??
Felypressin (Octapressin)
Venous microcirculation only
Safer for hyperthyroidism, MAO, TCA
Dose: 0.27 UI (9ml of 0.03IU)
Methods of Termination of vasoconstriction action
Reuptake and restorage
Deactivation by extraneuronal enzymes (Catechol O methyl transferase -COMT)
Uptake by blood stream
Intraneural enzymatic destruction (Monoamine oxidase)
Difference of esters and amides in chemical structure
Both has aromatic (lipophilic) and secondary/tertiary amino (hydrophilic) ends. Sa intermediate nagkakaiba. Ester and amide group
MRD of 2% procaine + 0.4% propoxycaine
6.6mg /kg
Amide type LA contraindicated with pxs receiving acetaminophen
Prilocaine
4% with 1:200 000
MRD: 6.0mg/kg
LA that can be used without vasoconstrictor
Prilocaine - can be for epi sensitive px (slight vasodilator)
Mepivacaine - slight vasodilator (short duration?)
Has delayed onset and long lasting anes
Bupivacaine
Not for children
LA that is usually associated with paresthesia
Articaine and prilocaine
Amide LA contraindicated to px allergic to sulfur containing drugs
Articaine
Depth of penetration of topical anesthetics
Only on surface of tissues (2-3mm)
Water insoluble vs water soluble topical anes and examples
Water insoluble - safer because it is not readily absorbed into ciculation
Benzocaine or ethyl aminobenzoate
Lidocaine base (5%) -indicated for ulcerated, abraded, lacerated tissues
Water soluble
Benzyl alcohol -shorter acting, very irritating on injection into the tissues
Tetracaine HCl - long duration ester, rapidly absorbed through mucous membrane –systemic toxicity
Lidocaine Hcl (2%) systemic absorption is greater than lido base thus higher toxicity
LA with 7-8times potency than procaine
Propoxycaine thus not used alone
4% Procaine + 0.4% propoxycaine - for allegic to amide anes
Long duration amide anes but faster onset
Etidocaine
Articaine lipophilic portion
Thiophene ring.
Articaine is the only amide type LA that contains thiophene group
Dissociation constant
pKa - half ionized half unionized
Low pH ▶️ inc H+ ▶️ inc RNH+ / dec RN
RN - lipid soluble, nonionized, free base
Drug of choice for intranasal sedation in pediatrics
Midazolam
Intranasal onset same as IM and as effective
Jorgensen technique
Barbiturates + opioids + anti-cholinergic drugs
Neurolept anesthesia is produced by?
Neuroleptic agent (Droperidol) + narcotic (Fentanyl) + nitrous oxide
Neurolept anes is production of tranquility and mental detachment without marked soporific effect
