P&A midterm

lower MRD for __________ children

overweight; immature liver

deep sedation

- assistance with airway

- pt responds to pain/repeated stimulation

peripheral nerve fiber classification

A fibers = fast large myelinated, beta & delta = afferent touch/pressure & pain/temp respectively

B fibers = partial myelination

C fibers = slow small unmyelinated

increased A & C fibers in oral cavity, A fibers = more anesthesia

10% of asthmatics are allergic to ______

bisulfites

best epi concentration

1:50,000 (1:100,000 better than 1:200,000)

vasoconstrictors (including levonordefrin) 1. 6x LA duration 2. decrease LA absorption (lower toxicity) 3. contraindicated heart surgery 3-6 mo

duration of LAs

short acting: 30 min pulpal anesthesia

- mepivicaine

- prilocaine

intermediate acting: 60 min

- lidocaine+ epi

- mepivicaine + epi

- prilocaine + epi

- articaine + epi

long acting: 90+ min

- bupivacaine + epi

epinephrine vs levonordefrin

epinephrine

- MRD 0.2 (0.04 CV ds or TCAs)

levonordefrin

- MRD 1.0 (0.2 CV ds)

- more affect alpha adrenergic receptors

- no with TCAs

topical lidocaine

- amide (ester allergy)

- 2-10min onset, 15-45min duration

- 2-5% concentration

- MRD 200mg safely

epi/carpule for limiting drug calculation

0.018mg epi/carpule

MRD healthy: 0.2

MRD cardiac: 0.04

local anesthetics increase/decrease blood pressure?

increase

high BP

NO2 for stress reduction

acceptable HR & RR

stress may increase

risk assessment

A: antibiotics?

B: bleeding conditions (hemostasis)?

C: pt tolerates laying down (supination)?

D: drugs or medical devices?

E: dental equipment adjustments needed?

iatrosedation

technique of communication between the dentist and the patient that creates a bond of trust and confidence

minimal sedation

- pt maintains airway

- pt responds to stimulation

- no loss of consciousness (wide margin of safety)

moderate sedation (conscious sedation)

- pt maintains airway

- pt responds to commands

general anesthesia

- assistance with airway & cardio

- loss of consciousness

- pt does not respond to stimulation

sedation permit

- CODA accredited post-doctoral training program required for higher than minimal sedation

- advanced cardiac life support (ACLS) or pediatric advanced life support (PALS) also required

oral benzos

- anti anxiety

- CNS depressant

- no driving

- no titration

- diazepam or triazolam

N2O documentation

- informed consent

- % N2O administered

- sedation time length

- flow rate

- indication for use

- pt response & tolerance

N2O side effects

short-term: nausea, vomiting, headache (technique-based)

long-term: bone marrow suppression, reproductive disturbance, neurological deficits, hepatotoxicity

N2O equipment

O2 cylinder (green) = only gas

N2O cylinder (blue) = liquid underneath gas, gauge will show 100% as long as liquid exists

N2O safety

- pin systems are different, won't hook up to one another

- if O2 delivery fails, N2O is terminated

- if gases stop, atmospheric air is let in

- emergency oxygen button

N2O administration

- removal: 100% O2 for 5 minutes

- NEVER leave pt unattended

nerve structure****

nerves only found in PNS

LA carpule dose

1.8 mL (unless manufacturer cannot provide guarantee, then 1.7 mL)

LA carpule contents

- LA drug

- NaOH: buffer

- NaCl: buffer

- epi/levonordefrin: vasoconstrictor

- Na bisulfite: vasoconstrictor preservative

LAs: ester vs amide

esters = more allergic rxns

amides = all injectable dental LAs

LA pharmacodynamics

- all LAs are vasodilators (more vasodilation = less duration)

- more lipid soluble = more potent

- higher protein (receptor) affinity = longer duration = slower recovery

ester LAs & MOA

benzocaine, tetracaine, procaine

- metabolized in blood via pseudocholinesterase or liver

amide LA carpules

lidocaine (xylocaine): GREEN AND RED (2,2%)

mepivacaine (carbocaine): TAN AND BROWN (3,2%)

prilocaine (citanest): BLACK AND YELLOW (4,4%)

articaine (septocaine): GOLD AND SILVER (4,4%)

bupivacaine (marcaine): BLUE (0.5%)

articaine (septocaine) dosage

3.2mg/lb, MRD none

highly lipid soluble, no topical, 1-3 min onset, C lactation unknown

bupivicaine (marcaine) dosage

no dosage, MRD 90mg

MOST TOXIC, need epi (most potent vasodilator), no topical, 5-10 min onset

calculate MRD

1. % x 10 = mg/ml (2% = 20 mg/ml)

2. mg/ml x 1.8ml/carpule (20 mg/ml = 36mg/carpule)

3. weightxMRD / mg/carpule (352 lidocaine / 36 = 9.7)

needle

- gauge: larger the gauge, the smaller the diameter

- hub: weakest part of needle, plastic attachment to needle

- replace needle after 3-4 penetrations

LA complications

syncope: drastic BP drop

hematoma: BV penetration

facial paralysis: parotid gland penetration (CN VII)

paresthesia: trauma to nerve sheath

in healthy pts, limiting drug is ______. in cardiac pts, limiting drug is ______.

LA agent

vasoconstrictor

stress increases/decreases pain?

decreases

IV benzos

- diazepam (valium) or midazolam (versed - better for amnesia & lacks rebound effects)

- titration for minimal side effects

- combined with fentanyl or propofol for <60 min sedation

N2O

- low blood solubility = 2-5 min onset

- rapid diffusion, crosses BBB & placenta

- little to no BP or HR effect

N2O indications & contraindications

indications: anxiety, fainting, gag reflex

contraindications:

absolute = nasal obstruction, B12 deficiency, alcoholic/recovering addict, uncommunicative/refusal

relative = marijuana, middle ear infection, balance disorder, motion sickness, claustrophobia, MED CONSULT for lung disease, immunocompromised, pregnancy, psychiatric disorder

topical or submucosal injection LA delivery is more toxic?

topical, higher absorption

LA chemical structure

1. lipophilic aromatic ring: inactive base, determines potency via membrane penetration, requires proton to bind receptors

2. intermediate linkage: ester vs amide

3. hydrophilic terminal amine: dissociates to enter nerve (loses proton, anion, active form) & picks up proton to bind receptors again

LA pharmacodynamics: acid/base

- cartridge contains both cations RNH+ (acid, active) & anions RN (base, inactive)

- all LAs are acidic

- low pKa = more base = rapid onset, crosses membrane more readily

- infected tissue = acidic = more anesthesia needed

reinjection of LA

- partially recovered nerve fibers = SMALL VOLUME effective with RAPID onset

- fully recovered nerve fibers = TACHYPHYLAXIS = LA tolerance = LA ineffective

LA toxicity directly related to amount of LA accumulated in _______

vascular organ tissues (brain, heart, liver, lungs, kidneys)

amide LAs & MOA

lidocaine, mepivacaine, bupivacaine (liver metabolized, liver toxicity with disease)

prilocaine (liver + lung metabolized, shorter half life)

articaine (blood 90% + liver metabolized, shortest half life)

lidocaine (xylocaine) dosage

3.2mg/lb, MRD 500mg

good hemostasis + epi, low toxicity, 2-3min onset, B lactation safe

mepivacaine (carbocaine) dosage

3.0mg/lb, MRD 400mg

bad hemostasis, no topical, 1.5-2 min onset, C lactation safe

prilocaine (cinest) dosage

4.0mg/lb, MRD 600mg > methemoglobinemia

LEAST TOXIC, 2 min onset, B - good for pregnancy, lactation unknown

topical anesthetics

- concentration 0.2-20%

- benzocaine sprays = methemoglobinemia

- tissue depth 2-3mm

topical benzocaine (hurricaine)

- ester

- 30s-2min onset, 5-15min duration

- 20% concentration

- methemoglobinemia with spray

cetacaine topical (benzocaine + butamben + tetracaine)

- ester

- 30s onset, 30-60min duration

- 14:2:2% benzocaine butamben tetracaine concentration

- MRD 200mg

- low toxicity

aspiration

negative pressure in cartridge before injecting to determine if needle is in BV, aspirate in 2 planes

positive: blood enters carpule

negative: no blood, maybe small bubble

PSA

- 27 short, 1/2 needle, 1/2 carpule

- apical to root of 3rd molar target

- go in lateral to 2nd molar at 45 degree angle in (medially) and up

- innervates molars & respective buccal gingiva

MSA

- 27 short, 1/3 needle, 1/2 carpule

- slightly apical to premolars target

- go in along long axis of premolars to apex

- innervates premolars, MB cusp of 1st molar, & respective buccal gingiva

ASA

- 27 short, 1/3-1/2 needle, 1/2 carpule

- apical & slightly distal to canine target

- go in along long axis of canine to target

- innervates anterior teeth & labial mucosa to midline

GP (AKA anterior palatine)

- 27 short + cotton tip applicator, buried bevel, 1/4 carpule until tissue blanches

- greater palatine foramen target

- go in just anterior to GP foramen, medial to disto-palatal cusp of 2nd molar, perpendicular to mucosa

- innervates palatal soft tissue & palatal bone distal canine to junction of hard+soft palate to midline

NP (AKA incisive)

- 27 short + cotton tip applicator, buried bevel, 1/4 carpule until tissue blanches

- incisive foramen target

- go in just lateral to incisive papilla to posterior portion at 45 degree angle to bone with bevel lateral to soft tissue

- innervates palatal soft tissue & bone of anterior hard palate distal canine to distal canine

IO (infra orbital)

- 25 long/27 short based on pt size, 1/2 needle, 3/4 carpule

- inferior to orbital rim near infraorbital foramen target

- go in parallel to 1st molar & angle towards IO foramen

- innervates anterior teeth to midline (75% premolars + 1st molar) with respective buccal gingiva, & skin up to lower eyelid

infiltration (supraperiosteal)

- 27 short, to apical region of tooth, 1/3 carpule

- apical to the tooth target

- go in along long axis of maxillary tooth to target

- innervates 1-2 maxillary teeth and soft tissue in the area

branches of V3

undivided: medial pterygoid & dura mater branches

anterior: lateral pterygoid, masseter muscle, temporal muscle & branches; long buccal nerve

posterior: auriculotemporal branch, lingual nerve, mylohyoid nerve, inferior alveolar nerve, mental nerve, incisive nerve

mandibular block

posterior zone (inferior alveolar nerve & lingual nerve)

anterior zone (long buccal nerve) *separate injection*

posterior mandibular block: IAN + lingual nerve

- 25 long, 2/3-3/4 until contact bone, entire carpule save 0.2cc

- retromolar triangle target (defined by 3 points)

- go in 6-10mm above occlusal plane parallel to it

- innervates mandible

anterior mandibular block: long buccal

- 25 long, until contact bone, 0.2cc

- anterior border of ramus target

- go in parallel to occlusal plane distobuccal to distal most molar

gow-gates mandibular block

- 25 long, until contact bone (3/4 needle), full carpule

- anteromedial side of condylar neck target (superior to conventional mandibular block)

- go in distal to max 2nd molar, aligned with imaginary line between tragus of the ear & corner of the mouth (middle finger on the tragus)

- anesthetizes IAN, lingual n, long buccal n

vazirani-akinosi mandibular block

- 25 long, 3/4 needle, full carpule

- medial border of ramus target

- go in with mouth closed (light occlusion), parallel to occlusal plane & insert at mucogingival junction of max 2nd molar, NO CONTACT BONE

- anesthetizes IAN, lingual n, long buccal n

mental nerve block

- 25 long/27 short, buried bevel, 1/2 carpule

- mental foramen target

- go in between premolars at depth of the vestibule, around neurovascular bundle (palpate)

mylohyoid nerve block

- 25 long/27 short, 1/4-1/3 needle until contact bone, 1/2 carpule

- lingual approach, just medial to distal tooth target

- go in at 45 degree angle to long axis of molar at depth of lingual vestibule

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