Oral surgery Flashcards
(204 cards)
basic functions of LA
2
prevent pain
reduce bleeding
how does LA work
blocks voltage gates Na channels
LA binds to site in Na channnels and blocks it
* preventing Na influx
this blocks action potential generation and propagation
blocks presist as sufficient number of channels are blocked
LA affects which type of axons
smaller diamter axons have fewer Na channels and are more suceptible to LA block
* e.g. A delta, C, A beta then A alpha
where are the sodium channels on a nerve
concentrated of nodes of Ranvier in myelinated axons
LA needs to act on several aong the axon
ester type LA
benzocaine
procain
cocaine
amide type LA
lidocaine
articane
prilocaine
bupivicaine
mepivicaine
vascocontrictors
purpose
acts locally to constrict Blood vessesl
reduce bleeding and blood flow to help increase duration LA works by holding LA in tissue (prevent wash out)
types of vasoconstricors in LA
2
adrenaline
felypressin
types of topical LA (2)
function
2% lidocaine gel
20% benzocaine
superficial soft tissue manipulation and surface anaesthesia
infiltration of LA
LA deposited beside nerve branches
inject distal to apex of tooth into mucogingival fold
nerve block
LA deposited beside nerve trunk
abolishing sensation distal to site
IDB technique
landmarks - pteygomandibular raphe, buccal fat pad, thumb on coronoid notch, fingers on external posterior border of mandible
needle advance from contralateral premolars, inject in 1cm above occlusal plane, advance till contact bone, withdraw slightly aspirate and deposite 2/3, 1ml/30secs
withdraw and deposit last 1/3 to get lingual nerve
how to check for numbness
ask pt - rubberly, tingle, numb, swollen, fat
IDB - to midline lip, inc tongue, buccal gingiva
complications of LA
failure
prolonged (temporary/permanent)
pain during/after
trismus
hametoma
intra-vascular
blanching
facial palsy - into parotid - CNVII
broken needle
interaction with other drugs
toxicity
soft tissue damage
how to manage facial palsy
test if brow can be raised/close eyes and raise arms - assess if stroke
reassure pt not stroke
cover eye with patch - no blink reflex
other LA techniques
not infiltration or block
palatal anaesthesia - chasing
intraligamentary
intraosseous
intrapulpal
Gow gates
akinosi
lidocaine max dose
4.4mg/kg
2.2% 1:80,000
articaine max dose
5mg/kg
4% 1:80,000
prilocaine
5.0mg/kg
4% - plaiin; 3% - octapressin
contraindication for felypression/octrapressin
pregnancy
functions of paracetamol
analgeisa
antipyretic
max dose of paracetamol
4g/day
cautions for paracetamol
hepatic/renal impairment
alcohol dependent
how does aspirin work
non selective cox inhibitor that reduces production of PGs by inhibiting COX-1 and COX-2