Local anaesthetic Flashcards
(215 cards)
1
Q
Which type of analgesic is this the definition of;
- a drug or agent which reversibly blocks neuronal transmission in the applied region causing a temporary loss of sensation/pain, without affecting consciousness
A
local anaesthetic
2
Q
Which type of analgesic is this the definition of;
- a drug or agent which produces loss of response to painful stimulation (analgesia) and loss of reflexes (motor and autonomic), with reversible loss of consciousness
A
general anaesthetic
3
Q
What is this the definition of?
- a drug or agent which relieves and prevents pain without loss of consciousness
A
analgesic
4
Q
What is this the definition of?
- a drug or agent which reduces irritability, excitement, or nervousness
A
sedative
5
Q
What are the 2 types of local anaesthesia?
A
local and regional
6
Q
Which type of local anaesthesia is being described?
- injection of local anaesthetic near nerves branches innervating a small, specific area of the body near surgical site
A
local
7
Q
Which type of local anaesthesia is being described?
- injection of local anaesthetic near major nerve bundles innervating larger, specific area of the body
A
regional
8
Q
What duration of cocaine use can cause the following?
CNS: headache, nausea, vomiting, muscle tremors, pseudohallucinations
Cardio: vasoconstriction, hypertension, tachycardia
Resp: increase in breathing rate & depth
Temp: elevation
Behaviour & other: euphoria, elation, excitation, restlessness, alert, energetic, strong paranoia
A
short term use
9
Q
What duration of cocaine use can cause the following?
CNS: generalised seizures, hallucinations, gross muscle tremors&twitching, decreased responsiveness to stimuli, incontinence
Cardio: hypertension, tachycardia, cardiac dysrhythmias, peripheral cyanosis
Resp: abnormally rapid breathing, shortness of breath, irregular breathing pattern
Temp: severe hyperthermia
Behaviour & other: paranoia, depression, agitation, violent or suicidal tendencies, difficulties in emotion and impulse control
A
long term use
10
Q
What duration of cocaine use can cause the following?
CNS: generalise convulsions, cerebral infarction & haemorrhage (stroke), pupils fixed and dilated, loss of vital support functions, coma
Cardio: aortic dissection, heart failure, cardiac arrest
Resp: resp depression, resp failure, gross pulmonary oedema, paralysis of respiration
Temp: severe hyperthermia
Behaviour & other: death
A
overdose
11
Q
What are the names of the 2 groups of synthetic local anaesthetics?
A
ester and amide
12
Q
What is a simple way of differentiating which synthetic local anaesthetics fall into esters or amides?
A
all amides have an ‘i’ before the ‘caine’ (lidocaine, bupivacaine) and all esters don’t (cocaine, procaine)
13
Q
What metabolises ester local anaesthetics?
A
plasma esterases
14
Q
What metabolises amide local anaesthetics?
A
hepatic enzymes
15
Q
Protonated forms of weak acids are … so therefore …
A
- lipophilic
- can cross the lipid bilayer
16
Q
Protonated forms of weak bases are … so therefore …
A
- not lipophilic
- cannot cross lipid bilayer as easily
17
Q
What percentage of lidocaine exists at an unionised form?
A
25%
18
Q
What percentage of bupivacaine exists at an unionised form?
A
15%
19
Q
The clinical performance of all local anaesthetics correlated with 4 principle properties: A?
A
property: lipid solubility
correlate: potency
20
Q
The clinical performance of all local anaesthetics correlated with 4 principle properties: B?
A
property: dissociation constant (pKa)
correlate: time of onset
21
Q
The clinical performance of all local anaesthetics correlated with 4 principle properties: C?
A
property: chemical linkage
correlate: metabolism
22
Q
The clinical performance of all local anaesthetics correlated with 4 principle properties: D?
A
property: protein binding
correlate: duration
23
Q
Which nerve fibres are myelinated and have fast conduction and conduct sharp pain?
A
A delta fibres
24
Q
Which nerve fibres are unmyelinated and have slow conduction and conduct dull pain?
A
C fibres
25
A delta and C fibres (nociception, temp, touch) blocked ... A beta fibres (touch, pressure, proprioception)
before
26
Myelinated nerve fibres blocked ... unmyelinated nerve fibres
before
27
Nerve fibres associated with pain are blocked ... other sensory modalities
before
28
What are the 4 factors that impact the absorption of local anaesthetics?
1. site of injection - impacts blood levels - areas of high vascularity results in greater uptake and higher blood concentrations
2. dose
3. addition of vasoconstrictor - most anaesthetics have a direct vasodilator action, increases the rate of absorption into systemic circulation
4. pharmacologic profile of the anaesthetic - individual local anaesthetics exhibit different rates of absorption
29
Patients with which deficiency are at a higher risk of LA toxicity from ester local anaesthetics due to them metabolising the LA more slowly?
pseudocholinesterase deficiency
30
Patients with dysfunction of what organ may represent a contraindication to amide local anaesthetics due to metabolising LA more slowly and therefore at a higher risk of LA toxicity?
liver dysfunction
31
Some ester LA (procaine, benzocaine) are hydrolysed to para-aminobenzoic acid (PABA) and are associated with... ???
- allergic reaction
- medical emergencies
- interfere with antibacterial affect of sulphonamides
32
Large doses of Prilocaine (amide) can lead to which?
methaemoglobinaemia
- metabolite produces methaemoglobinaemia
- patients shortness of breath, cyanosis, can be fatal, but is rare
33
Allergy to PABA - Esters symptoms?
hypersensitivity - swelling of tongue, throat and face
- onset normally within 5 mins may be delayed up to 40 mins
34
4 methaemoglobinemia symptoms associated with methaemoglobin levels?
- slight discolouration of the skin
- cyanosis
- headache, lightheadedness
- abnormal cardiac rhythms
35
What solution is LA prepared as in order to be stable in solution?
hydrochloride salt
36
What 3 forms do topical anaesthetics come in?
- lignocaine 5%, 10% spray
- benzocaine 20% gel
- EMLA (eutectic mixture of local anaesthetics) 2.5% lidocaine & 2.5% prilocaine
37
What is the name of the preservatives that can be found in local anaesthetics?
- 0.1% sodium meta-bisulphite
- 1mg/ml methyl para-hydroxybenzoate
38
Which ingredient in LA acts as a vasoconstrictor?
adrenaline
therefore:
- minimises the vasodilator effect of LA
- decreases the rate at which drug is removed from the site of action by absorption into the systemic circulation
- reduces traumatic blood loss from the site by the same mechanism
39
Which ingredient is added to LA which increases the pH of the environment when administered?
bicarbonate
therefore:
- more drug is present in its unionised form and speed of onset of anaesthesia is increased
- too much bicarbonate may result in precipitation of the local anaesthetic
- unionised form less soluble in water than the hydrochloride salt
40
A?
lidocaine (lignocaine)
41
B?
mepivacaine
42
C?
bupivacaine
43
D?
prilocaine
44
E?
articaine
45
Which LA has less tendency to cause CNS effects?
lidocaine
46
Which LA has more tendency for cardiotoxicity?
bupivacaine
47
What are 5 potential LA complications?
1. ischaemic necrosis of tissues and nerve damage may follow injections of local anaesthetics; irritating nature of solution, pressure from large volumes, constriction of vasculature by adrenaline
2. vascular damage; haematoma, LA can get into circulation easier leading to systemic toxicity
3. drug error; check drug type, concentration, dose, expiry date, check adrenaline content, interactions with other drugs - polypharmacy
4. needle breakage and dental cartridge failure - minimised by modern equipment
5. no anaesthetic block 'block failure';drug, poor delivery, altered anatomy
48
Branches of trigeminal... A?
ophthalmic nerve
49
Branches of trigeminal... B?
maxillary nerve
50
Branches of trigeminal... C?
mandibular nerve
51
Where does the V2 branch of trigeminal (maxillary nerve) supply?
- lower eyelid
- part of nose and nasal cavity
- upper lip
- upper dentition and gingiva
- palate
52
Where does the V3 branch of trigeminal (mandibular nerve) supply?
- mandible
- ear
- TMJ
- anterior 2/3 of tongue
- lower dentition
- muscles of mastication
53
Which branch of trigeminal is being described?
- moves into the pterygopalatine fossa via foramen rotundum
- purely sensory
- 2 types of branches - direct or indirect via a ganglion
- sensation to the mid face, lower eyelid, upper lip, posterior nasal cavity and nasopharynx, palate and the upper dentition/gingiva
V2 - maxillary nerve
54
What are the 3 direct branches of V2 maxillary nerve?
- meningeal
- zygomatic
- infraorbital
55
What nerve does the anterior, middle and posterior superior alveolar nerves branch off of?
infraorbital nerve (branch of V2 maxillary nerve)
56
What are the 3 important indirect branches of V2 maxillary nerve?
- greater palatine
- lesser palatine
- nasopalatine
57
Where does the greater palatine nerve (branch of V2 maxillary nerve) supply?
hard palate
58
Where does the lesser palatine nerve (branch of V2 maxillary nerve) supply?
soft palate
59
Which branch of trigeminal is being described?
- moves into infratemporal fossa via foramen ovale
- mixed sensory and motor
- sensation to the chin, scalp, mandible, lower teeth and gingiva, tongue and oral cavity
- 2 divisions - anterior and posterior
V3 mandibular nerve
60
Which nerve of the anterior division of V3 mandibular nerve is being described?
- sensory; skin over buccinator, inner surface of cheek and buccal gingiva
long buccal nerve
61
Which 3 main nerves make up the posterior division of V3 mandibular nerve?
- lingual nerve
- inferior alveolar nerve
- auriculotemporal nerve
62
Which nerve of the posterior division of V3 mandibular nerve is being described?
- sensory; lingual gingiva and anterior 2/3 of the tongue
lingual nerve
63
Which nerve of the posterior division of V3 mandibular nerve is being described?
- runs through the mandible via mandibular foramen and canal
- sensory to all lower teeth and gingiva
inferior alveolar nerve
64
Which nerve of the posterior division of V3 mandibular nerve is being described?
- sensory; angle of the mandible, TMJ and scalp
auriculotemporal nerve
65
Where is the pterygopalatine fossa in relation to the infra temporal fossa?
on the back wall of the infratemporal fossa
66
Which branch of V3 mandibular nerve is being described?
- runs along the medial aspect of the mandible, along the floor of the mouth
- then up into the oral cavity to supply the tongue
lingual nerve
67
Which branch of V3 mandibular nerve is being described?
- runs down the medial aspect of the mandible, enters inside the mandible via the mandibular foramen and into the mandibular canal suppling the lower dentition though little alveolar branches
inferior alveolar nerve
68
Which branch of the inferior alveolar nerve is being described?
- emerges from the mental foramen and out to supply the lower lip and chin
mental nerve
69
Which two nerves emerge from the end of the inferior alveolar nerve?
mental nerve and incisive nerve
70
Part of the inferior alveolar nerve continues to the lower incisors and this is called the...
incisive nerve
71
Which teeth does the middle superior alveolar nerve (or the superior dental plexus) supply?
- upper premolars
- MB root of upper 6
72
Some patients do not have a middle superior alveolar nerve, therefore which nerve supplies the upper premolar and the MB pulp of the upper 6s?
combination of the anterior and posterior superior alveolar nerves
73
Which teeth does the anterior superior alveolar nerve supply?
roots of upper canines and centrals
74
Where does the nasopalatine nerve innervate?
the anterior part of the hard palate and the mucosa of the nasal septum
75
Which nerve supplies the roots upper molars (expect MB root of 6s)?
posterior superior alveolar nerve
76
Which nerve supplies the palatal mucoperiosteum of upper anteriors (123)?
nasopalatine nerve
77
Which nerve supplies the palatal mucoperiosteum of upper posterior teeth?
greater palatine nerve
78
Which nerve supplies the roots of the lower anteriors (123)?
incisive nerve
79
Which nerve supplies the roots of lower premolars and molars (45678)?
inferior alveolar nerve
80
Which nerve supplies the lower buccal mucoperiosteum for anterior teeth and premolars (12345)?
mental nerve
81
Which nerve supplies the lower lingual mucoperiosteum for all teeth?
lingual nerve
82
Which nerve supplies the lower buccal mucoperiosteum for the molars (678)?
long buccal nerve
83
What are the 5 accessory nerves that can supply sensory to the roots of the lower teeth?
- lingual nerve
- long buccal nerve
- mylohyoid nerve
- auriculotemporal nerve
- cervical nerves
84
What is the term used to define the following?
- altered sensation
paraesthesia
85
What is the term used to define the following?
- loss of pain sensation only
analgesia
86
What is the term used to define the following?
- the loss or abolition of all modalities of sensation which include pain and touch
anaesthesia
87
Is an ester or an amide being described?
- long half life
- usually local analgesics
- metabolised in the liver only
amides
88
Is an ester or an amide being described?
- short half life
- usually topical analgesics
- metabolised by serum cholinesterase
esters
89
What type of LA is being described?
- is an exception to ester and amide category as it is both
- contains ester and amide
- contains a thiophene ring (instead of benzene ring)
- it is mainly amide - but the ester in it allows plasma metabolism, reducing its toxicity with an advantage of a 30 min half life compared to 90 min for lidocaine
articaine
90
Which type of LA is being described?
- derived from thiophene which allows for increased lipid solubility
- extra ester linkage which enables it to be hydrolysed by plasma esterase as well as enzymes in the liver
- 90-95% is metabolised in the blood and the remaining 5-10% is metabolised in the liver
- decreased risk of systemic toxicity due to being metabolised in the blood and therefore a shorter half life
- elimination half life is 30 mins
- thiophene ring gives the molecule better diffusion properties
- some studies of this LA have demonstrated that pulpal analgesic can occur in the dense bone of the mandible following a buccal infiltration due to bone penetration properties
articaine
91
What are 7 advantages of LA compared to GA?
- simple to do
- inexpensive equipment
- safer
- good operating time
- single operator
- rapid onset
- reduce bleeding
92
What are 5 factors that can affect the onset of the LA action?
- diffusion into the site (infil v block)
- nerve morphology (thin pain fibres blocked quicker than larger fibres
- concentration (increase dose leads to faster onset)
- lipid solubility (the more lipophilic the LA the greater the uptake)
- pH (acidity or low pH in infection leads to more ionised LA leads to delayed onset)
93
What are 6 factors that affect the duration of LA?
- diffusion away from site (LA vasodilating which would make the blood supply carry the LA away, so vasoconstrictor in the LA to counteract)
- concentration (double the dose will increase duration X 1.5)
- lipid solubility (longer, easily penetrate membrane and bind to channels)
- volume in vicinity of nerve
- site of fibre Aa vs. C (smaller the nerve the more sensitive)
- protein binding (higher have more attraction for receptor sites and remain within sodium channels for a longer period of time. So have a longer duration of action)
94
Which component of the oral cavity numbs first and remain anaesthetised for much longer?
soft tissues
95
What are 8 contraindications of LA?
- lack of cooperation
- acute infection - spread, pain, failure
- hypersensitivity, allergies
- haemophilia
- radiotherapy due to blood supply being reduced - mandible (preventative extractions), avoid vasoconstrictors
- medical - unstable angina or myocardial infarction (heart attack), liver disease, thyrotoxicosis (risk of crisis)
- age due to being more difficult to metabolise (remember max. dose)
- pregnancy (no octapressin or felypressin) due to having an affect on smooth muscles
96
What are the 5 contents of LA?
- sterile water
- analgesic agent (lidocaine, prilocaine)
- vasoconstrictor (adrenaline/epinephrine)
- reducing agent (sodium metabisulphate)
- buffer (alkali to slow ionisation)
97
What are the 4 benefits of an added vasoconstrictor in LA?
- more depth of analgesia, contract the blood vessels
- more duration of analgesia
- reduces toxicity
- better haemostasis
98
Which type of LA is being described?
- vasoconstrictor: epinephrine 1:80000
- cartridge size: 2.2ml/1.8ml
- dose per cartridge: 44mg/36mg
- max number of cartridges: 6.8/8.3 (max dose 300mg)
lidocaine 2% (lignospan, xylocaine)
99
Which type of LA is being described?
- vasoconstrictor: octapressin 0.54ml
- cartridge size: 2.2ml
- dose per cartridge: 66mg
- max number of cartridges: 6 (max dose 400mg)
prilocaine 3% (citanest)
100
Which type of LA is being described?
- vasoconstrictor: none
- cartridge size: 2.2ml
- dose per cartridge: 66mg
- max number of cartridges: 4.5 (max dose 300mg)
mepivicaine 3% (scandonest)
101
Which type of LA is being described?
- vasoconstrictor: epinephrine 1:10000 or 1:200000
- cartridge size: 2.2ml/1.7ml
- dose per cartridge: 88mg/68mg
- max number of cartridges: 5.5/7 (max dose 500mg)
articaine 4% (septanest)
102
What are the 7 points to check on a LA cartridge?
- expiry date
- batch number
- glass or plastic (plastic is unsuitable for intraligamentary injections)
- cloudiness
- partly used
- large air bubble
- pierced seal
103
What is the gauge and the length of the needle used for an infiltration?
gauge: 30G
length: 25mm
104
What is the gauge and length of the needle used for an IDB?
gauge: 27G
length: 35mm
105
What are the 3 types of LA syringes?
- aspiject
- conventional
- astra
106
Why does the assembly order of LA matter for older syringes where the needle will need screwing in?
if cartridge is inserted before the needle, coring can occur
107
What are the 6 points to write in notes regarding administration of LA?
- LA given
- type (infiltration or block)
- solution type and concentration
- amount given
- expiry date
- batch number
108
What are 6 examples of how to make the injection comfortable for the patient?
- avoid inflamed areas
- avoid injecting air bubbles
- keep tissues taut
- topical analgesic
- inject slowly
- do not scrape needle across periosteum
109
What is being described?
- usually esters eg. 20% benzocaine gel
- more use in infiltrations
- need dry mucosa
- takes at least 2 mins to act
- gels better than sprays; difficult to direct, tastes bad, numb tongue, can induce saliva
- useful especially in nervous patients and kids
topical analgesia
110
What anatomical landmark should you be aware of when giving an infiltration of an upper 6 due to the dense bone in the area of the roots?
zygomatic buttress
111
Which technique would be used to anaesthetise pulp of and buccal of upper molars?
buccal infiltration
112
Which technique would be used to anaesthetise palatal of the upper molars?
palatal infiltration
113
Which technique would be used to anaesthetise pulp of and buccal of upper premolars and anteriors?
buccal infiltration
114
Which technique would be used to anaesthetise palatal of upper premolars and anteriors?
palatal infiltration
115
What are 2 points to ensure before doing an infiltration?
- tip of the needle needs to lie at the root apex
- bevel of needle should face tissues
116
In what area should be injected when doing a palatal infiltration on upper posteriors (45678)?
distal to the tooth you want to work on
117
In what area should be injected when doing an upper anterior palatal infiltration (123)?
mesial to central to the tooth you want to work on
118
How much LA should be given for a buccal infiltration?
1.1ml approx.
119
What are 5 steps to be taken when doing an upper buccal infiltration?
- needle is placed parallel to long axis of tooth
- needle is advanced slowly above periosteum
- needle tip lies at root apex
- aspirate
- slowly inject ~1.0ml LA
120
In order to envision the point of needle insertion for an upper buccal infiltration, what could you imagine to help find this point?
1. vertical line parallel to long axis of the tooth
2. horizontal line along the muco-buccal fold
121
At what angle should the direction of the needle be inserted for an upper buccal infiltration?
45 degrees with buccal cortical plate
122
The steps for giving which type of LA is being described?
- lip or cheek retracted with finger and thumb to stretch tissues and allow visualisation
- point of insertion determined
- needle inserted with bevel towards bone and making 45 degree angle
- needle is pushed inwards until 2mm from bone (aspirate)
- solution is deposited
- needle withdrawn and safety sheath pushed down
- wait 2-3 minutes
- check anaesthesia
buccal infiltration
123
Where is the point of insertion for an upper palatal infiltration?
- midway between gingival margin of the tooth and the median palatine raphe
- along the axis of the tooth
124
At what angle should the direction of the needle be inserted for an upper palatal infiltration?
90 degrees to bone from opposite side
125
What are 3 steps to be done when administering an upper palatal infiltration?
- push needle until bone is reached
- aspirate
- deposit 0.2ml very slowly
126
What are 2 variations to consider when giving an upper buccal infiltration?
- 3rd molars: inject opposite 2nd molars to avoid injuring pterygoid plexus of veins
- upper centrals: may inject in opposite central due to anastomosis (connection made surgically between adjacent blood vessels, parts of the intestine, or other channels of the body)
127
What is 1 variation to consider when giving an upper palatal infiltration?
- third molars: inject opposite 2nd molars to avoid anaesthesia of lesser palatine nerve (may lead to gagging)
128
What are the 5 types of other maxillary blocks?
- posterior superior alveolar nerve
- infraorbital (anterior and middle superior alveolar) block
- nasopalatine nerve block
- greater palatine nerve block
- maxillary nerve block
129
Which technique of LA numbs the roots of the lower anteriors?
buccal infiltration
130
Which technique of LA numb the buccal of lower anteriors?
buccal infiltration
131
Which technique of LA numbs the lingual of the lower anteriors?
lingual infiltration
132
Which technique of LA numbs the pulp of lower 4-8s?
IDB
133
Which technique of LA numbs the buccal of the lower 4-8s?
long buccal block
134
Which technique of LA numbs the lingual of the lower 4-8s?
IDB or buccal infiltration
135
Anterior mandible bone is...
thin
136
Posterior mandible bone is...
thick
137
What are the 4 steps to be done when administering a lower anterior buccal infiltration?
- insert needle with bevel towards bone in a 45 degree angel
- push needle into soft tissue until within 2mm from bone
- aspirate
- slowly inject ~1.0ml local
138
How can it be worked out where the point of insertion should be for lingual of the lower anteriors?
- 2-3mm above the intersection of two imaginary lines;
- vertical line parallel to long axis of the tooth
- horizontal line above floor of mouth
or 3-5mm cervical to the free gingival margin
139
What are the 4 steps to be taken when administering LA to the lingual of the lower anteriors?
- tongue is retracted with mirror
- syringe directed from corner of the mouth from opposite side
- needle inserted with bevel towards bone, push the needle until it hits the bone (2mm)
- inject 0.2ml solution slowly
140
The cross over of which 2 nerves of the lower 1-1 region should be noted?
mental and incisive nerve
141
What 4 steps should be taken when giving a mental nerve block?
- insert between 4 and 5
- advance slowly
- aspirate
- inject ~2.0ml LA
142
When giving an IDB injection, where will this numb on the patient?
pulps of the teeth from the last molar to the central incisor
143
When giving a lower lingual infiltration, where will the patient be numb?
- lingual periosteum
- lingual soft tissues
- anterior 2/3 of the tongue
144
What can be visualised to help find the point of insertion for an IDB injection?
visualise the diamond shape formed in the mucosa;
- medially by the pterygomandibular raphe
- laterally by the mandibular ramus (internal oblique ridge)
- both these lines converge at the retromolar pad
145
What 7 steps need to be followed when giving an IDB?
- go across the arch from the contralateral 1st premolar
- 1cm above the occlusal plane
- insert the needle into the middle of the target area
- advance the needle until bone is felt - 2cm
- withdraw the syringe 1-2mm
- aspirate
- inject slowly (30 seconds) 1.5-2ml
in order to numb the lingual nerve too;
- withdraw the needle 0.5cm and aspirate and inject 0.3ml slowly
146
How much LA should be administered when giving an IDB?
1.5-2ml
147
What 5 steps should be taken when administering a long buccal block?
- infiltration to mucosal fold buccal to third molar
- hit bone
- withdraw
- aspirate
- inject 0.3-0.5ml slowly
148
Which LA technique should be used for upper 8-8 for restorations?
buccal infiltrations
149
Which LA technique should be used for upper 8-8 extractions?
buccal and palatal infiltrations
150
Which LA technique should be used for lower 3-3 for restorations?
buccal infiltration
or
mental block
151
Which LA technique should be used for lower 3-3 extractions?
buccal infiltration or mental block plus lingual infiltration
or
IDB
152
Which LA technique should be used for lower 4-5 for restorations?
mental block or IDB
153
Which 2 LA techniques should be used for lower 4-5 for extractions?
IDB plus long buccal infiltration
154
Which LA technique should be used for lower 6-8 for restorations?
IDB
155
Which 2 LA techniques should be used for lower 6-8 for extractions?
IDB plus long buccal infiltration
156
What are 5 ways to try and keep the injection pain free for the patient?
- topical analgesic
- keep tissue taut
- do not scrape needle across periosteum
- avoid inflamed areas where possible
- advance needle slowly and smoothly
157
What are 2 considerations that may need to be considered when administering LA to children?
- mandibular bone is thinner so infiltrations may be appropriate further back than in adults
- IDB technique should be modified as the foramina are in a slightly different position
158
How long of pulpal anaesthesia would a patient get from lidocaine when given as an infiltration or block?
45 mins
159
How long of pulpal anaesthesia would a patient get from an intraligamentary infection with lidocaine?
15 mins
160
Penetration of a blood vessel may cause bleeding into a muscle and this could cause ...
trismus
161
What are the 4 signs of a positive intravascular injection?
(during IDB estimated up to 20% of positive aspirates have been reported)
- pain
- localised blanching
- cranial effects
- systemic effects
162
Which group of patients are at increased risk of bruising of pterygoid muscles and other soft tissues which could lead to trismus?
patients taking anticoagulants
163
What needle is used for an intraligamentary injection?
- 30 gauge
- 10mm length
164
What needle is used for infiltrations?
- 30 guage
- 25mm length
165
What needle is used for an inferior alveolar block?
- 27 gauge
- 35mm length
166
How much topical analgesic should be used?
3-4mm length
167
How long should topical analgesic be applied to dry mucosa for analgesic effect?
2-5 mins
168
What is the term used for the following condition?
- An increased sensitivity to feeling pain and an extreme response to pain. Hyperalgesia may occur when there is damage to the nerves or chemical changes to the nerve pathways involved in sensing pain. This may be caused by tissue injury or inflammation or by taking certain drugs, such as opioids, for chronic pain.
hyperalgesia
169
Which anatomical feature is being described?
- consist of plates of compact bone found on the facial and lingual surfaces of the alveolar bone, typically about 1.5-3 mm thick compared to the posterior teeth. however, the thickness varies drastically around the anterior teeth
cortical plates
170
Which 2 nerves may also contribute to pulpal nerve supply in the maxilla?
greater palatine and nasopalatine nerves
171
What is the name of additional nerve fibres in the mandible?
- ipsilateral - inferior alveolar nerve - a branch occurs before entrance to mandibular foramen
- contralateral - inferior alveolar nerve - mandibular incisors have some supply from both inferior alveolar nerves
172
Which 5 nerves may also contribute to pulpal nerve supply in the mandible?
1. lingual nerve
2. long buccal nerve
3. mylohyoid nerve - leave inferior alveolar nerve 15mm before it enters foramen - may have some supply to pulpal tissue
4. auriculotemporal nerve - fibres enter mandible in condylar region - may have some supply to pulpal tissue
5. cervical nerves - fibres not arising from the mandibular nerve - may have some supply to the pulpal tissue
173
What is the most common failed LA?
IDB
174
How much of a 35mm needle should be being used to inject?
two thirds of the length
175
Which 3 types of injection techniques are defined as supplementary injections?
- intraligamentary
- intraosseous
- intrapulpal
176
What are the stages to try with failed maxillary anaesthesia?
- buccal infil
- repeat buccal infil
- palatal injection
- supplementary injections
- superior alveolar nerve block
177
What are the stages to try with failed mandibular anaesthesia?
- IDB
- repeat IDB
- buccal and lingual infill
- supplementary injections
- akinosi or gow gates approach
178
What is the maximum number of 1.8ml cartridges of lidocaine 2% (+ epinephrine) that can be used for an adult of 70kg?
8.3
179
What is the maximum number of 1.8ml cartridges of lidocaine 2% (+ epinephrine) that can be used for a 5 year old child of 20kg?
2.4
180
What is the maximum number of 2.2ml cartridges of lidocaine 2% (+ epinephrine) that can be used for an adult of 70kg?
6.8
181
What is the maximum number of 2.2ml cartridges of lidocaine 2% (+ epinephrine) that can be used for a 5 year old child pf 20kg?
2.0
182
What is the maximum number of 1.8ml cartridges of mepivacaine 2% (+ epinephrine) that can be used for an adult of 70kg?
8.3
183
What is the maximum number of 1.8ml cartridges of mepivacaine 2% (+ epinephrine) that can be used for a 5 year old child of 20kg?
2.4
184
What is the maximum number of 2.2ml cartridges of mepivacaine 2% (+ epinephrine) that can be used for an adult of 70kg?
6.8
185
What is the maximum number of 2.2ml cartridges of mepivacaine 2% (+ epinephrine) that can be used for a 5 year old child of 20kg?
2.0
186
What is the maximum number of 1.8ml cartridges of mepivacaine 3% (plain) for an adult of 70kg?
5.5
187
What is the maximum number of 1.8ml cartridges of mepivacaine 3% (plain) for a 5 year old child of 20kg?
1.6
188
What is the maximum number of 2.2ml cartridges of mepivacaine 3% (plain) for an adult of 70kg?
4.5
189
What is the maximum number of 2.2ml cartridges of mepivacaine 3% (plain) for a 5 year old child of 20kg?
1.3
190
What is the maximum number of 1.8ml cartridges of prilocaine 3% (+ felypressin) for an adult of 70kg?
7.4
191
What is the maximum number of 1.8ml cartridges of prilocaine 3% (+ felypressin) for a 5 year old child of 20kg?
2.2
192
What is the maximum number of 2.2ml cartridges of prilocaine 3% (+ felypressin) for an adult of 70kg?
6.0
193
What is the maximum number of 2.2ml cartridges of 3% prilocaine (+ felypressin) for a 5 year old child of 20kg?
1.8
194
What is the maximum number of 1.8ml cartridges of prilocaine 4% (plain) for an adult of 70kg?
5.5
195
What is the maximum number of 1.8ml cartridges of prilocaine 4% (plain) for a 5 year old child of 20kg?
1.7
196
What is the maximum number of 2.2ml cartridges of prilocaine 4% (plain) for an adult of 70kg?
4.5
197
What is the maximum number of 2.2ml cartridges of prilocaine 4% (plain) for a 5 year old child of 20kg?
1.4
198
What is the maximum number of 1.8ml cartridges of articaine 4% (+ epinephrine) for an adult of 70kg?
7.0
199
What is the maximum number of 1.8ml cartridges of articaine 4% (+ epinephrine) for a year old child of 20kg?
2.0
200
What is the maximum number of 2.2ml cartridges of articaine (+ epinephrine) for a 5 year old child of 20kg?
1.5
201
What is the maximum number of 2.2ml cartridges of articaine 4% (+ epinephrine) for an adult of 70kg?
5.5
202
What is the maximum dose of lidocaine 2% (+epinephrine)?
4.4 cartridges
300mg
203
What is the maximum dose of mepivacaine 2% (+epinephrine)?
4.4 cartridges
300mg
204
What is the maximum dose of mepivacaine 3% (plain)?
4.4 cartridges
300mg
205
What is the maximum dose of prilocaine 3% (+felypressin)?
6.0 cartridges
400mg
206
What is the maximum dose of prilocaine 4% (plain)?
6.0 cartridges
400mg
207
What is the maximum dose of articaine 4% (+epinephrine)?
7.0 cartridges
500mg
208
LA mode of action
LA inhibit the passage of which through the cell membrane therefore preventing the electrical impulses from travelling along the nerve?
sodium ions
209
What effect does an infected environment have on LA?
the presence of an infection shifts the environment to being more acidic, therefore when the LA solution is injected into an acidic environment the balance between non-charged and charged LA molecules shifts towards increasing the quantity of charged molecules and decreasing the quantity of uncharged molecules. this results in not enough uncharged molecules being available to pass through the cell membrane, consequently the LA solution cannot act.
210
What 5 factors affect the duration of local analgesic?
- size of the nerve fibre
- concentration of LA around the nerve
- type of La agent used
- accuracy of the injection
- size of the patient
211
What may contra-indicate using LA containing epinephrine?
patient with thyrotoxicosis
212
What 2 muscles meet together to form pterygomandibular raphe?
superior constrictor
&
buccinator
213
Identify the boundaries of the pterygomandibular fossa?
retromolar pad, pterygomandibular raphe, internal oblique ridge
214
What are 4 common reasons for LA failure?
- misplaced injection
- injection into a blood vessel
- injection into an infected area - taken away from the area more quickly
- additional nerve supply
215
What is the absolute ceiling dose of lidocaine for a healthy 70kg 30 year old?
300mg
