LA Delivery Flashcards

1
Q

How do you assemble a LA syringe?

A
  • open sterile packaging
  • check batch no and expiry date
  • insert LA cartridge into sheath
  • insert plunger into sheath with the handle at the top of the plunger
  • twist plunger into locked position
  • pull back sheath until click sound is heard
  • remove needle cap
  • needle is ready for use
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2
Q

How do you aspirate?

A
  • a light push of the needle

- if any blood is seen then retract slightly and aspirate again

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3
Q

How do you dispose of a LA syringe?

A
  • orange lidded sharps box if the entire cartridge was used
  • blue lidded sharps box if there is still LA left over
  • ensure the sheath has been locked in place
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4
Q

How do you close a syringe for disposal?

A
  • double click the sheath

- the needle cannot be used after this point

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5
Q

What is the IANB used for?

A
  • inferior alveolar nerve block

- used to numb the mandibular teeth on one side (to the midline), also numbs lower lip, parts of the tongue and chin

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6
Q

How do you administer the IANB?

A
  • LH thumb placed intra-orally
  • LH fingers placed extra-orally on the posterior border of the ramus
  • LH thumb feels for the coronoid notch
  • the needle advances from the opposing premolars, parallel to the occlusal plane
  • needle should be inserted into the mucosa at the centre of the V created by the coronoid notch and the pterygomandibular raphe, around 5-10mm above the last molar
  • the needle should contact bone, pull back slightly, aspirate, and deposit LA slowly
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7
Q

What is a palatal infiltration used for?

A
  • numbing the associated palatal soft tissues
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8
Q

How do you administer a palatal infiltration?

A
  • apply firm pressure posterior to the area to the injected
  • insert the needle at a 90 degree angle to the site, slightly distal to the tooth be anaesthetised
  • advanced needle until bone is contacted and withdraw slightly
  • aspirate
  • inject LA quickly due to high discomfort in this area, not much is required
  • when area blanches sufficient LA has been deposited
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9
Q

What is a buccal infiltration used for?

A
  • numbing the maxillary teeth and the anteriors in the mandibular
  • numbing associated buccal soft tissues
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10
Q

How do you administer a buccal infiltration?

A
  • stretch cheek
  • puncture mucosa in the deepest part of the sulcus, slightly distal to the apex of the tooth being anaesthetised
  • advance the needle until bone is contacted
  • pull back slightly and aspirate
  • deposit LA slowly
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11
Q

What are the contraindications for LA?

A
  • felypressin and a pregnancy, can induce labour
  • infection can have an effect of on the efficacy of LA
  • some heart conditions can contradict the use of LA which contains adrenaline
  • LA with adrenaline is absolutely contraindicated in patients with hyperthyroidism
  • IDB severely contraindicated in haemophiliacs
  • true allergy is very rare, these patients should be sent for testing and not treated in general clinic, some allergies relate to the preservative
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12
Q

What are the different types of LA?

A
Amides (more common)
- lidocaine 
- prilocaine 
- articaine 
Esters 
- cocaine 
- procaine 
- benzocaine
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13
Q

What is the typical preparation of lidocaine?

A
  • 2% lidocaine

- 2% lidocaine with 1:80,000 adrenaline

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14
Q

What is the typical preparation of prilocaine?

A
  • 4% prilocaine

- 3% prilocaine with 0.03U/ml felypressin

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15
Q

What is the maximum safe dose of lidocaine for a healthy adult?

A
  • max safe dose = 4.4mg/kg bw
  • assuming the adult is 70kg => 308mg is max dose
  • 2% lidocaine = 44mg per cartridge
    => 7 cartridges max
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16
Q

What is the maximum safe does of articaine for a healthy adult?

A
  • max safe dose = 7mg/kg bw
  • assuming the adult is 70kg => 490mg is max dose
  • 4% articaine = 88mg per cartridge
    => 5 cartridges max
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17
Q

What is the typical preparation of articaine?

A
  • 4% articaine with 1:100,000 or 1:200,000 adrenaline
18
Q

What is the maximum safe dose of prilocaine?

A
  • max safe dose = 8mg/kg bw
  • assuming the adult is 70kg => 560mg is max dose
  • 3% prilocaine = 66mg per cartridge
    => 8 cartridges max
19
Q

What are some local complications of LA?

A
  • failure to anaesthetise
  • prolonged anaesthesia
  • pain
  • trismus
  • Bell’s palsy
  • soft tissue damage
20
Q

What complications are associated with articaine?

A
  • due to its potency nerve damage can occur in blocks

- articaine should only be used for infiltrations

21
Q

How do you differentiate between Bell’s palsy and a stroke?

A
  • Bell’s palsy = full side paralysis, caused by peripheral lesion
  • stroke = forehead wrinkles , caused by central lesion, stroke on one side affects opposite side of the face
22
Q

Why is it difficult to achieve anaesthesia during infection?

A
  • low pH affects the efficacy of the LA
23
Q

Describe the wand.

A
  • uses controlled and regulated speed and pressure for LA delivery which makes it much more comfortable for the patient
  • smaller needle which is beneficial in children or the needle-phobic
  • pencil grip is used which can make it easier to manoeuvre
24
Q

Why are topical anaesthetics used?

A
  • make the procedure more comfortable for the patient
25
Q

How long should topical anaesthetic be applied for?

A
  • 1-2 minutes

- applied using a cotton wool roll

26
Q

What kind of topical anaesthetic is used?

A
  • 20% benzocaine

- 2% lidocaine

27
Q

How do you test for anaesthesia?

A
  • ask the patient how they feel, should feel “fat” or “swollen”, “tingly”
  • sensation to the patient should only be different on the side LA was administered
  • percuss the tooth
  • apply a cold stimulus to the tooth
28
Q

How much of a cartridge is required for a palatal infiltration?

A

1/8 cartridge

29
Q

How much of a cartridge is required for a buccal infiltration?

A

1/4 cartridge

30
Q

How much of a cartridge is required for a lingual block?

A
  • the remaining 1/3 of the cartridge that has been used for IDB, deposit as you retract the needle from the tissues
31
Q

How much of a cartridge is required for a lingual block?

A
  • the remaining 1/3 of the cartridge that has been used for IDB, deposit as you retract the needle from the tissues
32
Q

How long does infiltration anaesthesia last?

A

60 minutes

33
Q

How long does block anaesthesia last?

A

90 minutes

34
Q

What are systemic complications of LA?

A
  • psychogenic / stress
  • drug interactions
  • cross infection
  • allergy
  • collapse
  • toxicity
35
Q

What are the symptoms of psychogenic stress?

A
  • fainting (syncope)
  • palpitations
  • pallor
  • sweating
  • bradycardia
  • nausea
36
Q

How do you treat psychogenic stress?

A
  • lay flat and raise legs
  • sweet drink
  • loosen neck clothing
37
Q

What are common drug interactions with LA?

A
  • antidepressants (MAOIs and tricyclics)
  • hypertensive drugs (beta blockers and non-potassium sparing diuretics)
  • cocaine, increased adrenergic activity
38
Q

What typically causes allergy in LA?

A
  • preservatives (methylparaben)
39
Q

How does LA toxicity present?

A
  • convulsions
  • loss of consciousness
  • respiratory depression
  • circulatory collapse
40
Q

What is a contraindication for lidocaine?

A
  • liver problems

- heart block without a pacemaker

41
Q

What is a contraindication for articaine?

A
  • sickle cell anaemia or disease
42
Q

How do you numb the maxillary teeth?

A
  • buccal infiltration