LA Flashcards
1
Q
WHAT DO YOU PALPATE WHEN DOING AN IDB
A
coronoid notch
ascending ramus
pterygomandibular raphe
2
Q
HOW DO YOU ASPIRATE
A
push forward a tiny bit and let go
look for blood
3
Q
WHY ASPIRATE
A
to avoid injecting LA into the BV
4
Q
HOW LONG SHOULD YOU BE INJECTING IN AN IDB
A
30-45seconds
5
Q
WHEN DOING AN IDB HOW MUCH OF THE CARTRIDGE SHOULD U DEPOSIT BEFORE RETRACTING
A
2/3 - last bit for lingual nerve - continuously injecting as retracting out the tissue
6
Q
HOW LONG TIL FULLY ANAESTHETISED AFTER IDB
A
3-4 mins
7
Q
HOW DO YOU DISPOSE OF THE NEEDLE
A
re-sheath - 1 click
secure - 2 clicks
remove the LA cartridge - blue bin
needle in orange bin
8
Q
WHICH LA CANT BE USED IN PREGNANT WOMEN
A
prilocaine as it contains felypressin
9
Q
WHAT DOES FELYPRESSIN DO TO PREGNANT WOMEN
A
induces labour
10
Q
WHICH VASOCONSTRICTOR HAS CONSIDERATIONS WITH HEART PATIENTS AND WHY
A
adreneline as it can cause heart palpitations when acting on alpha receptors
11
Q
IN WHAT SCENARIO WOULD YOU USE ARTICAINE OVER LIDOCAINE
A
when you are trying to anaesthetise a bigger area with less injections / avoiding a palatal as articaine is 4% compared to 2% lidocaine ( same vasoC)
12
Q
WHY DOES FELYPRESSIN LA’S WASH OUT FASTER THAN ADRENLINE ONES
A
as adrenaline provides haemostatic control which means it doesn’t wash out as fast
13
Q
WHAT CAN HAPPEN IF WE INJECT TOO STRAIGHT ON FOR AN IDB
A
hit parotid gland which contains facial nerve causing bells palsy
14
Q
WHAT TO DO IF YOU GIVE THEM BELLS PALSY
A
don’t panic, pretty normal
send home with eyepatch so eye doesn’t dry up as cant close on own
15
Q
HOW TO TELL THE DIFFERENCE BETWEEN A STROKE AND LA INDUCED PALSY
A
stroke = can still use forehead muscles
bells palsy = cant move anywhere on that side, all droopy
16
Q
WHEN GIVING LA WHICH HAND IS USED FOR WHICH ACTION
A
dominant hand to inject
non dom to retract tissues
17
Q
WHICH LA INJECTION WOULD HAVE THE PATIENT LYING THE FLATTEST
A
palatal
then buccal
then IDB
18
Q
WHAT ARE THE MAIN LA PREPARATIONS
A
lidocaine 2% HCl = + 1:80000 adreneline
prilocaine 3% HCl + felypressin (0.03U/ml)
articaine 4% + 1:200000 adreneline
19
Q
WHAT IS THE RESTING MEMBRANE POTENTIAL
A
-70mV
20
Q
WHAT IS DEPOLARISATION OF AXON CAUSED BY
A
influx of Na+ ions through ion gated channels into the cell
21
Q
WHAT IS REPOLARISATION CAUSED BY
A
efflux of K+ ions through ion gated channels
22
Q
WHY IS THERE A REFRACTORY PERIOD IN ACTION POTENTIALS
A
as the Na+ ion channels are inactivated from previous AP
so AP cant propagate
23
Q
IS THE ICF NEGATIVE OR POSITIVE
A
negative - more K+
24
Q
WHAT FEATURES OF AN AXON MAKE IT HAVE QUICKER CONDUCTION SPEED
A
larger and myelinated
25
WHAT IS SALTATORY CONDUCTION
the AP passes along myelinated axons by skipping from one node of Ranvier to the next - fast
26
HOW DOES LA WORK PHYSIOLOGICALLY
blocks the Na+ voltage gated ion channels so depolarisation is blocked
27
WHICH AXON TYPES FUNCTION IS MOST LIKELY TO STILL BE FELT AFTER LA AND WHY
Aa as its the biggest axon with the most Na channels to be blocked so the least susceptible
28
COMPOSITION OF LA
the LA
- aromatic region
- ester or amide bond
- hydrophilic region
reducing agent
preservatives / fungicides
vasoC
29
WHICH COMPONENT OF LA IS HYDROPHOBIC AND WHY DO WE NEED IT
the aromatic region
| to pass through the membrane
30
WHY DO WE NEED A HYDROPHILIC REGION OF LA
to be soluble in water to be in an injection solution
31
WHY DO WE NEED A HYDROPHILIC REGION OF LA
to be soluble in water to be in an injection solution
32
WHEN IS LA IN ACTIVE FORM
when it is ionised (has H)
| after inside the cell
33
WHEN IS LA IN INACTIVE FORM
when its unionised (H removed)
| when passing membrane
34
HOW IS LA WRITTEN CHEMICALLY
B.HCl
35
WHAT IS THE REDUCING AGENT IN LA
sodium metabisulphide
36
WHICH LA ARE ESTER BOND
benzocaine
cocaine
procaine
37
WHICH LA ARE ESTER BOND
benzocaine
| cocaine
38
WHICH LA ARE AMIDE BOND
lidocaine
prilocaine
articaine
39
WHY DO LA SOLUTIONS NEED A VASOCONSTRICTOR
as LA work as vasodilators which washes the LA out faster
40
TYPES OF VASOCONSTRICTOR
adrenline
| felypressin
41
WHAT IS THE EFFECT WHEN ADRENLINE WORKS ON ALPHA ADRENORECEPTORS
vasoconstriction
42
WHAT IS THE EFFECT WHEN ADRENELINE WORKS ON B1 ADRENORECEPTORS
heart palpitations when given systemically
43
WHICH RECEPTORS DOES FELYPRESSIN WORK ON
ADH - anti diuretic hormone - receptors
44
HOW IS LA INACTIVATED FROM TISSUES
washed out by blood supply
esterases
liver amidases
45
HOW LONG DOES LIDOCAINE LAST
infiltration = 60 min
block = 90 min
soft tissues = 3-5hours
46
HOW LONG DOES PRILOCINE LAST
infiltration = 30-45 min
block = 60 min
soft tissues = 3-6 hours
47
HOW LONG DOES ARTICIANE LAST
infiltration = 120 min
block = 75 min
soft tissues = 3-5 hours
48
WHERE IS LA DEPOSITED IN INFILTRATIONS VS BLOCKS
around terminal branches of nerve
VS
beside nerve trunk
49
WHY CANT WE DO INFILTRATIONS ON POSTERIOR TEETH IN MANDIBLE
bone is too thick for infiltration to anaesthetise pulp
50
WHAT AREAS NEED ANAESTHETISED FOR EXTRACTION
everything = pulp, ging, surrounding soft tissues
51
WHAT AREAS NEED ANAESTISED FOR EXTRACTION
everything = pulp, ging, surrounding soft tissues
52
WHAT AREAS NEED ANAESTHETISED FOR A RESORATION
pulp and gingiva (clamp/dam)
53
WHAT AREAS NEED ANAESTHETISED FOR SCALING
gingiva and sometimes pulp
54
WHAT IS THE GAUGE
diameter of needle lumen
| lower number = larger lumen
55
SMALLER NEEDLE LUMEN ADVANTAGES
less deflection / reduced breakage risk / easier aspiration
56
SHORT NEEDLE GAUGE AND LENGTH
gauge 30
| length 20-25mm
57
LONG NEEDLE GAUGE AND LENGTH
gauge 27
| length 30-35mm
58
LA CLINICAL PROCESS
```
brief patient, consent
check batch no, expiry date and correct LA
make syringe
adjust seat and light
prep needle for use
injection
make needle safe again and dispose
```
59
HOW TO APPLY TOPICAL
dry mucosa
pea size on cotton wool
hold for 1-2mins
60
2 TYPES OF TOPICAL GELS
benzogel 20%
| xylonor gingiva gel (lidocaine 2%)
61
WHAT IS A SUPRAPERIOSTEAL INJECTION
infiltration
62
WHERE TO INJECT FOR A BUCCAL INFILTRATION
3/4mm above apex
| slightly distal
63
HOW LONG DO YOU WAIT BEFORE TESTING IF A BUCCAL INFILTRATION WORKED
2 mins
64
LIMITATIONS OF A BUCCAL INFILTRATION
pathology limits such as abscess
| dense bone limits
65
ADVANTAGES OF A BUCCAL INFILTRATION
atraumatic
easy
high success rate
66
WHY IS THERE MORE RESISTANCE IN A PALTAL INFILTRATION THAN BUCCAL
the mucosa is more tightly bound to the bone
67
WHERE IS THE INJECTION SITE OF A PALATAL INFILTRATION
5-10mm palatal of centre of crown
or
midway between ging margin and deepest vault of palate
68
delete
d
69
WHY USE MIRROR BEHIND INJECTION SITE IN PALATAL INFILTRATION
to compress the mucosa and distract from the discomfort
70
HOW TO DO A PALTAL INFILTRATION
```
mirror
needle at 45 degrees to injection site
bevel towards tissue
few mm in - if contact bone then withdraw
0.2-0.4ml anaesthetic (1/8 cartridge)
look for blanched tissue
```
71
WHAT LANDMARKS SHOULD YOU LOOK FOR WHEN DOING AN IDB
coronoid notch of mandible (thumb)
ascending ramus of mandible (fingers)
pterygomandibular raphe
72
HOW TO CONFIRM ANAESTHESIA IN IDB FROM PATIENT
tongue and lower lip extending to midline on that side should feel different
but still feel pressure
73
IDB PROCESS
```
locate site
inject
hit bone and withdraw
1cm of needle always visible
aspirate
inject for 30-45seconds
do lingual nerve of way out
```
74
WHY DO WE NEED TO DO A LONG BUCCAL INJECTION
as the buccal gingiva of the mandible is not innervated by the inferior alveolar nerve but the buccal nerve
75
INFILTRATION FINGER RESTS
```
maxilla = pinky of non injecting hand on chin
mandible = thumb of non injecting hand to balance barrel on
```
76
IDB FINGER RESTS
pinky of injecting hand around ramus of opposite side to injection
or
balance barrel on thumb of non injecting hand
77
LIDOCAINE CONTRAINDICATIONS
heart block and no pacemaker
allergy to LA or corn
hypotension
impaired liver function
78
INDICATIONS FOR ARTICAINE
better than lidocaine for mandible infiltrations
| when trying to minimise the amount of injections as its stronger than lidocaine
79
ARTICIANE CONTRAINDICATIONS`
stronger preparation increases risk of non-surgical parathesisa
sickle cell disease/ other haemoglobinopathies
80
SYSTEMIC COMPLICATIONS OF LA
```
stress
cross infection
allergy
collapse
toxicity
pregnancy
other drugs : diuretics
```
81
WHICH DRUGS INTERFERE WITH LA
MAOI : metabolises adreneline
tricyclics : hypertension
b blockers : reduce vasoC as on B2 adrenoreceptors
non potassium sharing diuretics : adreneline lowers K even more
82
WHEN TO AVOID LA WITH ADRENELINE
BP >200mmHg(systolic) / 155mmHg(diastolic)
83
WHICH DISEASES SHOULD YOU BE CAREFUL WITH WHEN USING ADRELEINE
CVS disease
hyperthyroidsm
hypertension
drug interactions
84
LOCAL COMPLICATIONS OF LA
```
fails to anaesthetise
bells palsy - hit parotid gland
pain
IV injection = blanch/visual disturbance
trismus - hit medial pterygoid
prolonged anaesthesia
haematoma - bleeding
broken needle
infection
soft tissue damage
contamination
```
85
WHAT TO DO IF SOMEONE GETS BELLS PALSY
give them eye patch
stay clam
say it will last a few hours then wear off
86
WHAT IS CHASING ANAESTHESIA
getting palatal anaesthesia by buccal infiltration then intrapapillary injection through until palate blanches
87
WHAT IS INTRALIGMENTARY ANAESTHESIA
inject into ging sulcus
88
WHAT IS INTRAOSSESOUS ANAESTHESIA
use stabident perforator to stab through mucosa and bone
then LA injected straight into the cancellous bone - miss out the dense cortical
fast but invasive
89
WHAT IS A TOPICAL JET INJECTOR
releases LA at high pressure so some goes into soft tissues
| scary and loud but no needle(good for bleeding diathesis)
90
WHAT ARE ALTERNATIVE IDB TECHNIQUES
gow gates : open mouth inject higher to get trigeminal ganglion
akinosi technique : mouth closed and we pull cheek open, insert higher to get the trigeminal ganglion
91
WHAT IS THE WAND TECHNIQUE
less scary as its held like a pen and lot shorter needle
| step on peddle to release LA at steady rate which reduces pain and human error
92
METHODS TO ACHIEVE SURFACE(SOFT TISSUE) ANAESTHESIA
physical = ethyl chloride
pharmacological = gel / controlled release devices / jet injectors
TENS /hypnosis
93
WHAT ARE THE USES OF TOPICAL GELS
```
pre injection
clamp
suture removal
exfoliating primary teeth
subgingival scaling
incision of abscess
```
94
HOW TO ACHIEVE PALATAL ANAESTHESIA IN CHILDREN
chasing anaesthesia technique
95
HOW TO GIVE AN INTRALIGMENTARY INJECTION IN A CHILD
ultrashort 32 gauge needle at 30 degress to the long axis of the tooth, insert into the mesio-buccal ging sulcus and give 0.2ml per root
96
HOW TO DO A MENTAL BLOCK
inject in between the 2 premolars at the apexes
97
DISADVANTAGE OF A MENTAL BLOCK
may need additional labial infiltration as incisors may have crossover of supply at midline
98
ACTIONS TAKEN TO PREVENT COMPLICATIONS
aspirating
slow injection
dose limitation
99
HOW TO TREAT TOXICITY
```
stop
BLS
call medical assistance
protect patient from injury
monitor vital signs
```
100
HOW MUCH OF A CARTRIDGE FOR A BUCCAL INFILTRAION
1/4
101
HOW MUCH OF A CARTRIDGE FOR A PALATAL INFILTRAION
1/8
102
SITE OF LONG BUCCAL INJECTION
paralell to occlusal plane
distal and buccal to the last standing molar
called retro molar fossa
operator sits at 8oclock
103
WHICH NEEDLE USED FOR LONG BUCCAL INJECTION
long
104
WHAT EQUIPMENT NEEDED FOR AN LA TROLLEY SET UP
```
blue bin
orange bin
cotton wool roll
topical
LA cartridge
long USP needle
short USP needle
black handle with rubber bung
```
105
HOW TO ASSEMBLE LA USP SYRINGE
remove sterile syringe from protective envelope
insert cartridge into syringe - gold end first
slide plunger to end of handle - make sure O-ring completely covered
line up the handle pins with syringe notches
push on
twist clockwise to lock
slide protective sheath backwards until clicks
remove needle cap
ready
106
HOW DOES THE LA USP SELF ASPIRATE
small protuberance at the bottom of the barrel which depresses the cartridge diaphragm throughout injection procedure
when injection pressure is released diaphragm goes back to normal - this causes back pressure in the needle resulting in aspiration
107
HOW CAN THE USER MANUALLY ASPIRATE THE LA USP SYRINGE
when the handle pulled back wards the o ring on the shaft creates a vaccuum providing active aspiration
108
HOW TO REPLACE A CARTRIDGE FOR A NEW ONE ON THE SAME LA USP SYRINGE
protective sheath to first holding position
ensure plunger fully retracted from cartridge
rotate handle anticlockwise to unlock
carefully pull 2 components straight apart
insert plunger with o ring back in to remove cartridge
insert new cartridge
109
WHY NOT USE THE SAME LA USP SYRINGE WITH MULTIPLE CARTRIDGES
can cause :
cannula penetration
canula breakage
self aspiration
110
HOW TO DISMANTLE AN LA USP SYRINGE
```
once procedure done
protective sheath 2nd click
twist and remove handle from barrel
insert the plunger with silicone bung back in to remove cartridge
dispose in sharps bins
```
111
HOW TO DISPOSE OF DIFFERENT LA NEEDLE HANDLES
white single use = medical waste
| blue resuable = reprocessed according to manufacturers instructions
112
TROUBLESHOOTING WITH THE LA USP SYRINGE
if unloading required = unlock handle and separate - don't bend
don't hold hub to align bevel = may unlock syringe
