LA Symposium Flashcards
Define a nerve block anaesthesia and what it is used to anaesthetise
Anaesthetic deposited beside nerve trunk
Used to produce soft tissue anaesthesia
Used where bone is too thick to allow infiltration (mandible)
What LA type would you use to anaesthetise dental pulp in maxilla?
Buccal infiltration
What LA type would you use to anaesthetise buccal gingivae in maxilla?
Buccal infiltration
What LA type would you use to anaesthetise palatal gingivae in maxilla?
Palatal injection
What LA type would you use to anaesthetise dental pulp in lower molars (and second premolar)?
Inferior alveolar nerve block (IAN/IDB)
What LA type would you use to anaesthetise the pulp of lower premolars and canine?
Mental (incisive) nerve block
What LA type would you use to anaesthetise the pulp of lower canine and incisors?
Buccal/labial infiltration
What LA type would you use to anaesthetise buccal gingivae in lower molars and second premolar?
(Long) buccal infiltration
What LA type would you use to anaesthetise buccal gingivae in lower first premolar and canine?
IAN block or mental block
What LA type would you use to anaesthetise buccal gingivae in lower incisors and canines?
Buccal/labial infiltration
What LA type would you use to anaesthetise lingual gingivae in mandible?
IAN block, if given
Lingual infiltration
What tissues need to be anaesthetised for a restoration?
Pulp
What tissues need to be anaesthetised for an extraction?
Pulp and gingivae
What are the 2 types of needles used for LA in adults and give their lengths
Short- 25mm
Long- 35mm
Name 4 steps taken to prep patient for LA injection
Check medical history
Position in chair (dictated by type of treatment)
Dry mucosa
Apply topical (pea size on cotton wool)
What are the 5 steps in injection technique?
Stretch mucosa
Puncture quickly- use distraction
Position needle tip at target point
Aspirate
Inject slowly- no less than 30 seconds
What is the role of the bevel?
To provide a cutting surface, that offers little resistance to mucosa as the needle penetrates and withdraws from tissue
Name the 4 important landmarks when giving IAN
Coronoid notch on mandibular ramus
Posterior border of mandible
Pterygomandibular raphe
Lower premolar teeth on opposite side
Where is the site of anaesthetic deposition for IANs
In the region of the mandibular foramen
How much of needle should be visible during IAN when bony contact is made?
1cm
What 3 effects does LA have on CVS?
- Myocardial depression
- decreased excitability
- decreased force of attraction - Vasodilation (arterioles)
- Inhibition of sympathetic system
What are 2 adverse effects of LAs
Overdosage (toxic)
Allergy (rare)
Name 3 ways overdosage can be avoided
Limiting volume
Aspirating
Slow injection
What 4 effects does adrenaline have on heart, and what receptors involved?
Increased HR
Increased force
Increased CO
Increased excitability
β1 receptors
What 3 effects does adrenaline have on blood vessels and what receptors are involved?
Coronary dilation
Skin contraction– α receptors
Muscle dilation– β2 receptors
What effect does adrenaline have on BP?
Increased systolic
Decreases diastolic
Overall- little effect
Name 7 symptoms of adrenaline overdose
Fear/anxiety Trembling Weakness Dizziness Pallor/sweating Palpitations Headache
What is the cause of fainting?
Lack of oxygenated blood to brain
Name 6 clinical features of fainting
Light headiness Pallor Beads of sweat Bradycardia (slow pulse) Nausea Pupil dilation
Name 4 ways to manage fainting
Lay flat and raise legs
Loosen neck clothing
Improve room ventilation
Sweet drink
Define trismus
Inability to open mouth fully
Cause of trismus
Probably damage to medial pterygoid
Injection too low, too forceful
Cause of facial palsy
Local into parotid gland- infection too far posteriorly
How would you diagnose palsy?
Test branches of facial nerve
3 clinical features of IV injection
Skin blanching
Visual disturbance
Aural disturbance
Define surface anaesthesia
Anaesthesia of the surface tissues I.e. Skin, mucous membranes
3 uses of surface anaesthesia
Decrease pain of LA injection
Decrease discomfort of venipuncture
For superficial soft tissue manipulation
2 types of surface anaesthesia
Physical (refrigeration anaesthesia)
Pharmacological (topical)
4 types of topical anaesthetic application
Intraoral topical agents
Topical anaesthesias for skin
Controlled release devices
Jet injectors
What are 2 advantages and 4 disadvantages of topical jet injectors?
Adv- allows anaesthesia upto 1cm
sole means achieving LA
Dis- could cause soft tissue damage if careless
Frightening sight and sound
Taste of solution
Expensive
What are 4 contradictions for using lidocaine?
Heartblock and no pacemaker
Allergy to LA
Hypotension
Impaired liver function
2 uses of intraligamentary LA
Supplement infiltration
May eliminate need for block
What volume of LA is used for intraligamentary LAs
0.2ml per root
How is intraligamentary LA given?
30° to long axis of tooth in mesio buccal gingival sulcus
How would you give a mental block in child?
Advance needle in buccal sulcus towards region between apices of first and second primary molars
One advantage and disadvantage of mental block in kid
Adv- v good soft tissue anaesthesia
Dis- not as reliable as ID
5 steps to deal with treatment of toxicity
Stop treatment Provide BLS Call for medical assistance Protect patient from injury Monitor vital signs
6 late localised complications of LA
Self-inflicted trauma Oral ulceration Trismus Long lasting anaesthesia Infection Developmental defects
What is Gow gates technique?
Open mouth technique
Patient lying flat
Aim for neck of condylar process
What is the Akinosi technique?
Closed mouth technique
Define an infiltration anaesthetic and what it’s used for
LA solution deposited around terminal branches of nerves
Used to anaesthetise soft tissues
Used to produce pulpal anaesthesia where alveolar bone is thin (maxilla, lower anterior teeth)
