Week Four: Local Anaesthetic Techniques Flashcards
Name the first six steps of basic local anaesthetic.
- Identify structures that need to be anesthetised. 2. Decide upon most suitable technique for individual patient to achieve anaesthesia of identified structures. i. age ii. bone density 3. Choose local anaesthetic type. i. length of anaesthesia required ii. Client age iii. Client medical history (illness and medications) iv. identify any precautions that need to be taken 4. Prepare syringe: i. cartridge: load and engage with piston ii. needle short or long? iii. check flow. 5, Place patient in supine position.
Once the patient is in supine position what are the next steps in administering local anaesthetic?
- Visualise the bony target area 7. Identify soft tissue landmarks and orientation of syringe required to access this area 8. prepare tissue i. dry target area ii. Apply topical anaesthetic > 1-2mins 9. Retraction. i. Retract cheek/lip with mirror, pulling the tissues taught, to ensure can clearly see landmarks identifying target area 10. Orient needle so that bevel face bone 11. Insert needle gently into target area 12. Advance needle to required depth
Once you have inserted the needle into the required depth, what are your final last steps?
- Aspirate i. in two planes for blocks ii. +ve: (blood in cartridge) discard cartridge, do not deposit solution. New Cartridge required. iii. -ve: safe to deposit solution 15. Deposit suitable amount for target area 16. Withdraw 17. Dispose of needle safely 18. Wait for onset of action i. differs amongst types of LA, and site of administration ii. Assess client
What is the infiltration technique?
Infiltration technique is able to be performed in the maxilla due to the thin cortical bone permitting diffusion of anaesthetic solution through the bone to the target nerve. It involves injecting into tissues immediately adjacent to the site that you want to anaesthetise. In doing this you also subsequently anaesthetise terminal branches of a larger nerve trunk.
What are the two types of infiltration techniques?
Buccal infiltrations Palatal Infiltrations
What is an indication for using a buccal infiltration technique?
Suitable if you require pulpal anaesthesia of one or two teeth.
What nerve is targeted in a buccal infiltration of the Maxilla?
PSA (Posterior Superior Alveolar), MSA (Middle Superior Alveolar) and ASA (Anterior Superior Alveolar)
What area is anaesthetised in a buccal infiltration?
Terminal branches on the innervating nerve of the adjacent tooth This results in anaesthesia of local pulp, root, buccal periosteum, connective tissue, buccal gingiva and mucous membrane.
What is the target bony site for a buccal infiltration?
Slightly distal and superior to the apex of the target tooth.
What is the soft tissue landmark for a buccal infiltration?
The height of the mucobuccalfold fold of the vestibule adjacent to the target tooth.
What is the orientation of the syringe for a buccal infiltration?
The syringe should be parallel to the long axis of the tooth - if it is an anterior tooth. It becomes more oblique as you move posteriorly.
What needle length is suggested for a buccal infiltration?
Short needle
What is the insertion for a buccal infiltration?
Approx 3-5mm (anterior -posterior)
What amount is deposited for a buccal infiltration?
0.5ml-1ml - (1/4 cartridge to 1/2 cartridge)
What is this picture of?
Buccal infiltration
What is this also a picture of? IMAGE
Buccal infiltration
What is this a diagram of? IMAGE
Buccal infiltration
What else is a buccal infiltration called?
Supraperiosteal injection
What are some considerations for a supraperiosteal injection?
When injecting a deciduous tooth you must note that it has flared roots. You must do the distal injection first. You must also consider the shape of the maxilla and the shape of the tooth root, Upper laterals have a slight distal inclination - if it can not achieve pulpal anaesthesia from the buccal aspect you may need to deposit palatally. It is important to consider that there are areas of poor diffusion in the maxilla. i.e. Where the cortical bone is thicker (attachment of zygomatic arch - zygoma)
What’s a cool trick with a buccal infiltration if you want to anaesthetise two teeth?
You can inject interproximally between apices of two teeth to target both.
Consideration: Is there a chance at multiple innervation with a buccal infiltration?
Yes there is. e.g. 16/26 can occur.
Although buccal infiltrations are useful, to minimise the use of them what should you consider?
Consider a block technique instead. PSA block, MSA block, ASA Blocks.
What is the indication for a palatal infiltration?
Anaesthetises the palatal gingiva of the corresponding tooth only.
What nerve is targeted for a palatal infiltration?
It is dependant on the region you want to anaesthetise. However it is the nasopalatine or the greater palatine.
What are is anaesthetised in a palatal infiltration?
The terminal branches on innervating nerve resulting in anaesthesia of the local palatal gingiva.
What is the target bony site for a palatal infiltration?
The greatest angle of the palate - the junction of the palatine process of maxilla and alveolar process of maxilla.
What are the soft tissue landmarks for a palatine infiltration?
The maximum tissue thickness of the palate (curvature of the palate)
What is the orientation of the needle for a palatal infiltration?
Insert the needle at approx 45 degree angle to the palate at the junction
What need length should you use for a palatal infiltration?
Short
What is the insertion depth for a palatal infiltration?
1-2mm
How much LA do you deposit in a palatal infiltration?
0.1-0.3mls ( a few drops) deposit slowly, you will see blanching.
What is this an IMAGE of?
Palatal infiltration
What is this a diagram of?
A palatal infiltration.
What are considerations regarding the palatal infiltration?
• Height of maximum curvature is lower in anterior teeth, so injection is much closer to tooth, don’t inject into rugae • May want to consider nasopalatine block • Palatal injections can be very sensitive, if need to anaesthetise gingiva of more than 2 teeth may want to consider greater palatine and/or nasopalatine block
What is the block technique?
It involves the anaesthetising of the more proximal branches of the larger nerve trunk. Usually at a site more distant from the operative site Minimises the need for multiple infiltrations Must aspirate in two planes (achieved by rotating barrel of syringe) except for nasopalatine block.
There are several types of blocks. Name those of the maxilla.
- Posterior Superior Alveolar Block - Middle Superior Alveolar Block - Anterior Superior Alveolar Block - Nasopalatine Block - Greater Palatine Block
What is an indication for a posterior superior alveolar block?
Suitable if requiring a pulpal/gingival anaesthesia of more than one molar tooth
What nerve is targeted in a PSA?
The posterior superior alveolar nerve.
Which area is anaesthetised in a PSA block?
It is used to anaesthetise the pulp tissue, alveolar bone, CT, PDL and buccal gingiva corresponding to the maxillary 1st (excluding MB root) 2nd, 3rd molar on the ipsilateral side of the injection.
What is the target bony site for a PSA block?
Lower infratemporal surface of maxilla
What is the soft tissue landmark for the PSA block?
The height of the mucobuccalfold over the second molar
How should you orientate your needle for a PSA block?
45 degree angle directed superiorly, medially and slightly posteriorly (one continuous movement)
What needle length should you use for a PSA block?
Short
What is the insertion depth for a PSA block?
15mm
How much LA should you deposit for a PSA block?
Approx 1.0-1.5mls (between 1/2 & 3/4 of a cartridge) You should deposit this slowly, over 30-60 seconds.
What block is displayed in this diagram?
The PSA block.
What block is displayed in this image?
The PSA block.
Which foramen is the PSA block near?
The greater palatine foramen. IMAGE
What are some considerations of the PSA block?
• Injecting near the pterygopalatine space, risk of haematoma formation if accidentally puncture maxillary artery or pterygoid plexus • Aspirate in two planes • Be wary of injection here in clients with coagulation disorders due to increased vascularisation of this area.
What is an indication for the MSA block?
Suitable if you require pulpal/gingival anaesthesia of both premolars.
Which nerve is targeted in a MSA block?
The middle superior alveolar block.
What area is anaesthetised in a MSA block?
The MSA is used to anaesthetise the pulp tissue, alveolar bone, CT, PDL and buccal gingiva corresponding to the premolars and MB root of the maxillary 1st molar on the ipsilateral side of the injection.
What is the target bony site of the MSA?
Superior and slightly distal to the apex of the second premolar
What is the soft tissue landmark for the MSA?
Height of the mucobuccalfold over the second premolar
What is the orientation for a MSA block?
Same as a buccal infiltration
What is the needle length for a MSA block?
Short
What is the insertion for an MSA block?
Ensure that the tip depth is above the apex of the second premolar
What amount is deposited for an MSA block?
Approx 0.9-1.2mls (approx half a cartridge)
What is this an IMAGE of ?
An MSA block
What are some considerations of the MSA block?
The lateral aspect of the maxilla is slightly concave, may need to angle slightly medially The facial artery branches are present in this region, you must remember to aspirate The technique can become slightly angled as working towards the posterior region of the mouth
What is an indication for the ASA?
Suitable if requiring pulpal or gingival anaesthesia of more than one anterior tooth