Armamentarium Flashcards
What are the 5 different types of syringes used for LAs in dentistry?
- Breech-loading, aspirating
- Breech-loading, self-aspirating
- pressure-type
- needleless-type
- C-CLAD-type
What are the five parts of a syringe?
Needle adapter, piston w/ harpoon, syringe barrel, finger grip, thumb ring
Normal aspirating, breech-loading, metallic, cartridge-type syringes allow for what three things?
side loading of cartridge, user-controlled aspiration, visualization of cartridge
What characteristics do self-aspirating syringes have?
An elastic rubber diaphragm obtains negative pressure for aspiration upon insertion
What kind of injection are pressure syringes great for?
they’re ideal for PDL/intraligamentary injections
How do needleless syringes inject LA?
with extremely high pressure forcing the solution into the tissue
What are the five parts of a needle?
Bevel, shaft, hub, syringe adaptor, and cartridge-penetration end
The gauge of a needle refers to what?
The diameter of the lumen inside the needle shaft - the larger gauge, the smaller the diameter
Which length of needle tends to break more often?
short needles tend to break more often because they don’t have as much “give” or bend
What does the phrase “larger gauge” mean in the clinic?
Unintuitively, it means the lumen diameter is larger despite the actual gauge measurement would be a smaller number
What is needle deflection?
It is the ‘bend’ of the needle that occurs as it is inserted into the tissue. The less deflection you can achieve, the more accurate your injection will be.
What are some factors that cause needle deflection?
greater bevel angle, smaller gauge needle (smaller lumen), and longer length
What can you do to minimize needle deflection?
One technique (Bi-Rotational Insertion Technique) is to rotate the needle as it’s being inserted into the tissue
What is the purpose of aspiration?
it is meant to check if the needle has entered a blood vessel - since we don’t want to inject LA into a vessel you should always aspirate
What is the most common site for a needle to break?
The hub
pre-bending of needle is most common cause of fracture
What are the four parts of a cartridge?
Glass tube, stopper (plunger), aluminum cap, rubber diaphragm
What purpose does Sodium (meta)bisulfite have on the injection?
It’s an antioxidant that protects the vasopressor from being degraded
How long should you allow topical anesthetic to anesthetize the site of insertion before doing so?
at least 1 min, but 2-3 can get even better results
don’t use topical anesthetics containing alcohol
What are the four basic steps to injection?
- dry area 2. apply minimal topical anesthetic 3. pull tissue taut 4. insert/inject
Why would you attach the needle to the syringe/cartridge AFTER inserting the cartridge?
The cartridge-penetrating end of the needle may break or bend if you’re also trying to harpoon the cartridge in the syringe
If you get a positive aspiration, what is the next step?
Positive aspiration means you’re in a vessel, so retract the needle and insert again
What should you do in the event of any complication associated with LA injection?
Take careful note of it in the pts chart
What injection has the highest frequency of needle fractures?
IA block (90% of needle breaks are during this injection)
The longer length of time that prolonged anesthesia/paresthesia persists raises potential for ____________.
complications
What can cause paresthesia?
mechanical trauma to the nerve, or the injection contaminated by alcohol
What is an adverse effect seen with infraorbital nerve blocks?
facial nerve paralysis
What is trismus?
prolonged, titanic spasm of jaw muscles that restrict normal opening of the mouth (locked jaw)
What causes soft tissue injury?
self inflicted injury caused by the patient inadvertently chewing or biting while anesthetized
What is a hematoma, and in what tissue is it more likely to occur?
It’s when a blood vessel (arteries more common) is inadvertently nicked during LA injection. it’s more common to occur in soft tissues away from any hard tissue
How can you manage a hematoma in the clinic?
DO NOT apply heat, apply ice instead, avoid dental work until problem resolves, and don’t release pt until hematoma stops bleeding
What causes the burning upon injection that pts can sometimes feel?
main cause is the acidic pH of the LA (vasopressor is acidic), but can also be caused by too rapid of injection, or alcohol contamination
What are two reasons why you shouldn’t inject LA into infected tissue?
LA is less effective in infected tissue, and if flow of the LA into the tissue can transport bacteria causing the spread of infection
How can you manage edema?
ensure airway is open, administer epinephrine if necessary, perform cricothyroidotomy if total airway obstruction
