Cause of Anesthetic Failure

Question 1

What is the most likely cause of anesthetic failure in a novice?

Answer 1

Incorrect placement of the needle

Reinjection along proper path will usually correct this

Question 2

What are two operator errors during local anesthesia?

Answer 2

Syring stability- moving during deposition, withdrawl during aspiration, advancing during administration

Syring position- improper landmark ID, gravitation toward midline, right vs. left side injection sites

Question 3

What are some reasons for anesthetic failure not due to operator error?

Answer 3

Anatomic variations
Intravascular injection
Needle deflection
Inflammation- changes pH

Question 4

Anatomic variation

Answer 4

Can be determined via palpation, radiographs and visual inspection

Fascial planes are more difficult to determine. Locations of nerves and other structures can vary

Question 5

What are good possible alternative injections in the case of anesthetic failure?

Answer 5

Gow-Gates block, PDL injections, supraperiosteal injections

Question 6

What may happen with use of a thinner needle?

Answer 6

Needle deflection from its intended path

Question 7

Inflammation

Answer 7

Anesthesia may be less effective in presence if inflammation.
Acidic by-products lower pH of tissue, hastening removal of anesthetic from injection site decreasing duration and profundity