local anesthesia concepts

Question 1

when pKa = pH

Answer 1

1) 50% is ionized and 50% is unionized
2) to be absorbed in a lipid membrane, it needs to be unionized, and to work in the cell, it needs to be ionized

Question 2

baseline vitals

Answer 2

1 )GOTTA take blood pressure and HR
2) respiratory rate is a bonus
3) saturation of oxygen is helpful in patients with respiratory compromise
- SpO2>95% is normal
<92% is poor blood saturation

Question 3

heart rate

Answer 3

1 )60-80 bpm
2) athletes can be as low as 40 bpm
3) maximum is 220 beats per minute minus their age
4 )elevated
- anxiety
- hot weather
- obesity
- medications: ex. albuterol

Question 4

hypertension

Answer 4

1) control anxiety
2) make sure the patient took all meds prior
3) if over BP>150, they will bleed
- break multiple extraction into small parts
- use local measures for bleeding control
- reschedule patients to control labile BP
4) have them take evening dose prior to afternoon appt

Question 5

local anesthesia

Answer 5

1) articaine / mepivacaine
2) marcaine / bupivicaine
3) etc.

Question 6

lidocaine (xylocaine)

Answer 6

1) 2% solution (1:100k)
2) 20 mg/ml
2) maximum dose is 500 mg or 7 mg/kg, whichever is lower!
4) 1.8 ml in cart
5) 60-90 min duration

Question 7

articaine (septocaine)

Answer 7

1) not very potent
2) 4% 1:100k epi
3) maximum dose is 500 mg or 7mg/kg
- 1.8 ml in cartridge
4) 60-70 duration, longer for soft tissue
5) it’s like burning the nerve because it is so alkaline
- but you shouldn’t use it for block
- can cause long term paresthesia

Question 8

mepivacaine (carbocaine)

Answer 8

1) supplied in 3% solution
2) 30 mg/ml
3) maximum dose is 400 mg or 6.6 mg/kg whichever is lower
4) 1.8 ml
5) 60-75 minutes (longer for soft tissue)
6) best anesthetic for an infection
- pH as low as 5

Question 9

bupivacaine (marcaine)

Answer 9

1) 0.5% solution (1;200k epi)
2) 5 mg/ml
3) maximum dose of 90 mg or 1.3 mg/kg
4) 1.8 in cart
5) 40-120 minutes, longer for soft tissue

Question 10

prilocaine (citanest)

Answer 10

1) good for drug abusers or if they are hard to numb
2) 4% solution (plain)
3) max dose is 600 mg

Question 11

LA toxicity

Answer 11

1)signs and symptoms of a LA toxicity are biphasic
- initial excitation
- secondary depression
2) their heart will stop
3) methemoglobinemia will treat this

Question 12

post operative vital signs

Answer 12

1) take the BP and HR before discharge
2) use modified aldrete scale
- vitals 20% below or above baseline

Question 13

in an acidic environment

Answer 13

1) which anesthetic works better
- mepivacaine (take less time to work)