Local Anesthetics - dosages Flashcards

1
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List max doses of LAs

Bupivacaine, cocaine, tetracaine, ropivacaine, etidocaine, lidocaine, mepivacaine, choroprocaine

A

Bupivacaine 2.5 mg/kg

Cocaine 3 mg/kg

Tetracaine 3 mg/kg

Ropivacaine 3 mg/kg (3.5 w epi)

Etidocaine 4 mg/kg

Lidocaine 4 mg/kg (7 w epi)

Mepivacaine 4 mg/kg (7 w epi)

Chloroprocaine 12 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when do you redose lidocaine (epidural)?

A

lidocaine lasts about 1.5-2 hours etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Chloroprocaine Max Dose

A

12 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Lidocaine Max Dose

A

4 mg/kg

7 mg/kg with epi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mepivacaine Max Dose

A

4 mg/kg

7 mg/kg with epi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Bupivacaine Max Dose

A

2.5 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Ropivacaine Max Dose

A

3 mg/kg

3.5 mg/kg with epi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Etidocaine Max Dose

A

4 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cocaine Max Dose

A

3 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Tetracaine Max Dose

A

3 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Mepivacaine duration after infiltration

A

1.5 - 3 hr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Bupivacaine/Levobupivacaine/Ropivicaine

duration after infiltration

A

4-8 hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ropivacaine duration after infiltration

A

4-8 hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Prilocaine duration after infiltration

A

1 -2 hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Chloroprocaine duration after infiltration

A

30 - 60 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Procaine duration after infiltration

A

45 - 60 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Arrange LAs in the order of non-ionization %

  1. cocaine
  2. lidocaine
  3. mepivacaine
  4. chloroprocaine
  5. prilocaine
  6. ropivacaine
  7. tetracaine
  8. procaine
  9. bupivicaine
  10. levobupivicaine
  11. Etidocaine
A
  1. Chloroprocaine 2%
  2. Procaine 3%
  3. Tetracaine and Cocaine 7%
  4. Bupivacaine / Levobupivacaine / Ropivacaine 17%
  5. Lidocaine/Prilocaine 24%
  6. Etidocaine 33%
  7. Mepivacaine 39%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

LAs used topically

A
  1. Tetracaine- spinal corneal and topical
  2. Lidocaine - patches, creams, gel
  3. Cocaine - for ENT surgeries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

LAs that can be given IV

A

Lidocaine

Prilocaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

LAs that cannot be given in a peripheral block

A

Tetracaine- high toxicity risk, profound mortor block- used in spinal, corneal anesthesia and topicallu

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

LAs that cannot be give epidurally

A
  1. Procaine - no longer used, was used for infiltration
  2. Tetracaine - high toxicity - spinal, corneal and topical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

LAs that are still questionable for a spinal block

A

Chloroprocaine

Lidocaine

Mepivacaine

Prilocaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

LAs with pKa in the ≈7s

A
  1. Mepivacaine = 7.6
  2. Etidocaine = 7.7
  3. Lidocaine/Prilocaine = 7.9
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

LAs with pKa in the ≈ 8s

A
  1. Bupivacaine/Levobupivacaine/Ropivacaine = 8.1
  2. Cocaine/Tetracaine = 8.5
  3. Chloroprocaine = 8.7
  4. Procaine = 8.9
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Its metabolite interferes with efficacy of sulfonamide antibiotics

A

Procaine

27
Q

Lidocaine solution concentrations

  1. topical
  2. regional IV
  3. PNB
  4. Spinal
  5. Epidural
A
  1. topical: 4%
  2. regional IV: 0.25-0.5%
  3. PNB: 1-2 %
  4. Spinal: 1.5 - 5%
  5. Epidural:3 1.5 - 2%
28
Q

LA not effective topically

A

Mepivacaine

29
Q

which has more CNS toxicity poptential

lidocaine or mepivacaine

A

mepivacaine

30
Q

LA great for differential nerve block (sensory>motor)

great for OB

A

Bupivacaine

31
Q

most cardiotoxic LA

A

Bupivacaine

32
Q

Bupivicaine E½t

A

3.5 hrs

33
Q

Bupivicaine solution concentration

  1. Spinal
  2. Epidural
  3. Peripheral Nerve Block
A
  1. Spinal: 0.5 - 0.75%
  2. Epidural: 0.0625 - 0.5%
  3. Peripheral nerve block: 0.25 - 0.5%
34
Q

Bupivicaine/Levobupivicaine/Ropivicaine max spinal dose

A

15-20 mg

35
Q

Lidocaine max spinal dose

A

30-100 mg

36
Q

Bupivacaine DOA after spinal

A

1.5 to 3.5 hr

37
Q

Bupivacaine onset and DOA w/ epidural

A

onset 15-20 min

DOA 3 - 6 hrs

38
Q

Lidocaine onset and DOA w/ epidural

A

onset 5-15 min

DOA 1.5-2 hours

39
Q

Mepivacaine onset and DOA w/ epidural

A

onset 2-15 min

DOA 1 - 3 hrs

40
Q

Shortest DOA for epidural

A

Chloroprocaine

41
Q

Chloroprocaine onset and DOA w/ epidural

A

onset 5-15 min

DOA 30-90 min

42
Q

Prilocaine max spinal dose

A

100-200 mg

43
Q

Mepivacaine max spinal dose

A

40-80 mg

44
Q

Tetracaine max spinal dose

A

5-20 mg

45
Q

Ropivacaine max spinal dose

A

15-20

46
Q

Long DOA for an ester

A

Tetracaine

1.5 - 3.5hrs

47
Q

pt cannot have epi

what LA is best alternative

A

Mepivacaine

it doesn’t vasodilate like lidocaine so can be used when avoiding epi

48
Q

Which LAs have slow, moderate, and fast onsets?

A

Slow Onset: procaine, tetracaine (esters)

Intermediate Onset: bupivacaine

Fast Onset: chloroprocaine, lidocaine, etidocaine, mepivacaine

49
Q

Lidocaine uses?

A
  • Regional/ neuraxial block
  • Cough suppression
  • Attenuate ICP/BP raise during laryngoscopy
  • Attenuate reflex bronchospasm that may occur with airway instrumentation
  • Suppress ventricular dysrhythmias
50
Q

How is cocaine metabolized?

A

Liver, plasma esterases, and about 10-12% eliminated by kidney

careful with renal disease

NOT PAVA like the other esters

51
Q

What is chloroprocaine used for?

A

OB epidurals

it has an ultra rapid serum hydrolysis (metabolism) which reduces toxicity risk to mom and baby

52
Q

Does lidocaine have an active metabolite?

A

YES.

2 Monoethylglycinexylidide (80% activity)

(Mono-ethyl-glycine-xylidide)

xylidide (10% activity)

53
Q

metabolism of prilocaine.

A

Rapid metabolism

TOXIC metabolite ortho-toluidine

Must be avoided in OB due to metabolite

Big doses will convert hgb to methemoglobin (treated with methylene blue)

54
Q

What is the dose of Lidocaine for epidural placement?

A

It depends on the level of blockade required and the density of blockade required. If you want profound motor blockade at T4 for example and the epidural is placed at the L2-3 interspace that is about 10 segments. Say this person is average size – I would give 1.5ml per segments I wanted blocked – so I would give 15cc of 2% lidocaine. 15cc X 20mg/cc = 300mg of lidocaine. I would need to make sure that this amount did not exceed the maximum dose allowed which is 5mg/kg for plain lidocaine. If the patient was 70kg that is 350mg – so 15cc is O.K. If I wanted to give more I might add epi which would increase my maximum dose to 7mg/kg or 490mg.

55
Q

LAs that come in racemic mixtures

A

Bupivacaine

Mepivacaine

56
Q

LAs that come as pure enantiometrs

A

Ropivacaine

Levobupivacaine

*advantage = less toxic, easier to resuscitate in case of toxicity

57
Q

what LAs are highly lipid soluble

A

Bupivicaine

Etidocaine

Tetracaine

BET

58
Q

what LAs have significant 1st pass effect by the lungs

A

Bupivicaine

Lidoicaine

Prilocaine

59
Q

Why is lidocaine avoided in spinals?

A

Linked to caudal equina syndrome

Epidural ok to use

60
Q

Bupivacaine pros and cons?

A

Pro

highly protein bound

  • low incidence of neuro complications with spinal
  • longer DOA (good for post-op pain and labor)

Also, A alpha, beta, and gamma fibers are not completely blocked, so sensory is blocked and motor is not completely blocked.

Con

TOXICITY! very cardio toxic; pressure is still felt, that can freak people out

61
Q

Cocaine toxicity sxs

A

cocaine ↓ reuptake of NE → leads to ↑ concentrations of NE

  • restlessness, tremors, seizures & euphoria
  • tachycardia/MI
62
Q

LA toxicity s/s?

A

CNS

circumoral numbness, tinnitus, vision changes, dizzy, slurred speech, restless, muscle twitching (especially in the face), seizures (which cause CNS depression, apnea, hypotension)

CV

hypotension, myocardial depression, AV block

Note: bupivacaine is most CV toxic

63
Q

S (or levo) enantiomer of bupivacaine

A

Ropivacaine

less cardio-toxic