Pharm Review - Regional & CSE Labor Analgesia Flashcards
1
Q
What are the 3 most common LAs we will use for regional blocks?
A
- Lidocaine
- Bupivacaine
- Ropivacaine
2
Q
Which LA has a faster onset but shorter DOA?
A
Lidocaine
3
Q
Which LAs (2) have a slower onset but longer DOA?
A
Ropivavaine & Bupivacaine
Cardiac Toxicity Risk ↑
4
Q
What is the main determinant of DOA for LAs?
A
- protein binding % of the LA
5
Q
What is the main determinant of potency for LAs?
A
- lipid solubility of the LAs
6
Q
What 6 medications can we give to prolong DOA of LAs?
A
- Epinephrine
- Dexmedetomidine
- Magnesium
- Clonidine
- Ketamine
- Decadron
7
Q
What 2 things can we do to increase the onset of LAs?
A
- Add HCO3 - not common
- combine a short acting and long acting LA
8
Q
Lidocaine Max (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 5mg/kg
- w/: 7mg/kg
9
Q
Prilocaine Max Dose (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 6mg/kg
- w/: 8.5mg/kg
10
Q
Mepivacaine Max Dose (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 5mg/kg
- w/: 7mg/kg
11
Q
Bupivacaine Max Dose (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 2.5mg/kg
- w/: 2.5mg/kg
12
Q
Ropivacaine Max Dose (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 3mg/kg
- w/: 4mg/kg
13
Q
Procaine Max Dose (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 7mg/kg
- w/: 8.5mg/kg
14
Q
Chloroprocaine Max Dose (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 6mg/kg
- w/: 14mg/kg
15
Q
Tetracaine Max Dose (mg/kg)
w/o Epi:
w/ Epi:
A
- w/o: 3mg/kg
- w/: 3mg/kg
16
Q
CSE Labor Analgesia
Bupivacaine Dosing
Epidural:
Spinal:
A
E: 0.0625 - 0.125%
S: 1.25 - 2.5 mg
17
Q
CSE Labor Analgesia
Ropivacaine Dosing
Epidural:
Spinal:
A
- E: 0.08 - 0.2%
- S: 2.5 - 4.5mg
18
Q
CSE Labor Analgesia
Lidocaine w/ Epi Dosing
Epidural:
Spinal:
A
- E: 2% in 5mL bolus
- S: none
19
Q
CSE Labor Analgesia
Fentanyl Dosing
Epidural:
Spinal:
A
- E: 50-100mcg
- S: 10-25mcg
20
Q
CSE Labor Analgesia
Sufentanil Dosing
Epidural:
Spinal:
A
- E: 5 - 10mcg
- S: 1.5 - 5mcg
21
Q
CSE Labor Analgesia
Morphine Dosing
Epidural:
Spinal:
A
- E: none
- S: 0.1 - 0.2 mg
22
Q
What 5 LAs are amides?
A
2 Is
1. Lidocaine
2. Prilocaine
3. Mepivacaine
4. Bupivacaine
5. Ropivacaine
23
Q
What 3 LAs are Esters?
A
- Procaine
- Chloroprocaine
- Tetracaine
24
Q
Lidocaine dosing
IV bolus:
IV gtt:
A
- IV bolus: 1-2mg/kg IV over 2-4min
- IV gtt: 1-2mg/kg/hr
stop in 12-72hrs
25
# Lidocaine Concentration → Effect
1-5mcg/mL =
Analgesia
26
# Lidocaine Concentration → Effect
5-10mcg/mL =
1. circum-oral numbness
2. tinnitus
3. skeletal muscle twitching
4. HoTN
5. myocardial depression
27
# Lidocaine concentration → Effect
10-15mcg/mL =
* seizures
* unconsciousness
28
# Lidocaine Concentration → Effect
15-25mcg/mL =
* Apnea
* Coma
29
# Lidocaine Concentration → Effect
> 25mcg/mL
* CV depression
30
How many nodes of Ranvier need to be blocked?
* 3 nodes = 1cm
31
How are **amide** LAs metabolized?
* CYP enzymes - Hepatic
32
How are **ester** LAs metabolized?
* Hydrolysis - plasma cholinesterase enzymes
33
What **ester** LA is the one that IS metabolized in the liver?
Cocaine
34
Do Esters or Amides cause allergic reaction?
Ester
35
Which class of LAs is more likely to cross the placenta?
Amides
* non-ionized crosses
* Cautious w/ ion trapping
36
The metabolites of which LAs can lead to methemoglobinemia?
Lidocaine, Benzocaine, Prilocaine
37
Methylene blue dose to tx methemoglobinemia:
* 1-2mg/kg
* max: 7-8 mg/kg
38
T/F: We can give pregnant women Mepivacaine
False: long E 1/2 time in fetus
39
What LA is used to test plasma cholinesterase activity?
* Dibucaine
* MOA: inhibits activity of normal butyrylcholinesterase
40
If a Dibucaine level is low, what drug should we avoid giving?
* Succinylcholine - they won't metabolize it
41
# Epi Concentration
1:200,000
* 1,000,000/200,000 = 5mcg/mL
42
# Epi Concentration
1:500,000
* 1,000,000/500,000 = 2mcg/mL
43
# Epi Concentration
1:10,000
* 1,000,000/10,000 = 100mcg/mL
44
# Epi Concentration
1:1,000
* 1,000,000/1,000 = 1,000mcg/mL
45
# LA Strengths
0.25% =
2.5mg/mL
46
# LA Strengths
0.5% =
* 5mg/mL
47
# LA Strengths
1% =
* 10mg/mL
48
# LA Strengths
2% =
* 20mg/mL
49
# LA Strengths
4% =
* 40mg/mL
50
What does **LTA** stand for?
Laryngotracheal atomizer (Lidocaine)
51
What is the Lidocaine dose for Tumescent Liposuction?
* Lido w/ Epi: 35-55 mg/kg
* diluted Lido: 0.05% - 0.10%
* Epi: 1:100,000
52
What are 5 **absolute** contraindications to Neuraxial?
1. Coagulopathy
2. Pt refusal
3. site infection
4. Infection
5. severe valvular heart dz
53
Is a spinal or epidural volume dependent?
* Epidural
## Footnote
Spinal is dose-dependent
54
Where does the spinal cord end?
Adult:
Pedi:
* A: L1
* P: L3
55
Desired dermatome level for peri-anal/anal surgery (saddle block):
* S2-S5
56
Desired dermatome level for foot/ankle surgery:
L2
57
Desired dermatome level for Thigh/lower leg/knee surgery:
L1
58
Desired dermatome level for vaginal delivery, uterine, hip procedure, tourniquet pain, and TURP
* T10
59
Desired dermatome level for scrotum surgery:
S3
60
Desired dermatome level for penile surgery:
* S2
61
Desired dermatome level for testicular procedures:
* T8
62
Desired dermatome level for Urologic, gynecologic, & lower abdominal procedures:
* T6
63
Desired dermatome level for C-section & upper abdominal surgery:
* T4
64
At what level does a "sympathectomy" occur?
T1-T4
65
What 2 medications should we **always have ready** when doing a spinal/epidural?
1. Ephedrine (HR low)
2. Neosynephrine (HR high)
66
What is a **co-loading** dose of fluids?
* 15mL/kg during the procedure
* NS/isotonic solution
67
These medications/fluids can be used to Tx **spinal anesthetic HoTN**
1. Vasopressors
2. Anticholinergics (Atropine)
3. Crystalloids - Colloids
68
Organize the different regional anesthetic techniques that result in highest blood concentrations → lowest concentration
Highest → Lowest
1. Intravenous
2. Tracheal
3. Intercostal
4. Caudal
5. Paracervical
6. Epidural
7. Brachial
8. Sciatic
9. Subcutaneous
69
**isobaric** density:
* density equal to CSF - stays in place
70
**hyperbaric** density:
* density > CSF - sinks in the CSF
71
**hypobaric** density:
* density < CSF - rises in the CSF
72
Bupivacaine 0.5%-0.75%
T10 dose:
T4 dose:
* T10: 10-15mg
* T4: 12-20mg
73
Ropivacaine 0.5-1%
T10 dose:
T4 dose:
* T10: 12-18mg
* T4: 18-25mg
74
What is the initial volume for epidural dosing?
1-2mL/segment
75
What is the top-up vol. dosing for epidural?
* 50-75% of initial dose
**↓ by 2 dermatome levels**
76
**LA** Onset & Duration: fastest → slowest & shortest → longest
Onset fastest → slowest & DOA shortest → longest:
1. 2-Chloroprocaine
2. Lidocaine
3. Ropivacaine
4. Bupivacaine
5. Levobupivacaine
77
# Opioid Epidural Infusion Dosing
Sufentanil
10-20mcg/hr
78
# Opioid Epidural Infusion Dosing
Fentanyl
25-100mcg/hr
79
# Opioid Epidural Infusion Dosing
Hydromorphone
0.1-0.2 mg/hr
80
# Opioid Epidural Infusion Dosing
Meperidine (Demerol)
* 10-60 mg/hr
81
# Opioid Epidural Infusion Dosing
Morphine
* 0.1-1 mg/hr
82
Dexmedetomidine dosing for spinal/epidural:
3 mcg
83
Clonidine dosing for epidural/spinal:
15-45mcg
84
Epinephrine dosing w/ LA:
* 0.2-0.3mg "epi wash"
85
Phenylephrine dosing w/ LA:
2-5mg
86
T/F: Neuraxial is contraindicated in pts on thrombolytic therapy
True!
87
What is the most cardiotoxic LA?
* Bupivacaine
88
LAST management:
1. airway mgmt
2. bzd for seizures
3. modified ACLS (cautious w/ epi)
4. Lipid emulsion 20%
89
What is the epidural test dose?
**3mL** of 1.5% Lidocaine w/ 1:200,000 Epi
90
Recommended "Top Up" time for Lidocaine:
60min
91
Top up time for Bupivacaine & Ropivacaine
120min
