Locals and Blocks Flashcards
1
Q
Plasma Lidocaine Concentration 1-5
A
Analgesia
2
Q
Plasma Lidocaine Concentration 5-10
A
Circum-oral numbness
Tinnitus
Skeletal Muscle twitching
Systemic hypotension
Myocardial depression
3
Q
Plasma Lidocaine Concentration 10-15
A
Seizures
Unconsciousness
4
Q
Plasma Lidocaine Concentration 15-25
A
Apnea
Coma
5
Q
Plasma Lidocaine Concentration >25
A
Cardiovascular depression
6
Q
Lidocaine (Xylocaine)
A
- Onset: Rapid
- DOA: 60-120
- Max dose: 300 & 500 w/ Epi
- pK: 7.9
- PB: 70
- 1st-Pass Pulmonary Extraction
7
Q
Bupivacaine (Marcaine)
A
- Onset: Slow
- DOA: 240-480
- Max dose: 175 & 225 w/ Epi
- pK: 8.1
- PB: 95
- 1st-Pass Pulmonary Extraction
8
Q
Ropivacaine (Naropin)
A
- Onset: Slow
- DOA: 240-480
- Max dose: 200
- pK: 8.1
- PB: 94
9
Q
Order of Nerves affected
A
- Preganglionic B fibers (SNS) -hypotension/ bradycardia
- C and A-delta- loss of pain/ temperature
- A-gamma- loss of motor tone
- A-beta= loss of touch and pressure
- A-alpha= loss of motor function & proprioception
10
Q
4 Factors that influence absorption
A
- Site
- Dose
- Epi
- Rate of distribution
11
Q
Subarachnoid Block (SAB)
A
Dose is more important than concentration or volume
* 5ft= 1 mL
* + 0.1 mL/ every inch above
12
Q
Epidural
A
- Volume-based
- Onset: slow
- Spread: as expected (volume dependent)
- Nature of block: Segmental
- Motor block: Minimal
- Hypotension: < than spinal
- Gravity Influence: Baricity
13
Q
Spinal
A
- Dose-based
- Onset: Rapid
- Spread: Higher than expected
- Nature of block: Dense
- Motor block: Dense
- Hypotension: Likely
- Gravity Influence: Baricity
14
Q
Absolute Contraindications
A
- Coagulopathy
- INR >1.5
- Platelets <100k
- Nagelhout x2
- Known coagulation disorder or taking anticoagulants
- TPA
- Pt refusal
- Evidence of dermal site infection
- Severe or critical Valvular heart disease
- AS </= 1.0 cm2 or MS < 1.0 cm2
- HSS
- Increased ICP
- Severe CHF
- preload dependence
- EF< 30-40%
15
Q
Bleeding Labs
A
- Extrinsic Pathway
- PT= 12-14 (Nagelhout)
- INR= 0.8-1.1
- Intrinsic Pathway
- aPTT= 25 (Nagelhout)
- Bleeding time = 3-7 minutes (Nagelhout)
- platelet activation, aggregation & adhesion
- Platelets= 150- 300 K
16
Q
Spinal Controllable factors (factors that affect block height)
A
- Barcity
- Pt position
- Dose
- Site of injection
Addition of Vasoconstrictor does not affect the spread
17
Q
Spinal Noncontrollable factors (factors that affect block height)
A
- CSF Volume
- lower volume= higher block
- Increased intra-abdominal pressure
- obesity/ pregnancy
- Age
18
Q
Epidural Controllable factors (factors that affect spread)
A
- Significantly affects
- LA Volume
- Level of injection
- LA dose
- Small affects
- LA Concentration
- Pt position
Additives in LA might change onset time/ duration but not spread
19
Q
Epidural Noncontrollable factors (factors that affect spread)
A
- Significantly affects
- Pregnancy/ Old age
- Small affects
- Pt height
20
Q
Differential Blockade sensory level
A
2 levels higher than the motor
21
Q
Differential Blockade sympathetic level
A
2-6 levels higher than the sensory level
22
Q
CV Effects of LA
A
- Decreased preload (dilates veins, reducing the blood returning to heart)
- Decreased afterload ~15% in healthy pts (partially dilates arterial circulation)
- Decreased CO: decrease in SVR and venous return (may increased initially)
- Decrease HR- blockade of Cardiac accelerator fibers, reduces SNS tone
- Activation of Bezold-Jarisch Reflex mediated by the CNX
23
Q
Prevention of SA induced hypotension
A
- Vasopressors
- 5-HT3 Antagonists
- Co-loading (>preloading)
- Positioning
24
Q
Effects of adjuncts
* NaHCO3
* Opioids
* Alpha-2 agonists
* Vasopressors
A
- 1 mEq/ 10 mL LA
- increases concentration, rate of diffusion, onset
- Sufentanil, Fentanyl, Morphine
- NO extension of duration (intensifies sensory block)
- Dexmedetomidine/ Clonidine
- improves density, duration, & analgesia
- Epinephrine/ Phenylephrine
- duration only
25
Lidocaine Infiltration
* Rapid
* 0.5-1%
* Max: 300 & 500 w/ Epi
* DOA: 60-240
26
Lidocaine IVRA
* Rapid
* 0.25-0.5 %
* Max: 300
* DOA: 30-60 min
27
Lidocaine PNB
* Rapid
* 1-1.5%
* Max: 300 & 500 w/ Epi
* DOA: 60-180 min
28
Lidocaine Epidural
* 10-20 min
* 2 %
* Max: 300 & 500 w/ Epi
* DOA: 60-120 min
29
Lidocaine Spinal
* Rapid
* 1.5-5%
* Max: 100
* DOA: 30-60 min
30
Bupivacaine Infiltration
* Rapid
* 0.25
* Max: 175 & 225 w/ Epi
* DOA: 120-480 min
31
Bupivacaine PNB
* Rapid
* 0.25-0.5%
* Max: 175 & 225 w/ Epi
* DOA: 240-960 min
32
Bupivacaine Epidural
* 15-20 min
* 0.0625-0.5%
* Max: 175 & 225 w/ Epi
* DOA: 160-220 min
33
Bupivacaine Spinal
* 4-8 min
* 0.5-0.75 %
* Max: 20 mg
* DOA: 130-220 min
34
Ropivacaine Infiltration
* Rapid
* 0.2-0.5 %
* Max: 200 mg
* DOA: 120-360 min
35
Ropivacaine Epidural
* 15-20 min
* 0.1-0.75 %
* DOA: 140-220 min
36
Ropivacaine Spinal
* 3-8 min
* 0.5-1 %
* Max: 25 mg
* DOA: 80-210 min
37
Intralipid 20% Dose
Bolus: 1.5 mL/ Kg
Infusion: 0.25 mL/ Kg/ min
Max: 10 mL/ Kg
38
Peri-anal/ anal surgery "Saddle Block"
S2-S5
39
Foot/ ankle surgery
L2
40
Thigh/ Lower leg/ knee
L1
41
Vaginal delivery/ uterine/ hip procedure/ tourniquet/ TURP
T10
42
Scrotum
S3
43
Penis
S2
44
Testicular Procedure
T8
* Testicles are embryonically derived from the same level as the kidneys for pain transmission (T10-L1)
45
Urologic/ gynecologic/ lower abdominal
T6
46
C-section/ Upper abdominal
T4
47
Branches of Trigeminal Nerve (CN V)
* V1- Ophthalmic Nerve
* V2- Maxillary Nerve
* V3- Mandibular Nerve
48
L1-4
Anterior & inner surface of lower limbs
49
L4-S1
Foot
50
L4
Medial side of great toe
51
L5-S2
Posterior and outer surface of lower limbs
52
S1
Lateral margin of foot and little toe
53
S2-S4
Perineum
54
T10
Umbilicus
55
T12
Inguinal or groin regions
56
C5
Clavicles
57
C5-7
Lateral parts of upper limbs
Phrenic Nerves
58
C8-T1
Medial sides of upper limbs
59
C6
Thumbs
60
C6-8
Hand
61
C8
Ring and little fingers
62
T4
Level of nipples
