Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anesthesia Principles II > Regional Lecture I Part I > Flashcards

Regional Lecture I Part I Flashcards

1
Q

What was the first regional anesthetic?

A

Cocaine
(probably ice actually was first)

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

First documented application of a druge to produce localized anesthesia?

A

Karl Kollar, a college and friend of Freud demonstrated the use of local anesthesia allowing him to perform painless eye surgery in 1884.

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

Who started injecting cocaine into nerves?

A

William Halsted and Alfred Hall

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

What was the first percuntaneous block?

A

axillary by G. Hirschel in 1911

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

types of regional anesthesia?

A

topical
local infiltration
field block
intravenous regional - bier block
peripheral nerve block
neuraxial

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

advantages of topical anesthesia?

A

super easy
low skill
low risk
great for mucous membranes

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

disadvantages of topical anesthesia?

A

short DOA 1-4hrs
slow onset over skin (needs soak time)
doesn’t work well on inflamed or infected tissue

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

DOA of local infiltration?

A

short 1-6 hours

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

what is a field block?

A

infiltration of LA around an area you wish to anesthetize

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

Uses for field blocks?

A

carotid endarterectomy (superficial cervical plexus)

I&D of wounds

intercostobrachial and medial brachial cutaneous nerves

dentistry

plastic surgery

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

good option to supplement patchy peripheral or neuraxial blocks?

A

field block

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

good option to supplement patchy peripheral or neuraxial blocks?

A

field block

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

disadvantages of field blocks?

A

inconsistent coverage
only covers superficial structures
relatively short duration of action

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

what is the only medication that can be used for a bier block?

A

0.5% lidocaine

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

What is bier block best suited for?

A

short soft tissue upper extremity procedures

can be used for lower extremity procedures too, but doesn’t work as well and has more risk of systemic toxicity.

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

advantages of bier block?

A

relatively easy to perform
provides surgical anesthesia quickly

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

disadvantages of bier block?

A

tourniquet pain limits useful duration

tourniquet must be inflated for at least 20min

must be able to get IV access

pt habitus must be suitable for proper tourniquet fit

failed tourniquets risk large volume of LA immediately entering central circulation > actue LA toxicity

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

how soon does tourniquet pain start?

A

within 30min

by 1 hour will have significant tourniquet pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Procedure steps for Bier Block

A

place IV

double lumen tourniquet to upper arm (pad arm with cotton)

arm exanguination with esmarch bandage

inflate distal cuff, inflate proximal cuff, deflate distal cuff (always inflated to 50-100mmHg above SBP)

inject LA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

LA dosing for bier block?

A

30-50ml of 0.5% lidocaine.

3mg/kg MAX!

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

how quickly does bier block work?

A

less than 5 min

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

what do you do once tourniquet pain starts?

A

inflate distal cufff, then deflate proximal cuff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how do you end a bier block?

A

use two stage tourniquet deflation

(deflate for 10sec, inflate for 1 min) x3

results in more gradual LA washout

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

indications for peripheral nerve blocks?

A

surgical anesthesia
post-op pain control
vascular dilation
chronic pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

contraindications to RA?

A

contralateral paralyzed diaphragm
severe aortic stenosis
preexisting peripheral neuropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

4 blocks we should all know?

A

interscalene
axillary
femoral
popliteal

these will cover 90% of cases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Example of when SAB can be sole anesthetic?

A

C- section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Example of when wrist block can be sole anesthetic?

A

carpal tunnel surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Example of when infraclavicular block can be sole anesthetic?

A

AV fistula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Example of when intra-articular block can be sole anesthetic?

A

knee arthroscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Example of when topical lidocaine can be sole anesthetic?

A

cataracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which LAs have fast onset, short duration, and dense block?

A

lidocaine
mepivicaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

LA that has slower onset, long duration, and provides a dense block?

A

bupivicaine
exparel (liposomal bupivicaine) with very long action and ver slow onset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

LA with sloer onset, long duration, but not as profound of a block?

A

Ropivicaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does epi do when added to LAs?

A

work as intravascular marker

decrease uptake > longer DOA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what does phenylephrine do when added to LAs?

A

decrase uptake > longer DOA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what does dexamethasone do when added to LA?

A

prolong duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what does clonidine do when added to LAs?

A

prolong duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what does bicarb do when added to LAs?

A

speed onset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Complications/risks of peripheral nerve blocks?

A

infection (very rare, still keep sterile though)

hematoma

indidental blockade

pneumothorax

nerve injury

intravascular injection

LA toxicity

total spinal anesthesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What to know about infection risk with PNBs?

A

Risk is < 1%

cPNB ^ risk compared to single shot

femoral and axillary sites have ^ risk

localized infection more frequent than full sepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

how to lower risk of infection with PNBs?

A

avoid puncture of infected tissue

ensure goo aseptic technique
skin prep, sterile technique, catheter
dressed well (biopatch etc)

judicous pt selection

reduce trauma with block placement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What about PNBs in pt that are already septic or infected?

A

no clear data

some say no ^ risk for SS

Eddie would not place continuous catheter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what factors increase risk of infection with PNB?

A

recent trauma
recent ICU admission
compromised immunity (including DM)
catheter in place for > 48hrs
absence of ABX use

45
Q

What increase risk of hematoma with PNBs?

A

prolonged needling
larger size needle
trans-arterial technique
pt with coagulopathy

46
Q

what are the coagulopathy guidelines for PNBs?

A

same as neuraxial

Caveat - common and well accepted to judiciously practice outside of these guidelines

different blocks have different risks

47
Q

how to decrease risk of hematoma with PNBs?

A

consciously avoid vascular structures (both deep and superficial, veins collapse easily with minimal pressure from needle or US, so you may pierce vein and not see it, or get bloody aspiration)

hold pressure after inadvertent vascular puncture (5min for arterial)

48
Q

what is the risk of hematoma from PNB?

A

can put pressure on the nerve > nerve injury

49
Q

risk of incidental blockade of what nerve with ISB/supraclavicular/superficial cervical blocks?

A

phrenic nerve

recurrent laryngeal nerve

sympathetic cervical ganglion

50
Q

what happens with incidental blockade of phrenic nerve?

A

diaphragm paralysis > decreased ventilation

this is VERY common, approaching 100%

usually not clinically significant in healthy patients.

51
Q

what happens with incidental blockade of recurrent laryngeal nerve?

A

Ipsilatetal vocal cord paralysis > hoarseness

52
Q

what happens with incidental blockade of sympathetic cervical ganglion?

A

horner’s syndrome

53
Q

what incidental blockade can occur with a paravertebral block?

A

costal or epidural spread

54
Q

why could intrarterial injection of LA be less dangerous than venous?

A

because most flow to periphery and allow time for LA to be absorbed by other tissues.

most veins flow directly to the heart

55
Q

which arteries flow directly to the brain?

A

vertebral and carotid

56
Q

What LA volume can cause almost immediate seizure and neurological LA toxicity?

A

even 1-3ml

57
Q

What is LAST?

A

local anesthetic systemic toxicity

58
Q

are neurological s/s always visible in LAST?

A

no, maybe be delayed or absent

59
Q

what might be the first sign of LAST?

A

CV instability

60
Q

why is it easy to not notice intravenous injection?

A

compression of vessels during US/needling can hide it with no aspiration of blood.

61
Q

Methods to prevent LAST?

A

monitors: ECG, BP, Sat
communication with pt
frequent gentle aspiration every 3-5 ml
slow injection of LA
avoid traumatic needling
judicious dosing of LA
epi marker in blocks with ^ volume
be prepared to treat

62
Q

how long is continuous monitoring required after high dose blocks?

A

30min of ECG, BP, and Sat

63
Q

what symptoms of LAST should pt be aware of and be told to communicate

A

metallic taste, ears ringing, circumoral numbness, anxiety, double vision, dizziness, etc.

64
Q

when to decrease LA dose in PNBs?

A

advanced age
poor cardiac function
preexisting conduction abnormalities
decreased plasma proteins

65
Q

How should you be prepared to treat LAST?

A

have 20% lipid emulsion in area where blocks are performed

have a plan: ASRA/NYSORA checklists

66
Q

What epi dose is used in PNBs?

A

1:200,000

67
Q

when do you not add epi to blocks?

A

fingers, nose, PP, and toes. (also ears)

68
Q

Epi ammount in normal (emergency) epi syringe?

A

1mg/10ml or 100mcg/ml or 1:10,000

69
Q

CNS symptoms of LAST?

A

first: excitation: agitation, confusion, twitching, seizure

later: depression: drowsy, obtunded, coma, apnea

neuro symptoms may be subtle/absent

also, benzos can hide the seizures

70
Q

CV signs of LAST

A

excitation followed by depression

^BP ^HR, ventricular ectopy, multiform VT, VF > decrease in BP, bradycardia > asystole

71
Q

hallmark sign of cardiac toxicity of LA?

A

Ventricular ectopy, multiform VT, VF

72
Q

hallmark of severe LA toxicity?

A

progressive decrease in BP, bradycardia>asystole

73
Q

how does LAST progress?

A

maybe slow or fast, and some S/S may be subtle or absent

74
Q

when should you be vigilant in monitoring RA?

A

always during and after RA!!!

75
Q

LAST treatment

A
  1. call for help/lipid emulsion therapy
  2. ASRA/NYSORA checklists
  3. alert cardiopulmonary bypass team/nearest facility that has it
  4. Airway mgmt (100% FIO2 mask or vent)
  5. abolish seizure, versed or propofol but avoid propofol if CV is unstable
  6. manage cardiac arrhythmias ACLS
76
Q

what meds to avoid during LAST?

A

Ca++ chanel blockers
beta blockers
lidocaine
phenytoin
vasopressin (contraversial)

77
Q

Lipid emulsion dosing for LAST?

A

Bolus 1.5ml/kg about 100ml (based on lean body weight)

infusion of 0.25ml/kg about 18ml

repeat bolus Q 5 min if persistent CV collapse

infusion doubled to 0.5ml/kg if hypotension continues

continue infusion for at least 10min after CV is stable

this is with all other ACLS meds as well

78
Q

what is upper limit for lipid emulsion therapy?

A

10ml/kg over first 30min.

79
Q

what is a rare but profound complication of PNB?

A

pneumothorax

80
Q

which PNBs have the higest risk of pneumothorax?

A

Brachial plexus blocks
supraclavicular highest
ISB, ICB, and suprascapular lower

Thoracic blocks
paravertebral
PEC blocks
intercostal blocks

81
Q

Do you get JVD with pneumothorax?

A

yes

82
Q

late sign of pneumothorax?

A

tracheal shift away from pneumothorax

83
Q

gold standard for diagnosing a pnemothorax?

A

CT scan

84
Q

are chest X-rays sensitive to finding pneumos?

A

no

85
Q

What is likely best way to diagnose pneumo and also has 100% negative predictive value?

A

ultra sound

86
Q

what kind of probe should you use for lung ultrasound?

A

linear trasnducer - best image
phased array - gets deeper for obese pts or large breasts, but image quality goes down

87
Q

where to start with probe during lung ultrasound?

A

midclavicular line and 2nd-4th interspace,

probe oriented parasagittally

move from midclavicular line to ant axillary line

88
Q

what are you looking for with lung ultrasound?

A

pleural sliding during respiration

acoustic artifacts seen with pleural layers are touching

lung edge - where lung stops touching chest wall d/t air pocket

89
Q

What does it mean if you don’t see pleural sliding?

A

air is present = pneumothorax

sliding looks like shimmering line

90
Q

in what mode do you see pleural sliding?

A

2D

91
Q

what is M-mode?

A

shows motion over time

92
Q

what does normal lung look like in m-mode?

A

sea shore pattern

93
Q

what does pneumothorax look like in M bode?

A

bar code pattern

no motion seen, so same appearance above/below pleural line

94
Q

When are B-lines and comet tails present?

A

normal lung tissue

95
Q

What are B-lines?

A

acoustic differences of air/water in lung tissue

96
Q

what are comet tails?

A

US waves bouncing off interface of the pleural layers. they move synchronously with respiration

97
Q

What does it mean if B-lines and comet tails are not present?

A

pneumothorax

98
Q

regarding B-lines and comet tails, even if you only have 1 what does that mean?

A

no pneumo

99
Q

what are A lines?

A

horizontal lines equally spaced emanating from the pleural lines. Just an echo of the sound waves back to prove because there is nothing for them to bounce off of.

a lines equal pneumothorax

100
Q

what is the most specific sign for a pneumothorax?

A

lung point assessment. it is also the most difficult to find, even for experienced operators.

101
Q

what is lung point assessment?

A

shows location on chest where lung stops touching the chest wall.

by finding edges of air pockets allows for calculation to estimate size of the pnemo

102
Q

can pneumos resolve spontaneously over time?

A

yes, sometimes

103
Q

how often do transient nerve injuries occur with PNBs?

A

Up to 10%

usually resolve in days to weeks, rarely weeks to months for resolution

104
Q

are nerve injuries from PNB common?

A

no, they are an infrequent complication

105
Q

how often to permanent nerve injuries occur from PNB?

A

1.5/10,000

106
Q

what are the effects of a permanent nerve injury from PNB?

A

range from localized numbness to paralysis

107
Q

how does risk of nerve injury varry throughout the body?

A

risk decreases distally

108
Q

pre-existing diseases the increase risk of nerve injury?

A

DM, PVD, atherosclerosis

Anesthesia Principles II (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions