Week 1a Anesthetic Considerations of the Difficult Airway Flashcards
1
Q
What is the most common cause of adverse respiratory events for patients undergoing anesthesia?
A
difficult tracheal intubation
2
Q
LEMONS
A
Look externally Evaluate the mandibular space mallampati classification obstructions neck mobility
3
Q
BONES
A
beard obesity no teeth elderly (>55yrs) snores
4
Q
MOANS
A
Mask seal obesity Age >55 no teeth stiff lungs
5
Q
What has decreased instances of difficult airways?
A
Video laryngoscopes
6
Q
What is the most severe difficult airway emergency?
A
can’t intubate can’t ventilate
7
Q
Failed intubation and failed ventilation accounts for what percentage of all anesthesia related deaths?
A
25%
8
Q
Using the ASA Difficult airway algorithm, how do you arrive at the Emergency Pathway?
A
The emergency pathway occur when you can’t mask ventilate and the supraglottic airway is not adequate (LMA)
OR fail or deteriorating ventilation
9
Q
Using the ASA Difficult airway algorithm, describe the emergency pathway?
A
limit attempts and be aware of the passage of time
call for help/ invasive access
Attempt to intubate approaches as you prepare for emergency invasive airway
10
Q
Describe Cormack-Lehane Grade 1 View
A
most or full view of the glottic opening
11
Q
Describe Cormack-Lehane Grade 2a View
A
only the posterior portion of the glottic opening can be visualized anterior commissure not seen; partial view of the glottis
12
Q
Describe Cormack-Lehane Grade 2b View
A
arytenoids or posterior part of the vocal cords only just visible
13
Q
Describe Cormack-Lehane Grade 3 View
A
only the epiglottis can be visualized; no portion of the glottic opening can be seen
14
Q
Describe Cormack-Lehane Grade 4 View
A
epiglottis cannot be seen only view of soft palate
15
Q
What are distinguishing features of a bougie?
A
long 60cm
coude tip (35-40 degree bend)
malleable, yet firm
NO LUMEN FOR INSUFFLATION
16
Q
Can you ventilate with a bougie?
A
NO
17
Q
The Bougie
A
portex venn introducer
cheap reliable and familiar tool many anesthesia providers utilize
18
Q
Indications for a Bougie
A
unable to pass ETT grade 3 or 4 view ETT exchange digital intubation adjunct to invasive techniques
19
Q
Describe how to use a bougie
A
obtain the best possible view hold bougie like a pencil with Coude tip anterior advance and "hook" under epiglottis anticipate "clicking" DO NOT remove laryngoscope Slide ETT over bougie
20
Q
Pearls of the Bougie
A
LEAVE the laryngoscope IN PLACE during procedure
Rotate ETT 90 degrees counter clockwise
use flexible- tip tube
capnography
21
Q
Tip to utilizing a Standard Tube with a Bougie
A
pull the tube back 2 cm then rotate counter clockwise and re-inserted to advance
22
Q
Complications of Bougie Placement
A
failed intubation
perforation
vocal cord trauma
23
Q
When are airway exchange catheters commonly used?
A
when a secure airway should be changed or temporarily removed, but laryngoscopy is likely difficult
24
Q
Common Features of an airway exchanger include:
A
distance markings
central lumen and/or side ports
adapter for TTJV or 15mm connection
25
In relation to a Bougie, Airway exchanger catheters are
longer, less flexible and have a hollow lumen
26
Pediatric size of a Cook Catheter
8Fr, 45cm >3.0 ID ETT
27
Adult sizing of a Cook Catheter
11,14,19 Fr 83cm >4.0, 5.0, 7.0 ID ETT
| blunt tip, semi-rigid
28
Describe Cook Airway Exchange Catheter
radiopaque
distal and side ports
rapi-fit adapter: Luer Lock 15mm
Distance markers
29
Standard Adult Sizing of an Sheridan Exchange Catheter
Standard
81mm
6-10 ETT
30
Extended Adult Sizing of an Sheridan Exchange Catheter
for DLT exchange
100 mm
35-41 Fr DLT
31
Other Airway Exchange Catheters include:
Frova Intubation Introducer
Endotracheal tube Introducer
Parker Flex-It Directional Stylet
32
Frova Intubation Introducer
similar to bougie, but with a hollow lumen that allows for O2 delivery
Pediatric version is available
33
Endotracheal tube Introducer
similar to a bougie, but 10 cm longer and stiffer
34
Parker Flex-It Directional Stylet
allows provider to elevate tip of ETT from proximal end
35
Pearls of Airway Exchange Catheters
```
HIGH risk procedure
Have a Plan A, B and C
two providers minimum
review to all previous airway and intubation notes/history
perform a direct laryngoscopy first
```
36
Lighted Stylets
use the principle of transillumination of soft tissues of the anterior neck to guide the tip of the ETT into the trachea
37
Indications for a lighted Stylet
routine intubation (studies show high success rates and lower airway trauma)
patients with difficult airways
can be used to locate tip of ETT when performing a percutaneous tracheotomy
can be used with laryngoscopy, LMA or Bullard and during retrograde intubation
38
A trachlight tip needs to be bend to form a
field hockey stick
39
What does the field hockey stick formation of a trachlight do?
enhances the movement through the glottic opening
| once the light passes through the glottis the wire stylet is retracted 10cm
40
How do you prep a trachlight?
lubricate wire stylet
lubricate the flexible wand
attach ETT, clamp proximal end to handle
Bend tip 90 degrees like a field hockey stick
41
How do you position a patient for a trachlight?
bed in the low position
head neutral or slightly extended
do not place the patient in the sniffing position
42
Explain the technique of using a trachlight
Device is inserted mid-line and advanced along the sagittal plane
when the illumination of the light is noted below the laryngeal prominence, retract the wire stylet 10cm
advance the wand (without the wire stylet) until glow disappears below the sternal notch (this is about 5cm above the carnia)
unclamp ETT from handle and advance
43
Pearls of a trachlight
full muscle relaxation is recommended
jaw thrust or mandible lift
insert device mid-line
when a faint glow is seen above the larynx, lifting the jaw or tongue will raise the epiglottis and facilitates the wand toward the vocal cords
when the wand enters the glottic opening a well defined light will be observed below the laryngeal prominence
if resistance is met when attempting to advance ETT, rotate it 90 degrees
44
Needle Cricothyromtomy
final option is ASA difficult airway algorithm
provides rapid access to the airway
ability to oxygenated, but CO2 removal ineffective
can be performed either using landmark technique or with ultrasound-guidance
45
Equipment needed for a Needle Cricothyromtomy
14 gauge needle with angiocatheter attached to a syringe partially saline-filled
46
Landmark technique of Needle Cricothyromtomy
provider positioned on the same side as the patient's dominant hand
larynx stabilized with non-dominant hand; thumb and long finger
index finger to identify CTM
needle inserted with dominant hand at a 45 degree angle CAUDALLY
needle aspirated until presence of air noted
47
TACA Technique for Needle Cricothyromtomy
begin at the thyroid notch
slide transducer caudally and identify CTM/ air tissue interface
continue caudal to the hypoechoic cricoid cartilage
slide cephalad to CTM/ air tissue interface and mark CTM
48
Indications for Retrograde intubation
failed intubations
| urgent airway required, but cords cannot be visualized
49
Contraindications to retrograde intubation
unfavorable anatomy
laryngotracheal disease
coagulopathy
infection
50
Preparation for Retrograde Intubation
positioning
skin preparation
anesthesia
entry site
51
What is the ideal patient position for retrograde intubation?
sniffing position with head and neck hyper-extended
52
Awake Retrograde Intubation
if possible the airway should be anesthetized
53
What blocks should be performed for an Awake Retrograde Intubation
trans-laryngeal with superior laryngeal nerve block
trans-laryngeal with topicalization of the pharynx
glossopharyngeal nerve block with nebulized anesthetic
54
Entry Site of Retrograde Intubation
puncture can occur either above or below the circoid cartilage
55
Cricothyroid Membrane vs Cricotracheal ligament for Retrograde Intubation
cricothyroid membrane- less bleeding, greater chance of failed intubation
cricotracheal ligament - higher success rate, lower incidence of vocal cord trauma and greater risk of bleeding
56
Cricothyroid Ligament
attaches from the inferior border or the thyroid cartilage to the upper border of the cricoid cartilage
it measures approximately 1 cm in height and 2cm in width
avascular
57
Guidewire Technique of Retrograde Intubation
Classic Epidural Catheter
J-wire
J-wire/Introducer
58
Guide Wire Technique of Retrograde Intubation
A: needle with catheter is passed through entry site until air is aspirated
B: guidewire is threaded through needle until it passes through the oropharynx or nasopharynx
C: a hemostat clamps the guide-wire at the trachea insertion site
D: endotracheal tube is passed over guide wire until it meets resistance in larynx
59
FOB Technique for Retrograde Intubation
Guide wire passed through trachea in normal fashion
guide wire passed through suction port of FOB allowing for straight path to vocal cords
ETT can be passed over FOB through vocal cords
continuous O2 can be delivered
60
Pull Through Technique for Retrograde Intubation
epidural catheter is passed as previously described
silk suture tied to epidural catheter extending from pharynx
catheter pulled through tracheal incision site with silk suture
catheter removed. ETT tied to cephalad end of suture
hold slight pressure, ETT is passed until it abuts against the cricothyroid membrane
61
Pearls of Retrograde Intubation
CTM associated with less bleeding, lower success rate
| use a smaller ETT (6.5-7mm)
62
Pearls with Silk Pull Through Retrograde Intubation
less railroading, can perform multiple attempts with one puncture, ability to re-intubate postoperatively
63
Pearls with J-Wire Retrograde Intubation
```
less traumatic
easier to retrieve
less prone to kinking
can be used with FOB
takes less time to perform
```
64
Complications of Retrograde Intubation
bleeding
subcutaneous emphysema
nerve injury
broken wire
65
Awake Intubation is
the gold standard for the management of difficult airway
66
Why is Awake intubation the gold standard?
patient spontaneously breathes
airway patency maintained
larynx does not move into anterior position
67
When is awake intubation commonly used?
Cervical spine injury
adequate topicalization to reduce coughing
judicious sedation for self airway protection
68
What sedation is utilized for awake intubation?
precedex because it maintains spontaneous ventilation
69
What is the leading cause of mortality and morbidity ASA closed claims analysis?
Airway management failure
70
When does a difficult airway occur?
routine induction/ intubation sequence
awake intubation with known/ anticipated difficult airway
as part of the ASA difficult airway algorithm
71
What is an endoscope?
an instrument composed of over 10,000 glass fibers that transmits light and allows for visualization of images
72
Three main parts of a flexible endoscope?
handle
insertion tube
flexible tip
73
What are the parts of the FOB handle?
```
power source
suction/valve
working channel
angulation control lever
lens with focus capability
```
74
All lenses of the FOB have
an eyepiece that can be focused
75
How do you orient yourself in the lens of a FOB?
a visible block notch in the eyepiece at the 12oclock position aids in orientation
76
New FOB lens systems may have (3)
video output adapter
video screen
camera
77
What are the four components inside the insertion tube?
light guide bundles
transmit light source
angulation wires
working channel
78
What are light guide bundles?
light is transmitted by one or two non-coherent glass fibers
| high intensity light is focused at the proximal bundles
79
What is a transmit source in the FOB?
continuous glass fibers run the length of the insertion tube, transmitting images
80
What does a black spot represent in a FOB image?
damage to the fibers
81
Purpose of Angulation Wires
move the flexible tip in opposite directions
| two wires course along the sagittal plane of the bronchoscope
82
How long is the working channel?
runs the length of the insertion tube
83
What can the working channel provide?
oxygen
suction
medication portal
specimen collection
84
What is contained in the flexible tip?
charged coupled devices (CCD) chip and second lens that allows viewing of structures
85
What is the field of view for the flexible tip?
approximately 75-120 degrees
86
Has there ever been a documented case of infection or cross contamination by fiberoptic intubation?
no
87
What are the most likely ares for ineffective FOB sterilization?
valves and working channels
88
What are other sources of contamination for a FOB?
```
sentinel patients
contaminated water
inadequate sterilization technique
repeated use of brushes or cleaning fluid
FOBs with design errors or defects
```
89
Care of the Endoscope includes:
universal precautions are mandatory
| disinfection can take up to an hour
90
After using the FOB:
inspect for any damage
dissemble moving parts, pass a cleaning brush through working port
nondisposable parts are placed in an approved cleaning solution
after sterilization time, bronchoscope washed and rinsed with water
working port must be dried with 70% alcohol and compressed air
91
How and what sterilization is required for endoscopes?
ethylene oxide sterilization for 24 hours may be required after use in patients
92
Successful airway anesthesia requires:
```
trigeminal nerve block (nasal intubation)
glossopharyngeal nerve (GPN) block
laryngeal nerve blocks
```
93
Orotracheal airways are innervated by
cranial nerve V (trigeminal)
Cranial nerve IX (glossopharyngeal)
Cranial nerve X (vagus)
94
Trigeminal nerve
provides sensory innervation to the face
95
What are the three divisions of the trigeminal nerve?
opthalamic (v1)
maxillary (v2)
mandibular (v3)
96
Glossopharyngeal Nerve
provides sensory innervation to posterior 1/3 of tongue, oropharynx, vallecula, anterior epiglottis
Afferent limb of the gag reflex
97
internal branch of superior laryngeal nerve
sensory innervation to posterior epiglottis to vocal cord folds
98
external branch of superior laryngeal nerve
motor innervation below the vocal cords
99
Sensory innervation of the recurrent laryngeal nerve
innervates below the vocal folds and trachea
100
Motor innervation of the recurrent laryngeal nerve
all intrinsic laryngeal muscles
101
Recurrent Laryngeal Nerve branches off the vagus
in the thorax
102
Right RLN loops under
the subclavian artery
103
What recurrent Larygneal nerve is susceptile to injury?
left
104
L RLN loops under
the aorta
105
What is included in the FOB cart?
bronchoscopes
ancillary equipment
local anesthetics
emergency airway equipment
106
What is included in the Ancillary Equipment?
```
swivel adapters
endoscopy masks
intubating oral airways
nasopharyngeal airways
endo tracheal tubes
```
107
Advantages to an intubating oral airway
protects the bronchoscope
shields FOB from tongue, tissues
allows for passage of ETT (up to 9.0mm)
108
Nasal Pharyngeal Airways
cut laterally along the length of the airway
| can serve as a conduit for oxygen adminstration
109
Swivel adapter
used mostly for bronchoscopy
| allows for continuous ventilation without an airway leak
110
Flexible Tip ETT vs regular PVC ETTs can get caught on what structure?
arytenoids
111
Awake Fiberoptic Intubation Indications
anticipated difficult mask ventilation and intubation
difficult airway with comorbidites likely to result in poor outcome if intubation is not achieved
failed asleep intubation
small mouth
112
Equipment and monitoring for Awake Fiberoptic Intubation
```
IV access
FOB cart and airway cart (test FOB for light and movement)
oxygen delivery system
two suctions
monitors (SpO2 is mandatory)
medications
```
113
Psychological Preparation for Awake Fiberoptic Intubation
explain and re-assure patient in a professional manner
114
What should you include in patient prep for Awake Fiberoptic Intubation
benefits of FOB
probably amnesia
local airway anesthetic administration
patient assistance during the procedure
115
Pre-medication for Awake Fiberoptic Intubation
antisialagogue 15-20 minutes prior (glycopyrrolate/ atropine)
Sedation
Induction agents
Nasal drops
116
What are the doses for the antisialagogue?
glyco 0.2-0.4mg
| atropine 0.4-0.6mg
117
How can you perform local airway anesthesia for Awake Fiberoptic Intubation?
```
drops
injection
nebulizer
paste
spray as you go
```
118
Complete local airway anesthesia requires
glossopharyngeal block
superior laryngeal block
transtracheal block
nasal (both sides)
119
Glossopharyngeal Block
patient may be required to assist
tongue moved medially
local anesthetic applied on inspiration to the tonsillar pillar
injection of the area with local anesthetic is not recommended
commonly applied with long cotton tipped swabs
120
How to perform a Superior Laryngeal Nerve Block
local the hyoid cornua with non dominant hand brace the contralateral side
advance needle until ipslateral bone is contacted
aspirate then inject
repeat other side
121
How to perform a transtracheal block
straddle the trachea with the non-dominant hand
locate the cricothyroid space, slowly advance the needle while aspirating
stop when air is freely aspirated
instruct patient to take a small breath, then maximum exhalation
122
Awake Fiberoptic Intubation Procedure
position patient
an assistant to help with airway
hold insertion tube so that FOB remains straight
FOB is passed in a down up down motion
123
Explain down up down technique with FOB
down- through oropharynx
up- toward anterior commissure
down through vocal cords
124
preparation for Routine Fiberoptic Intubation
nasal drops
antisialgogue pre-operatively
standard induction
125
Unsuccessful Awake Fiberoptic Intubation
reinstitute face mask ventilation
| giver more anesthetics prior to second attempt
126
Contraindications for FOB
```
lack of skill by anesthesia provider
lack of trained assistant or ready to use equipment
wild, uncooperative patient
near total upper airway obstruction
another technique
```
127
Extubation and the DAW
have a strategy
128
Facts to consider for Extubation and the DAW
awake vs deep
clinical symptoms that will impair ventilation
management of plan if unable to maintain adequate ventilation
short term use of an airway exchanger
129
Follow Up care of the DAW
document presence and nature of difficulty
differentiate between ventilation and intubation
description of managemnet techniques used
provide patient information for future care
