RE1: Chapter 23: Airway Management II Flashcards
(85 cards)
0
Q
Upper airway consists of
A
nose, mouth, pharynx, hypopharynx and larynx
1
Q
Difficult ventilation is the inability of a trained anesthetist to maintain the O2 sat > _______% using a facemask for ventilation and ________FiO2 provided pre-op sats was w/in normal range.
A
92%
100%FiO2
2
Q
The nose provides almost ______ of the resistance to breathing?
A
2/3
3
Q
What 3 arteries supply blood to the nasal mucosa?
A
Maxillary (sphenopalatine),
Ophthalmic, &
Facial
4
Q
Parasympathetic innervation to the nose arises from _______________ & _______________.
A
7th CN (Facial) and pterygopalatine ganglion
5
Q
Sympathetic innervation to the nose is derived from ____________
A
superior cervical ganglion
6
Q
At day _____, is the development of the pharyngeal arches.
A
22
6 arches develop from 5 structures (1-4 & 6 develop airway structures and 5 dissapears)
7
Q
What separates the mouth from the nasal passages?
A
Hard and soft palate
8
Q
The soft palate covers the posterior ____ to ____ of the oral cavity
A
1/3 to 2/3
9
Q
The pharynx is divided into what 3 compartments?
A
Nasopharynx, oropharynx and hypopharynx
10
Q
The nasopharynx lies anterior to ____
A
C1
11
Q
The oropharynx lies anterior to ______. It is bounded superiorly by the ________ and inferiorly by the _______.
A
C2-C3
Soft palate
Epiglottis
12
Q
The hypopharynx lies posterior to the larynx at ______ level. It is bounded superiorly by the _______ and inferiorly by the __________.
A
C5-C6
Epiglottis
Cricoid cartilage
13
Q
What separates the upper and lower airway?
A
Cricoid cartilage
14
Q
The larynx lies anterior to _______. It begins with the ______ and extends to the _______.
A
C3-C6 (Begins at C3-C4 & ends at the cricothyroid muscle at C6 in adults)
Epiglottis
Cricoid cartilage
15
Q
The larynx is composed of three single cartilages and three paired cartilages. What are they?
A
Single
- Epiglottis
- Thyroid
- Cricoid
Paired
- Arytenoids
- Corniculates
- Cuniforms
16
Q
What acts as a barrier to regurgitation in the conscious pt?
A
Cricopharyngeus muscle
17
Q
What arises from the cricopharyngeus muscle?
A
Upper esophageal spincter
18
Q
What is the role of the intrinsic muscles in the larynx?
A
Control tension of vocal cords and the opening and closing of the glottis
19
Q
What does the posterior cricoarytenoid do?
A
Separates the vocal cords and opens the glottis (abducts)
20
Q
What does the lateral cricoarytenoid muscles do?
A
Closes the cords (adducts)
“Lets Close Airway”
21
Q
What does the cricothroid muscles do?
A
Tenses the vocal cords
22
Q
What does the thyroarythenoid muscles do?
A
Relaxes the vocal cords
23
Q
What nerves innervates all the muscles of the pharynx, larynx and soft palate?
A
Glossopharyngeal (afferent stimuli)
Vagus (efferent response - gag reflex)
Spinal accessory nerve
24
What two branches of the vagus nerve innervate the hypopharynx?
SLN and RLN
25
What does the SLN divide into?
Internal and external branches
26
What does the internal branch of the SLN provide?
Sensory innervation ABOVE the vocal cords
27
What does the external branch of the SLN provide?
Motor fnx to the CRICOTHYROID MUSCLE of the larynx
28
What does the RLN provide?
Sensory intervention BELOW the vocal cords
| Motor intervention to all muscles of the larynx EXCEPT the cricothyroid muscle
29
Where does the right RLN travel?
Right RLN loops around the innominate artery
30
Where does the left RLN travel?
Left RLN loops around the aorta
31
What does unilateral injury to the RLN do? Bilateral injury?
Unilateral - hoarseness
Bilateral - Acute: respiratory distress or death
Chronic: develops comp. mechanisms, gruff/husky speech
32
What consists of the lower airway?
trachea, bronchi, bronchioles, terminal bronchioles, & resp bronchioles
33
What develops from the foregut and becomes the primitive lung bud?
Laryngotracheal groove
34
What day doe the lung bud divide into R and L bronchial buds?
28
35
What day does the bronchopulm. segments appear?
42
36
During _____ weeks, cuboidal cells of the terminal sacs differentiates into __________ and secretion of _________ begins.
16-26th weeks
Alveolar type II cells
Surfactant
37
During _______ weeks, alveoli develops and capillaries proliferate.
24-36th
38
By _____ week, a blood-gas barrier is developed.
26th
39
By _____ week, there are mature alveoli.
36th
40
The trachea originates at the _______ and extends to the _______.
What is the approx length?
How many C-shaped rings are there?
Cricoid cartilage and extends to the carina
10-20cm
16-20 C-shaped rings
41
The cartilaginous rings continue until bronchi reach _____ mm in size.
0.6-0.8mm
42
What is the R mainstem bronchus angle and distance from the carina?
25-30 degrees
2.5cm
43
What is the L mainstem bronchus angle and distance from the carina?
45 degrees
5cm
44
What is the sympathetic and parasympathetic innervation of the tracheobronchial tree?
Sympathetic: 1-5th thoracic ganglia
Parasympathetic: vagus
45
What are the most prominent physical factors associated with a difficult intubation?
Obesity, decreased head and neck movement, decreased jaw movement, receding mandible and buck teeth
46
What three axis are you aligning in the sniffing position?
oral, pharyngeal, and tracheal axis
47
Incisor distance should be at least?
Thyromental distance should be at least?
4cm
less than 6cm or 3 fingerbreaths
48
What joint is capable of extending the head/neck up to 35degrees?
Atlantooccipital joint - provides the highest degree of mobility in the neck (should be able to touch tip of chin to the chest)
49
What is considered full range of motion?
How much does it decrease between ages 16 - 75 years?
90-165 degrees
20%
50
Mallampati classification is an indirect method of relating _____ to _____.
tongue to the oral cavity
Class 1: soft palate, fauces, uvula, tonsillar pillars
Class 2: same as 1 except tonsillary pillars
Class 3: only base of uvula seen
Class 4: even the uvula is not visulalized
51
What are the components of the Lemon Law?
- Look externally
- Evaluate 3-3-2 (3FB b/t incisors,3FB b/t chin & hyoid bone & 2FB b/t thyroid notch
- Mallampati
- Obstruction
- Neck Mobility
52
What are the 4 endpoints of the difficult airway algorithm?
Intubation awake or asleep
Intubation emergent or nonemergent
Approach supraglottic or subglottic
Airway access surgical or nonsurgical
53
Difficult airway is defined as any intubation that takes a skilled anesthetist more than ______ attempts or greater than _____ minutes.
3 attempts
10 minutes
54
What is the purpose of pre-oxygenating the patient?
Increase O2 content and eliminate nitrogen (79% of room air) from the FRC
55
With adequate pre-O2, the FRC has enough O2 to last almost ____ minutes.
12 minutes
Without pre-O2, the O2 reserve in the FRC will last approx 2-5minutes in a difficult airway situation.
56
With adequate pre-O2, the patient should breath normal VT for ____ minutes with FGF no less than ____L and have a tight mask fit.
With a fast-track patient, pre-O2 where the patient take _______ breaths in _______ seconds.
3-5 minutes & 5L
4 VC breaths over 30 seconds
57
What situations should awake FO intubation be used?
Unstable neck fx
Halo device
Small or limited oral openings
Intubation of awake pts in the ICU
58
What is most commonly used to anesthetize the airway for FO awake intubations?
When is the peak serum levels?
2% Lidocaine in a nebulizer
30 minutes
59
Describe a superior laryngeal nerve block.
-Provides a dense block of the supraglottic region
-Locate hyoid bone and displace it towards side bring injected
-Palpate inferior border of cornu, insert needle perpendicular to skin
(site where SLN pierces the thyrohyoid membrane)
-Deposit 1-2mL of LA ABOVE membrane and 2mL of LA BELOW membrane
-Repeat on opposite site
60
Describe a transtracheal block.
- Inject LA through the cricothyroid membrane
- Attach a 23G needle w/5mL of 2% lidocaine
- With CONSTANT aspiration, advance needle in a CAUDAD direction
- When air bubbles are visualized, tip of needle is in tracheal lumen
- Inject LA into lumen on INSPIRATION (pt will cough spraying LA onto vocal cords)
61
Describe a glossopharyneal block.
- To block the lingual branch of this nerve, have pt open mouth and displace tongue to opposite side to create a gutter.
- Where the gutter meets base of the palatoglossal arch, insert 26G needle 1/4 inch deep.
- If air is obtained, needle is too deep
- If blood is obtained, withdraw needle and reposition
- Inject 1-2ml of 2% lidocaine and repeat on opposite side
62
What is BURP?
Backward, Upward, Rightward & Pressure
63
To prevent aspiration, cricoid pressure must be applied before or after loss of consciousness.
BEFORE
64
What is the recommended force of cricoid pressure needed prior to loss of consciousness and on loss of consciousness?
Prior to loss of consciousness: 20N or 2kg of pressure
| On loss of consciousness: 44N or 4kg of pressure
65
When should cricoid pressure by released?
AFTER placement of ETT is verified
66
Where is an LMA positioned in the airway?
Positioned in the hypopharynx below the base of the tongue and above the epiglottis
67
What should you keep the positive pressure below with an LMA to avoid inflating the stomach?
20 cmH20
68
How does a pro-seal LMA differ from a traditional LMA?
1. Pro-seal LMA has a second tube to pass a OG with passing through the hypopharynx
2. Pro-seal LMA provides a seal against the posterior wall of the pharynx allowing positive inspiratory pressures of up to 30 cmH2O
69
What is the confirmation of placing in bougie blindly?
Confirmation of proper placement is made by feeling the stylet bounce along the tracheal rings as it is advanced.
70
What are the limitations of a FO laryngoscope?
1. Can become fogged
2. Broken/damaged FO strands
3. Vision can be obstructed by secretions or blood
71
Instillation of ____L flow provides the pt with up to ____% O2 and keeps debris from collecting on the port or lens of the FO laryngoscope.
2-4L
26%
72
What scopes do NOT require the sniffing position?
1. Airtraq Optical laryngoscope
| 2. Bullard scope
73
With transtracheal jet ventilation, the delivery pressure of 50psi, a 20G catheter delivers approx ____mL of O2 per second.
16G delivers approx ____mL of O2 per second
14G delivers approx ____mL of O2 per second
20G - 400mL
16G - 500mL
14G- 1600mL
74
What is a sufficient inspiratory pressure with jet ventilation?
25psi
75
What gauge IV catheter or Cook needle is needed for a retrograde intubation?
Is this an emergent process?
14 to 18G catheter or Cook needle
NOT an emergent process and can be completed in 5-7 min
(An EMERGENT method of ventilation is percutaneous dilated cricothyrotomy)
76
Where is a tracheotomy placed?
Performed at the level of 4th-5th tracheal rings BELOW the isthmus of the thyroid gland.
NOT PERFORMED BY A CRNA
77
What are the signs of a esophageal intubation?
1. Absence of BS over lung fields
2. Gurgling over epigastrium w/progressive distention of abd
3. Lack of sustained ETCO2
78
What are signs of endobronchial intubation?
1. Increased PIPs
2. Uneven chest rise
3. Decreased BS on the unventilated side
4. Drop in ETCO2 conc.
5. Tachycardia
6. Hypoxemia
79
What are most susceptible to injury during a ETT placement?
Arytenoids, posterior half of vocal cords and posterior tracheal wall
80
What can an obstruction of an ETT lead to?
Negative pressure pulmonary edema (NPPE)
Caused by movement of fluid from interstitial space of lung into the plural cavity
Treatment: diuretics and positive pressure ventilation
81
What is the most common post-op complaint following intubation?
What are the risk factors?
Sore throat
Risk Factors:
1. ETT size
2. Difficulty with intubation
3. Use of NG/OG tube
4. Female gender
5. History of smoking
82
What is a laryngospasm and what is the sensory stimulation?
Forceful, involuntary spasm of the laryngeal muscles
Occurs through sensory stimulation of the SLN and afferent response from the RLN
83
What are the 2 phase mechanisms with laryngeal spasms?
Shutter mechanism - results in PARTIAL airway obstruction
Treatment: positive pressure ventilation with 100% FiO2 (10-20cm H2O). If condition persists, give partial dose of succ 0.1mg/kg IV
Ball-valve mechanism - COMPLETE airway obstruction
Treatment: intubating dose of succ 1-2mg/kg IV or 4mg/kg IM
84
What is the treatment for croup?
Aim is reducing the swelling of the glottis / subglottic region
1. Inhalation of cool, moist O2
2. Inhalation of racemic epi
3. Dexamthasone (0.1-0.5mg/kg)
