Airway Anatomy Flashcards
1
Q
Upper Airway
A
- Nasal Passages
- Oral Cavity
- Pharynx
- Larynx
2
Q
Nasal Passage Components
A
- septum
- turbinates
- adenoids
3
Q
Nasal Passage function
A
- 1/2 upper airway resistance
- humidify/filters air
4
Q
Nasal Passage Innervation:
A
-Trigeminal Nerve (CN V)
5
Q
Oral Cavity Components:
A
- teeth
- tongue
- soft palate
- hard palate
6
Q
Oral Cavity Innervation:
A
1) Trigeminal (CN V): hard and soft palate, 2/3 anterior tongue
2) Glossopharyngeal (CN IX): posterior 1/3 tongue, soft palate, oropharynx
7
Q
Pharynx
A
- muscular tube
- connects base of skull to cricoid cartilage
8
Q
Pharynx components:
A
- nasopharynx (soft palate to uvula)
- oropharynx (tonsilis/uvula to epiglottis)
- laryngopharynx (epiglottis to cricoid cartilage)
9
Q
Larynx
A
cartilage, muscle, and ligaments from C4-C6; epiglottis to trachea
10
Q
Larynx functions:
A
- airway protection
- respiration
- phonation
11
Q
How many cartilages in Larynx?
A
9
12
Q
How many paired/unpaired cartilages?
A
3 paired
3 unpaired
13
Q
Paired Cartilages
A
- Arytenoid
- Corniculate
- Cuneform
14
Q
Unpaired Cartilages
A
- Thyroid
- Cricoid
- Epiglottis
15
Q
Cricoid
A
- connected by CTM
- only complete cartilagenous ring
- pushing on it can occlude esophagus
- signet-shaped
- narrowest portion of the pediatric airway
16
Q
Epiglottis
A
covers opening to the larynx
17
Q
Thyroid Cartilage
A
-anterior attachment for vocal cords
18
Q
Arytenoid
A
-posterior attachment for vocal cords
19
Q
Corniculate
A
posterior portion of hte aryepiglottic fold
20
Q
cuneiform
A
- in the aryepiglottic fold
- lateral to corniculates
21
Q
vocal cords
A
-appear pearly white
22
Q
glottic opening
A
- triangular fissure
- narrowest portion of the adult airway
23
Q
Intrinsic Laryngeal Muscles: Glottic Opening
A
- Lateral Cricoarytenoid
- Arytenoid Muscles
- Posterior Cricoarytenoid
24
Q
Lateral Cricoarytenoid
A
-adducts the vocal cords
25
Arytenoid Muscles
- oblique arytenoids
- transverse arytenoids
- adduct the vocal cords
26
Posterior Cricoarytenoid
-the only vocal cord abductors
27
Intrinsic Laryngeal Muscles: Vocal Cord Length
- Cricothyroid
- Thyroarytenoid
- Vocalis
28
Cricothyroid
-tenses, elongates vocal cords
29
Thyroarytenoid
-relaxes/shortens vocal cords
30
Vocalis
relaxes/shortens vocal cords
31
cricothyroid muscle innervated by:
external branch of the superior laryngeal nerve (branch of the vagus)
32
all other laryngeal muscles innvervated by :
recurrent laryngeal nerve (branch of vagus)
33
Vagus Nerve
superior laryngeal nerve
internal laryngeal nerve
external laryngeal nerve
recurrent laryngeal nerve
34
Extrinsic Laryngeal Muscles
- move larynx as a whole
- suprahyoid group
- infrahyoid group
35
Suprahyoid group
moves larynx cephalad
36
Infrahyoid group
move larynx caudad
37
Lower airway
- trachea
- carina
- bronchi
- terminal bronchioles
- respiratory bronchioles
- alveoli
38
Trachea
-fibromuscular tube
-10-20cm length; 22mm diameter
16-20 U-shaped cartilages
posterior lacks cartilage
39
Carina
bifurcates trachea between T-4
40
R mainstem bronchi
2.5cm at 25 degrees
41
L mainstem bronchi
5cm at 45 degrees
42
Airway Assessment Components:
- general appearance (head/neck size)
- range of motion neck/jaw (Thyromental Distance, Mandibular Protusion)
- dentition
- mouth (Mallampati, Cormack, Lehane)
- mouth opening
- voice
- body habitus (pregnant, fat)
43
PMH that would concern you regarding airway placment
```
Diabetes
Rheumatoid Arthiris
OSA
history of difficult airway
asthma
```
44
Mallampati Classification
- correlates the oropharyngeal space with the ease of DL and tracheal intubation
- hypothesis: when the base of the tongue is disproportionally large is overshadows the larynx, making it difficult to expose the vocal cords
45
How to test of Mallampati
- patient upright
- mouth wide open
- NO AHHH
46
Mallampati Class I
I: faucial Pillars, entire uvula, soft/hard palates
47
Mallampati Class II
II: Uvula tip masked by tongue and soft and hard palates
48
Mallampati Class III
III: Soft and hard palates uvula base only
49
Mallampati Class IV
IV: Hard Palate only
50
Cormack and Lehane Score
the laryngoscopic view of the glottis
51
Cormack and Lehane Score Grade I
most of glottis visible
52
Cormack and Lehane Score Grade II
only posterior portion of the glottis visible
53
Cormack and Lehane Score Grade III
only epiglottis visible
54
Cormack and Lehane Score Grade IV
no airway structures visible
55
Thyromental Distance
- distance from lower border of mandible to thyroid notch with neck fully extended
- normal = 6-6.5cm
- difficult intubation = <3 fingers/ receding mandible
56
Mandibular Protrusion Test looks at what?
good jaw thrust
57
Mandibular Protrusion Test Class A
lower incisors can be protruded anterior to upper incisors
58
Mandibular Protrusion Test Class B
The lower incisors can be brought to edge to edge with upper incisors
59
Mandibular Protrusion Test Class C
The lower incisors cannot be brought edge to edge with upper incisors
60
Preparation for Induction
| MsMAIDS
```
Monitors
Suction
Machine checked
Airway
IV
Drugs
Special Equipment
```
61
Preoxygenation
- washes out Nitrogen
| - proper preoxygenation gives you safe apnea time
62
3-5 minutes of "tight" mask fit during normal tidal breathing with 100% FiO2 at >6L/min
gives 10 minutes of safe apnea time
63
4 vital capacity breaths within 30 seconds with 100% FiO2 at >6L/min
gives 5 minutes safe apnea time
64
High Risk for Aspiration
- loss of AW reflexes
- full stomach
- GERD
- hiatal hernia
- NGT presence
- morbid obesity
- diabetic gastroparesis
- pregnancy
65
Goals of aspiration prophylaxis
- decrease gastric volume
- increase gastric pH
- antacids, promotility drugs, H-2 receptor antagonists
66
NPO orders
clears up to 2H prior
| solids up to 6H prior
67
Airway Setup
- face mask
- PPV source
- suction
- tongue depressor
- OPA
- NT
- laryngoscope handle
- 2 blades
- ETT (2 sizes)
- stylet
- syringe 10cc
- LMA
- tape
68
Anesthesia Face Masks
- hyperoxygenate and induct
| - hold with C-E technique
69
Predictors of difficult mask ventilation
-OSA
-older than 55
-male
-BMI >30
Mallampati III or IV
beard
edentulousness (no teeth)
70
Airway Obstruction signs
- no Vt
- capnography <20/no waveforms
- resistance to bagging
- poor O2 sat
- no condensation on tube
71
Possible causes of obstruction
1) tongue
2) laryngospasm
3) bronchospasm
72
Tongue obstruction etiology
relaxation of the genioglossus muscle; snoring JAW TRUST, OPA
73
laryngospasm
- exaggerated glottic closure
| - innervated via glossopharngeal or vagal stimulation
74
treatment of laryngospasm
- remove irritants
- remove blade
- sedate/paralyze
75
bronchospasm
- spasm of the bronchus
- sedate
- anticholinergic
76
OPA
- patient must be deeply seated
| - measured from corner of mouth to angle of jaw or earlobe
77
complications of OPA
- laryngospasm
- bleeding
- soft tissue damge
- lingual nerve palsy
- damage to teeth
78
Nasal Trumpet
- patients can be more awake
- measured nares to meatus of ear
- lubricate
79
complications of nasal trumpet
- epistaxis
- basal skull fracture
- adenoid hypertrophy
80
Risk of Difficult Intubation
-long incisors
-overbite
-small mouth
-Mallampati III or IV
high arched palate
-short thyromental distance
-short thick neck
-limited cervical mobility
81
Laryngoscope Blades
Mac (1-4) vs Miller (0-4)
82
Mac insertion
- insert R side mouth
| - position in the veleculum
83
Miller insertion
-position posterior to epiglottis
84
Indications for ETT
- difficult airway (failed SGA)
- NMBA
- type of surgery (positioning or area being operated on)
- full stomach/high risk aspiration
- critically ill/post-op vent need
- lung abnormalities
85
ETT components
- 15mm connector
- pilot balloon
- high volume, low pressure cuff
- bevel
- Murphy eye
86
Murphy Eye
-distal opening in the side wall for ventilation should the distal end become obstructed
87
high volume, low pressure cuff vs low volume high pressure cuff
Low P/High V =
High P/ Low V =
88
ETT sizes
- based on internal diameter
- adult: 6.5mm-8mm
- 4cm above carina
- 2cm below vocal cords
- 3xID = depth
89
stylet
- shapes ETT; malleable
| - shape into hockey puck about 60 degrees
90
What is the optimal intubating position?
-sniffing position
91
Sniffing Position
- aligns oral axis, pharyngeal axis, laryngeal axis
- 35 degree cervical flexion; 7-9cm head elevation
- achieved with pillow and neck extended
- obese patients = ramps; tragus aligned with sternum
92
LMA
- supraglottic airway device
- rescue airway
- conduit for ETT intubation
93
LMA size
3-6
| use largest size possible for tightest seal
94
LMA components
- airway tube
- drain tube
- fixation tab
- bite block
- modified cuff (allows up to 30cm H2O)
95
LMA insertion equipment needed
- 20-50cc syringe
- lubricant
- stethoscope
- tape
- soft bite block
96
LMA insertion
- adequate anesthesia
- lubricate posterior of cuff
- inflate to 40-60cm H20
- measure cuff pressure periodically if N2O is administered
97
Advantages of LMA
- improved HD stability
- lower frequency of coughing
- lower incidence sore throat
98
Disadvantages of LMA
- inability to use PPV at higher peak pressures
- higher frequency gastric insufflation
- no protection against laryngoscopy
99
Confirmation of correct airway placement
- chest rise
- lung sounds
- capnography
- condensation in tube
- waveform on vent
