Unit 1 Respiratory Unit 4: Airway Management Flashcards
(159 cards)
1
Q
What are the classes of the Mallampati exam?
A
Class I: (tonsills) Pillars, Uvula, soft palate, hard palate
Class II: Uvula, soft palate, hard palate
Class III: soft palate, hard palate
Class IV: hard palate
2
Q
What does the inter-incisor gap affect? Normal measurements?
A
The ability to align oral, pharyngeal, and laryngeal axes.
2-3 finger breadths or 4 cm
3
Q
What are the 3 borders of the submandibular space?
A
Superior border: mental
Inferior border: hyoid bone
Lateral border: either side of neck
4
Q
What test helps estimate the size of the submandibular space?
A
Thyromental distance
5
Q
What 2 thyromental distance measurements may indicate a more difficult laryngoscopy?
A
Less than 6 cm - 3 fingerbreadths
Greater than 9 cm
6
Q
What test assesses the function of the temporomandibular joint?
A
Mandibular protrusion test (upper lip bite test)
7
Q
What are the classes of the mandibular protrusion test?
A
Class I: can move lower incisors past upper and bite vermilion of lip
Class II: can move lower incisors in line with upper
Class III: cannot move lower incisors past uppers
8
Q
What test assesses the ability to place patient into a sniff position?
A
Atlantic-occipital join mobility
9
Q
What is normal AO flexion and extension?
A
90-165 degrees
10
Q
What is normal AO extension? What degree suggests laryngoscopy will be difficult?
A
35 degrees
<23 degrees
11
Q
What 8 conditions impair AO mobility?
A
DJD Rheumatic arthritis Ankylosing spondylitis Trauma Surgical fixation Klippel-Feil Down syndrome DM (joint glycosylation)
12
Q
What test grading system is used for the view obtained during direct laryngoscopy?
A
Cormack and Lehane score
13
Q
What are the grades of the Cormack and Lehane score?
A
Grade I: complete or nearly complete view of glottic opening
Grade II: posterior region of the glottic opening
Grade III: epiglottis only
Grade IV: soft palate only
14
Q
What is a IIA and IIB score of Cormack and Lehane?
A
IIA: posterior region of the glottic opening
IIB: corniculate cartilages and posterior vocal cords, no part of the opening
15
Q
Risk factors for difficult mask ventilation? Mnemonic
A
“BONES” Beard Obese - BMI > 26 No teeth Elderly - > 55y Snoring
16
Q
What are 10 risk factors for difficult laryngoscopy and endotracheal intubation?
A
Small mouth opening Long incisors Prominent overbite High, arched palate Mallampati class III or IV Retrognathic jaw Inability to subluxation jaw Short, thick neck Short thyromental distance Reduced cervical mobility
17
Q
What are 6 risk factors for placement of a supraglottic airway/ will it work?
A
Limited mouth opening
Upper airway obstruction
Altered pharyngeal anatomy
Poor lung compliance - requires excessive PIP
Increased airway resistance - requires excessive PIP
Lower airway obstruction
18
Q
What are 5 risk factors for difficult invasive airway placement?
A
Abnormal neck anatomy Obesity Short neck Laryngeal trauma Limited access to cricothyroid membrane
19
Q
What are the current fasting guidelines?
A
2 hrs - clear liquid
4 hrs - breast milk
6 hrs - nonhuman milk, infant formula, solid food
8 hrs - fried or fatty food
20
Q
What does ingestion of clear liquid 2 hours before surgery do to gastric volume and pH?
A
Reduces gastric volume and increases gastric pH, this reduces risk of Mendelson syndrome
21
Q
What is Mendelson syndrome risk factors?
A
Gastric pH < 2.5
Gastric volume > 25 mL (0.4 mL/kg)
22
Q
During an RSI how much pressure is applied to the cricoid ring before, and after LOC?
A
Before - 20 Newtons or ~ 2 kg
After - 40 Newtons or ~ 4 kg
23
Q
What are 6 complications of cricoid pressure?
A
Airway obstruction
Difficult with laryngoscopy
Impaired glottic visualization
Difficult intubation
Reduced lower esophageal sphincter pressure
Esophageal rupture if patient is actively vomiting
24
Q
List 3 causes of angioedema
A
Anaphylaxis
Angiotensin-converting enzyme inhibitors
Hereditary angioedema (C1 esterase deficiency)
25
What it the cause and treatment for anaphylaxis?
Cause - exposure to triggering agent
| TX - epinephrine, antihistamines, steroids
26
What is the cause and treatment for angioedema caused by ACE inhibitors?
Cause - ACE inhibitor prevents bradykinin breakdown
TX - discontinue ACE
Icatibant (bradykinin receptor antagonist)
Ecallantide (plasma kallidrein inhibitor - stops conversion of kininogen to bradykinin)
FFP (contains enzymes that metabolize bradykinin)
C1 esterase concentrate
27
What is the cause and treatment of hereditary angioedema?
Cause: genetics (C1 esterase deficiency)
TX: C1 esterase concentrate, FFP, ecallantide, icatibant
28
What patients should receive prophylactic treatment for angioedema?
Those with C1 esterase deficiency for procedures requiring tracheal intubation
29
What is Ludwig’s Angina?
A bacterial infection characterized by rapidly progressing cellulitis in the floor of the mouth
30
What are the airway implications of Ludwig’s Angina?
Inflammation and edema compresses the submandibular, submaxillary, and sublingual spaces, most significant concern is posterior displacement of the tongue resulting in complete, supraglottic airway obstruction
31
What is the best way to secure an airway in a patient with Ludwig’s Angina?
Awake nasal intubation
| Awake tracheostomy
32
Why is retrograde intubation contraindicated in a patient with Ludwig’s Angina?
Retrograde intubation is contraindicated in anyone with infection about the level of the trachea
33
What congenital conditions have large tongue?
“Big Tongue”
Beckwith syndrome
Trisomy 21
34
What congenital conditions have small/underdeveloped mandible? (Micrognathia)
```
“Please Get That Chin”
Pierre Robin
Goldenhar
Treacher Collins
Cri du Chat
```
35
What congenital conditions have cervical spine anomaly?
“Kids Try Gold”
Klippel-Feil
Trisomy 21
Goldenhar
36
What 3 symptoms are seen with Pierre Robin?
Small/underdeveloped mandible - micrognathia or mandibular hypoplasia
Tongue that falls back and downwards - glossoptosis
Cleft palate
Neonates often require intubation
37
What 4 symptoms are seen with Treacher Collins?
Small mouth
Small/underdeveloped mandible
Nasal airway is blocked by tissue - choanal atresia
Ocular and auricular anomalies
38
What 4 symptoms are seen with Trisomy 21?
Small mouth
Large tongue
Atlantoaxial instability
Small sub glottic diameter - subglottic stenosis
39
What symptoms is seen with Klippel-Feil?
Congenital fusion of cervical vertebrae
40
What 2 symptoms are seen with Goldenhar
Small/underdeveloped mandible
| Cervical spine anomaly
41
What symptom is seen with Beckwith syndrome?
Large tongue
42
What 3 symptoms are seen with Cri du Chat?
Small/underdeveloped mandible
Laryngomalacia - congenital softening of tissues of the larynx
Stridor
43
The sniffing position involves what movement of the cervical vertebra and Atlanta-occipital joint?
Cervical flexion
| Atlanta-occipital extension
44
What 3 axes does the sniff position align?
Oral
Pharyngeal
Laryngeal
45
What is the HELP position?
A modification of the sniff position for obese patients.
Head Elevated Laryngoscopy Position.
AKA ramping
46
How far can head position change the depth of the ETT?
Neck flexion and extension moves the tube ~ 2cm
| Lateral rotation of the neck moves the tip of the tube away from the carina ~ 0.7 cm
47
What are the 4 types of oral airways?
Guedel
Berman
Williams
Ovassapian
48
What are the 2 specific uses of a Williams oral airway?
Blind orotracheal intubation
| Fiberoptic intubation
49
What is the specific use for a Ovassapian oral airway?
Fiberoptic intubation
50
Why is a nasal airway better tolerated than oropharyngeal in a lightly anesthetized patient?
It can precipitate laryngospasm
51
What are 5 complications of placing a oral/nasal airway?
```
Laryngospasm
Vomiting if gag reflex is intact
Dental injury
Oropharyngeal trauma
Ischemia from compressing blood flow to affected areas
```
52
List 5 contraindications to a nasopharyngeal airway
```
Cribiform plate injury
Coagulopathy
Previous transsphenoidal hypophyesctomy
Previous Caldwell-Luc procedure
Nasal fracture
```
53
What 5 things should alert to a cribiform plate injury?
```
LeFort II or III fracture
Basilar skull fracture
CSF rhinorrhea
Raccoon eyes
Periorbital edema
```
54
What should cuff pressure be in an ETT?
< 25 cm H2O
55
What are the 2 types of cuffs? Which is the more common today?
Low-volume, high pressure cuff
| High-volume, low pressure cuff: nearly all tubes today in modern practice
56
Which type of cuff has better protection against aspiration?
Low-volume, high pressure cuff
57
Which cuff’s pressure can be measured with a monometer?
High-volume, low pressure cuff
58
Which cuff has a lower incidence of sore throat?
Low-volume, high pressure cuff
59
What type of cuff is a “microthin cuff”? What are it’s benefits?
High-volume, low pressure cuff.
Lower pressure on tracheal mucosa
Better protection against liquid aspiration
60
What are 4 ways to minimize cuff pressure?
Use a manometer periodically during case
Fill cuff with same O2/N2O mixture
Full cuff with water or saline - provides more stable pressure but takes longer to deflate
Use ETT with Lanz pressure-regulating valve
61
What is the Murphy eye?
The small hole on the opposite site of an ETT from the bevel
62
What is the purpose of the Murphy eye?
Provides an alternative passage for air moment in case the tip becomes occluded
63
How do you calculate the size and depth of a pediatric ETT?
ETT size without cuff: (age / 4) + 4
ETT size with cuff: (age / 4) + 3.5
Depth: ID x 3 (size of tube x 3)
64
What is max PPV pressure that can be used with an LMA?
20 cm H2O
65
What is the max cuff pressure for an LMA?
60 cm H2O
| Target: 40 - 60
66
What is the most common cause of nerve injury with an LMA? What nerves are at risk?
Over inflation of the cuff.
| Lingual, hypoglossal, RLN
67
What are 4 risk factors for nerve injury with an LMA?
Over inflation of the cuff
LMA that is too small
Lidocaine lubrication
Traumatic insertion
68
What increases the risk of sore throat and pharyngeal necrosis with an LMA?
Cuff over inflation
69
LMA size : Patient size : Cuff inflation : Largest ETT that fits : Largest scope
1 : < 5kg : 4 mL : 3.5 : 2.7
1. 5: 5-10 : 7 mL : 4.0 : 3.0
2: 10-20: 10 mL : 4.5 : 3.5
2. 5: 20-30 : 14 mL : 5.0 : 4.0
3: 30-50 : 20 mL: 6.0 : 5.0
4: 50-70 : 30 mL : 6.0 : 5.0
5: 70-100 : 40 mL : 7.0 : 5.5
70
What are the features of a ProSeal LMA?
Double lumen LMA designed for:
Gastric drainage
Larger mask
Bite block
71
How do you use a ProSeal LMA to drain the stomach?
You must pass an OGT through the tube, do not place suction directly to the drain tube
72
What are 2 benefits of the ProSeal vs classic LMA?
Better seal
| Max pressure for PPV < 30 cm H2O
73
What is an LMA Supreme?
A disposable version of the LMA ProSeal
74
What is an LMA Fastrach?
LMA designed for intubating
| -comes with a specifically designed ETT
75
Why is the LMA fastrach not suitable for MRI?
It has a metal handle
76
What is the LMA C-Trach?
An intubating LMA that includes a camera
77
What is an LMA Flexible?
A wire-reinforced, longer, narrower LMA that is useful for head and neck surgery
78
List 4 contraindications of an LMA
1. Risk of gastric regurgitation and aspiration: full stomach, hiatal hernia, small bowel obstruction, symptomatic GERD, delayed gastric emptying
2. Airway obstruction at the level of the glottis or below it
3. Poor lung compliance
4. High airway resistance
79
Should an LMA be used in a “cannot intubate and cannot ventilate” situation in a person with risk for aspiration?
Yes. Hypoxemia in this situation is the greatest risk to the patient
80
List 6 steps if gastric content is seen inside the LMA
1. Leave it in place
2. T burg and deepen anesthetic if necessary
3. 100% FiO2 via ambu bag
4. Use low FGF and low Vt
5. Use flexible suction catheter to suction through LMA
6. Use FOB to evaluate the presence of gastric content in the trachea, if present consider intubation and aspiration protocols
81
Describe the benefit of using an LMA with asthma
During emergence pulmonary reflexes “wake-up”, since the LMA is over the glottis there is nothing inside the trachea causing stimulation
82
List in order from most stimulating to least: LMA, DVL, Combitube, FOB
Combitube
DVL
FOB
LMA
83
What are the 6 guidelines given for using an LMA with Laparoscopy
1. “15 rule”: < 15 degrees tilt, < 15 cm H2O intraabdominal pressure, < 15 minutes of insufflation
2. Use LMA that allows gastric drainage
3. Normal BMI
4. Observe traditional NPO guidelines
5. Avoid light anesthesia
6. Be an experienced LMA user
84
What is a Combitube?
A supraglottic, double lumen device designed for blind placement in the hypopharynx
85
Combitube sizes are 37 and 41, what size patient should these be used in?
37: height 4-6 ft
41: height > 6 ft
No options for < 4 ft
86
Where are the 2 balloons on a Combitube?
```
Oropharyngeal balloon (proximal cuff) - occludes the hypopharynx
Distal balloon - occludes the esophagus (usually)
```
87
Which balloon is inflated first on a Combitube?
The oropharyngeal balloon (proximal cuff)
88
How much air is placed in each cuff of a Combitube?
Size 37: Oropharyngeal (proximal) cuff 40-85 mL, distal cuff 5-12 mL
Size: 41: Oropharyngeal (proximal) cuff 40-100 mL, distal cuff 5-12 mL
89
Where should ventilation be attempted with use of a Combitube?
Since the tip usually enters the esophagus, attempt ventilation through the blue (proximal or esophageal) lumen
90
Where should a Combitube be ventilated if the tip enters the trachea?
The clear (distal or tracheal) lumen
91
What is the max cuff pressure for a Combitube?
60 cm H2O
92
List 7 benefits of a Combitube?
1. Secure airway (aspiration protection)
2. Ability to decompress the stomach
3. Useful for obese population
4. Minimal training required for blind technique
5. Does not require neck extension
6. Allows high ventilatory pressure up to 50 cm H2O
7. Does not need to be taped
93
List 6 contraindications to a Combitube
1. Intact gag reflex
2. Prolonged use >2-3 hrs due to risk of ischemia from oropharyngeal balloon
3. Esophageal disease (Zender’s diverticulum)
4. Ingestion of caustic substances
5. Do not use size 37 F in someone < 4ft
6. Do not use size 41 F in someone < 6 ft
94
What hand is used to move the lever of a FOB? Which holds the cord?
Non-dominant moves the lever
| Dominant holds the cord
95
Moving the lever on a FOB in what direction moves the tip in what direction?
Push the lever down to point the tip up
| Push the lever up to point the tip down
96
How do you achieve horizontal movement with a FOB?
Rotate the scope in either direction
97
What is the gold standard for managing a difficult airway?
Flexible fiberoptic bronchoscopy in the awake, spontaneously ventilating patient
98
What are the contraindications of FOB?
```
No absolute contraindications.
Relative ones:
Hypoxia (lack of time)
Secretions not relieved by suction or an antisialagogue
Hemorrhage that impairs visualization
Uncooperative patient for awake attempt
Local anesthetic allergy
```
99
What oral airways can help with FOB?
Williams or Ovassapian help keep FOB midline
100
During FOB what do you do if the bevel of the ETT hands up on the right arytenoid?
PUll back a little
Rotate the ETT 90 degrees counterclockwise
Advance ETT
101
During FOB what do you do if the FOB gets stuck in the Murphy eye?
Remove the FOB and ETT start over
102
Nerve blocks for FOB?
Glossopharyngeal block
SLN block
Transtracheal block
103
What are the 3 branches of the Trigeminal nerve and what does it innervated in the airway?
V1: ophthalmic : nares and anterior 1/3 of nasal septum
V2: maxillary : turbinates and septum
V3: mandibular : anterior 2/3 of tongue
104
What does the glossopharyngeal nerve innervate in the airway?
```
Soft palate
Oropharynx
Tonsils
Posterior 1/3 of tongue
Valllecula
Anterior side of epiglottis
```
105
What nerve is the afferent limb of the gag reflex?
Glossopharyngeal nerve CN IX
106
What does the SLN innervate in the airway?
External branch: cricothyroid muscle
| Internal branch: posterior side of epiglottis to level of vocal cords
107
What does the RLN innervate in the airway?
Sensory below level of vocal cords to trachea
| Motor all intrinsic muscles except cricothyroid
108
What is a Bullard Laryngoscope?
A rigid, fiberoptic device used for indirect laryngoscopy
109
List 5 situations to use the Bullard laryngoscope
1. Small mouth opening - minimum of 7 mm
2. Impaired cervical spine mobility
3. Short, thick neck
4. Treacher Collins syndrome
5. Pierre-Robin syndrome
110
What are the contraindications to a Bullard Laryngoscope?
No absolute contraindications.
| The learning curve is high
111
What angle is the Bullard pulled for glottic exposure?
Straight up (90 degrees to the spine), not up and caudal like DVL
112
List 2 other rigid fiberoptic laryngoscopes similar to the Bullard
WuScope
| UpsherScope
113
List 3 names for the Eschmann introducer
Eschmann introducer
Intubating stylet
Gum elastic bougie
114
What is another name for angled tip of the bougie?
Coude
115
What is the best time to use the bougie?
Grade III Cormack-Lehane view
| next best Grade IIb
116
When is the worse time to use a bougie?
Grade IV Cormack-Lehane view - the chance of successful intubation is unacceptably low
117
Explain how to use the bougie
1. Hook the angled tip under the epiglottis
2. Advance the tip to 23-25 cm, feel for clicks on the tracheal rings “railroading”
3. If you don’t feel click and think you’re tracheal, feel for “hold up sign” - resistance at carina at 35-10 cm
4. If neither of these are felt, you’re in the esophagus
118
What 2 or other intubation methods can a bougie be used?
Nasotracheal intubation
| Orotracheal intubation through a supraglottic airway
119
How can you tell with a lighted stylet if you are in the trachea vs the esophagus?
In the trachea the light has to travel through less tissue, so there is a well-defined circumscribed glow below the thyroid prominence.
In the esophagus the light has to travel though more tissue, so there is a more diffuse trans illumination of the neck without the circumscribed glow.
120
When should a lighted stylet NOT be used?
In an emergency or cannot intubate cannot ventilate situation
In the presence of a tumor, foreign body, airway injury, or epiglottitis
Traumatic laryngeal injury
It is also difficult to use in the patient with a short, thick neck
121
What angle should the Trachlight be bent when using in an adult? Child?
Adult: 90 degree
Child: 60-80 degree to better accommodate a more cephalad glottic opening
122
Unlike a double lumen tube, what 3 things can the bronchial blocker NOT do?
Suction secretions from the isolated lung
Prevent contamination from contralateral lung infection
Ventilate the isolated lung
123
The lumen on a bronchial blocker can be used for what 2 things?
1. Insufflate oxygen into the non-ventilated lung
| 2. Suction air from the non-ventilated lung
124
What age can a double lumen tube NOT be used?
Children under 8 years old
| The smallest DLT is 26 F for kids 8-10 y
125
Where is the puncture created for the wire for retrograde intubation? What size needle is used for this?
The cricothyroid membrane
| 14-18 g
126
What is the most common use for retrograde intubation?
Unstable cervical spine
127
Should retrograde intubation be used in a cannot intubate cannot ventilate situation?
No. Retrograde intubation takes time (5-7 min) and best used when intubation has failed but ventilation is still possible
128
Name 2 situation that are indications for retrograde intubation
Unstable cervical spine
| Upper airway bleeding
129
Name 7 contraindications for retrograde intubation
Neck flexion deformity
Unable to identify landmarks
Pretracheal mass (thyroid goiter)
Tracheal stenosis under the puncture site
Tumor that obstructs the path of the wire
Coagulopathy
Infection
130
What 6 complications are associated with retrograde intubation?
```
Bleeding
Pneumomedistinum
Pneumothorax
Trigeminal nerve trauma
Breath holding
Wire travels in wrong direction
```
131
Name 3 ways to create a surgical airway (invasive airways)
Transtracheal jet ventilation
Cricothyroidotomy
Tracheostomy
132
What is Transtracheal jet ventilation?
A percutaneous technique that requires a high-pressure oxygen source
133
Where is the needle inserted for Transtracheal jet ventilation?
Through the cricothyroid membrane
134
What pressure of oxygen is required for Transtracheal jet ventilation?
~50 psi or wall pressure
135
Why is the patient at risk for hypercapnia with Transtracheal jet ventilation?
Ventilation cannot be controlled
136
What are 2 contraindications to Transtracheal jet ventilation?
Upper airway obstruction - air passively still exits the mouth/nose
Laryngeal injury
137
What is a cricothyroidotomy?
The creating of a small, horizontal incision through the cricothyroid membrane and then inserting a cuffed entotracheal tube
138
What are the 3 contraindications for cricothyroidotomy?
Children
Laryngeal fracture
Laryngeal neoplasm
139
Why are cricothyroidotomies contraindicated in children?
They have a more pliable and mobile laryngeal and cricoid cartilage, making this procedure incredibly challenging.
The thyroid isthmus commonly covers the cricothyroid membrane as well.
140
What is the emergency surgical airway of choice for children less than or equal to 6 y (some books say less than 10)?
Percutaneous Transtracheal jet ventilation
141
Name 5 complications of cricothyroidotomy
```
Tracheal stenosis
Tracheal or esophageal injury
Hemorrhage
Disordered swallowing
SQ or mediastinal emphysema
```
142
What surgical airway procedure has no absolute contraindications?
Tracheostomy
143
What are 4 acute and 4 long term complications from tracheostomy?
Acute: airway obstruction, hypoventilation, pneumothorax, bleeding
Long term: tracheal stenosis, tracheomalacia, tracheoesophageal fistula, tracheal necrosis
144
When should and shouldn’t a patient be extubated?
Extubate awake or deep
| Not inbetween
145
During a deep anesthetic plane (Guedel stage ___), airway reflexes are _____
III
| Attenuated
146
During a light anesthetic place (Guedel stage ___), airway reflexes are _____
II
| Hyperreactive
147
Awake, airway reflexes are _____
Intact
148
A light plane of anesthesia is characterized by what 3 things?
Disconjugate gaze
Breath holding
Unable to follow commands
149
List 3 pros and 5 cons of awake extubation
Pros:
Airway reflexes intact
Ability to maintain airway patency
Decreased risk of aspiration
```
Cons:
Increased CV and SNS stimulation
Increased coughing
Increased intracranial pressure
Increased intraocular pressure
Increased intraabdominal pressure
```
150
List 2 pros and 3 cons of deep extubation
Pros:
Decreased CV and SNS stimulation
Decreased coughing
Cons:
Airway reflexes are ineffective
Increased risk of airway obstruction
Increased risk of aspiration
151
What can be done to prevent the complications of awake extubation?
CV & SNS stimulation:
BB
CCB
Vasodilators
Coughing and increased pressures:
Lidocaine IV or in ETT cuff
Opioids
152
The risk of difficult extubation is increased if you can answer yes to any of these 3 questions:
1. Was the airway abnormal or difficult during induction
2. Did anything change during surgery that would make the airway difficult (edema, bleeding, restricted access)
3. Any risk factors for increased extubation risk (known difficult airway, aspiration risk, OSA, obesity, cardiopulmonary disease, neuromuscular disease, or metabolic abnormality such as acidosis, electrolyte imbalance, hypothermia)
153
List 10 risk factors for increased extubation risk
```
known difficult airway
aspiration risk
OSA
obesity
cardiopulmonary disease
neuromuscular disease
metabolic abnormality such as acidosis, electrolyte imbalance, hypothermia
```
154
What is the best technique to manage the patient at high risk for failed extubation?
Airway exchange catheter
155
where are the lip should the airway exchange catheter sit?
~25-26 at the lip
156
How long can the airway exchange catheter be left in place?
Up to 72 hours
157
What is the Seldinger technique?
ETT is passed over the airway exchange catheter like a stylet
158
What can be done through the airway exchange catheter?
```
EtCO2
Jet ventilation (via luer-lock adapter)
Oxygenation insufflation (via 15 mm adapter)
```
159
What complications can occur with airway exchange catheter?
Barotrauma - via jet ventilation with upper airway obstruction
Pneumothorax
Inability to replace ETT
