Week 13 - Advanced Airway Flashcards
1
Q
What is an unexpected failed airway?
A
Same thing as unanticipated difficult airway –> Although pre-operative airway assessments preformed didn’t indicate the patient as having a difficult airway, they do.
2
Q
What two things are generally the common causes of unanticipated difficult airways?
A
- Enlarged lymphoid tissue at the base of the tongue
- Lingual tonsil hyperplasia –> Some indicators include sore throat, dysphagia, globus sensation, snoring, palpation of lump in the throat, and OSA
3
Q
Experiencing difficulty with either face mask ventilation, laryngoscopy, intubation, or all of these terms the patient as what?
A
Difficult airway
4
Q
What are the 4 strategies of airway management?
A
- Bag mask ventilation
- Placement of a SAD (LMA)
- ETT into the trachea
- Cricothyrotomy
5
Q
What are indicators of a potential difficult airway?
A
Anatomic (Mallampati III or IV)
Pathophysiologic (laryngeal mass, neck hematoma)
Trauma (face/neck)
Physiologic (servere hypoxia or hypotension, acidosis)
6
Q
What are some indications of a difficult face mask ventilation seal/oxygenation?
A
Gas flow leaks –> increasing the use of the O2 flush, poor chest rise, absent or inadequate breaths, gastric air entry, poor EtCO2 and altered waveform, O2 saturations less than 92%, necessity of oral/nasal airways or two handed mask ventilation
7
Q
What are some indications for tracheal intubation?
A
Aspiration risk, NMBA used, patient positioning (prone, lateral decubitus)…
8
Q
What is considered a difficult tracheal intubation on the Cormack & Lehane grading scale?
A
Inability to visualize a portion of the vocal cords (Cormack and Lehane III or IV)
9
Q
What is considered a difficult invasive airway placement (cricothryotomy)?
A
Bleeding at insertion site, inability to identify correct anatomic structures, and trouble accessing the cricothyroid membrane and puncturing the trachea.
10
Q
Major complications associated with airway management?
A
1:22,00 –> Brain damage, emergency surgical airway placement, and unanticipated ICU admission
1:180,000 –> Death
11
Q
Common causes of SAD failure
A
Inadequate seal from improper placement, surgical table rotation, poor dentition, male gender, and increased BMI.
12
Q
What patient population are placed at the highest risk of difficult intubation/ventilation?
A
Patients with neck or mediastinal pathology, previous surgery, or radiation.
13
Q
Where are difficult airways encountered more frequently?
A
Outside the OR –> 30 to 60 times more common in the ED or ICU because these providers aren’t AIRWAY EXPERTS
14
Q
What 5 questions need to be considered which are part of the airway approach algorithm?
A
- Is airway management necessary?
- Is DL or VL and TI anticipated to be difficult?
- Can a SAD be used or deemed potentially difficult?
- Risk of aspiration?
- Patient at risk for rapid desaturation?
If all questions are answered yes –> Proceed, airway is deemed manageable
If any question is answered no –> Abandon airway management and proceed with an alternative plan (MAC)
15
Q
What are the two most commonly used airway algorithms?
A
ASA and DAS –> ASA is cited and used more.
16
Q
Should airway algorithms always be used?
A
No, dependent of the patient.
These ARE NOT a replacement for sound clinical judgement and implementation of interventions you deem necessary, only a guide.
17
Q
Simplified ASA airway algorithm
A
- Tracheal intubation via DL, if failed –> attempt calling for help, awakening the patient, and returning to spontaneous ventilation from this point forward –> 2
- Face mask ventilation, if failed –> 3
- SAD ventilation, if failed –> 4
- Intubation by special means (different blades, LMA with intubation conduit, fiber optic…), if failed –> 5
- Emergency airway
18
Q
What are the 4 endpoints in the ASA airway management algorithm?
A
- Awake or asleep intubation
- Face mask (1st) or LMA ventilation (2nd)
- Approach to intubation by special means (different blades, LMA with intubation conduit, fiber optic…)
- Surgical and non surgical emergency airway access
19
Q
What should be done if you are suspicious of airway trouble?
A
Awake intubation
20
Q
When making intubation choices, you should ___________
A
Do what you do best
21
Q
If you get into trouble but can still ventilate the patient, what should be the next step?
A
Awaken the patient.
22
Q
What is the key component in the DAS algorithm?
A
Communication with the OR team and verbalizing failure and moving onto a new step.
23
Q
According to the DAS algorithm, you should maximize the patient for intubation success on what attempt?
A
1st! –> includes preparation, positioning, and pre oxygenating. Limit attempts to 3 tries before moving onto the next step.
24
Q
According to the DAS algorithm, what is plan B?
A
Insertion of the supraglottic airway –> Use a 2nd generation because of its benefits (high seal pressures, first time placements, can be used as a conduit)
Placement should be limited to three attempts
25
According to the DAS algorithm, what should be done in plan C after face mask ventilation fails?
Provide complete paralysis and move to plan D.
26
According to the DAS algorithm, what should be done in plan C if face mask ventilation is adequate?
Awaken the patient
27
Why are laryngoscope attempts limited to 3 attempts or less?
To prevent excessive airway trauma.
28
When you have a patient with an anticipated difficult airway, what should be done during the first attempt at intubation?
This should be your best attempt with proper patient position, pre oxygenation and preparation.
29
When you have a patient with an unanticipated difficult airway, what should be done during the first attempt at intubation?
This is used as the awareness look or view, scoping out the airway. The second attempt should be the "best" attempt with the most experienced provider.
30
What should be included in a difficult airway cart?
Each facility should have one! --> No standardized list but developed by each department. Some good things to have are -->
Standard laryngoscope, intubation supplies by alternative means, tube position control, equipment to anesthetize the airway, and may or may not include video/FOB laryngoscopy
31
Awake intubation generally calls for what 2 intubating techniques?
Video laryngoscopy to facilitate TI or determine a difficult airway AND fiberoptic endoscope with preloaded ETT
32
What are some benefits to awake intubation?
Patient maintains their own ventilation and preserves their pharyngeal and laryngeal muscle tone improving the size of the pharynx and decreased risk of aspiration
33
Absolute contraindications to awake intubation?
None, if it is your safest option then you do it.
34
Sedative medications may be appropriate for awake intubations, when do they become problematic?
When the patient is over sedated. This takes away all the benefits of awake intubation. Causes respiratory depression and relaxation of muscle tone which can lead to total obstruction of the airway.
(DEXMED, propofol, etomidate, midazolam, fentanyl...)
Can generally do without these and just use local.
35
For an awake intubation with a patient who has topical anesthetic allergies, what medication should be used?
Dexmedetomidine
36
How would you define "awake" in an awake intubation?
Patient is cooperative and ventilating spontaneously.
37
How might awake laryngoscopy to determine a difficult airway be useful?
Allows you to decide
1. Proceed with video or FIS while the patient is awake
2. Proceed with anesthesia induction and NMBA to optimize airway conditions
38
What is something that can be done preoperatively to determine airway difficulty?
Preoperative endoscopic airway exam using minimal sedation and topical prior to entering the OR
39
What are some situations that awake intubation would be necessary?
Patients with previous airway difficulty, unstable neck fractures, halo devices, small or limited oral openings, upper airway mass, facial or neck trauma, physiologic compromise, and in the critical care setting.
40
What must be done for maximal patient cooperation during an awake intubation?
Procedure must be clearly explained and consent must be obtained.
41
What antisialagogue can be given in an awake intubation? How does this help with intubation?
Atropine --> 0.5 - 1 mg IV
Glycopyrolate --> 0.2 - 0.4 mg IV or IM
Give 20 minutes prior!
These will decrease sections which will maximize laryngeal view
42
True or False
Antisialagogue can enhance topical anesthetics penetration?
True, these decrease secretions allowing more of the anesthetic to penetrate the mucosa.
43
How is the risk of aspiration affected in an awake intubation?
Decreased, patient will maintain more esophageal sphincter tone while awake
Medications to decrease stomach acid production and promote gastric emptying should still be considered (H2 blockers)
44
What precautions should be taken prior to a nasal intubation?
Give a vasoconstrictor such as Afrin (0.05%) or Phenylephrine 2-3 minutes prior to application of local anesthetic to decrease risk of mucosal damage and hemorrhage.
45
What is the most commonly used local anesthetic?
Lidocaine 2% --> Peak levels are highest after 30 minutes
Others used are cocaine (4%), benzocaine (20%), and tetracaine
46
Maximum safe dose of lidocaine shouldn't exceed _________________
4-5 mg per kg IV --> Always assess for signs and symptoms of toxicity!
47
Methods of airway blockade via medications
Topical, infiltration or both
48
What three nerves/branches are we blocking when preforming an airway all day block?
Trigeminal, glossopharyngeal, and the vagus nerves.
49
What nerve provides sensory innervation to the lateral wall and nasal septum? What branches of this nerve?
Trigeminal --> Ophthalmic and maxillary branches
50
What nerve provides sensory innervation for the anterior 2/3 of the tongue?
Lingual nerve --> This stems from the trigeminal nerve which branches into the mandibular nerve and then into the lingual.
51
Where does the glossopharyngeal nerve innervate?
Posterior 1/3 of tongue, upper pharynx, and the inner surface of the tympanic membrane via its lingual branches.
52
What does the vagus nerve innervate in the mouth/airway?
Hypopharynx, larynx, and trachea via the SLN and RLN
53
What does the internal SLN innervate specifically?
Sensation above the vocal cords
54
What does the RLN innervate?
Subglottic area (below the cords)
55
What nerve branches are blocked via topical anesthetic to the nasal septum and lateral wall?
Anterior ethmoidal, nasopalatine, and sphenopalatine nerves stemming from the ophthalmic and maxillary branches of the trigeminal nerve
56
How can the nasal septum and lateral walls be anesthetized using topical?
Viscous 4% lidocaine can be sprayed down each nostril
Can use a CTA and slowly work lidocaine into each nare
57
How can the nasal and oral cavities (nasopharynx and oropharynx) be anesthetized via topical methods?
Adding 4-10 mL of 4% lidocaine and 1 mL of 1% phenylephrine to a nebulizer --> This takes 10-20 minutes, may need additional topical if doing awake intubation!
This method is also used during anesthetization of the subglottic tissue
58
What is atomization?
This is like nebulization but it produces much larger droplets, resulting in more medication coating the upper airway mucosa and producing a denser block.
Should be done via 5-8 big breaths through nose/mouth
59
What is a good concoction for atomization of the oral and pharyngeal cavities?
10 mL or less of 4% lidocaine and a small amount of 5% lidocaine paste.
60
What is the purpose of anesthetizing the mouth and oropharynx prior to intubations?
Decreases the cough and gag reflexes associated with awake intubations.
61
Why should you be careful when anesthetizing the tongue and mouth with Benzocaine 20% spray?
Because the toxic dose of this drug is 100 mg or more. With just a half of a second spray, this delivers 0.15 mL or 30 mg of medication, a third of the toxic level
62
What common side effect has been reported with the use of benzocaine topical spray?
Methemoglobinemia (affects how Hgb delivers oxygen throughout your body) --> Treatment includes Methylene blue
63
What is a good method for anesthetizing the posterior tongue, vallecula, and anterior epiglottis?
Lidocaine lollipop --> Coat a tongue blade with 5% lidocaine paste and apply to the back of the tongue --> This allows the paste to melt and coat the base of the tongue, vallecula, anterior epiglottis, and sometimes even the vocal cords.
Should allow 1-2 minutes for this paste to liquify and coat the tongue
64
What is a good method for anesthetizing the posterior tongue, vallecula, and anterior epiglottis if lidocaine paste isn't available/lidocaine lollipop method?
Atomization with a 4% lidocaine solution
65
Best method for anesthetizing the vocal cord?
Directly spraying them --> Can be done by depositing local down the ET tube when in close proximity of the vocal cords and instructing the patient to take a deep breath.
This causes the patient to cough which sprays the vocal cords.
66
How can you anesthetize the vocal cords via atomization?
While viewing the vocal cords with a flexible intubating endoscope or video laryngoscope, you can visually deposit 4% lidocaine onto the cords.
If using fiberoptic scope --> place an 18 gauge epidural catheter through the suction channel and inject topical onto cords.
67
Step by step process to preforming a glossopharyngeal nerve block. 5 steps.
1. Anesthetize the tongue with topical, have the patient open their mouth and protrude the tongue forward.
2. Displace tongue to opposite side of where you will inject with a tongue blade
3. Insert a 23-25 gauge spinal needle approximately 0.25-0.5 cm into the lingual gutter (where lingual gutter meets palatoglossal arch)
4. Aspirate --> If air you are too deep and needle should be withdrawn until no air is aspirated, if blood you are too lateral and should reinsert more medial to avoid possible intra carotid injection (Injecting here can cause seizures)
5. Once correct placement, inject 1-2 mL of 2% lidocaine. Repeat this process for the other side
68
Swish and gargle/spit method for topical anesthetic?
Use 2-4% lidocaine, have patient swish and gargle this for 2 minutes --> then spit out
69
Step by step process to preforming a superior laryngeal nerve block. 6 steps
1. Locate the greater cornu of the hyoid bone (beneath the angle of the mandible and can be palpated on either side of the neck as a rounded structure)
2. Displace hyoid bone towards the side you are injecting to stabilize the bone and to facilitate identification of structures.
3. Insert needle perpendicular to the skin and advance to contact the inferior boarder of the greater cornu
4. Needle is then "walked off" the caudal edge of the hyoid bone where it hits the thyrohyoid membrane --> Needle may feel resistance and bounce on this membrane
5. Aspirate and ensure no blood or air --> air = too deep and needs to be withdrawn until no air. blood = needs to be withdrawn and reinserted
6. Inject 1 mL (2% lidocaine) above the thyrohyoid membrane, then pierce membrane and inject 2 mL. Repeat on other side
70
Step by step process to preforming a transtracheal nerve block.
1. Palpate the cricothyroid membrane
2. Insert 22-24 gauge needle puncturing the membrane in a caudal direction (prevents potential vocal cord injury) while aspirating continuously
3. When you start seeing air bubbles, you know you are in the trachea --> Instruct the patient to take a deep breath then inject 3-5 mL of 2% lidocaine
4. This will cause the patient to cough spraying the vocal cords, make sure to stabilize needle! Use of a softer angio catheter may decrease trauma
71
What is the purpose of cricoid pressure?
Posterior displacement of the cricoid cartilage against the cervical vertebrae preventing regurgitation of gastric contents by compressing the esophagus during the induction of general anesthesia --> Should be done with the patients head elevated 20 degrees.
72
How much pressure should be applied to the cricoid during cricoid pressure?
10-20 N (1-2 kg of force) prior to loss of consciousness
30-40 N (3-4 kg of force) after loss of consciousness
This is equivalent to applying firm pressure to the bridge of the nose that would cause discomfort
73
Drawbacks to cricoid pressure?
Been questioned of its efficacy -->
Studies only conducted on cadavers, can interfere with the visualization of the airway on laryngoscopy, and may even INDUCE relaxation of the lower esophageal sphincter!
MRI found that in 50% of patients their esophagus is lateral to the cricoid ring, not directly posterior as suggested
74
What should be done if you are holding cricoid pressure and your patient begins to vomit?
Should release pressure immediately! This can actually cause a buildup of pressure if you don't release, leading to a perforated esophagus
75
What are some contraindications to cricoid pressure?
Cervical spine injury and RSI (decreases upper and lower esophageal tone)
76
What are supraglottic airway devices? (SAD)
Devices which provide ventilation above the glottic opening --> LMA, face mask
77
What are some common retroglottic or infraglottic airway devices (still considered SADs because ventilation is provided superiorly to the glottic opening)?
Combitube, King LT airway --> These devices pass behind the larynx and enter the upper esophagus.
No mask that covers the laryngeal opening but two cuffs --> distal balloon sealing the esophagus.
NOT SUITABLE AS A CONDUIT
78
What are the 3 reasons to use a supraglottic airway device?
1. Rescue ventilation after difficult mask ventilation or failed tracheal intubation
2. A primary means of ventilation or alternative to ETT if appropriate
3. As a conduit to facilitate ET tube intubation
79
In daily clinical use, the LMA can be used in place of __________ during general anesthesia, if apporpriate.
Bag mask ventilation
80
How are LMA's sized?
Weight based in kg
81
What size LMA would a 80 kg patient get?
Size 5 --> 70 - 100 kg
82
How is an LMA inserted?
Fully deflate the cuff and apply a water soluble lubricant to the posterior surface. Place LMA against the patients hard palate midline and advance with the index finger until final resistance is felt, indicating it is in the correct position in the hypopharynx. Inflate cuff which will seal the airway over the larynx (generally with about 20-40 mL of air for LMA sized 3-5)
83
What should be done if initial attempts of LMA placement is difficult?
LMA is removed and place patient in a proper sniffing position.
If resistance is felt when it reaches the posterior pharyngeal wall this is generally due to the distal tip folding back --> Retract and re advance or used index finger to flip distal tip back over to its correct position.
84
What cuff pressures should an LMA not exceed?
60 cm H2O
85
What can happen if an LMA cuff is overinflated?
This can become so rigid that is loses its seal in the hypopharynx
Can also open the upper esophageal sphincter or potentially cause posterior cricoarytenoid muscle fatigue.
86
How can a tongue blade be used when inserting a supraglottic airway device?
Can be used to reposition the tongue into the thyromental space allowing for a larger oral opening and easier SAD placement.
87
What guided techniques have been used for supraglottic airway placement?
Using a laryngoscope or Eschmann stylet (bougie)
88
What are some benefits to second generation supraglottic devices?
Decreased risk of aspiration due to gastric decompression suctioning channel, reinforced tips to prevent folding, better cuff seals allowing for higher pressure ventilation, more rigid design to prevent rotation and facilitate easier insertion and can serve as a CONDUIT for ETT placement
89
The PLMA (Proseal) offers a better airway seal than the LMA classic allowing for ______________
increased peak ventilation pressures (up to 28-30 cm H2O)
90
What is the disposable version of the PLMA (Proseal)
LMA supreme (curved fixed design) --> Allows less peak ventilation pressures of 26-28 cm H2O, compared to PLMA of 28-30 cm of H2O but first time insertion rates are higher with the LMA supreme over the PLMA
91
What 2 second generation SADs can serve as a conduit for ETT tracheal intubation?
PLMA and LMA Supreme
92
What is an i-gel SAD?
Second generation SAD, no inflatable cuff --> just medical grade thermoplastic elastomer. Can also be used as a conduit for ETT intubation.
Associated with high seal pressures, lower incidence of sore throat, and relative ease of insertion
93
What SADs are used in the prehospital environment due to the ease of insertion?
Retrograde airway SADs --> King LT and Combitube
94
What is the most well known and used intubating LMA?
LMA Fastrach --> Allows continuous ventilation until TI is accomplished
95
After successful intubation when using the LMA Fastrach, what should occur next?
Remove the rigid LMA Fastrach to avoid sustained pressure on the hypopharyngeal tissue
96
What intubating SAD can be used in pedatrics?
air-Q --> LMA Fastrach doesn't provide pediatric sizes
97
Why can retrograde or infraglottic tubes (SADs) be placed blindly?
Because if they are placed correctly into the (hypopharynx) or incorrectly (larynx), ventilation can still occur. These devices have two balloons blocking off the esophagus and upper airway, with a ventilation port in between the balloons at the level of the trachea.
98
What is the most important factor to consider when using the combitube?
Because placement is blind, this could end up in the larynx or hypopharynx --> You need to determine what port is actually ventilating the patient because this device has two lumens.
99
What is the main benefit of why SAD are viewed as extremely valuable airway devices?
The speed of their insertion and high likelihood of success
100
What is a significant concern when using SADs?
Risk of aspiration --> 2nd generation SAD's reduce this
101
What position should a patient be in if a SAD is going to be used?
Supine --> Need to be used with caution in other positions.
102
What is the Trachlite lighted stylet?
A lighted stylet that uses transillumination of the neck to accomplish ET intubation
- Blind approach
- Less stimulation than other methods and can be used when awake
- LESS affected by anterior airway
103
What would be seen if the Trachlite was inserted into the esophagus?
A much more diffuse light would be seen, if any light at all
104
When is Trachlite not recommended?
1. Patients a upper airway anomaly such as foreign body, tumor, polyps, or soft tissue injuries --> This is a blind technique and can cause further damage of the pharynx
2. Patients with short, thick necks, redundant soft tissue (obese) or darkly pigmented --> May be harder to see the light in these patients
105
Why has use of the Trachlite declined?
Because the use of VL, fiber optics, and disposable FIS has become more prevalent and available
106
Does the patient need to be placed in a sniffing position to use the Trachlite?
No, minimal head and neck movement occurs because this is a blind technique and nothing needs to be visualized
Also can be used in patients with limited mouth opening
107
What is the most critical step when preforming Trachlite intubation?
Identification of the pre tracheal glow --> can generally be seen when the stylet is around the base of the tongue.
108
When using the Trachlite, what drawbacks are present when intubating extremely thin patients?
False positive --> The glow will look brighter, making you think you could have correct placement but are in the esophagus.
109
What is the Eschmann Stylet (Gum eleastic bougie)?
Blind intubation technique --> Used when the glottic opening is difficult to visualize (Grade IIb or III)
15 Fr, 60 cm long with a 40 degree bent tip
110
What can be an indication that the Eschmann Stylet (Gum eleastic bougie) is in the trachea?
Can feel the stylet bounce along the tracheal rings --> May not always be felt though.
Once this is in the trachea, an ETT is slid over the stylet and guided into the trachea.
111
What is an airway exchange catheter (AEC)?
Very long tube that can be used for ET tube change, or placed prior to extubation in a difficult airway
112
Can an airway exchange catheter (AEC) be used for jet insufflation?
Yes, but muscle paralysis should be used to prevent glottic closure --> Only a bridge until another means of ventilation can be placed like an ETT threaded over this device.
113
Indications for use of the flexible fiberoptic intubating scope (FIS)?
114
When can flexible fiberoptic intubating scope (FIS) be used?
To evaluate the airway, facilitate awake intubation with an identified difficult airway, check ETT placement...
115
What are some of the working channels used for in the flexible fiberoptic intubating scope (FIS)?
Suction, O2 delivery, instill local anesthetic
116
What can be done to prevent fogging in a flexible fiberoptic intubating scope (FIS) is anti fog liquid isn't available?
Place in warm saline or place scope in buccal mucosa of the patients lip for 5 seconds
117
How can copious secretions and blood be removed when using a flexible fiberoptic intubating scope (FIS)?
Instillation of O2 at 10-15 L per min to push these secretions away or suctioning.
Suctioning is difficult to do so usually just using O2 helps keep the airway structures and scope clear
118
When should you be cautious when using a flexible fiberoptic intubating scope (FIS)?
Patients presenting with airway trauma or inflammation from burns, epiglottitis, bacterial tracheitis...
119
Can flexible fiberoptic intubating scope (FIS) be used in an inexperienced provider or with time restraints present?
NO --> Very steep learning curve and time consumptive
120
What are some indications of flexible fiberoptic intubating scope (FIS)?
Anticipated difficult airway, cervical spine immobilization, anatomic abnormalities, failed intubation with ventilation still possible via face mask
121
How is flexible fiberoptic intubating scope (FIS) primarily used?
In awake intubation with an anticipated difficult airway.
122
Radiation can cause loss of mucous producing glands, what medications should be limited?
Antisialagogue --> Can cause extensive drying
123
What device should be used to prevent damage to the flexible fiberoptic intubating scope (FIS)?
An FSI guide --> Basically an OPA which protects the scope from the patient biting down and guides it down to the pharyngeal area
124
What patient position should be used when using the flexible fiberoptic intubating scope (FIS)?
Sitting position --> may decrease anxiety, relieve upper airway obstructions, and prevent tissue from falling against the posterior pharynx
Light sedation can be used to facilitate this placement such as Precedex or Remifentanyl
125
When using the flexible fiberoptic intubating scope (FIS), how should to cord look during the procedure?
Should be kept taut
126
What should the provider do if view is lost or is unsure about the scopes location when using flexible fiberoptic intubating scope (FIS)?
Should be retracted until identifiable airway anatomy is visualized
127
At what point should the ETT be advanced over the flexible fiberoptic intubating scope during an awake intubation?
When the tip of the scope has passed the glottic opening and the tracheal rings/carina can be viewed.
128
Common reasons for failed flexible fiberoptic intubating scope (FIS)?
129
What are some disadvantages to flexible fiberoptic intubating scope (FIS)?
130
What is the most utilized rigid fiberoptic device?
Bullard laryngoscope --> Lost much use due to video laryngoscopes
131
What is required when using the Bullard laryngoscope?
A light source
132
What two things are necessary to consider when choosing a Bullard laryngoscope (rigid fiberoptic device)
Patient height and the minimal size of the ETT that can be fitted onto the stylet.
Available for both adults and pediatric patients
133
When using the Bullard laryngoscope (rigid fiberoptic device), where is the blade placed?
Can be used like a MAC blade by sliding into the superior vallecula or as a Miller blade by directly lifting the epiglottis
134
What are the two semi rigid fiberoptic stylets? Why are they useful?
The Shikani and Bonfils Retromolar --> Can flex the tip of the fiberoptic scope over the ET tube aiding in placement.
135
What is the most used video laryngoscope? What is the most portable?
Glidescope is most used, MacGrath is most portable
BOTH have disposable blade sleeves unlike the C-MAC
136
What are the 4 types of video laryngoscopes?
Glidescope
C-MAC
MacGrath
Air Traq --> Poor mans version, no actual video. Uses prisms, mirrors, and light to give "image"
137
What is a downside to using the C-MAC over the Glidescope video laryngoscope?
C-MAC doesn't have disposable blades. Instead needs to be washed and sterilized after use. This can be problematic if you only have 1 with multiple OR's --> people are having to wait around to use this.
Glidescope has disposable blades making it reusable immediately after use.
138
Does antifog solution need to be placed on glidescope camera?
No, has a built in antifog system that heats the lens.
139
How should the Glidescope be inserted?
MIDLINE --> NOT to the right of the mouth like the C-MAC and DL blades are used.
Should focus on the monitor for insertion as soon as the blade passes the teeth.
Blade is placed into the vallecula followed by a gentle tilt to see the vocal cords --> ETT is now inserted
140
Absolute contraindication for a cricothyrotomy
NONE, besides the patient being able to be ventilated via a more non invasive way --> This is an emergency procedure
141
What are the three types of cricothyrotomy procedures
Needle with TTJV, percutaneous or wire guided, and open surgical
142
Which cricothyrotomy procedure is reserved as the last resort between the three procedures?
Needle with TTJV --> Evidence of significant failure rates
143
How does needle cricothyrotomy with TTJV work?
Large bore catherter (18 gauge or larger) inserted through the cricothyroid membrane caudally while applying negative pressure on the syringe. Remove syringe and needle while advancing the catheter. Attach O2 tubing and oxygenate.
144
What I:E ratios are used during needle cricothyrotomy with TTJV?
1:3 or 1:4 --> Allows adequate time for exhalation because this is accomplished PASSIVELY
145
What risk to the lungs are present with needle cricothyrotomy with TTJV
Barotrauma, the O2 source is plugged directly into pipeline pressure of 50 psi --> regulator is present and should be decreased to 25 psi
146
1 second inspiration at 25 psi with 10 breaths per minute delivers how many liters of O2 per second when using needle cricothyrotomy with TTJV?
0.5 - 1 L/sec
147
What is a percutaneous (wire-guided) cricothyrotomy?
Needle or sharp trocar pierces through the cricothyroid membrane. Once in place a trachea cannula is placed over the wire or trocar device --> Done using a kit
148
What are some absolute contraindications to percutaneous or surgical cricothyrotomy?
In patients who would favor needle cricothyrotomy OR in patients less than 12 years of age --> Children have very a small, pliable, and movable larynx.
149
After the cricothyroid membrane has been pierced with a needle or trocar device and the wire in threaded into the trachea, what is the next steps for a percutaneous (wire-guided) cricothyrotomy?
150
What can be heard during a percutaneous (wire-guided) cricothyrotomy when inserting the dilator tube indicating that you have penetrated the cricothyroid membrane?
A loss of resistance may be felt first preceded by a "pop" --> Indicates you have broke through the cricothyroid membrane
151
What is a surgical cricothyrotomy?
Cutting through the cricothyroid membrane with a scalpel and then placing a cuffed tracheostomy or ETT.
152
How should the initial incision be preformed in a surgical cricothyrotomy? What do you do next?
Make a horizontal incision first at the top of the cricoithyroid membrane and then rotate scalpel 90 degrees, now --> vertical cut down incision from the thyroid cartilage, moving caudad several centimeters to the cricoid cartilage.
153
What happens during a surgical cricothyrotomy after the incision has been made to the cricothyroid membrane?
A bougie is advanced into the trachea while the scalpel is still in place
154
After a surgical cricothyrotomy has been prefromed, what is the best indicator of correct placement?
EtCO2 or/and visual confirmation of the tube with a scope observing the tracheal rings and carina
155
What is retrograde intubation?
Front of neck technique --> (Seldinger technique) cricothyroid membrane is penetrated cephalad, wire is advanced into the oropharynx where it can be retrieved via Magill forceps or through the nose. ETT is then advanced over wire back into the trachea
156
How long can a cricothyrotomy provide adequate ventilation for?
About 45 minutes, hypercarbia being the limiting factor
157
What is the Seldinger technique?
158
Before inserting the ETT over the wire when using a retrograde intubation approach, what needs to occur?
CLAMP the wire at the insertion site --> If you lose this access then this technique can't work.
Maintain control of both ends of the guide wire
159
Why has the retrograde technique been limited in its use?
Increased time required, potential difficulty of wire/suture removal, and the failure to pass the ETT
160
When is the wire removed when preforming a retrograde intubation?
Once the ETT is up against the end of the wire at the insertion site --> Wire is removed and then the ETT is further advanced.
161
What are some potential tracheostomy complications?
Damage to the RLN, large vessels, and posterior tracheal wall perforation with esophageal trauma
162
At what level is a tracheostomy preformed?
Tracheal rings 4-6
163
Complications of tracheal extubation?
164
Standard extubation criteria?
165
When is a laryngospasm likelihood increased when extubation?
During Guedel stage II --> Excitatory stage
Should only be done when patient is fully awake or deep sedation (stage III)! No inbetween!
166
During an awake extubation, how can cardiac stimulation be minimized?
Via the used of BB, CCB, and vasodilators
167
During an awake extubation, how can coughing or straining be minimized?
Local anesthetics (lidocaine) and opioids --> Use cautiously as these can cause hypoventilation
168
About ______ of significant airway emergencies happen during extubation.
1/3
169
Four things that can be done during extubation in a patient with a difficult airway to aid in re intubation if indicated?
1. Extubate over a flexible intubating endoscope
2. Extubate followed by the placement of an SAD
3. Extubate over an AEC
4. Leave ET tube in place until extubation criteria has been met.
170
How should an Airway Exchange Catheter (AEC) be sized?
The internal diameter of the re intubating ETT should approximate the external diameter of the AEC
171
What should be done when using a blind intubating technique or AEC and the ETT encounters obstruction?
Slight retraction of the ETT followed by 90 degree counter clockwise rotation to avoid arytenoid and vocal cord impingement.
172
Why is it important that the patient doesn't exhibit any signs of residual NMBA effects prior to extubation?
Because this can lead to upper airway obstructions, hypoxia, increased risk of aspiration, and decreased ventilatory response to hypoxia
173
What drug can be used to reverse the effects of paralytic agents like Roc or Vec?
Sugammadex --> Works by trapping roc or vec and removing this drug from the synaptic gap rendering it inert.
174
What is the process of a laryngospasm?
From sensory stimulation of the vagus nerve via the internal branch of the SLN --> Afferent responses result in the spasm closing the vocal cords which occurs from the external branch of the SLN and the RLN
175
How is a laryngospasm treated?
Jaw thrust, apply PEEP, deepen the anesthetic, administer succ (0.2-2 mg/kg IV)
176
What is another name for croup? How does this occur?
Laryngotracheobronchitis --> Inflammation and edema of the airway BELOW the vocal cords
Caused by
1. Post intubation edema
2. Multiple intubation attempts
3. Too large of an ETT
4. Excessive head and neck movement
177
What are distinguishing features a patient may present with if you are suspecting croup?
Stridor or a barking cough --> Pediatric patients are more susceptible due to their more narrow airways.
178
When does croup typically occur?
3 hours after extubation
179
How is croup treated?
Decreasing inflammation and edema
1. Humidified O2
2. Racemic epinephrine (0.5 mL of 2.25 % solution in 2.5 mL of NS)
3. Dexamethasone (0.1-0.5 mg/kg)
180
Most common cause of airway trauma?
Dental injury --> Maxillary incisors most at risk
181
What can cause massive tongue swelling?
Obstruction of the submandibular duct --> Extreme head flexion, surgical manipulation/trauma, or impingement via an ETT or bite block
182
Most common causes of pharyngeal injury?
1. Direct trauma via DL, VL, or blind intubation/suctioning techniques
2. Prolonged compression from ETT or OPA
3. Pressure induced nerve injury
183
What is a good indicator that the patient may expereince a sore throat from intubation?
In 40-65% of patients if blood is observed on intubation tools (laryngoscope)
Usually lasts no more than 24-48 hours
184
What part of the larynx is most susceptible to injury during intubation?
Posterior half of the vocal cords, the arytenoids, and the posterior tracheal wall
185
When can esophageal perforation or laceration occur when intubating?
During any attempt, especially in difficult airways.
186
What is generally the culprit of tracheal laceration or perforation?
Overinflation of the ETT cuff
187
What can unilateral or bilateral vocal cord paralysis present with?
Most often due to mechanical or nerve injury --> Can cause partial or complete airway obstruction
Unilateral - hoarseness
Bilateral - complete obstruction
188
What should be considered for a patient experiencing hoarseness or airway obstruction in the post operative period?
Possible emergent re intubation or tracheostomy
189
What symptom with esophageal laceration due to intubation correlates with a high degree of morbidity and mortality despite treatment?
Mediastinitis
190
What patient presenting problems increase the likelihood of tracheal injury during intubation?
Tracheal distortion (neoplasm or enlarged lymph nodes), membraneous trachea weakness, corticosteroid therapy, and COPD
191
What 2 things need to occur for aspiration to be possible?
1. Movement of gastric aspirate from stomach to pharynx
2. Movement of gastric aspirate from pharynx to lungs
192
Most common outcome from aspiration?
Aspiration pneumonitis --> The development of this with subsequent V/Q mismatch is dependent on
1. Type of aspirate
2. Volume of aspirate
3. Patients comorbid conditions
193
What actual problems can gastric aspirate flowing into the lungs cause? 4 things
1. Chemical destruction of pulmonary tissue
2. Alveolar capillary membrane edema and degeneration
3. Alveolar type II cell destruction
4. Microhemorrhage
194
Management of aspiration?
Positive pressure ventilation and intensive physiologic support
195
How can gastric aspiration be limited in regard to the patients peak airway pressures?
Limit to less than 15-20 cm H2O
25 cm H2O or more may cause gastric insufflation leading to gastric aspiration
196
What can be done during RSI to help decrease the risk of gastric aspiration?
Cricoid pressure --> Mixed evidence as some say this can make aspiration easier by relaxing esophageal sphincter tone.
197
What pharmacologic measures can be taken to decrease the risk of gastric aspiration?
Administration of --> Antacids (10 to 20 minutes prior to intubation. 30 mL of sodium citrate), H2 blockers (45-60 minutes prior to intubation), PPI, and possibly a gastric prokinectic (Metoclopramide 10 mg IV) 20-30 minutes prior to intubation.
198
What patients should not receive metoclopramide?
Patients with a bowel obstruction or any type of dopamine deficiency like (Parkinsons)
199
What does endobronchial intubation present with?
High peak inspiratory pressures, asymmetric chest expansion, unilateral breath sounds, contralateral lung deflation, hypoxemia
200
How much can an ETT move from full head extension to flexion?
Up to 6 cm (3.8 cm average)
201
How should endobronchial intubation be treated?
Deflate the cuff and retract tube into the trachea --> Re inflate cuff
202
How should a partially occluded ETT be cleared?
Suction
203
How should a complete ETT obstruction be treated?
Removal of ETT with insertion on new tube (re intubation)
