Airway Anatomy and Airway Management Flashcards
3 paired cartilages of larynx
arytenoids
corniculates
cuneiforms
What is the Mallampati Classification?
Correlates the oropharyngeal space with the ease of direct laryngoscopy and tracheal intubation
hypothesis: when the base of the tongue is disproportionately large, the tongue overshadows the larynx resulting in difficult exposure of the vocal cords during laryngoscopy
components of laryngopharynx
tip of epiglottis to cricoid cartilage
Innervation of nasal passages
Branches of the trigeminal nerve (CN V)
How do you assess the Mallampati Score?
Pt sitting upright, head neutral, mouth open as wide as possible and tongue maximally protruded. No AAAAHH!
Innervation of anterior 2/3 tongue
Trigeminal nerve (CN V)
Compare and contrast the right and left bronchus.
Right bronchus is short and fat (2.5 cm long) with an angle of 25°
Left bronchus is long and skinny (5 cm long) with an angle of 45º
Discuss the disadvantes of using an LMA.
- NOT a definitive airway
- lower seal pressure
- higher frequency of gastric insufflation
- esophageal reflux more likely
-
inability to use mechanical ventilation
- **patient should be spontaneously breathing**
- CANNOT use NMBD (neuromuscular blockade)
Should use an oral airway for a patient that is semi conscious?
Why or why not?
No, oral airways are not well tolerated in awake or moderately awake patients. The patient should be “deep.”
Complications can include:
- laryngospasm
- bleeding
- soft tissue dammage
Function of the arytenoid muscles. Are they intrinsic or extrinsic laryngeal muscles?
intrinsic laryngeal muscle
oblique arytenoids and transverse arytenoids
Adduct the vocal cords also
What is the greatest predictor of a difficult airway?
“No single test has been devised to predict a difficult aiway accurately 100% of the time”
*previous difficult intubation should always raise suspicion*
**It is not one factor but a combination oof factors that create the difficult airway**
Questions/factors to consider for airway assessment.
Radiation or burn to head/neck
body builder or large body habitus - neck > 40 cm
C spine pain or LROM
TMJ pain
Rheumatoid arthritis
abscess or tumor
prior intubation or tracheostomy (old trach scar?)
snoring or sleep apnea
dysphagia, stridor, hoarse voice quality
ankylosing spondylitis
components of oropharynx
begins at base of uvula, tonsils, ends at epiglottis
What is the ideal postion for placement of ETT?
4 cm above the carina and 2 cm below the vocal cords
Males: approximately 23 cm
Females: approximately 21 cm
If unsure (peds population): ID (internal diameter) x3
i.e. 4.0 mm = 12 cm
How do you measure for proper sizing of an oral airway?
Center of the mouth to the angle of the jaw
OR
Corner of the mouth to the ear lobe
Vocal cords: appearance, formation, attachments
appear pearly white
formed by the thyroartyenoid ligaments
attached anteriorly to the thyroid cartilage and posteriorly to the arytenoid cartilages
Function of thyroarytenoid muscle
intrinsic laryngeal muscle
relaxes/shortens vocal cords
“they relax”
What components of the laryngoscope handle and blade need to be checked before use?
Handles - check the battery!
Blades - check the light! (to see if it’s working AND to make sure the light bulb is tight so it does not fall into the patient’s airway!)
Connect handle and blade to ensure proper fit and working
Want one of each macintosh and miller blade for set up
Describe the classes of the mandibular protrusion test and the significance of each class.
How do we ALWAYS check for proper placment of our ETT?
- bilateral breath sounds
- bilateral chest rise
- presence of end-tital CO2
- note fogging breaths in tube
General Anesthesia - Mask Case: When do we use?
- Difficult airway not present
- Surgeon does not need access to head/neck
- No airway bleeding/secretions
- Case of short duration
- No table position changes - head available
- Obstruction easily relieved with oral nasal airway/chin lift
- Patient will spontaneously breathe - no neuromuscular blocker used
What is a Laryngeal Mask Airway (LMA) and what is it used for?
- supraglottic airway device
- used for routine AND difficult airway managment
- can be used as a conduit for ETT placement
- appropriate size is based on patient weight
- adult sizes
- 30-50 kg → LMA 3
- 50-70 kg → LMA 4
- 70-100 kg → LMA 5
- >100 kg → LMA 6
- adult sizes
Innervation of soft palate (mostly uvula)
glossopharyngeal nerve (CN IX)
Considerations/complications for a nasal trumpet.
Is the patient on anticoagulation?
epistaxis
nasal or basal skull fractures
adenoid hypertrophy
Where are the intrinsic laryngeal muscles?
At the glottic opening
Components of lower airway
trachea
carina
brochi
bronchioles
terminal bronchioles
respiratory bronchioles
alveoli
Hard and soft palate innervation
trigeminal nerve (CN V)
What are the corniculates? Where are they located?
paired cartilages
posterior portion of the aryepiglottic fold
Arytenoids
paired cartilages
attach directly to the cricoid cartilage
posterior attachment for vocal cords
*falsely identified in an anterior airway*
3 unpaired cartilages of larynx
thyroid
cricoid
epiglottis
In the oral cavity, the trigeminal nerve (CN V), innervates which structures?
hard and soft palate
anterior 2/3 tongue
Placement of fingers on the soft tissues of the neck while masking can occlude the airway of which population?
Pediatric population
Cormack and Lehane Score: Grade II
only the posterior portion of the glottis visible
All intrinsic muscles, except for the cricothyroid muscle, are innervated by the _____ ______ ______, a branch of the ______ ______.
recurrent laryngeal nerve; vagus nerve
Cuneiforms
paired cartilages
lateral to corniculates in the aryepiglottic fold, not always present
Describe the technique for masking
Hold mask in left and resevoir bag in right.
Put thumb on upper aspect of the the mask, index and middle fingers on lower aspect, and 4th/5th fingers under chin for chin lift/jaw thrust.
*Try to keep fingers on bridge of the jaw bone, not soft tissue*
Vocalis muscles
intrinsic laryngeal muscle
ALSO relaxes/shortens vocal cords
Who should get an airway assessment?
EVERYONE
regardless of whether you work with the for 5 minutes or >12 hours.
regardless of types of procedure taking place.
Cormack and Lehane Score: Grade I
Most of the glottis visible
During mask ventilation, if we cannot achieve adequate tidal volumes at < 20 cm H2O, what kinds of things should we assess?
Airway patency
Pulmonary compliance
components of nasopharynx
starts posterior to turbinates, includes adenoids, stops at base of uvula
How can we measure the effectiveness of our mask ventialtion?
chest rise
exhaled tidal volumes
pulse oximetry - readings and sound
capnography - ETCO2
What happens to the trachea at the carina?
Divides the trachea into right and left mainstem bronchi.
INFO CARD
Various ETT options
- Double Lumen ETT
- Lung isolation - deflate right, ventilate left(vice versa)
- Tubes with place for nerve monitoring
- could be used in thyroid surgery
When is the best time to try a new airway technique?
Novel techniques for difficult AW management must be learned and practiced in a controlled environment with non-challenging airways.
***AN EMERGENCY IS NOT THE TIME TO A TRY A NEW TECHNIQUE***
Mallampati Class I
Generally associated with easy intubation.
“Think “P.U.S.H.”
Pillars, Uvula, Soft Palate, Hard Palate
faucial pillars, entire uvula, soft and hard palates
Mallampati Class II
Base of Uvula tip masked by tongue, uvula tip masked by tongue
Soft and Hard palates
Function of the Posterior Cricoarytenoid
intrinsic laryngeal muscle
The only vocal cord ABductors
“Please come apart”
Mallampati Class IV
Hard palate only
What are the turbinates?
hard ridges of cartilage bottom turbinate is a bone in itself
What is the larynx?
complex structure of cartilage, muscles, and ligaments that serves as the inlet to the trachea and anterior commisure
Describe the anatomy of the trachea: length, diameter, structure
fibromuscular tube
10 - 20 cm length; 22 mm diameter (adult)
16-20 U shaped cartilages (posterior side lacks cartilage, its just muscle posteriorly)