Airway Flashcards
Where are the turbinates?
nasal passages
What are the turbinates?
hard ridges of cartilage bottom turbinate is a bone in itself
Function of nasal passages
warms, humidifies, and filters air
(air becomes “turbinate” and creates non linear flow, which is what heats up air)
accounts for 2/3 total upper airway resistance
When the pharyngeal tonsils become inflamed, what are they referred to as?
Adenoids
Components of nasal passage anatomy
septum
turbinates
adenoids
Innervation of nasal passages
Branches of the trigeminal nerve (CN V)
Components of oral cavity anatomy
teeth
tongue
hard palate
soft palate
Hard and soft palate innervation
trigeminal nerve (CN V)
Innervation of anterior 2/3 tongue
Trigeminal nerve (CN V)
Innervation of posterior 1/3 tongue
glossopharyngeal nerve (CN IX)
Innervation of soft palate (mostly uvula)
glossopharyngeal nerve (CN IX)
Innervation of oropharynx
glossopharyngeal nerve (CN IX)
What is the pharynx and what are its components?
Portion of the upper airway that connects the nasal and oral cavities to larynx and esophagus
- nasopharynx
- oropharynx
- hypopharynx/laryngopharynx
components of nasopharynx
- starts posterior to turbinates, includes adenoids, ends at the tip of the uvula and soft palate
- Border is the soft palate
Components of the oropharynx
- Border is the epiglottis
- Tonsils, Uvula
Components of the laryngopharynx
Tip of epiglottis down to cricoid cartilage. It leads to the glottic opening.
Innervation of superior components of the pharynx
Glossopharyngeal (CN IX)
Innervation of inferior components of the pharynx
Vagus (CN X) (laryngopharynx)
Where is the larynx located in regard to the spine?
C4-C6 in the adult
Functions of larynx
Airway protection (with epiglottis)
Respiration
Phonation (with air passing through vocal cords)
Unpaired cartilages of the larynx
- Thyroid
- Cricoid
- Epiglottis
Paired cartilages of the larynx
- Arytenoids
- Corniculates
- Cuneiforms
Describe the thyroid cartilage
Unpaired cartilage of the larynx
Large and most prominent
Anterior attachment for vocal cords.
Describe the epiglottis
Unpaired cartilage of the larynx
Cartilaginous flap that serves as the anterior border of the larygneal inlet
Covers opening to the larynx during swallowing
Describe the cricoid cartilage
Unpaired cartilage
Only complete cartilaginous, signet - shaped, ring
Narrowest portion of the pediatric airway
Describe the arytenoids
- Paired cartilages of the larynx
- Attach directly to the cricoid cartilage
- Posterior attachment for vocal cords
- Falsely identified in an anterior airway
What attaches posteriorly and anteriorly to the vocal cords?
Anterior: thyroid cartilage
Posterior: arytenoids
Describe the corniculates
Paired cartilages of the larynx
Posterior portion of the aryepiglottic fold
Cuneiforms
Paired cartilages of the larynx
Located lateral to the corniculates in the aryepiglottic fold; not always present
Describe the vocal cords
Appear pearly white
Formed by the thyroartyenoid ligaments
Attached anteriorly to the thyroid cartilage and posteriorly to the arytenoid cartilages
Describe the glottic opening
Opening leading to trachea
Triangular fissure between the cords
Narrowest portion of the adult airway
Function of lateral cricoarytenoids
Intrinsic laryngeal muscle that adducts the vocal cords
“Lets close the airway”
Arytenoid Muscles
Intrinsic laryngeal muscle (oblique arytenoids and transverse arytenoids) that adduct the vocal cords
Function of the posterior cricoarytenoid
Intrinsic laryngeal muscle that abducts the vocal cords
“Please come apart”
Function of the cricothyroid muscle
Intrinsic laryngeal muscle that tenses/elongates vocal cords
“cords tense”
Function of thyroarytenoid muscle
Intrinsic laryngeal muscle that relaxes/shortens vocal cords
“they relax”
What is the vocalis?
Intrinsic laryngeal muscle that relaxes/shortens vocal cords
Function of the intrinsic laryngeal muscles
- Control the movements of the laryngeal cartilages
- Control the length and tension of the vocal cords and the size of the glottic opening
Except for the cricothyroid muscle, what is the innervation for the other intrinsic larygeal muscles?
The recurrent laryngeal nerve, a branch of the vagus nerve (CN #10)
Describe the innervation of the cricothyroid muscle.
Innervated by the external branch of the superior laryngeal nerve, a branch of the Vagus nerve (CN X)
True or False: the internal laryngeal nerve, of the superior laryngeal nerve is purely sensory.
True.
the external laryngeal nerve is motor and innervates the cricothyroid muscle.
Function of extrinsic laryngeal muscles
Move larynx up or down as a whole
What is the suprahyoid group of the extrinsic laryngeal muscles responsible for?
Raising larynx cephalad (or up towards the head)
What is the infrahyoid group of the extrinsic laryngeal muscles responsible for?
Moving the larynx caudad (or down)
Components of lower airway
- Trachea
- Carina
- Bronchi
- Bronchioles
- Terminal bronchioles
- Respiratory bronchioles
- Alveoli
Describe the anatomy of the trachea
Fibromuscular tube
10 - 20 cm length; 22 mm diameter (adult)
16-20 U shaped cartilages (non-complete cartilages)
Posterior side lacks cartilage (cartilage on anterior side only; posterior side is muscle)
Bifurcates at lower border of T4–carina
Where does the trachea birfuctate?
The carina, at the lower border of T4
What happens to the trachea at the carina?
It bifurcates, dividing the trachea into right and left mainstem bronchi
Compare and contrast the right and left bronchus
Right bronchus is 2.5 cm long and branches off at an angle of 25°
Left bronchus is 5 cm long with an angle of 45º
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.
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
- Abscess or tumor
- Prior intubation or tracheostomy (old trach scar?)
- Dysphagia, stridor, hoarse voice quality
- Snoring or sleep apnea
- TMJ pain
- C spine pain or LROM
- Rheumatoid arthritis
- Ankylosing spondylitis
Airway Assessment
- General appearance (head, neck size and fullness)
- Range of motion
- Mouth (tongue, lips, tissues, gums/bleeding or friable tissue?)
- Mouth opening (30-40 mm or 2-3 fingers)
- Dentition
- Body habitus (pregnancy, large breasts)
- Diagnosis
- Planned surgery
- Mallampati classification
- Mandibular Protrusion test
- Thyromental distance
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
How do you assess the Mallampati Score?
Pt sitting upright, head neutral, mouth open as wide as possible and tongue maximally protruded. No AAAAHH!
What can be seen with Mallampati Class I?
faucial Pillars, entire Uvula, Soft and Hard palates
Generally associated with easy intubation.
“Think “P.U.S.H.”
Pillars, Uvula, Soft Palate, Hard Palate
Which component of the mouth is the predominate cause of airway resistance in the oral cavity?
Tongue
In the oral cavity, the glossopharyngeal nerve (CN IX) innervates which structures?
- posterior 1/3 tongue
- soft palate (mostly uvula)
- oropharynx
In the oral cavity, the trigeminal nerve (CN V), innervates which structures?
- hard and soft palate
- anterior 2/3 tongue
Laryngospcopic view of the epiglottis
Anatomy of the larynx
Mallampati Class II
Uvula tip masked by tongue, Soft and Hard palates