AIRWAY Flashcards
Nasal passages includes
septum, turbinates, adenoids
Function of nasal passages
accounts for 2/3 of total upper airway resistance
Humidifiy
filter and warm
Innervation of nasal passages
Branches of the trigeminal nerve (CN V)
Oral cavity includes
Teeth
Tongue (Predominate cause of airway resistance in oral cavity)
Hard palate soft palate
Innervation of oral cavity
Trigeminal Nerve (CN V) Hard and soft palate and * anterior 2/3 tongue Glossopharyngeal (CN IX) Posterior 1/3 tongue Soft palate Oropharynx
The pharynx connects
The nasal and oral cavities
Pharynx is divided into
Nasopharynx (Border is soft palate)
Oropharynx (Border is the epiglottis Tonsils, Uvula)
Hypopharynx/ Larygopharynx
Innervation of the pharynx
Glossopharyngeal (CN IX)
Vagus (CN)
Larynx is located
Located at C4 - C6
in the adult
Larynx functions:
Airway protection, Respiration,
Phonation
Inlet to trachea
Thyroid Cartilage (Unpaired cartilage)
Large and most prominent
Anterior attachment for vocal cords
Epiglottis (Unpaired cartilage)
Covers opening to the larynx during swallowing
: cartilaginous flap that serves as the anterior border of the laryngeal inlet. It functions to divert food away from the larynx during the act of swallowing
Cricoid cartilage (Unpaired cartilage)
Only complete cartilaginous signet-shaped ring
Narrowest portion of the pediatric airway
Larynx made is up of?
9 cartilages
3 pair and
3 unpaired- Thyroid cartilage, cricoid cartilage and epiglottis.
Paired cartilages of the larynx
Arytenoid
Corniculate
Cunieform
Arytenoid
Posterior attachment for the vocal cords
falsely identified in an anterior airway
Corniculate
Posterior portion of the aryepiglottic fold
cuneiform
In the aryepiglottic fold, not always present
Lateral to the corniculates
Vocal Cords are formed and attached
Appear pearly white
Formed by the thyroarytenoid ligaments
Attached anteriorly tot he thyroid cartilage and posteriorly to the arytenoid cartilages.
Glottic Opening
Triangular fissure between the cords
Narrowest portion of the adult airway.
Intrinsic Laryngeal Muscles Glottic Opening
Lateral Cricoarytenoid
Arytenoid Muscles
Posterior Cricoarytenoid
Lateral Cricoarytenoid Muscle
adducts the vocal cords
Arytenoid Muscles
Oblique arytenoids and transverse arytenoids
Adduct the vocal cords
Posterior Cricoarytenoid muscle
The only vocal cord abductor
Intrinsic Laryngeal Muscles Vocal Cord Length
Cricothyroid
Thyroarytenoid
Vocalis
Cricothyroid Muscle
Tenses/Elongates vocal cords
Thyroarytenoid Muscle
Relaxes/ Shortens vocal cords
Vocalis Muscle
Relaxes/ shortens vocal cords
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
Cricothyroid muscle is innervated by
The external branch of the superior laryngeal nerve a branch of the Vagus nerve (CN X)
All others innervated by the recurrent laryngeal nerve a branch of the Vagus nerve (CN X)
Extrinsic Laryngeal Muscles
Move larynx as a whole
Suprahyoid Group
Infrohyoid Group
Suprahyoid group
Suprahyoid Group
Stylohyoid, mylohyoid, geniohyoid, digastric
Raises larynx cephalad
Infrahyoid Group
Sternothyroid, sternohyoid, thyrohyoid, omohyoid
Moves larynx caudad
Trachea
Fibro muscular Tube
10 to 20 cm length 22 diameter
16-20 U shaped cartilages
Bifurcates lower border T4
Trachea
Fibro muscular Tube
10 to 20 cm length 22 diameter
16-20 U shaped cartilages
Bifurcates lower border T4- Carina
Carina-Trachea divides into Right & Left mainstem bronchi
Right bronchi is 2.5 cm long with angle of 25
Left bronchi is 5 cm with an angle 45
Airway assessment
Critical:
“No single test has been devised to predict a difficult airway accurately 100% of the time”
p. 1651
Previous difficult intubation should always raise suspicion
Review prior anesthetic records when possible for guidance on prior AW management
Airway assessment goal
Is to identify potential airway problems and identify a difficult airway.
Airway Assessment
Thorough and systematic airway assessment and physical exam should be performed in the preoperative period.
Followed by a patient specific plan for anesthesia.
Airway Assessment Questions to ask
Radiation or burn to head/neck? C-spine pain of LROM? TMJ pain? Rheumatoid arthritis? Ankylosing spondylitis? Abscess or tumor? Prior intubation or tracheotomy? Snoring or sleep apnea? Dysphagia or stridor?
Airway Assessment
General appearance --Head, neck size and fullness Range of motion Dentition Mouth Tongue, lips, tissues, gums Mouth opening --30-40 mm or 2-3 fingers
Airway Assessment
Body habitus Mallampati classification* Thyromental distance* Mandibular Protrusion Test* History of previous difficult airway Diagnosis Planned surgery