airway anatomy Flashcards
what cranial nerve is trigeminal
CN 5
what are the 3 branches of trigeminal
V1- opthalmic
V2- maxillary
V3- mandibular
V1 branch of trigeminal
opthalmic
sensory to nares and anterior 1/3 of nasal septum
v2 branch of trigeminal
maxillary
sensory to turbinates and nasal septum
v3 branch of trigeminal
mandibular
sensory to anterior 2/3 of tongue
what nerve is glossopharngeal
CN9
-sensory for soft palate, oropharynx-> anterior side of epiglottis (valecula)
-afferent limb of gag reflex
-motor for swallowing and phonation
what nerve is vagus
cn 10
what does vagus divide into
SLN (internal and external)
RLN
where does SLN divide into branches
at level of hyoid bone
SLN internal branch
SENSORY to posterior side of epiglottis-> vocal cords
penetrates thyrohyoid membrane
SLN external branch
motor to cricothyroid membrane (tenses vocal cords)
bilateral injury-> hoarseness but no resp distress
RLN
sensation and motor
sensory from below VC-> trachea
motor: all intrinsic muscles of larynx (thryoarytenoid, lat cricoarytenoid, post cricoarytenoid)
what happens with unilateral injury to RLN
no respiratory distress
what happens with acute bilateral injury to RLN
respiratory distress from unopposed action of cricothyroid m
what happens with bilateral chronic injury of RLN
no respiratory distress
risk factors for bilateral RLN injury
-overinflation of ETT/LMA
-excessive neck stretching
-neck surgery (thyroidectomy most common)
risk factors for specific L sided RLN injury
-PDA ligation
-L atrial enlargement (mitral stenosis
-aortic arch aneurysm
-thoracic tumor
what side of RLN is more susceptible to injury
Left! loops around aortic arch
how to do a glossopharyngeal block
inject at base of palatoglossal arch (anterior tonsillar pillar) to depth of 0.25-0.5 cm
inject 1-2 cc local
risks with glossopharyngeal block
seizure from accidental intracarotid injection
how to do sueprior laryngeal injection
inject at inferior border of greater cornu of hyoid bone (1 mL outside of thyrohyoid membrane) and 2 mL deep to this structure
how to block RLN
transtracheal block- insert needle through cricothyroid membrane in CAUDAL direction
pt takes deep breath- inject 3-5 cc of local into tracheal lumen
landmarks for larynx
anterior to c3-c6
tensor palantine role
opens nasopharynx
obstruction at level of soft palate
genioglossus role
opens oropharynx
obstruction at level of tongue
hyoid muscle role
opens hypopharynx
what are the unpaired cartilages
thyroid, cricoid, epiglottis
what are the paired cartilages
arytenoid, corniculate, cuneiform
what is the narrowest region in the airway for adults
glottic opening
trachea begins and ends at
cricoid cartilage (c6)- carina (t4/5)
trachea rings open posterior or anterior
posterior
what cells produce mucus in the trachea
goblet
where is carina located
t4/5
angle of louis
R vs L bronchus
L bronchus 5 cm 45 degrees
R bronchus 2.5 cm 25 degrees
how are bronchi different in children
children up to 3 - both bronchi take off at 55 degrees
whats different in airway bifurcations
decreased airflow velocity, cartilage, cilia, and goblet cells
type 1 pneumocytes
provide surface for gas exchange
type 2 pneymocytes
produce surfactant- can also produce type 1
type 3 pneumocytes
macrophages, fight infection
laryngospasm reflex arc
afferent limb: internal branch of SLN
efferent limb: external branch of SLN (cricothyroid m.) and RLN (lateral cricoarytenoid and thyroarytenoid m.)
complications from laryngospasm
airway obstruction, neg pressure pulm edema, pulm aspiration of gastric contents, cardiac dysrhythmias, cardiac arrest, death
s/s of laryngospasm
inspiratory stridor, suprasternal/ supraclavicular retractions, “rocking horse”, apperance of chest wall, increased diaphragmatic excursion, lower rib flailing, absent/ altered etco2 waveform
causes of laryngospasm
airway manipulation (light anesthesia), secretions, airway surgery, active or recent resp infeciton (<2 weeks), age < 1 yr
tx of laryngospasm
fio2 100% remove stimuli, deepen anesthesia, larsons, chin lift, cpap 15-20, succ
succ dose adult/child
IV 0.1-1 mg/kg
IM=4 mg/kg
succ neonate/ infant dosing
IV = 2 mg/kg
IM = 5 mg/kg
succ give with atropine ___ mg/kg in children < _ yrs
0.02 mg/kg in children < 5 yrs old
larsons maneuver is also called
laryngospasm notch
pressure applied backward bilateral toward skull base for 3-5 seconds than released 5-10 sec
borders for larsons
superior= skull base
anterior= ramus of mandible
posterior= mastoid process
