Airway Flashcards
Nasal Passages - cricoid cartilate
septum, turbinates UPPER AIRWAY
trigeminal nerve CN X
nasal passage very responsive to transmucosal anesthesia (lidocaine, afran)
Oral cavity
teeth, tongue, hard palate, soft palate
posterior 1/3 tongue back,
glossalpharyngeal nerve
hard to eliminate gag reflex, not as responsive to transmucosal
pharynx
nose to cricoid cartilage
nasopharynx - seperates soft palate
oropharynx - tonsils, uvula, epiglottis c2-c3
cricoid cartilage
c6
larynx
c3-c6
airway protection
respiration
phonation
tube size
6.5-7 female
7-7.5 male
8-8.5 long term intubation
pressure of tube against cords can cause swelling therefore try for smallest possible
3 paired cartilages
arytenoid
corniculate
cuneiform
3 unpaired cartilages
thyroid
cricoid - external superior laryngeal
epiglottis
cricoid
complete signet shaped ring of cartilage
external external superior laryngeal
narrowest point of pediatric airway (in adults, glottal opening)
intrinsic laryngeal muscles
open and close glottis
all innervated by recurrent laryngeal (AB and AD) lateral cricoarytenoid (ADD) arytenoids (ADD) posterior cricoarytenoid (only ABD)
intrinsic laryngeal muscles
tension on vocal ligament
elongate and shorten
cricothyroid - elongates (external superior laryngeal)
vocalis - shortens
thyroarytenoid - shorten and relax
Extrinsic laryngeal muscles
sternohyoid
thyrohyoid
omohyoid
sternothyroid
carina
5th thoracic vertebrae
lower airway
main function - conduction of air and gas exchange
trachea, carina, bronchi, bronchioles, terminal bronchioles, resp bronchioles, alveoli
innervated by superior laryngeal
trachea
sits opposite 6th cervical vertebrae flattened in back 16-20 horse shoe cartilages 10-20 cm length and 22 mm diameter R 2.5cm long 25 degree angle L 5cm long 45 degree angle
class I airway
faucil pillars
soft palate
uvula
full vocal cords
class II airway
uvula masked by tongue
class III airway
soft palate
uvula base
maybe just arytenoid (post attachement vocal cords)
class IV airway
only hard palate
epiglottis
thyromental distance
lower border mandible to thyroid notch with neck fully extended
normal 6-6.5cm or 4 finger breadths
less than 3 is difficult airway
optimal intubating position
“sniffing” position
oral
pharyngeal
laryngeal
preoxygenation
increased O2 conc in FRC. decreased nitrogen in FRC (79% in RA)
3-5 min tight mask tidal breathing of 100% O2 over 5L/min flow (healthy person tolerates up to 10 min apnea)
4 vital capacity breaths in 30 sec (healthy person tolerates up to 5 min apnea)
airway setup
laryngoscope/ 2 blade types oral/nasal airway tongue depressor ETT tubes 2 sizes suction ambu bag stylet LMA (difficult airway)
nasal airways/trumpets
provide passageway (nose to pharynx) beneath obstructing tongue
length estimate dist from nare to meatus of ear
complications - epistaxs, nasal/basal skull fx, adenoid hypertrophy, anticoagulants???? bleeding
laryngoscopes and blades
macintosh (curved, behind velicula) 1-4
miller (straight, pick up epiglottis) 0-4
Adult ETT sizes
- 5, 7 females
7. 5, 8 males
how far does ETT go?
4cm above carina
2cm below vocal cords
males approx 23 cm
females approx 21 cm
order of events
preoxygenate induction drug lash reflex test vent muscle rela laryngoscopy
sensory innervation of airway
glossal pharyngeal internal branch superior laryngeal (above cords) recurrent laryngeal (below cords)
motor innervation of airway
external branch superior branch laryngeal
recurrent laryngeal
glossal pharyngeal CN IX
sensory o posterior 1/3 tongue and oropharynx to vallecula
interior superior laryngeal (sensory)
branch of vagus, sensory to vocal cords and above
epiglottis base of tongue supraglottic mucosa thyroepiglottic joint cricothyroid joint
recurrent laryngeal (sensory)
branch of vagus, mucosa below vocal cords
muscle spindles
external branch superior laryngeal (motor)
motor to cricothyroid (adductor
tension on vocal cords)
recurrent laryngeal (motor)
ALL intrinsic muscles of larynx (except for cricothyroid muscle)
thyroarytenoid
lateral cricoarytenoid
interarytedoid (add)
post arytenoid (ABD)
external branch superior laryngeal (sensory)
anterior subglottic mucosa
responses to tracheal intubation
cv - HTN, tachy, MI,
resp - laryngospasm, bronchospasm
trauma, esophageal intubation, et ignition, sore throat, croup
induction sequence
1) preoxygenation
2) position in sniffing
3) monitors on/working
4) induction agent
5) lash reflex
6) test vent
7) check NM blocking monitor working
8) paralytic
9) tape eyes closed
10) continue bag/mask vent until paralytic drug takes effect (loss of twitches)
11) laryngoscopy and intubation
12) confirm ETT placement - bilat breath sound, chest rise, etco2
13) cont vent bag or ventilator
14) begin maintenance anesthetic
15) tape ETT
indications for airway blocks
abolish or blunt reflexes
provide comfort and airway anesthesia during performance of these procedures
complication of airway blocks
systemic toxicity (metal taste, seizure) hematoma formation
transtracheal block
block recurrent laryngeal nerve - cricothyroid membrane (sensory but not motor) for awake laryngoscopy, riberpotic and/or retrograde intubation
abolition of gag reflex, hemodynamic response
results in anesthesia of trachea below vocal cords, cough stimulus spreads to upper
continuously aspirate, caudad direction, visualize air bubbles, instruct to take deep breath, inject lidocaine on inspiration
cough sill spread (SLN above VC)
superior laryngealblock
internal (sensory) branch SLN
blocks supraglottic region, abolition gag and hemodynamic respons
palpate hyoid, displace toward side to be injected, inferior border cornu 23 g 1/75cm needle perpendicular into skin, 1/4 caudal, 1/4in medial
1-2cc LA 1-2cc above and helow thyrohyoid membrane, aspiration, if air, you are deep in pharynx
repeat on other side… dont want air or blood
glossopharyngeal nerve block
lingual branch GPH nerve sensory to back of tongue
abolition gag and hemodynamic
when topical application ineffective
move tongue with blade, form gutter, 25g spinal needle at base of palatoglossal arch .5 cm deep and .5 cm lateral to tongue base
aspirate before inn 1-2cc lidocaine
air - too deep
blood - withdraw and redirect needle medially
