Chapter 47 - Acute Pediatric Airway Flashcards
What causes stridor? (physiologically)
turbulent airflow
How does pt having a syndrome affect your assessment of their airway?
Syndromic patients w/ mandibular hypoplasia more likely to have multilevel collapse/obstruction
What condition do you think of when you see respiratory distress with inspiratory or biphasic stridor in setting of strong cry
bilateral TVC paralysis
How much smaller is infant larynx compared to adult? Average diameter of subglottis in infant
1/3
3.5mm subglottis, adult is 10-14mm
Cervical level where larynx is located in infant vs adult
Infant: C2-3
Allows supraglottic structures to interdigitate with soft palate to optimize airway for suck-swallow-breathe
Adult: C7
How does chest wall compliance affect neonatal respiratory distress
Greater compliance –> easier collapse –> quicker O2 desats, higher O2 consumption at baseline, smaller lung capacity
How poisuelle’s law affects neonatal respiratory distress
resistance inversely proportional to radius^4
1mm obstruction (edema) in infant subglottis (which is 1/2 of the radius) leads to 16-fold increase in resistance, 75% decrease in airway cross-section
1mm obstruction in adult subglottis (r = 6) would decrease cross section area by 30% and increase resistance by 2x
How to tell if inspiratory stridor is at level of VC or above
at VC: high pitched
above VC: lower pitched (may be stertor)
Expiratory stridor
distal trachea/bronchi
more prolonged, sonorous sound
prolongs expiratory phase
Biphasic stridor
fixed lesion, usually subglottis
Signs of impending respiratory failure
biphasic stridor or quiet breathing after prolonged stridor, suprasternal/subcostal retractions, accessory mm use, nasal flaring, diaphoresis, AMS, neck hyperextension/tripod (lean forward/chin up/mouth open/brace hands), tachypnea, tachycardia, pallor and cyanosis
What does O2 desaturation tell you about severity of respiratory distress
ominous sign
because tachypnea and tachycardia can compensate and keep O2 up, the O2 going down indicates impending decompensation frequently
Causes of neonatal airway obstruction at birth: Nose
rhinitis, piriform aperture stenosis, NLD cyst, nasal mass, choanal atresia, encephalocele, midface hypoplasia (Downs, Crouzon)
Nasal obstruction leads to respiratory distress relieved by crying
Causes of neonatal airway obstruction at birth: OC/OP
Micrognathia (Pierre Robin, Treacher-Collins), macroglossia (Downs), lingual thyroid, mass/cyst
Causes of neonatal airway obstruction at birth: Larynx
laryngomalacia, VC paralysis, subglottic stenosis, web, atresia, cyst/mass
Causes of neonatal airway obstruction at birth: trachea
tracheobronchomalacia, stenosis/atresia, extrinsic compression (vascular ring, double aortic arch, pulmonary artery sling), complete tracheal rings
Until what age are neonates obligate nasal breathers?
4-6 mo
Choanal atresia: definition, embryology
Posterior nasal cavity doesn’t communicate with NP
Failure of nasobuccal membrane to rupture
Choanal atresia: Unilateral vs Bilateral
2/3 unilat, usually present later with rhinorrhea, chronic congestion
1/3 bilateral, present neonatal period with cyanosis during feeding relieved by crying, 50-75% have associated congenital anomaly
Diagnosis of choanal atresia
Failure to pass catheter through nose
confirm with endoscopy, CT
CHARGE
Coloboma Heart Atresia choanae Retardation Genitourinary disorder Ear anomaly/hearing loss
Robin sequence
Glossoptosis and retrognathia –> BOT obstruction
Micrognathia and glossoptosis –> prevent fusion of palatal shelves at midline –> U-shaped cleft palate
Syndromes with Robin sequence
Treacher Collins, Stickler, velocardiofacial
How to Tx Robin sequence
Evaluate with laryngobronchoscopy/sleep endoscopy/PSG
O2, prone position, nasopharyngeal trumpet, CPAP
If FTT, OSA, respiratory failure –> escalate
Surgery: tongue-lip adhesion, mandibular distraction, tracheostomy
Laryngomalacia: what it is, anatomic causes
collapse of supraglottic larynx –> inspiratory stridor
may result from aryepiglottic fold shortening, redundant supraglottic tissue, hypotonia
Cause of bilateral VC paralysis
Idiopathic 46%
Arnold Chiari, CP, hydrocephalus, spina bifida, birth trauma, hypoxia
Workup of bilateral VC paralysis
MRI
genetics
laryngoscopy and palpate cricoarytenoid joint (delineate VC paralysis from joint fixation)
Treatment and prognosis of bilateral VC paralysis
tracheotomy
recovery in time usually with idiopathic cases
Epiglottitis: age, onset, prodrome, temp, sx, pathogens, xr
2-7 yo Rapid onset No prodrome or mild URI High fever Muffled voice, speech limited (pain) Late inspiratory stridor, none at first No cough Odynophagia/drool Toxic appearing H Flu B, GABHS (S Pyogenes) Thumb print sign lateral XR (thick/round epiglottis, lose normal vallecula air space
Laryngitis
Any age, slow onset, URI prodrome, no fever
hoarse, no stridor, variable cough, no odynophagia/drool
Non-toxic
virus
Croup
6mo-3yr Slow onset, URI progrome No fever or low grade Hoarse, inspiratory stridor (progress to biphasic if severe), barky cough, no odynophagia/drool Non-toxic PIV RSV Steeple sign (narrow subglottis)
Tracheitis (bacterial)
6mo-8yr
Rapid onset, URI progrome
High fever
Hoarse, biphasic stridor, barky cough, no odynophagia/drool
Toxic appearance
S Aureus, M Catarrhalis
XR- normal epiglottis, tracheal lumen obscured by sloughed mucosa…called “pseudomembranes”
How to differentiate epiglottitis from tracheitis: age, sx
Epiglottitis younger (6mo-3yr), tracheitis 6mo-8yr Epi has no prodrome, no hoarseness, no stridor, no cough Trach has prodrome, hoarseness, biphasic stridor, barky cough Both are rapid onset, high fever, toxic-appearing
Why is the name epiglottitis not really correct?
Typically involves entire supraglottis
When did HIB vaccine get implemented?
1988
Management of supraglottitis
If stridor/respiratory distress –> may have impending need for surgery
Close airway surveillance, ABx IV, 10-14d course
If operation necessary: DL w/ ET tube or trach
Usually extubate within 48 hr when edema improves and air leak present around ETT
Management of croup
Supportive care
85-99% outpatient
Steroids if significant sx (1 dose dex), race epi
If inpatient –> repeated dex/race epi until resolve
1-5% require intubation
When to DL patients with croup
very young
severe or recurrent to r/o underlying pathology (subglottic stenosis, hemangioma, subglottic cyst)
Tx bacterial tracheitis
not as severe as epiglottitis usually rigid bronch, debridement 60-80% require intubation extubation after fever resolves, secretions diminish, air leak present IV ABx, 10-14d course
Presentation of PTA vs RPA/PPA
PTA: hot potato voice, stertor, milder airway sx (obst at OP)
RPA/PPA: fever, sore throat, dysphagia, decreased neck mobility, more likely to have airway obstruction (es with RPA)
Why are 1-3 yo more prone to FB aspiration?
explore with mouths poor swallowing coordination lack posterior dentition necessary for chewing properly lack appreciation of what is edible likely to be playing when eating
Items most likely to be aspirated
incompletely chewed food - nuts, seeds, beans
toys
Most common esophageal FB
coins
Sx of FB aspiration: Larynx
cough, hoarse, obstruction –> edema
Sx of FB aspiration: trachea
stridor, wheeze, dyspnea, coughing
No hoarseness!
Sx of FB aspiration: bronchi
most common location 80-90%
cough, wheeze, decreased unilateral breath sounds
Sx of FB: esophagus
dysphagia, odynophagia, drool, vomit
more common than airway FB
cricopharyngeus, where esophagus crosses aortic arch
x-ray to get for FB
inspiratory and expiratory XR
FB may allow air to enter but not escape –> trapping/hyperinflation exaggerated by expiratory phase
atelectasis, pneumonia
How many FB pts have NL XRs?
25-50%
How to manage FB aspiration
DL, bronch to remove
steroids if severe obst, mucosal damage, or significant edema
How to manage coin ingestion
Allow pass if in distal esphagus or if older child if no signs of airway compromise
When you need acute intervention for FB
acute or potential airway obstruction
esophageal injury
disc/button battery
Image findings with button battery, and complications
double halo or double ring sign on AP, or step off on lateral
may be mistaken for coin
caustic injury within 1 hr
perf within 6 hr
If >20mm, 12% of young kids swallowing will have major complication (perf, TEF, major vessel injury, stricture, VC paralysis, C-spine injury)
