Airway Flashcards
How do you broadly classify airway obstruction?
upper and lower airway
What is the anatomical landmark to differentiate upper and lower airways?
thoracic inlet
What are the symptoms for upper airway obstruction?
Stridor
What are the symptoms for lower airways obstruction?
Expiratory wheeze
What are the xrays requested for acute respiratory distress?
Xray neck AP/ Lat (upper airway)
Xray chest AP/ Lat (lower airway)
Will you take neck AP/ lat in a patient with expiratory wheeze (lowe airway symptoms)?
Yes
What are the differential diagnosis for upper airway obstruction?
Croup (LTB)
Epiglotitis
exudative tracheitis
retropharyngeal abscess / Cellulitit
What is the age range for croup?
6 months to 3 years
What is the age range for Epiglotitis/ Exudative tracheitis/ retropharyngeal abscess?
more than 3 years. Upper limit varies for each disease
Clinical presentation of croup?
barky cough
intermittent strido
may be associated with lower respiratory tract infection
How is croup treated?
inhaled steroid
OP treatment
Xray findings of croup?
Steeple sign: narrowing of subglottic trachea extending below the pyriform fossa
Loss of normal shouldering of subglottic trachea
Lateral: narrowing of subglottic trachea
Summarize croup
Occurs in less than 3 years age
barking cough, intermittent stridor.
Xray - steeple sign, lateral shows narrowing of subglottic trachea.
epiglottis is normal
treatment is reassurance, inhaled corticosteroids outpatient treatment
How common is epiglottitis?
It was fairly common prior to Hib vaccination. Now it is less common
Why should you worry about epiglottits?
It is a fatal condition and cause death
clinical presentation of epiglottitis?
toxic, fever, dysphagia, stridor and increased respiratory distress while lying down.
Prior to vaccination what was the peak age of presentation?
3.5 years, after vaccincation it is 14 years
What additional care should be taken in patients with croup?
patient should not be forced to lye down if uncomfortable. all maneuvre should be avoided
xray finding in croup?
thumb like appearance of epiglottis in lateral radiograph
thickening of aryepiglottic fold
Where is aryepiglottic fold located?
it extends from epiglottis anterosuperiorly to arytenoid cartilage posteroinferiorly
what is the normal appearance of areyepiglottic fold?
it is convex inferiorly
What is abnormal in aryepiglottic fold in croup?
It has superior convexity
Sometimes the epiglottis appears spuriously enlarged! how do you confirm or defer epiglottitis?
No aryepiglottic fold thickening - no epiglottitis.
Summarize epiglottitis
Occurs more than age of 3.
prior to vaccine - peak 3 years
post vaccinne - peak at 14 years
fatal condition - can cause death
manuevres and incomcortable position should be avoided
presents with fever, stridor, dysphagia
xray shows thumb sign (thickened epiglottis) with thickening of aryepiglottic fold
How do you differentiate epiglottitis from LTB?
LTB will never have thumb sign, will always have subglottic narrowing (steeple sign)
Epiglottitis will always have thumb sign with or without subglottic narrowing
what is Exudative tracheitis?
life threatening upper airway obstruction due to purulent bacteral infection of the trachea, commonly staph aureus
What is the age range of Exudative tracheitis?
6-10 years
What are the 2 xray presentation of exudative tracheitis?
- ) intraluminal linear filling defect
2. ) plaque like irregularity of the tracheal wall
Non adherent mucous Vs exudative membrane. How do you differentiae?
make the child cough and repeat xray. mucous will move
why is it important to take both AP and lateral in exudative tracheitis?
because membranes maybe seen in both, or either one. Sometime you might miss it on lateral but pick it in the AP film or vice versa.
What is the complication of exudative tracheitis?
sloughing of membrane and respiratory arrest.
what is the treatment of exudative traceitis?
endoscpic removal of membranes with intubation
what is Retropharyngeal cellulitis?
It is a pyogenic infection of the retropharyngeal space that is due to a recent upper or lower respiratory tract infection
What is the clinical presentation retropharyngeal cellulitis?
fever, stiff neck, dysphagia and stridor
what is the age of presentation retropharyngeal cellulitis?
more than half occur between 6-12 months
xray features of retropharyngeal abscess?
prevertebral soft tissue thickening
How do you differentiate retropharyngeal abscess from cellulitis?
retrophyngeal abscess will have air, cellulitis will not have air.
CT will show low attenuation collection in case of abscess
What is pseudothickening of prevertebral soft tissue?
false thickiening due to positioning (flexion). should be repeated in extension to confirm
When do you do a CT?
You always do a CT when you see a prevertebral soft tissue thickening
When do you call there is prevertebral soft tissue thickening?
when the soft tissue is more than than AP length of the adjacent cervical vertebra
Do you drain a retropharyngeal abscess or cellulitis?
only abscess (most common). cellulitis is treated conservatively
Summarize retropharyngeal abscess
Occurs between 6-12 months
prevertebral soft tissue thickening
patient usually undergoes CT
Abscess will have air
Large aiway obstruction differential diagnosis?
Intrisic obstruction
fireign body
tracheomalacia
nedobronchial mass
Extrinisic compression:
Vascular sling
lymphnode enlargement
Tracheomalacia
traceal wall softening due to abnormal tracheal cartilage rings
can tracheomalacia diagnosed with lateral film alone?
it cannot be diagnosed with static films
How is tracheomalacia diagnosed?
dynamic imaging - lateral fluoroscopy or endoscopy
What are the most common mass of trachea in children?
hemangiomas
What is the location of tracheal hemangiomas?
subglottic
What is the imaging appearance of tracheal hemangioma?
asymmetric subglottic narrowing
What additional finding would you see in patient with tracheal hemangioma?
facial hemangioma
What are the differential for endotracheal mass?
papilloma/ tracheal granuloma
What is the common location for foreign body?
brochus
what is the clinical presentation?
It is usually silent if in the brochus. Tracheal foreign body presents with stridor
What is the appearance of xray in a patient with foreign body?
It can reduced, normal or increased
how do you confirm a foreign body?
You take in inspiration and expiration.
The affected lung will remain the same due to air trapping.
What do you do if the child is uncooperative ?
take bilateral double decubitus
what is the differential diagnosis for foreign body?
Swyer James syndrome and pulmonary hypoplasia 11111
What is the presentation of tracheal foreign body?
acute respiratory distress, stridor
xray shows soft tissue density within the trachea
Differential diagnosis of extrinisc lower airway obstruction - vascular causes?
Cardio vascular causes? Vascular sling enlargment of ascending aorta enlargement of pulmonary arteries malposition of descending aorta enlargement of the left atrium
Differential diagnosis of extrinisc lower airway obstruction - vascular causes?
Pulmonary slings Enlarged ascending aorta (Marfan's) enlarged pulmonary arteries (due to cong. absence of pulmonary valve) malposition of descending thoraic aorta enlargement of left atrium
Differential diagnosis of extrinisc lower airway obstruction - mediastinal causes?
middle mediastinal mass (bronchogenic cyst)
large anterior mediastinal mass
narrow thoracic inlet
What is double aortic arch
congenital anomaly due to persistence of bboth right and left fourth aortic arche
Presentation of DAA?
presents soon after birth.
usually symptomatic
Mostly isolated
xray lateral
anteriorr indentation of trachea and posterior indentation of esophagus
In AP there is bilateral indentation on either side
Which arch in DAA is dominant?
the bigger arch
Which side is usually dominant in DAA?
right side
Which arch is superior in DAA?
Right side
Why is it immportant to which one is dominant?
because the treatment is ligation of the non dominant arch. If right side is dominant -left thoracotomy. If left is dominant - right thoracotomy
which tracheal level does the DAA compress?
mid/ lower trachea
What is a pulmonary sling?
It is the anomalous origin of lrft pulmonary artery from right pulmonary artery.
It passes between the trachea and esophagus.
what is characteristic finding in pulmonary sling?
impression in the posterior aspect of trachea
impression over the anterior aspect of esophagus
What is the CT finding of pulmonary sling?
pancake trachea - due to anterioposterior compression
what is the association of pulmonary sling?
asymmetric lung inflation
congenital heart disease
complete tracheal ring
anomalous origin of right bronchus
what should you suspect if the trachea is narrowed and round superior to the pulmonary sling?
complete ring
what is right aortic arch with aberrant left SCA
it is the same as mentioned in the question. haha
Is right aortic arch with aberrant left SCA a complete ring?
yes, the right arch indents the trachea anteriorly. Aberrant left SCA causes posterior indentation. The ring is completed by ligamnetum arteriosum
Is left aortic arch with aberrant right SCA a ring?
no, it is not a ring. It causes posterior indentation of esophagus
It may rarely cause dyspahgia
What is the dysphagia called in left aortic arch with aberrant right subclavian artery?
dysphagia lusoria
What additional investigation you have to do in right aortic arch with aberrant left SCA?
CT, as it cannot be reliably distinguished from DAA
What are the mechanisms by which a RAA with ALSCA can cause air compromise?
- Kommerell diverticulum - dilated root of SCA arising from RAA.
- Descending aorta may lie in the midline (usually it is on the side) and cause tracheal compression
What is the difference between inominate artery compression syndrome Vs Innominate artery compression?
asymptomaic patients are called syndrome
what are the findings in innominate artery compression syndrome?
the innominate artery arises slightly towards the left from the aortic arch
and due to the presence of thymus, the thoracic inlet is crowded. this causes compression
As the child grows and thymus involutes, improves.
What are the finding in xray and CT in innominate artery compression syndrome?
anterior compression of trachea
differential for posterior indentation of esophagus?
DAA
RAA with ALSCA
LAA with ARSCA
Obstructive sleep apnea (OSA) what are the causes in children?
adenoid/ tonsillar enlargement
What are the problems with OSA?
morbitites, excess sleep, attention deficit, poor performance
Lateral radiograph finding of adenoids?
> 12 mm soft tissue convex mass in the nasopharynx
how is tonsils evaluated?
physical exam, though it can be seen in lateral radiographs as soft tissue mass extending from soft palate
When is MRI done for OSA?
when symptoms dont improve after adenoid/ tonsil removal
multilevel obstruction as in Down’s
severe obesity
prior to major airway surgery
What is the technique of MR?
MR with T1, T2, GRE (cine) images
When do you call recurrent enlarged adenoids tonsils?
More than 12 mm anterior posterior diameter
Associated intermittent collapse of hypopharynx
V shaped defect maybe seen.
What is the imaging feature of enlarged lingual tonsils?
Dumbbell shaped mass immediately posterior to the tongue in MRI
Why is it important to diagnose lingual tonsils?
It is missed in physical examination
Easily treatable
What is glossoptosis?
Posterior motion of tongue during sleep
What is glossoptosis associated with?
Large tongue
Small jaw
Decrease muscular tone
What syndromes are associated with glossoptosis?
Pierre Robin syndrome
Down syndrome
Neuromuscular disorders
What are the imaging findings of glossoptosis in cine MRI?
Intermittent falling of tongue posteriorly and abutting posterior pharyngeal wall
What are the causes of hypopharyngeal collapse?
It can be primary or secondary
What is the definition of primary hypopharyngeal collapse?
Idiopathic
What is secondary hypopharyngeal collapse?
Is due to a superior obstruction comma example adenoid tonsils
What is the characteristic imaging feature of hypopharyngeal collapse?
Cylindrical collapse of the retroglossal Airway.
The anterior posterior left and right Airway all collapse centrally
How do you differentiate hypopharyngeal collapse from glossoptosis?
Glossoptosis has only anterior posterior motion of tongue whereas hypopharyngeal collapse has Central collapse
What are the constellation of findings in chaos?
Increase lung volumes, flattened hemidiaphragms, hydrops, polyhydramnios.
How is the chaos patient treated?
Exit procedure
What is exit procedure?
The head of Infant is delivered via cesarean, Airway is established with intubation, then the baby is delivered
