This edition of The Reading Room is all about airway films. Drs. Kopp (Emergency Medicine) and Hasweh (Radiology) shared these cases at a recent conference in the Division of Emergency Medicine at Cincinnati Children’s.
The first case is a 2 year old healthy immunized male with stridor at rest and a barky cough. He is tachypneic, and very obviously has croup. The X-Rays obtained are significant for loss of the normal “shoulder” with gradual symmetric tapering of the subglottic trachea. The “steeple sign!”
Here is a helpful, annotated side by side diagram of normal versus croup appearance in the airway film.
This is an 11 year old fully immunized girl with a PMH of OSA s/p T&A who presents with fever, sore throat, wheezing and difficulty breathing. She is tripoding on arrival, is tachypneic and her sats are 97% on RA. On exam she has stridor at rest, is hoarse, has suprasternal retractions and the anterior of the neck is tender to palpation. She did have some improvement in the stridor following a racemic epinephrine treatment – but didn’t completely normalize, hence the following X-Ray.
These films show subglottic narrowing consistent with atypical croup vs tracheitis. ENT performed a flexible scope of the nasopharynx due to noted tenderness of the anterior airway and saw no exudate or pooling of secretions. She was admitted to medicine for observation with no further issues with an ultimate diagnosis of Croup/Laryngitis.
This is a second grader with stridor at rest and difficulty breathing for the past three hours. Mom specifically noted periods of breath holding that seemed to be related to not being able to handle her secretions while sleeping. On exam she has inspiratory stridor at rest with no retractions noted, but significant tenderness over the anterior trachea
These films show subglottic narrowing with irregularity of the tracheal walls suggesting pseudomembranes and the diagnosis of tracheitis.
There are some significant X-Ray findings here. The lateral shows multiple irregular intraluminal filling defects (white open arrow), tracheal wall irregularity (white solid arrow) caused by the pseudomembranes and moderate tracheal lumen narrowing. This is also called the “Candle dripping sign”: plaque-like irregularity with loss of well defined smooth parallel tracheal walls with filling defect.
Pro-Tip: Airway films for tracheitis are specific but not sensitive. A Negative X-Ray does not rule out tracheitis!
The 4th and final case is a grade schooler with with complaint of neck pain for the past few days, now with difficulty now opening mouth and swallowing solids. She has trismus and pain on neck extension on exam.
The film shows an enlarged retropharyngeal space concerning for retropharyngeal cellulitis/abscess.
Normal Prevertebral soft tissue:
- C2: less than or equal to 7mm at any age
- C6: less than or equal to 14mm if less than 15, less than 22mm otherwise
To adequately show the retropharynx the X-Ray must be performed during inspiration with neck extension. I’ve definitely been fooled by this before. Neck flexion and exhalation can make the prevertebral space look wider than it is on lateral X-Ray.
Though the patient was admitted on IV Ampicillin/Sulbactam they failed to improve. A CT of the head and neck was performed and revealed a well-defined left retropharyngeal space abscess that was ultimately managed in the OR with I&D.