Serous Otitis Media Flashcards
What is the main mechanism behind serous otitis media?
Non-infective obstruction of the ET
What are the 2 major causes of ET obstruction?
- Obstruction (structural/functional)
- Increased fluid production (ex. Allergies)
Name the 3 structural causes of ET obstruction
- Adenoid hypertrophy
- Nasopharyngeal carcinoma
- Allergies
In which age group is adenoid hypertrophy most common?
Children
What type of serous otitis media is associated with midline adenoid hypertrophy?
bilateral serous otitis media
What cause of ET obstruction should be suspected in unilateral serous otitis media in adults?
Nasopharyngeal carcinoma
What is the major functional cause of ET dysfunction?
Cleft palate
How does allergic conditions contribute to serous otitis media?
By increasing fluid production in middle ear
Describe the pathology of serous otitis media due to ET obstruction
- ET obstruction
- -ve middle ear pressure
- Tympanic membrane retraction
- Transduction of fluid into middle ear due to increased vascular pressure
What is the C/F of serous otitis media in children?
- painless
- fluctuating
- B/L hearing loss (due to waxing nature of adenoid hypertrophy)
What is the findings in an otoscopy?
Collection of fluid -> thickening of fluid -> cholesterol granuloma -> TM has bluish hue
What is the findings of tuning fork test?
- rinne’s = -ve
- Weber’s = localises to same (worse) ear
What is the finding in pure tone audiometry (PTA)?
AB gap + = conductive hearing loss
What is the finding of tympanometry?
- best investigation used in young children
- B-type curve (-ve pressure decreases compliance)
What is the medical management for SOM?
- Nasal steroid spray = reduces size of adenoid
- Auto inflation = valsalva or pulitzerization
What is the surgical management of SOM?
Done if there is not benefit of medical management for 3 months
Adenoidectomy + myringotomy + grommet insertion
What is a grommet?
A ventilation tube that performs the function of ET until ET returns to normal
Gets extruded once ET regains function, dont need to remove
What are the short term (up to 6 months) grommet used?
Sheperds & Donaldson
What are the mid term (6 months-2yrs) grommet used?
Shah
Armstrong
What are the long term (2yrs) grommet used?
T-tube
What is the site and shape of incision in SOM?
Site = anteroinferior (mimic ET function)
Shape = radial (to hold grommet)
What is the beer can technique in myringotomy?
- Additional incision is made on anterosuperior quadrant
- Air entry pushes fluid out through main incision
- Aids drainage of thick fluid
What is otitic barotrauma?
Pressure-induced damage to the ear in aircraft/scuba diving
Describe the pressure change that normally happens during ascent?
- Decreasing -ve pressure outside middle ear and +ve pressure inside middle ear
- With a pressure difference of >15 mmHg
- ET opens
- Pressure equalized
