Eustachian Tube Dysfunction Flashcards
How does eustachian tube dysfunction impact the pressure in the middle ear?
Eustachian tube dysfunction (ETD) results in negative pressure in the middle ear cleft.
Briefly describe eustachian tube dysfunction
Eustachian tube dysfunction is when the tube between the middle ear and throat is not functioning properly. The Eustachian tube is present mainly to equalise the air pressure in the middle ear and drain fluid from the middle ear.
When the Eustachian tube is not functioning correctly or becomes blocked, the air pressure cannot equalise properly and fluid cannot drain freely from the middle ear. The air pressure between the middle ear and the environment can become unequal. The middle ear can fill with fluid.
What can cause eustachian tube dysfunction?
Eustachian tube dysfunction may be related to a viral upper respiratory tract infection (URTI), allergies (e.g., hayfever) or smoking.
What are the risk factors for eustachian tube dysfunction?
- Cleft palate
- Adenoid hypertrophy
- Allergic rhinitis
- Chronic rhinosinusitis
- Eustachian tube trauma
- Eustachian tube infection
What are the clinical features of eustachian tube dysfunction?
Eustachian tube dysfunction may present with:
- Reduced or altered hearing
- Popping noises or sensations in the ear
- A fullness sensation in the ear
- Pain or discomfort
- Tinnitus
Symptoms tend to get worse when the external air pressure changes and the middle ear pressure cannot equalise to the outside pressure, for example, flying, climbing a mountain or scuba diving.
How does eustachian tube dysfunction present on otoscopy?
Otoscopy may appear normal, but it is important to exclude other causes (e.g., otitis media).
How is eustachian tube dysfunction diagnosed?
Often Eustachian tube dysfunction gives a typical set of symptoms and is associated with a clear cause, for example, a recent viral upper respiratory tract infection or hayfever. In this situation, investigations are not required as the symptoms will resolve with time or simple treatments.
What investigations should be ordered for eustachian tube dysfunction?
In persistent, problematic or severe symptoms, investigations to help establish the diagnosis and cause include:
- Tympanometry
- Audiometry
- Nasopharyngoscopy
- CT scan to assess for structural pathology
Briefly describe the role of tympanometry
Tympanometry involves:
- Inserting a device into the external auditory canal (ear canal)
- Creating different air pressures in the canal
- Sending a sound in the direction of the tympanic membrane
- Measuring the amount of sound reflected back off the tympanic membrane
- Plotting a tympanogram (graph) of the sound absorbed (admittance) at different air pressures
The amount of sound absorbed by the tympanic membrane and middle ear (not reflected back to the device) is known as the admittance.
Normally, sound is absorbed best when the air pressure in the ear canal matches the ambient air pressure. The ambient air pressure is equal to the middle ear pressure in healthy ears.
How does eustachian tube dysfunction present on tympanometry?
When there is Eustachian tube dysfunction, the air pressure in the middle ear may be lower than the ambient air pressure because new air cannot get in through the tympanic membrane to equalise the pressures. As a result, the tympanogram will show a peak admittance (most sound absorbed) with negative ear canal pressures.
Briefly describe the management of eustachian tube dysfunction
Treatment options for Eustachian tube dysfunction include:
- No treatment, waiting for it to resolve spontaneously (e.g., recovering from the viral URTI)
- Valsalva manoeuvre (holding the nose and blowing into it to inflate the Eustachian tube)
- Decongestant nasal sprays (short term only)
- Antihistamines and a steroid nasal spray for allergies or rhinitis
- Surgery may be required in severe or persistent cases
Otovent is an over the counter device where the patient blows into a balloon using a single nostril, which can help inflate the Eustachian tube, clear blockages and equalise pressure.
What are the surgical options for eustachian tube dysfunction?
There are three main surgical options:
- Treating any other pathology that might be causing symptoms, for example, adenoidectomy (removal of the adenoids)
- Grommets
- Balloon dilatation Eustachian tuboplasty
Briefly describe the role of Grommets
Grommets are tiny tubes inserted into the tympanic membrane by an ENT surgeon. This allows air or fluid from the middle ear to drain through the tympanic membrane to the ear canal. Grommets are usually inserted using a local anaesthetic. The procedure is relatively safe with few complications. Grommets typically fall out within 18 months.
Briefly describe the role of Balloon dilatation Eustachian tuboplasty
Balloon dilatation Eustachian tuboplasty involves inserting a deflated balloon into the Eustachian tube, inflating the balloon for a short period (i.e., 2 minutes) to stretch the Eustachian tube, then deflating and removing it. This is usually done under general anaesthetic.
What are the complications of eustachian tube dysfunction?
- Serous otitis media (otitis media with effusion, glue ear)
- Chornic otitis media
- Acute otitis media
