What is the Eustachian Tube?
FUNCTION OF THE EUSTACHIAN TUBE
The Eustachian tube is a narrow tube that connects the middle ear with the upper throat area in back of the nose. The Eustachian tube functions as a pressure equalizing valve of the ear. Under normal circumstances, the Eustachian tube opens for a fraction of a second when swallowing or yawning. This allows air into the middle ear to equalize pressure changes. Anything that interferes with the opening and closing of the Eustachian tube may result in a hearing loss or other ear symptoms.
Blockage of the Eustachian tube results in a negative middle ear pressure, which causes a sucking in of the eardrum. In an adult, this is usually accompanied by some discomfort, such as a fullness or feeling of pressure. It may result in a mild hearing impairment and tinnitus. There may be no symptoms in children. If the blockage does not go away, the fluid may be sucked in from the mucous membrane in the middle ear, creating a fluid in the middle ear or an ear infection. This occurs frequently in children in connection with an upper respiratory infection or allergies and can cause temporary hearing loss.
On the other hand, sometimes the tube remains open for a prolonged period. This is called abnormal patency of the Eustachian tube. This is less common than fluid in the middle ear, but occurs mainly in adults. Because the tube is constantly open, the patient may hear himself breathe or hear his voice resonate in the affected ear. The patient may feel fullness and a blocked feeling. Abnormal patency of the Eustachian tube is annoying, but does not cause a hearing loss.
EUSTACHIAN TUBE PROBLEMS RELATED TO FLYING
Individuals with a Eustachian tube problem may experience difficulty equalizing middle ear pressure when flying. When an airplane flies up or down, the air pressure in the cabin changes. Either situation may result in discomfort in the ear due to abnormal middle ear pressure compared to the cabin pressure if the Eustachian tube is not functioning properly. Usually, this discomfort is experienced when the airplane is landing.
SEROUS OTITIS MEDIA
Serous otitis media is a term used to describe fluid in the middle ear. Serous otitis media is the most common cause of hearing loss in children. Fortunately, the hearing loss associated with this condition usually is not permanent. Proper treatment restores the hearing back to what it was and prevents secondary complications.
In serous otitis media, the external and inner ear and hearing nerve are normal. The problem stems from inadequate function of the Eustachian tube. The tube becomes blocked and does not allow air to fill the middle ear space. Subsequently, fluid forms from the middle ear lining. The presence of this fluid dampens the vibration of the eardrum and causes a mild to moderate hearing impairment. This fluid makes the ear more susceptible to back-to-back ear infections in many children. The trapped fluid is an ideal place for bacteria to grow rapidly. The pus produced from the bacteria puts pressure on the eardrum, resulting in pain.
Serous otitis media may be present without ear infections, and a mild hearing loss may be the only sign of its presence. Severe serous otitis media is usually the result of blockage of the Eustachian tube from an upper respiratory infection or an allergy attack. The fluid may become infected when bacteria is present, leading to an ear infection in the middle ear.
When an infection does not develop, the fluid remains in the middle ear until the Eustachian tube begins to function properly again, at which time the fluid is absorbed or drains down the tube into the back of the throat.
Longstanding serous otitis media results from a blocked Eustachian tube or from a thickening of the fluid so that it cannot be absorbed or drained down the tube. This condition is usually associated with a hearing impairment. There may be ear pain, especially when the individual catches a cold. Ear infections that continue to occur for long periods of time may result in middle ear damage.
CAUSE OF SEROUS OTITIS MEDIA
Serous otitis media may result from any condition that interferes with the opening and closing of the Eustachian tube. The causes may be present at birth, due to infection or allergy, or may be due to physical blockage of the tube.
Treatment of serous otitis media is usually handled by a physician. They may aim to treat an upper respiratory infection or allergy attacks. This may include antibiotics, antihistamines (anti-allergy drugs), decongestants or nasal sprays. As the upper respiratory infection subsides, it may leave the patient with a Eustachian tube blockage that requires antibiotic treatment. Allergy is often a major factor in the development or persistence of otitis media. Mild cases can be treated with anti-allergy drugs. More persistent cases may require allergic evaluation and treatment, including injection treatment.
Treatment of longstanding fluid may be medical or, in some cases, surgical. The primary goal of surgical treatment of longstanding middle ear fluid or infections is to re-establish ventilation of the middle ear and equalize the pressure. This keeps the hearing at a normal level and prevents recurring infections that might damage the ear drum and ear bones. Some surgical approaches include cutting a small slit in the eardrum from which the fluid can drain before the ear heals, or inserting a semi-permanent tube in the slit that allows fluid to drain over a period of time. If the tubes do not come out of the ear on their own, they can be removed at a later date, but most of the time it is preferable to let the tubes work their way out of the eardrum. When the tube comes out, the eardrum heals. The Eustachian tube generally resumes its normal pressure-equalizing function.
In adults, the incision in the eardrum and insertion of a ventilation tube is usually performed in the office under local anesthesia. In children, general anesthesia is required.