The Eustachian tube is a narrow channel, connecting the middle ear with the nasopharynx (the upper throat area just above the palate and behind the nose). The Eustachian tube is approximately 1-½ inches in length and its narrowest portion is the area near the middle ear space. Several small muscles that control its opening and closing surround it. In children, the Eustachian tube is in more of a flat or horizontal position between the middle ear and the nasopharynx. Additionally, the tubes are narrower and closer to the adenoids. In adults, it slopes or slants downward. The difference in the tube position in children is due to facial and base of the skull structure. As children grow, the Eustachian tube will move further from the adenoids and begin to slant downward as the skull enlarges.
The Eustachian tube has two functions. The primary function is as a pressure-equalizing valve for the middle ear. The middle ear space is filled with air, and this air needs to remain like the “outside” air pressure. The Eustachian tube is normally closed. It needs to open to equalize the pressure to that of the atmosphere. In so doing, it allows air into the middle ear to replace air that has been absorbed by the middle ear lining (mucous membrane), or to equalize pressure changes occurring with altitude changes. Under normal circumstances, the Eustachian tube opens for a fraction of a second in response to swallowing or yawning. Anything that interferes with this periodic opening and closing of the Eustachian tube may result in a negative pressure in the middle ear and other ear symptoms, such as fullness or a “plugged” sensation. The Eustachian tube’s secondary function is to drain accumulated fluid, blood, or infection from the middle ear space. Due to its anatomical placement in infants and children, there is a higher risk for middle ear infection to occur, as a result of nose or throat infections.
Obstruction of blockage of the Eustachian tube results in a vacuum effect in the middle ear, creating negative middle ear pressure. As a result, the eardrum gets “sucked inward” and becomes retracted. In an adult, this is usually accompanied by some discomfort, such as fullness or pressure in the ear, and may result in a mild hearing loss. In children, there maybe no symptoms. If the obstruction is prolonged, fluid may be sucked into the middle ear from the lining of the mucous membranes or across the capillary wall. As this clear or amber colored fluid accumulates in the middle ear it is called serous otitis media . Serous otitis media is very common in young children. Eustachian tube dysfunction also occurs in older children and adults, and is typically associated with upper respiratory infections or allergies. The limitation of mobility of the eardrum due to the presence of a vacuum or fluid in the middle ear accounts for the hearing impairment associated with a Eustachian tube dysfunction.
On occasion, the opposite of blockage occurs, and the Eustachian tube remains excessively open for a prolonged period. This is called abnormal patency of the Eustachian tube (e.g. patulous Eustachian tube). This is less common than Eustachian tube dysfunction and serous otitis media, and it occurs primarily in adults. It sometimes begins after a significant weight loss and sometimes after an ear infection. Because the tube is constantly open, the patient may hear himself breathe, and his voice may reverberate in the affected ear. Fullness and a blocked feeling are also common sensations experienced by the patient. The typical symptoms are generally worse with exercise, and relieved when lying supine, because the head becomes level with heart, and the Eustachian tube becomes more congested and therefore blocked in the supine position. Typically no aural symptoms are present while lying in bed in the morning, but upon arising and moving about the symptoms re-occur. Abnormal patency of the Eustachian tube can be extremely annoying but does not produce a hearing impairment.
- Estrogen (Premarin) nasal drops (25 mg in 30 cc normal saline, 3 drops several times a day) has been used to temporary occlude the Eustachian tube opening.
- Myringotomy and insertion of a ventilating tube can result in increasing the symptoms and generally is recommended.
Treatment of abnormal Eustachian tube function
There are many alternatives to treat a poorly functioning Eustachian tube. Nasal steroid sprays are frequently tried, and in adults nasal and oral decongestants may be recommended. If an infection is thought to be present, then antibiotics are appropriate. If allergies are thought to be contributing to the Eustachian tube dysfunction, allergy testing (which can be performed through our office) and allergy treatment may be indicated.
When Eustachian tube dysfunction persists despite maximal medical therapy, surgical procedures can be utilized. Ventilation tube placement into the eardrum is indicated for persistent or frequently recurrent ear infections. For most adults and older children, the procedure can be performed in the office, with the use of topical or local anesthetic. Younger children require the assistance of an anesthesiologist so that the delicate surgery can be safely completed. The procedure takes roughly 10 minutes, and most children resume normal activities and diet several hours after the operation, once the effects of the anesthetic wear off. Pain is minimal to none. The tubes in the eardrum are designed to be temporary, and typically fall out 9 - 12 months. Long term tubes may be used and can remain present a couple of years after placement. The hope is that the Eustachian tube will have a chance to grow, develop more normally, and resume normal function once the tube extrudes. In children with a hearing loss caused by otitis media, after the tube placement, hearing typically returns to normal and they become more sensitive to sounds around them.
Individuals with a Eustachian tube problem may experience difficulty equalizing middle ear pressure when flying. When an aircraft ascends, the atmospheric pressure decreases. This results in a relative increase in the middle ear air pressure compared to the surrounding cabin pressure. When the aircraft descends, just the opposite occurs: atmospheric pressure increases in the cabin of the aircraft, and there is a relative decrease in the middle ear pressure compared to the surrounding cabin pressure. Either situation may result in discomfort in the ear due to pressure and stretching of the eardrum, when the Eustachian tube is not functioning properly to equalize the pressure between middle ear and cabin pressure. Usually, this discomfort is experienced during descent of the aircraft. To avoid middle ear problems associated with flying, you should not fly if you have an acute upper respiratory problem such as a common cold, allergy attack, or sinus infection. Should you have such a problem, or a history of chronic Eustachian tube problems, and must fly; you may help avoid ear difficulty by observing the following recommendations:
- Obtain from your drug store the following over the counter items:
- Antihistamine tablets such as Allegra and a plastic squeeze bottle of Afrin decongestant nasal spray.
- One must be careful using these medications if you are not otherwise healthy and have conditions such as hypertension or heart rhythm disturbances. If you do have other medical conditions, you may discuss these recommendations with your primary care physician.
- Following the container directions, begin taking Allegra tablets the day before your air flight. If you experienced any problems equalizing your middle ear pressure during the flight, continue the medication for 24 hours after the flight.
- Following the container directions, use the nasal spray shortly before boarding the aircraft. Should your ears "plug up" upon ascent, hold your nose and swallow while attempting to force air up the back of the throat. This will help equalize your middle ear pressure with the cabin pressure in the aircraft.
- Forty-five minutes before the aircraft is due to land, use the nasal spray every five minutes for fifteen minutes. Chew gum to stimulate swallowing. Should your ears "plug up" despite this, hold your nose and blow gently toward the back of the throat, while swallowing. This will help to gently force air up the Eustachian tube into the middle ear (termed the Valsalva maneuver).
None of these recommendations or precautions need to be followed if you have a tube in your eardrum.