| Eustachian Tube Dysfunction The ear is divided into three parts: the external ear includes the visible part of the ear (the pinna) and the ear canal; the middle ear is the air-filled space behind the eardrum that contains the three middle ear bones (the ossicles); and the inner ear contains the sensory organs of hearing (cochlea) and balance (semicircular canals). The Eustachian tube is a narrow tube that connects the middle ear to the back of the nose. Normally, the Eustachian tube opens with every swallow or yawn to act as a pressure-equalizing valve for the middle ear. It also serves to drain the mucus produced by the lining of the middle ear. Blockage of the Eustachian tube isolates the middle ear space from the outside environment. The lining of the middle ear absorbs the trapped air and creates a negative pressure that pulls the eardrum inward. The eardrum is thin and pliable, like plastic wrap, and is densely innervated. When it becomes stretched inward, patients often experience pain, pressure, and hearing loss. Long-term blockage of the Eustachian tube leads to the accumulation of fluid in the middle ear space that further increases the pressure and hearing loss. This is called serous otitis media. Should bacteria contaminate this fluid, a middle ear infection may result, called acute otitis media. Chronic blockage of the Eustachian tube is called Eustachian tube dysfunction. This can occur when the lining of the nose becomes irritated and inflamed, narrowing the Eustachian tube opening or its passageway. Illnesses like the common cold or influenza are often to blame. Pollution and cigarette smoke can also cause Eustachian tube dysfunction. In many areas of the country, nasal allergy (allergic rhinitis) is the major cause of Eustachian tube dysfunction. For reasons which are unclear, the incidence of allergies is increasing in the United States. Obesity can also predispose a patient to Eustachian tube dysfunction because of excess fatty deposits around the passageway of the Eustachian tube. Rarely, Eustachian tube blockage may be the sign of a more serious problem such as nasal polyps, a cleft palate, or a skull base tumor. Young children (especially ages 1 to 6 years) are at particular risk for Eustachian tube dysfunction, serous otitis media, and acute otitis media because they have very narrow Eustachian tubes. Also, they may have adenoid enlargement that can block the opening of the Eustachian tube. Since children in daycare are highly prone to getting upper respiratory tract infections, they tend to get more ear infections compared to children that are cared for at home. Interestingly, the anatomy of the Eustachian tube in infants and young children is different than in adults. It runs horizontally, rather than sloping downward from the middle ear. Thus, bottle-feeding should be performed with the infants’ head elevated, in order to reduce the risk of milk entering the middle ear space. The horizontal course of the Eustachian tube also permits easy transfer of bacteria from the nose to the middle ear space. This is another reason that children are so prone to middle ear infections. Most children older than 6 years have outgrown this problem and their frequency of ear infections should drop substantially. Medical Treatment
Surgical Treatment The primary goal of surgical treatment is to bypass the Eustachian tube and re-establish ventilation of the middle ear. This will restore hearing, relieve pressure sensation in the ear, and reduce the tendency for middle ear infections. Myringotomy: Pressure Equalization Tubes: The major disadvantage of pressure equalization tubes is that water must be kept out of the ear. This requires using earplugs or a cotton ball smothered in petroleum jelly while bathing. Swimming usually requires custom earplugs fit individually to the patient’s ear. Water that gets into the ear canal can carry bacteria through the tube into the middle ear space and cause an ear infection. This is noted as a purulent drainage (white, green, or yellow pus) from the ear. This type of ear infection can be easily treated with antibiotic eardrops. The other risk of either a myringotomy or a pressure equalization tube is that the incision may not heal. This may eventually require surgery (tympanoplasty) to patch the hole. Eustachian Tube Dysfunction Related to Flying Individuals with Eustachian tube problems may experience difficulty equalizing their middle ear pressure when flying. During airplane travel the ears are subject to large swings in barometric pressure. As you ascend, the cabin air pressure drops and a relative positive pressure builds up in the middle ears. For most people, this pressure easily escapes out through the Eustachian tube. Thus, the pressure of the middle ear equilibrates with that of the cabin air pressure (about 6000 feet above sea level). Pressure equalization during descent is much more difficult. The cabin air pressure gradually increases during descent. Thus, a relative negative pressure develops in the middle ear that tends to lock the Eustachian tube closed. Yawning, swallowing, chewing gum, or trying to “pop” ones ears usually will help the Eustachian tube to open at some point, equalizing the middle pressure. Most adults can fly without difficulty unless they have an illness that has temporarily swollen the lining of the Eustachian tube and narrowed its passageway. Some adults have very mild Eustachian tube dysfunction and only have symptoms when flying. Prevention of Middle Ear Problems with Flying
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