Barotrauma is an injury caused by rapid changes in environmental pressure, as occur during airplane flights or scuba diving. Barotrauma can cause ear pain or damage the eardrum.
The eardrum (tympanic membrane) separates the ear canal and the middle ear. If air pressure in the ear canal from outside air and air pressure in the middle ear change rapidly or are unequal, the eardrum can be damaged. Normally, the eustachian tube, which connects the middle ear and the back of the nose, helps maintain equal pressure on both sides of the eardrum by allowing outside air to enter the middle ear. When environmental pressure changes suddenly—for example, during the ascent or descent of an airplane or a deep-sea dive—air must move through the eustachian tube to equalize the pressure in the middle ear. (See also Barotrauma.)
If the eustachian tube is partly or completely blocked because of scarring, a tumor, an infection, the common cold, or an allergy, air cannot move in and out of the middle ear. The resulting pressure difference causes pain and often hearing loss and may bruise the eardrum or cause it to tear (rupture) and bleed. If the pressure difference is very great, the oval window (the entrance into the inner ear from the middle ear) may also rupture, allowing fluid from the inner ear to leak into the middle ear. This type of rupture is called a perilymph fistula. Hearing loss or vertigo occurring during descent in a deep-sea dive, particularly if there is vertigo, suggests that such leakage is taking place.
The Eustachian Tube: Keeping Air Pressure Equal
The eustachian tube helps maintain equal air pressure on both sides of the eardrum by allowing outside air to enter the middle ear. If the eustachian tube is blocked, air cannot reach the middle ear, so the pressure there decreases. When air pressure is lower in the middle ear than in the ear canal, the eardrum bulges inward. The pressure difference can cause pain and can bruise or rupture the eardrum. |
Treatment of Barotrauma of the Ear
Maneuvers to relieve pressure
When sudden changes in pressure cause a sense of fullness or pain in the ear, often the pressure in the middle ear can be equalized and the discomfort can be relieved by several maneuvers. If outside pressure is decreasing, as in a plane ascending, the person should try breathing with the mouth open, yawning, chewing gum, or swallowing. Any of these measures may open the eustachian tube and allow air to pass out of the middle ear. If outside pressure is increasing, as in a plane descending or a diver going deeper underwater, the person should pinch the nose shut, hold the mouth closed, and try to blow gently out through the nose. This maneuver forces air through the blocked eustachian tube.
Occasionally, if people have hearing loss and severe pain, myringotomy may help. For this procedure, an opening is made through the eardrum to allow fluid to drain from the middle ear (see figure Myringotomy)
If people have a perilymph fistula, surgery may be necessary to close the fistula and stop the leak.
