Dr. Greene’s Answer:
Dear Dr. Fitzgerald, Thank you for sharing your concern. Although I have at least two readers review every answer before it is posted, I welcome additional input. It is an honor for me to be “reviewed” by other physicians.
After receiving your email, I re-read the answer you are referring to. It is to a reader who was concerned about when ear tubes should be used. That answer used to say, “This pressure-equalization (PE) tube provides a temporary, extra Eustachian tube to allow bacteria and fluid to drain from the middle ear.” This statement was a shorthand summary of a more complicated process. I agree with you that it could lead parents to be concerned about fluid continually draining out of the ear. I have changed that entry to read, “This pressure-equalization (PE) tube provides a temporary, extra Eustachian tube which can help in several ways.” That statement is linked to this page for a more complete explanation of how ear tubes facilitate the drainage of bacteria and fluid from the middle ear.
Here is an excerpt from my book, The Parent’s Complete Guide to Ear Infections:
In the first half of the twentieth century, it was noticed that spontaneous holes in the eardrum often cured ear infections. These spontaneous holes, however, appeared and closed unpredictably. Several innovators tried various ways of keeping the holes open, including inserting fish bones, lead wires, and gold rings. Since 1954, the practice of intentionally making a small hole in the eardrum and inserting a small tube to keep the hole open has become very common. Today, more than 2 million ear tubes are implanted every year in the United States (Pediatric Clinics of North America, December 1996).
Ear tubes are made from a variety of materials, including ceramic, gold, plastic, Silastic, stainless steel, Teflon, and titanium. There is no proven advantage of one material over another.
A tube in the eardrum improves drainage of the middle ear space. Years ago, when a can of soda was opened with a can opener, a hole was made on both sides of the lid. While fluid poured out one hole, air was able to enter the can through the other, thus improving outflow. Ear tubes function in much the same way. When the middle ear space is closed, a suction effect prevents easy clearance of the contents down the eustachian tube. A blocked eustachian tube makes this even more difficult. When a tiny hole is made in the eardrum, the contents of the middle ear space flow far more easily either down the eustachian tube or out the inserted ear tube.
Unfortunately, this can also make it easier for bacteria to enter the middle ear space. It is easier for the contents of the nose and throat to travel up the eustachian tube if there is an opening at the other end. Also, bacteria can enter through the outer ear. Studies have shown, however, that for most children, improved drainage far outweighs the increased vulnerability.
It is my editorial goal to make every entry on Dr. Greene’s HouseCalls the best piece of its length, for parents, that is available on the Internet or in print. Thank you, Dr. Fitzgerald, for helping me achieve my goal.