Ear Infections, Hearing and Ear Tube Surgery




What is an ear infection?

There are several types, but in children, an "ear infection" usually means otitis media, a bacterial infection of the middle ear.

There are three main parts of the ear- the outer ear, the middle ear and the inner ear. The outer ear is just the pinna (the part that sticks out of the head) and the ear canal, which ends at the eardrum. The ear canal is where earwax accumulates. The middle ear is the space behind the eardrum. This space is drained and ventilated by a pathway called the Eustachian tube, which runs from the ear to the back of the nose, near the adenoids. The inner ear is deep inside the skull, and is where the nerves and other structures controlling hearing and balance are located. It is rarely affected by childhood ear infections.





In the case of otitis media, the middle ear fills up with infected fluid (pus). This can cause pain, fever, irritability and a temporary hearing loss. Acute otitis media is often treated with antibiotics. Click here to see the normal eardrum, and here to see what the ear looks like with otitis media.

Another common type of ear infection is otitis externa, or "swimmer's ear", an infection of the skin of the ear canal (outside of the eardrum). The ear canal is a warm, moist place which is not easily cleaned, and a superficial skin infection can linger in this region (just like a diaper rash!). These patients have ears which hurt when moved and which itch severely. Otitis externa is usually treated with ear drops, but it is often important to thoroughly cleaning the ear (possibly using a microscope and suction). Cleaning is NOT something that should be done by anyone but a doctor with experience in this procedure. Do not try to clean the ear yourself, this may make things worse. In severe cases of otitis externa, antibiotics are also used.

Although otitis media and otitis externa can both be present at the same time, they generally have nothing to do with each other. In some cases, though, if there is a hole (or ear tube) in the eardrum, fluid can drain from a middle ear infection into the ear canal, causing swimmer's ear.

If there is no hole, the eardrum is watertight. Therefore, getting water in the ear canal from swimming or bathing cannot cause otitis media or any other type of middle ear fluid.


Why do children get more ear infections than adults?

The main reason why children are prone to ear infections is related to the tube that connects the middle ear to the back of the nose (the Eustachian tube). This tube is the body's natural way to ventilate the ear, to allow fluid to drain when the ear is infected, and to allow air to enter the ear and keep it healthy. A child's Eustachian tube does not function as well as an adult's tube for a variety of reasons. Although this is often oversimplified by saying that the child's tube is "flatter" or "narrower", there really are many differences. For example, the tube cartilage is floppier, it is angled differently, and the muscles which open the tube do not work as well. The bottom line is that a child's ears have relatively poor ventilation.

Just as with all other aspects of human biology, there is a broad range of Eustachian tube function in children- some children get lots of ear infections, some get none. But overall, young children are more prone to ear infections and ear fluid. This tends to improve in most children by age 6-8, when the tube matures towards the adult levels of function.

In addition to problems with the Eustachain tube, young children have immature immune systems and may be exposed to other sick children in a school or day care setting. Upper respiratory tract infections (such as colds) can make the child's Eustachian tube function even worse, by causing swelling in the walls of the tube. Furthermore, children have large adenoids, a pad of tissue like a tonsil in the back of the nose which can block or contaminate one end of the Eustachian tube.






Can my child catch an ear infection from another child?

Ear infections are not contagious, but are often associated with upper respiratory tract infections (such as colds). Such an infection causes swelling in the lining of the nose and the natural drainage pathways of the ears (the Eustachian tube), which makes ear ventilation worse and makes an ear infection more likely. Also, bacteria or viruses can move from the nose to the ear through the Eustachian tube. If your child simply has an ear infection but no cold symptoms, he or she should not be contagious.


What is the difference between fluid in the ear and an ear infection?

Otitis media (middle ear infection) means that the space behind the eardrum (the middle ear) is full of infected fluid (pus). If there is no fluid, there is no ear infection (no matter how red the eardrum appears).

Sometimes, the fluid behind the ear is not infected, but instead is clean ("sterile"). This can happen after treating an ear infection with antibiotics, or can occur without any previous infection. Sterile fluid can be clear, yellow, thick, thin, or filled with bubbles. This photograph shows an ear which is partially filled with this type of fluid.

Clean middle ear fluid (also known as an effusion) and otits media can occur in the same child at different times. This is because the underlying cause (poor ventilation through the Eustachian tube) is the same in both cases, not because the sterile fluid is prone to becoming infected.


How do ear infections and fluid affect hearing?

The good news here is that hearing loss associated with fluid in the middle ear is not permanent, and if the ear has no other underlying problems (which would be very rare), hearing will return to normal levels when the fluid goes away. Infected fluid (acute otitis media) can cause a hearing loss just like sterile fluid, but unless the fluid persists after the infection is gone, the brief reduction in hearing is usually not noticed.

Sound reaching the eardrum and is normally transmitted to the inner ear by a chain of 3 tiny bones in the middle ear (the ossicles). Sound waves hit the eardrum and cause a vibration, which then vibrates the ossicles, which vibrate the inner ear. The inner ear turns these vibrations into electrical signals, which are then sent to the brain. The brain interprets the electrical signals as sound. If the chain of bones and the eardrum are intact, they amplify the sound coming in to the inner ear.

Fluid in the middle ear affects hearing by interfering with the normal vibration of this system. You can imagine that a drum filled with water would not make a loud sound when hit, since the water stops the drumhead from vibrating. In the same way, middle ear fluid stops the eardrum and ossicles from vibrating properly.


What can be done about recurrent ear infections?

Recurrent ear infections are usually treated with antibiotics. In many cases, the "milder" antibiotics (such as amoxicillin) no longer work when the bacteria become resistant to them, and more "powerful" antibiotics must be used. There are some vaccines that may be effective in certain cases; these should be discussed with your pediatrician. Although a variety of allergies can contribute to swelling in the lining of the nose and in the drainage pathway of the ear (the Eustachian tube), allergies will usually cause other symptoms besides ear infections. It is uncommon to have ear infections as the only sign of an allergy. If there are other clear indications of allergies, they should be addressed separately.

It may be desirable to try to prevent ear infections before they occur. One way to do this is with prophylactic (preventative) antibiotics. This is a low dose of an antibiotic given for a longer time (1-3 months) to keep bacteria from gaining enough of a foothold in the middle ear to cause infection. The antibiotics used for this are usually the "milder" ones, such as amoxicillin or gantrisin. While the general trend seems to be away from this approach (because of concerns regarding overuse of these drugs), prophylactic antibiotics still may be used in certain situations.


What can be done about fluid in the ear without infection?

A "sterile" effusion (no infection) may follow the successful treatment of an ear infection. This fluid will usually go away by itself as the body's own natural ventilation pathway (the Eustachian tube) gradually drains the ear. Although some physicians feel that a single, short course of a mild antibiotic may help the fluid to resolve over a few months, there is no clear evidence that this is helpful. There is also no use in giving many courses of powerful antibiotics in an attempt to clear up the fluid once the infection is gone.

There are a number of other medications (nasal steroid sprays, oral steroids, antihistamines and decongestants) that are occasionally used in children with middle ear fluid. At present, these are not generally recommended since a clear benefit has not been shown, and they may have undesirable side effects.


Why do some children need surgery for ear infections or fluid?

Some children with persistant ear fluid or many ear infections may be offered surgery. This is usually a last resort after it has become clear that medical (non-surgical) treatment is not helping, or that the risks of medical treatment (such as reactions to antibiotics) are too high. If the effusion has persisted for some time (2-3 months) it is less likely that the fluid will resolve on its own and the child may need surgery. Similarly, if a child has had more than five or six ear infections in a year, and the medical treatment described above has not been successful in controlling the problem, the child may need surgery. The surgery done for these conditions is known as "pressure equalizing tube placement", or "BMT".

BMT stands for Bilateral (performed on both ears) Myringotomy (the creation of a tiny hole in the eardrum) and Tubes. "Tubes" refers to the placement into that hole of a small plastic, rubber or metal tube to keep it open. The operation works because the tube keeps the ears drained and ventilated, doing the work of the poorly functioning Eustachian tube. The tube acts as a crutch, keeping the ear ventilated while awaiting the natural process of maturation that will cause the Eustachian tube function to improve. Remember, the tube does not "fix" the Eustachian tube, it only bypasses it.

There are two basic types of tubes, short acting and long acting. Although there are dozens of styles and brands, they all fall into one of these two categories. Each surgeon has his or her own preferences with regard tube selection. Generally, short acting tubes are used in otherwise normal children for their first or second set of tubes. These tubes reliably fall out of the eardrum within 4 months to a year. Here is a photograph showing a set of short acting tubes next to a dime for comparison, and here you can see a short acting tube in place, through the eardrum.

Long acting tubes are used with children suspected of having severe, long-term Eustachian tube problems. Such problems may be seen in children with cleft palate, Down syndrome, various head and neck syndromes, or older children (teenagers) who have required multiple sets of tubes. While they make tube replacement surgery less likely, they have a greater chance of leaving a permanent hole in the eardrum after they fall out or are removed, which would then require more surgery to repair.

The operation is done through the ear canal using a microscope and very delicate instruments. After cleaning out the wax from the ear canal, a tiny hole is made in the eardrum with a small knife, and any fluid is suctioned from the ear. The tube is then inserted into the hole, where it is held in place by its flared ends (shaped like a small dumbell). No external cuts or sutures are used, and the entire operation usually takes less than ten minutes. Click here to see how the operation is done.

Some surgeons recommend removing the adenoids at the same time that tubes are placed. The logic behind this practice is that the adenoids sit at one end of the Eustachian tube (in the back of the nose), and may contribute to ear infections and fluid. It is not totally clear why the adenoids have this effect. One theory is that they physically block the Eustachian tube, interfering with its function. Another theory is that they provide a place for bacteria to grow which then travel up the Eustachian tube into the ear.

Adenoidectomy adds a small amount of time and risk to the surgery, and like all operations, should not be done unless there is a good reason. I generally recommend adenoidectomy at the same time as tube placement only if the adenoids are large and causing significant blockage of the nose (such as sleep apnea). However, each child is different, and there are a many factors which contribute to the decision to remove the adenoids.


What are the benefits of inserting pressure equalizing tubes?

In children who have persistent ear fluid, the benefit is immediate. Once the fluid is suctioned from the ear, hearing is improved. Sometimes, especially if the fluid is thick, drainage from all the small spaces throughout the middle ear may continue for a day or two. The ventilation that the tube provides keeps the fluid from coming back as long as the tube is functioning (not clogged with wax or other debris).

For children with recurrent ear infections, the tube makes it less likely that the ear will become infected in the future, reducing the need for antibiotics. However, it is still possible to get an ear infection, especially during a cold. In this case, though, the ventilation tube serves to drain the infected fluid out of the ear. Therefore, the child experiences less pain and fever than they would if the infection were undrained (as before surgery). Furthermore, antibiotics are rarely needed. If the ear drainage persists, eardrops are sometimes used.


What are the risks of inserting pressure equalizing tubes?

The most common complication of tube placement is persistent drainage of liquid from the ear. Although the tube is placed to allow for drainage as well as ventilation, sometimes the drainage continues for several days and may cause symptoms such as itching or a foul odor. In this case, it may require specific treatment. The ear is suctioned to keep the tube from getting clogged and to keep the drainage from infecting the skin of the ear canal ("swimmer's ear"). Also, a medicated ear drop may be perscribed to help fight the infection. It is important not to use these drops for too long, so be sure to ask you doctor about when they should be stopped. Occasionally, an antibiotic may be added to help the infection clear up more quickly, especially if the drainage lasts for more than a few weeks.

Persistent perforation of the eardrum can occur after the tube is out, although this is very rare with short acting tubes. Scarring of the eardrum can occur with or without tubes, and does not seem to have any effect on hearing after the tube is out. Serious injury to the middle or inner ear mechanism during surgery is extremely uncommon.

The surgery to insert tubes is done under general anesthesia. This is usually the most frightening part of the whole process, for children and for parents. However, it is extremely safe. While the operation only takes a few minutes, it is vital that the child be absolutely still, as even a small amount of movement could cause permanent injury. Although tubes can be placed in adults with local anesthesia, it is simply not possible to do this safely in most younger patients. General anesthesia is actually safer than sedation, since the anesthesiologist has better control over the patient. In fact, the risk of a serious complication in a healthy child getting general anesthesia from a trained anesthesiologist is less than the risk from taking an antibiotic such as penicillin.




Doesn't the hole in the eardrum cause a hearing loss?

No, the hole actually improves the hearing by draining fluid if it is present. The size of the hole is so small compared to the overall size of the ear, that it does not significantly reduce the surface of the eardrum. Even with a tube in place, the drum vibrates well enough for normal hearing to occur.


What do I have to do after the tubes are placed?

In general, tubes do not require much attention.

I see my patients with tubes around 3 weeks after surgery, and then every six months until the tubes fall out and the ears are healed and healthy. I obtain an audiogram if the hearing test before surgery was abnormal. I do not require any special ear protection with swimming or bathing in most children (see below).

If a child has a draining ear for more than 3-4 days, I ask that he or she be brought into the office for an examination with the microscope. Fluid is scutioned clean using an ear microscope, to prevent the tube from becoming clogged. In some case, ear drops are recommended. Occaisonally, a little bit of earwax or dried blood can block the tube, making it non-functional. This should be taken care of by the ENT doctor in the office.


What happens when the tubes fall out?

The tube is pushed out as the eardrum grows. When this happens, the tube is designed to fall outward, into the ear canal. Once it is there, it does not cause any harm and may be removed in the office. Sometimes, it can work its way out of the canal and fall out of the ear entirely.

Once the tube is out and the hole in the eardrum has closed, the child is once again dependant on his or her own natural ear ventilation to prevent ear infections and the accumulation of fluid. Tubes are placed to "buy time" and allow for ventilation while the child's ears mature; ideally, by the time the tubes are out the child has outgrown the ear problem that required the operation. However, this is not always the case.

About 15% of children will need a second set of tubes, and a smaller number will need a third set. Such children may have underlying problems which make them take a long time to grow out of their ear disease (such as cleft palate), while others are otherwise normal but take longer to develop good Eustachian tube function. Long acting tubes make the chances of a second operation less likely, but this must be balanced against the possibility of the hole in the eardrum not healing by itself. In each child, a number of factors go into the decision as to what type of tubes to place and whether or not they need replacement.


Can my child swim with tubes in place?

For many years, surgeons have gone to great lengths to make sure that no water enters a child's ear while a tube is in place. A variety of earplugs and headbands were recommended, and some doctors forbade swimming altogether. While there are still differences of opinion about this, most of the recent research in this area suggests that special water precautions are not necessary.

The reason that water precautions were recommended was to prevent water from flowing into the ear through the tube, causing infection and drainage. However, it seems that the pressure required to force water through the tiny tube is not reached unless the child's head is at least a foot or so under water. Even then, there is no clear evidence that water will be pushed into the ear during swimming. Furthermore, the rate of infection has been found to be about the same whether children swim with protection (earplugs), swim without protection, or don't swim at all. Bathing also is unlikely to result in water entering the ear through the tube in most cases.

While research has not been done on all possible water exposure situations (such as lake water) here are some general guidelines for water protection with tubes in place:


Can my child travel by airplane with tubes in place?

Yes, and airplane travel can be made immediately. One of the additional advantages of tube placement is that the ear pain of takeoff and landing will be eliminated. This pain is caused by the ear's inability to rapidly equalize pressure between the level in the cabin and the level behind the ear drum. With tubes in place, the pressure equalizes instantly, and no pain should be felt unless the tube has become clogged.