Chronic middle ear infection: Are ear tubes an appropriate treatment?

Treating prolonged middle ear infection with tympanic effusion with ear tubes (grommets) can temporarily improve hearing somewhat. But they no longer have a benefit after about half a year because hearing gets better without this procedure during that time anyway.

Children often get colds, and it is not uncommon for their ears to be affected too. Infections in the nose or throat area can easily spread to the middle ear, particularly in small children. Although acute middle ear infections are very painful, they usually get better within two to three days. In almost one third of all children between the ages of one and three who have a middle ear infection, fluid builds up behind the eardrum and causes hearing loss. This is known as tympanic effusion or glue ear.

Directly behind the eardrum there is a space in the middle ear called the tympanic cavity. This small space is usually filled with air which sound waves travel through to reach the inner ear. If due to a cold or tonsillitis the mucous membranes lining the tympanic cavity swell up and secrete a fluid, the tympanic cavity fills up with fluid. This is called tympanic effusion. Sometimes the tube leading from the middle ear to the throat (the Eustachian tube) becomes blocked too.

If the fluid cannot escape, it builds up behind the eardrum and the child cannot hear properly. If there is too much pressure on the eardrum, it bursts and the fluid flows out into the outer auditory canal. This relieves the pain, and the eardrum usually heals without any problems.

Tympanic effusion can also develop without any obvious signs of an inflammation. This usually goes away on its own too. Still, some children develop chronic middle ear infection. This happens gradually and hardly hurts, but the fluid builds up in the middle ear again and again, making it difficult to hear. This could slow down the development of speech in small children. The signs of a chronic infection include poor hearing and repeated leaking of fluid from the ear.

Treatment options

Treatment is usually started with drugs that reduce the swelling and fluid (for example, nose drops) and antibiotics. But research has not shown that these drugs have a significant positive effect on the healing process. You can read more about whether antibiotics can relieve the symptoms of middle ear infections in babies and young children here. If the tympanic effusion does not clear up, a small surgical procedure called paracentesis can be carried out. This involves puncturing the eardrum so that the fluid can drain out, or be sucked out.

If fluid still keeps on building up in the child’s ear and he or she still cannot hear well after three months, ear tubes are often recommended. These are fine tubes made out of plastic or metal that allow air to flow between the middle ear and outside. They aim to relieve the symptoms of tympanic effusion, improve hearing and prevent delayed speech development. The ear tubes are normally inserted while the child is under general anesthesia and usually fall out on their own after about six to twelve months.

Research on ear tubes

Because there is some disagreement about the benefit of ear tubes in the treatment of chronic middle ear infections, researchers from the Cochrane Collaboration – an international research network – looked for randomized controlled trials in this area. In these types of trials the participants are randomly divided into two or more treatment groups. Afterwards, the results of the different treatments are compared. For children who have a middle ear infection with tympanic effusion, this means that one group of children has ear tubes put in, while the other group either has a tiny cut made in their eardrum, or no treatment. You can read more about how good-quality trials are done here.

The researchers found 10 trials involving more than 1,700 children with middle ear infections and tympanic effusion. After analyzing these trials, they concluded that the use of ear tubes can somewhat improve hearing within the first six months. You can read more about hearing and how it is measured here.

Ear tubes only improve hearing temporarily

The trials evaluated by researchers at the Cochrane Collaboration also show that there is hardly any difference between the hearing of children with and without grommets after six to nine months. After one year there were no longer any differences at all. The children heard equally well, independently of whether they had received ear tubes or not.

There is currently no proof that ear tubes positively influence language development. But they did have adverse effects. They led to increased ear mucous discharge from the ear, particularly in children under the age of three. About one third of the children with ear tubes had scarring of the eardrum, which may slightly impair hearing.

Waiting is usually a good strategy

Because the effects of using ear tubes are generally unclear, the researchers suggest waiting longer than three months before using ear tubes in children, under close medical supervision. This treatment strategy was found to be just as effective as using ear tubes in the long term.

The researchers have not ruled out that some children benefit more than others from treatment with ear tubes. Like any operation, though, the use of ear tubes does involve certain risks. More research is needed to be surer about when the short-term use of ear tubes is worth the associated risks.

Author: Institute for Quality and Efficiency in Health Care(IQWiG)

© IQWiG (Institute for Quality and Efficiency in Health Care)