Glue Ear

Approximately one in three children with a middle ear infection may develope a collection of fluid (effusion) in the middle ear, resulting in some degree of temporary hearing loss.

The Eustachian tube which extends from the middle ear to the throat becomes blocked and the middle ear cannot drain.  The Eustachian tube normally adjusts pressure by draining three to four times daily with swallowing.

Most effusions tend to resolve spontaneously without treatment.  In fact, studies of pre -schoolers have shown that  80% of effusions resolve spontaneously;  63% of children will have persistent middle ear effusion after two weeks;  40% after four weeks  and 26% after twelve weeks.

Antibiotic therapy does not decrease the prevalence of glue ear after a middle ear infection.   Quite the contrary, antibiotics may worsen the situation.

3000 children with a first episode of a middle ear infection were given either paracetamol alone or paracetamol and an antibiotic.  The antibiotic treated group had a significantly greater incidence of glue ear and recurrence of middle ear infection than the group given paracetamol alone.  Growth of bacteria was found in only 26% of cases.

The authors concluded that middle ear infection in children is viral in origin in the great majority of cases.  They also concluded that antibiotic treatment seems to impede the full resolution of infection and predispose to recurrence of infection.

Glue Ear and Grommets

The insertion of grommets (myringotomy) remains a popular treatment for glue ear.

In the U.S. one million myringotomies (grommet operations) are performed each year.  In Australia it is one of the most common reasons for hospital attendance in children.

Grommets allow drainage of the ear, relieve pressure and supposedly restore hearing.  The adenoids are often removed at the same time.

The procedure does have some drawbacks.

• Tubes often fall out prematurely after four to seven months.
• There is a 35-77% rate of replacement surgery and a 40% rate of recurrence of effusion.
• Children continue to get ear infections after surgery.
• Placement of tubes may cause permanent scarring in approximately 50% of cases.
• A general anaesthetic is required and anaesthesia adds to the dangers of surgery.  One in three children may suffer minor adverse effects such as nausea, infection or bleeding whilst one in one thousand may have a life-threatening complication.

The indications and timing of the procedure are much argued among the medical community.  There is difference of opinion amongst E.N.T. surgeons about when to operate.  Some operated after thirty days of antibiotic treatment,  some after two months or longer of antibiotic treatment. 

There is a difference of opinion on the indications for grommets.  An analysis of appropriateness of myringotomy in 6000 patients reported that  41% of cases had appropriate indications for surgery,  32% equivocal indication  and that in 27% of cases, surgery was considered to be  inappropriate.

A long term study of unilateral myringotomy (grommets in one ear but not in the other) showed that after six months there was no difference in hearing in the two ears;  and after two years there was no difference in fluid accumulation in the two ears.  However, after five years there were complications in the operated ear. - 13% incidence of scarring and 42% incidence of tympano schlerosis in the tubed ear.  There was no incidence of such complications in the non-surgical ear.

Children commonly out-grow chronic ear problems, usually by age of seven years.  By this age, the adenoids have reduced in size, the skull has become longer and higher with normal growth and the Eustachian tube drains more easily.

One Scottish study showed that serious complications such as meningitis or brain abscess are rare following ear infection.  The incidence of these complications between 1966 and 1986 remained stable despite a sixty fold increase in surgery.