Placing tubes into the eardrums of young children who have moderately persistent accumulation of fluid in the middle ear does not appear to have any effect on the children's speech, language, intellectual, psychological, or social development by age three, according to a study funded by the National Institute of Child Health and Human Development and the Agency for Healthcare Research and Quality.
A report of the study, conducted by researchers at Children's Hospital of Pittsburgh and the University of Pittsburgh, appears in the April 19 issue of the New England Journal of Medicine.
"This finding provides important information for parents and physicians to use in deciding whether or not a child is a candidate for typanostomy tube insertion," said NICHD director Duane Alexander, M.D.
The surgical procedure, called tympanostomy tube insertion, is used to treat a persistent form of otitis media, or middle-ear inflammation, resulting in the accumulation of liquid in the middle-ear cavity, explained the study's principal investigator, Jack L. Paradise, M.D. Otitis media may result from infection of the middle ear by bacteria or viruses, or from blockage of the Eustachian tube, which normally carries air from the back of the throat to the middle-ear cavity. Approximately 280,000 children under the age of three undergo tympanostomy each year.
As part of the immune system's attempt to fight off the infection, or in response to the interruption of the middle ear's air supply, fluid accumulates in the middle-ear cavity. In children below age three, especially, the fluid may fail to be absorbed or to drain from the ear for long periods of time, resulting in correspondingly long periods of mild to moderate hearing loss.
This condition is known medically as otitis media with effusion, or OME, Dr. Paradise added Although hearing loss resulting from OME is usually temporary, many researchers have believed that it often lasts long enough during supposedly sensitive or critical periods of development to cause long-term impairments, particularly in language abilities.
Tympanostomy-tube insertion consists of making a small incision in the eardrum, removing the fluid, and placing a small tube through the eardrum incision, to provide an artificial means of keeping the middle ear ventilated until the Eustachian tube regains its normal function. Once the tube is inserted, hearing usually returns to normal immediately.
Between May 1991 and December 1995, the investigators enrolled 6350 infants within the first 2 months of life. Of these, 402 of the children had developed persistent OME within the first 3 years of life. Children were considered for tympanostomy if they had OME in both ears for 90 days, or in one ear for 135 days. The investigators randomly assigned these children to receive tubes either promptly or after a delay of 6 to 9 months if their OME persisted. When the children were 3 years old, both the 402 children with persistent OME and a representative sample of the remaining children received a battery of tests to assess their abilities in speech, language, cognitive (intellectual), psychological, and social functioning.
The researchers found no differences in any of these tests between those who had the surgery relatively soon after study assignment (64 percent within 60 days) and those who either had the procedure more than 6 months after assignment (23 percent) or had not received the procedure by age 3 years (66 percent).
Dr. Paradise and his coworkers recommended against applying their findings to other children who have experienced OME for longer periods of time than those the researchers studied, or to children with more severe degrees of hearing loss. They also warned that any possible effects of early hearing loss might not be apparent until the children are older-perhaps until ages 4 or 6.
The researchers concluded that for children under three whose only ear-related problem is persistent OME and who do not have OME for any longer than did the children in the study, tympanostomy-tube insertion offers no benefit in respect to development at age three. They added that, when considering whether a child should undergo tympanostomy-tube insertion, this lack of benefit should be weighed against any hypothetical risks of developmental impairments at later ages.