and tympanometric findings were compared among 129 patients with clinically manifest persistent otitis media (OM) with effusion. Ears with thick effusion (mucoid OM) had significantly larger air-bone gaps and higher prevalence of flat tympanograms than either of the thin effusion types (purulent [POM] or serous OM [SOM]) or ears with no effusion (dry). Ears with thin effusion (POM and SOM) had similar air-bone gaps, thresholds for air and bone conduction, and prevalences of flat and underpressure tympanograms. Ears with no effusion had significantly smaller air-bone gaps, slightly poorer bone conduction thresholds, and lower prevalence of flat tympanograms than ears with effusion (MOM, POM and SOM). Ears with clinically manifest OM and no effusion at tympanocentesis appear to represent patients with a spontaneously resolved episode of OM with thin effusion (POM or SOM) or with ears that evacuated during anesthesia prior to tympanostomy. (Arch Otolaryngol 1983;109:360-363) Otitis media (OM) is a common illness affecting the majority of children on at least one occasion before the age of 5 years.14 Despite the high prevalence of OM, few children Reprints not available. reach adulthood with chronic OM and intractable middle ear abnormalities.It is not known which factors predis¬ pose an individual to persistent effu¬ sion nor is it known in which patients intractable middle ear abnormalities will develop.Paparella3 proposed a classification scheme defining OM based on the refractive properties of middle ear abnormalities and specific physical characteristics of middle ear effusion (MEE). Physical characteristics of MEE that are readily apparent on careful inspection of the fluid include clarity (clear or cloudy) and viscosity (thin or thick). Accordingly, serous effusion has been defined as a thin, clear liquid; mucoid effusion as a thick, usually cloudy liquid; and puru¬ lent effusion as a thin, cloudy liquid. Laboratory observations in humans and experimental animals show that the biochemical, microbiologie, and cytologie characteristics of these effu¬ sions change over time." Thus, OM may be thought of as a continuum of different clinical entities that may have a common etiopathogenesis.Hearing impairment remains a major sequela of this disease and may affect a child's language and educa¬ tional abilities.8·9 The classic audiometric profile associated with OM is a mild, conductive hearing loss with excellent speech discrimination. Al¬ though the low frequency, mild con¬ ductive hearing loss is viewed as pathognomonic of OM, variations in this audiometrie characteristic are not thought to distinguish one effu¬ sion type from another.The tympanograms seen for ears having OM with effusion are the flat type or its variants, and the under¬ pressure type C and its variants.10·" The type tympanogram is an excel¬ lent indicator of the presence of MEE,12 but it is unsettled whether it can distinguish one effusion type from another.1316 The purpose of this study was to determine whether audiometry and tympanometry can ...
