Evaluation of acoustic reflectometry in detecting otitis media in children

Accurate detection of middle-ear effusion in children is not only useful but also necessary for diagnosis, management and follow-up of otitis media. A relatively new device, the Acoustic Otoscope (model 101, ENT Medical Devices) has been introduced for detecting middle-ear fluid in children. We tested 158 ears and the diagnosis was confirmed by acoustic admittance, acoustic reflex and pneumatic otoscopy. We propose 4.5 as a better breakpoint (the number on the vertical scale of the instrument which is the lower limit indicating middle-ear effusion) than 4.0 which is proposed by the manufacturer. In our results the 4.5 breakpoint maximizes both positive and negative predictive values (83 and 82% respectively) with satisfactory sensitivity and specificity (86 and 79% respectively) in detection of otitis media. Our clinical experience with this instrument, during the past 2 years, has led us to conclude that it is simple, non-invasive and objective. Unlike tympanometry, it requires no hermetic seal and is effective even if the child is crying. However, it is not sensitive enough when there are bubbles or negative pressure in the middle ear. When the user is aware of the flexibility of the instrument's breakpoints (in our opinion this is an advantage of the device) for different uses and different populations, the reflectometer often reduces the need for tympanometry and confirms the otoscopic examination.