Objective: To determine the accuracy of a hand-held microtympanometer (Microtymp, Welch Allyn) used by a general practitioner when compared with findings at myringotomy.
Method: Independent preoperative assessment of children's ears using microtympanometry by a general practitioner, microscopy and pneumatic otoscopy by a specialist otologist and impedance bridge tympanometry by a specialist audiologist were performed and compared with findings at myringotomy.
Subjects: Fifty children (100 ears) on the waiting list for bilateral myringotomies and ventilation tube insertion for recurrent acute otitis media or otitis media with effusion.
Results: Microscopy with pneumatic otoscopy had a 90.9% sensitivity and a 92.9% specificity in detecting middle ear effusions. Impedance bridge tympanometry had a 94.4% sensitivity and a 71.8% specificity if type B and C2 were combined to predict middle ear effusion. Microtympanometry had 100% sensitivity and 75% specificity if type B and C tympanograms were combined; if type B tympanograms alone were used, a sensitivity of 83.4% and specificity of 75% in predicting middle ear effusions was obtained.
Conclusion: The Microtypm is a useful instrument in general practice for assessment of middle ear effusions as no ears with fluid were missed in this study if type B and C tympanograms were considered abnormal. The Microtymp would also be useful as a screening instrument by suitably trained personnel.