Comparison of a eustachian barotubometer with a tympanometer to evaluate eustachian tube function in chronic suppurative otitis media.

ABSTRACT

OBJECTIVE: To compare the eustachian tube function results of a eustachian barotubometer with those of a tympanometer in the dry and quiescent stages of tubotympanic chronic suppurative otitis media. This study was undertaken to find a simple, reliable, and inexpensive alternative to the conventional tympanometer that is used on a perforated ear drum. DESIGN: Prospective cross-sectional study of 1 year's duration. SETTING: Otolaryngology outpatient clinic of a tertiary referral centre. METHODS: A forced opening test and a physiologic opening test of the eustachian tube were performed on 31 ears with quiescent tubotympanic chronic suppurative otitis media and 38 ears with dry tubotympanic chronic suppurative otitis media selected at random. Both tests were performed by two separate observers using a eustachian barotubometer first and then the tympanometer in perforated mode. MAIN OUTCOME MEASURES: Forced opening response and physiologic opening response of the eustachian tube. RESULTS AND OBSERVATIONS Contingency tables (2 x 2) were drawn using the findings of the tests on the two instruments separately for the forced opening test and the physiologic opening test. For the former test, the sensitivity was 100%, specificity was 20%, validity was 94.20%, and positive likelihood ratio was 1.25. For the latter test, the sensitivity was 96.87%, specificity was 60%, validity was 94.20%, and positive likelihood ratio was 2.42. CONCLUSION: The eustachian barotubometer is a simple, reliable, and inexpensive alternative for preoperative screening of eustachian tube function in the dry and quiescent stages of tubotympanic chronic suppurative otitis media.