Use of the nine-step inflation/deflation test and resting middle-ear pressure range as predictors of middle-ear barotrauma in aircrew members

Abstract

OBJECTIVE: To explore the role of the nine-step inflation/deflation tympanometric test and resting middle-ear pressure range as predictors of barotrauma in aircrew members. METHODS: A prospective, non-randomised study was conducted on 100 aircrew members. Resting middle-ear pressure was measured and the nine-step inflation/deflation test performed on all subjects before flights. Subjects were allocated to two groups according to resting middle-ear pressure range (group A, within the range of +26 to +100 and -26 to -100 mmH2O; group B, -25 to +25 mmH2O). All aircrew members were assessed after flights regarding the presence and the grade of barotrauma. RESULTS: In both groups, the sensitivity and specificity values of the entire post-inflation/deflation test were close to those of the post-deflation part of the test. The post-deflation test had a higher negative predictive value than the post-inflation test. Ears with resting middle-ear pressure lower than -55 mmH2O experienced barotrauma, regardless of good or poor post-inflation or post-deflation test results. CONCLUSION: In an aircrew member, a resting middle-ear pressure within the range of -55 and +50 mmH2O, together with good post-deflation test results, are considered reliable predictors for fitness to fly.