[Acute acoustic trauma, a retrospective analysis about 225 military cases]

Studying the epidemiology, the evolutionary audiometric profile and the after-effects of acute acoustic trauma managed in military environment. Assessing the influence beyond the audiometric recovery of earplugs, precocity of the treatment and hyperbaric oxygen therapy.

This retrospective cohort gathered 225 military cases of acute acoustic trauma hospitalized between 2003 and 2008. The cochlear supportive therapy associated intravenous methyl-prednisolone and pentoxyfilline, completed sometimes with hyperbaric oxygen therapy. The evolution was appreciated with pure-tone audiometry at the admission, at the end of hospitalization and one month after. Perceptive deafness and recovery shifts were statically calculated on 109 ears.

On the 225 cases, 90% were males, middle-aged of 23 years. Initially 95% of the patients complained about tinnitus, associated with hearing loss felt for 71%. The left ear was more frequently affected. The initial audiometric loss was average of 34 dB HL, concentrated on 4000 and 6000 Hz frequencies. The therapy allowed an average recovery of +18,3 dB in a month. The audiometric sequela concerned 40% of the cases, and residual tinnitus a third. These rates were significantly higher with people whose initial hearing loss average exceeded 40 dB HL. Concerning the audiometric recovery and the after-effects, no significantly difference was found between the groups treated before or after 12 hours. There were either no difference with the earplugs and hyperbaric oxygen groups.

Despite the effectiveness of early corticotherapy, after-effects of acute acoustic trauma remain frequent and invalidating. Its prevention suffers from non-observance and malposition of earplugs.