Several authors reported the effect of steroid administration for inner ear barotrauma as clinical results, however, there is no experimental study to prove its effect. The purpose of this study is to investigate the effect of steroid administration for inner ear barotrauma in the experimental study. Guinea pigs were subjected to rapid compression and decompression between 1 absolute pressure (ATA) and 2 ATA in a chamber within 5 seconds. The guinea pigs that had hearing threshold shift were randomly divided into steroid administrated group (treatment group)(19 ears) and control group (16 ears). In the treatment group, guinea pigs were administrated with dexamethasone at a dose of 2.0mg/kg/day intraperitoneally once a day for 5days after the pressure loading. Before, just after pressure loading, 2, 3, 5, and 7 weeks after pressure loading, auditory brainstem response (ABR) testing was performed, and the healing threshold shift was evaluated. The time course change of the healing threshold shift was compared between the two groups. The time course change of the healing threshold shift was significantly different between the two groups (repeated measured ANOVA, p<0.05), and the healing threshold shift was more remarkable in the treatment group. When compared two groups in the moderately to severely damaged ears, the hearing threshold shift of the treatment group was significantly lower than that of the control group at 2 and 7 weeks after pressure loading (non paired t-test, p<0.01 and p<0.05). In conclusion, we suggested that steroid administration would be effective for the treatment of inner ear barotraumas.
