PROBLEMS/OBJECTIVES: We investigated the effect of secondary hyperbaric oxygen therapy (HBO) for patients with idiopathic sudden sensorineural hearing loss after unsuccessful conventional treatment. METHODOLOGY: We retrospectively evaluated 3 groups: 100 patients without further treatment (group 1), 160 patients with secondary HBO at 1.5 ATA (group 2), and 56 patients with secondary HBO at 2.5 ATA (group 3). RESULTS: In group 1, a mean hearing gain (MHG) of 2.6 +/- 15 dB was found at the end of the follow-up period. After HBO, a MHG of 3.1 +/- 9 dB in group 2 and 19.7 +/- 23 dB in group 3 was achieved. The results in group 3 were statistically significant in comparison to group 1 (p <0.007) and to group 2 (p <0.009). With HBO after initial therapy failure, there is a significant correlation of MHG with time delay before HBO (p <0.03). CONCLUSIONS: HBO at 2.5 ATA in patients with idiopathic sudden sensorineural hearing loss after unsuccessful conventional treatment yields significant improvement of hearing. MHG is higher when time delay before HBO is shorter.
