Hyperbaric Oxygen Therapy for Sudden Sensorineural Hearing Loss - A Comorbidity Lens.

Objective: To determine the outcomes of patients receiving hyperbaric oxygen therapy for sudden sensorineural hearing loss and the impact of patient comorbidities on outcomes.

Study design: Retrospective chart review.

Setting: Tertiary referral center.

Methods: All patients over 18 diagnosed with sudden sensorineural hearing loss between 2018 and 2021 who were treated with hyperbaric oxygen therapy were included. Demographic information, treatment regimens and duration, and audiometric and speech perception outcomes were recorded and analyzed.

Results: 19 patients were included. The median age was 45 years. 53% were female and 21% had pre- existing rheumatologic disorders. The mean duration between hearing loss onset and physician visits was 9.6 days. All patients received an oral steroid course, while 95% also received a median of 3 intratympanic steroid injections. Patients began hyperbaric oxygen therapy an average of 34.2 days after the hearing loss onset for an average of 13 sessions. No significant relationships were found between patient comorbidities and outcomes. Of those who reported clinical improvement, 57% demonstrated complete recovery per Siegel's criteria. There was significant improvement after hyperbaric oxygen therapy for pure tone averages (50.3dB vs. 36.0dB, p<0.01) and word discrimination scores (73% vs 79%, p<0.05) for all patients regardless of reported clinical improvement.

Conclusion: Hyperbaric oxygen therapy, as an adjunct to steroids, significantly improves recovery from sudden sensorineural hearing loss. The Charlson comorbidity index was not significantly associated with patient outcome, but patients with rheumatologic disorders were less likely to respond. Differentiating the natural history of the disease from hyperbaric oxygen therapy-associated improvements remains a challenge.