Hyperbaric oxygen therapy as salvage treatment for sudden sensorineural hearing loss: review of rationale and preliminary report.

BACKGROUND The management of sudden sensorineural hearing loss has not yet been standardised. Hyperbaric oxygen therapy influences recovery from sudden sensorineural hearing loss, but the underlying mechanism is unknown and the appropriate indications and protocols undetermined. MATERIALS AND METHODS Nineteen patients affected by sudden sensorineural hearing loss were treated after unsuccessful medical therapy, either in an acute or chronic setting. Pure oxygen inhalation at 2.5 atmospheres absolute pressure was administered for 90 minutes, for 30 sessions. Frequency-specific and average pure tone hearing thresholds were determined before and after hyperbaric oxygen therapy. The number of hyperbaric oxygen therapy sessions, the patient's age and any therapeutic delay were considered as quantitative variables possibly influencing outcome. Stepwise multivariate analysis was performed. RESULTS Salvage hyperbaric oxygen therapy appeared to improve patients' pure tone hearing thresholds, particularly at low frequencies. Positive results were more likely with increased patient age and reduced delay in receiving hyperbaric oxygen therapy. CONCLUSION Hyperbaric oxygen therapy has a strong scientific rationale, and improves pure tone hearing thresholds in cases of sudden sensorineural hearing loss unresponsive to medical therapy. Further research may be able to identify those patients with sudden sensorineural hearing loss for whom hyperbaric oxygen therapy would be most cost-effective.