The Management of Blast-induced Auditory Trauma: Considerations for Hyperbaric Oxygen Therapy

Acoustic barotrauma is an uncommon presentation to the ENT clinic; however, in the context of blast injuries, the auditory system is particularly susceptible to damage. Blast-induced sudden sensorineural hearing loss (SSNHL) is a result of barotrauma to the cochlea and its substructures secondary to combined mechanical and biochemical insult, and can be problematic to treat. The oxidative stress induced within the cochlea during such events has previously raised questions as to the roles of therapies targeting such mechanisms. Conventional management with systemic corticosteroids remains the mainstay of treatment, with alternative options such as hyperbaric oxygen therapy (HBOT) being recommended in salvage settings. HBOT, in particular, has preclinical evidence demonstrating a reduction in the extent of cochlear outer hair cell injury and may partially restore their functional integrity. Secondary injury pathways, including ischemia, excitotoxicity, and oxidative stress, may also be muted by HBOT. We describe two cases of blast-induced SSNHL treated with salvage options, including HBOT and N-acetyl cysteine at our institution. One case, which presented promptly, had a near complete resolution of profound sudden SNHL while treated with HBOT alongside standard of care. Our second case was a patient referred for a second opinion who was unsuitable for HBOT, who was therefore treated with N-acetyl cysteine as a salvage option. These cases add to the currently limited evidence in the salvage setting of blast-induced SSNHL.