Five consecutive cases of sensorineural hearing loss associated with inner ear barotrauma due to diving, successfully treated with hyperbaric oxygen

Introduction: This report describes the outcomes of sensorineural hearing loss (SNHL) due to cochlear inner ear barotrauma (IEBt) in five divers treated with hyperbaric oxygen (HBOT). Methods: The case histories of five consecutive divers presenting with SNHL from IEBt due to diving, were reviewed. All divers provided written consent for their data to be included in the study. All had reference pre-injury audiograms. All noted ear problems during or post-dive. Independent audiologists confirmed SNHL in all divers prior to HBOT, then assessed outcomes after HBOT. Results: Three divers breathed compressed air on low risk dives, and two were breath-hold. None had symptoms or signs other than hearing loss, and none had vestibular symptoms. All could equalise their middle ears. Inner ear decompression sickness was considered unlikely for all cases. All were treated with HBOT 24 hours to 12 days after diving. Two divers received no steroid treatment, one was treated with HBOT after an unsuccessful 10-day course of steroids, and two divers received steroids two days after commencing HBOT. All divers responded positively to HBOT with substantial improvements in hearing across multiple frequencies and PTA4 measurements. Median improvement across all frequencies (for all divers) was 28 dB, and for PTA4 it was 38 dB. Conclusions: This is the first case series describing use of HBOT for IEBt-induced SNHL. The variable treatment latency and use/timing of steroids affects data quality, but also reflects pragmatic reality, where steroids have minimal evidence of benefit for IEBt. HBOT may benefit diving related SNHL from IEBt with no evidence of perilymph fistula, and provided the divers can clear their ears effectively. A plausible mechanism is via correction of ischaemia within the cochlear apparatus. More study is required including data collection via national or international datasets, due to the rarity of IEBt.