HBO2 for sudden sensorineural hearing loss

Sudden sensorineural hearing loss (SSNHL) presents as an abrupt onset of hearing loss; 88% of these presentations are idiopathic (ISSHL). Many mechanisms of injury and etiopathologies have been postulated, but they share a common result - hypoxia of the organ of Corti leading to hair cell-cilia fusion, synaptic, dendritic swelling and sustained depolarization. Of all of the various treatments tried, only corticosteroids and hyperbaric oxygen (HBO2) therapy have shown benefit in randomized controlled trials (RCTs). This paper reviews the pathophysiology of SSNHL, the variety of treatments studied, and the best evidence (both retrospective case controlled and prospective randomized controlled studies) for the use of HBO2 and corticosteroids. The best results are obtained when these two treatments are combined and initiated within 14 days of symptom onset. HBO2 is given at 2-2.5 ATA for 90 minutes for 10-20 sessions. Steroids should be dosed at 1mg/kg/day and slowly tapered over two to three weeks. If a patient is not a good candidate for or refuses systemic steroids, good results have also been obtained using intratympanic (IT) steroids in combination with HBO2. Patients should be followed by and otolaryngologist before, during and following HBO2. For severe hearing loss treatment with HBO2 improves by 37.7 dB, 19.3dB for those with moderate loss and 15.6 dB improvement overall. These recoveries, on average, improve a patient's hearing from ranges requiring hearing aids and sign language, to levels at which normal or near-normal hearing is restored.