The Role of Hyperbaric Oxygen Therapy in the Treatment of Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSNHL) is defined as acute hearing loss of >30 dB at three consecutive frequencies, with an abrupt onset (within 3 days). In most patients with SSNHL, an exact cause is rarely identified. Diverse etiological theories have been proposed, including vascular disease, viral infection, autoimmune disease, inner ear hydrops, and genetic factors. Based on these hypotheses, various treatments have been tried, including corticosteroids (systemic and/or intratympanic), antivirals, vasoactive drugs, and hyperbaric oxygen therapy (HBOT), but the evidence remains inconclusive. The 2019 American Academy of Otolaryngology-Head and Neck Surgery guideline had suggested that HBOT can be provided as either initial or salvage treatment when combined with steroid therapy. HBOT, a noninvasive treatment involving the inhalation of 100% oxygen at a pressure of >1 atmosphere absolute (ATA) is another treatment option as a method to improve oxygen supply after cochlear damage. Although the pressure, frequency, and total time of HBOT remain variable among different studies, a protocol of 2.0-2.5 ATA and 10-20 sessions in total are commonly used. The treatment strategies for SSNHL have been evolving, and recent attempts involved increasing the effectiveness through various combinations of systemic steroid, intratympanic steroid, and HBOT. In this review, we will review various studies about HBOT and discuss the efficacy of HBOT in SSNHL.