Sudden hearing loss and early hyperbaric oxygen therapy: a preliminary study

Purpose: Sudden sensorineural hearing loss (SSNHL) is a time-sensitive urgent condition. The aim of this study was to evaluate the frequency of hearing improvement in patients with idiopathic SSNHL who only received hyperbaric oxygen (HBO2) therapy within 3 days of symptom onset, instead of conventional corticosteroid treatment. Methods: The medical charts of patients who experienced SSNHL between January 1, 2012, and December 31, 2021, were reviewed. The present study included all adult patients who were diagnosed with idiopathic SSNHL and started HBO2 therapy within 72 hours of symptom onset. These subjects did not take corticosteroids due to contraindications or because they were concerned about possible side effects. The HBO2 therapy protocol consisted of at least 10 sessions of 85 minutes each with pure oxygen inhalation at 2.5 atmospheres absolute pressure. Results: Overall, 49 subjects (26 males and 23 females) met the inclusion criteria, with a mean age of 47 (± 20.4) years. The mean initial hearing threshold was 69.8 dB (± 18.0). After HBO2 therapy, complete hearing recovery was observed in 35 patients (71.4%), and the mean hearing threshold improved significantly (P<0.001) to 31.4 dB (± 24.5). In patients with complete hearing recovery, no significant differences were found between males and females (P=0.79), right and left ears (P=0.72) or initial grades of hearing loss (P=0.90). Conclusion: This study suggests that, in the absence of the confounding effect of concurrent steroid therapy, starting HBO2 therapy within 3 days of symptom onset could have a positive impact on patients with idiopathic SSNHL.