title: Hyperbaric oxygen therapy in the treatment of sudden sensorineural hearing loss: a retrospective analysis of outcomes.
abstract: To analyse predictive factors affecting outcome after treatment with hyperbaric oxygen (HBOT) in patients with idiopathic sudden sensorineural hearing loss (ISSHL).
  
  
  
  This is a retrospective audit of outcome in 77 consecutive patients referred for consideration of HBOT for ISSHL for either adjunctive treatment or after failure of steroid therapy. The hearing measured from the pre- and post-HBOT pure-tone audiogram (PTA4) at four frequencies; 500 Hz, 1 kHz, 2 kHz and 4 kHz, was averaged and compared. The PTA4 score was classified into three groups: complete improvement (≤ 25 dB residual hearing loss); moderate improvement (11-50 dB gain) and no improvement (≤ 11dB gain). Data were also analysed using mean residual loss on completion as the outcome measure.
  
  
  
  Seventy-six patients underwent 1,029 HBOT sessions. Twenty five of 78 ears (33%) had complete resolution of deafness after HBOT. A further 31 (40%) had a significant improvement in PTA4. Delay (〉 28 days) and older age were associated with worse outcomes in PTA4 improvement. Those with less severe hearing loss and short delay (〈 15 days) had the best outcome (mean residual loss 28 dB). Eight of nine patients who were delayed 〉 28 days had no improvement in PTA4.
  
  
  
  Fifty-six of 76 (74%) patients had complete (25) or moderate (31) improvement in hearing loss after HBOT. Short delay to HBOT, a severer degree of hearing loss and younger age were the best predictive factors of improved PTA4. Outcome was poor if treatment was delayed over 28 days. Well-designed randomised controlled trials are needed to clarify the role of HBOT and steroids.
authors.affiliation: Burns, Trauma, and Critical Care Research Centre, RBWH and University of Queensland, Royal Brisbane and Women's Hospital Hyperbaric Medicine Unit, Butterfield Street, Herston QLD 4026, Australia. susannah.sherlock@health.qld.gov.au.
authors.forename: Susannah
authors.initials: S
authors.lastname: Sherlock
authors.affiliation: Hyperbaric Medicine Unit, Royal Brisbane and Women's Hospital (RBWH), Brisbane, Queensland, Australia.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Thistlethwaite
authors.affiliation: School of Public Health, Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, Australia.
authors.forename: Mohsina
authors.initials: M
authors.lastname: Khatun
authors.affiliation: Queensland Institute of Medical Research, Brisbane.
authors.forename: Christopher
authors.initials: C
authors.lastname: Perry
authors.affiliation: Hyperbaric Medicine Unit, Royal Brisbane and Women's Hospital (RBWH), Brisbane, Queensland, Australia, Burns, Trauma, and Critical Care Research Centre, RBWH and University of Queensland.
authors.forename: Alexis
authors.initials: A
authors.lastname: Tabah
mesh_terms: D000367:Age Factors; D001301:Audiometry, Pure-Tone; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000628:therapy*; D003639:Hearing Loss, Sudden / Q000628:therapy*; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000706:statistics & numerical data; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D012189:Retrospective Studies; D061665:Time-to-Treatment; D016896:Treatment Outcome
keywords: ENT; inner ear; risk factors