{ "abstract": "Introduction Idiopathic sudden sensorineural hearing loss (ISSNHL) can lead to permanent sequelae with functional impairment of hearing. Hyperbaric oxygen treatment (HBOT) may improve outcomes but conclusive evidence for its efficacy is currently lacking.Methods and analysis This is a multicentre, 1:1 randomised, controlled, assessor-blind trial comparing standard care alone versus HBOT plus standard care. Adult patients with ISSNHL, at least 50 dB hearing level (HL) in pure tone average (PTA4) on the affected ear and who were eligible for commencement of HBOT within 7 days from onset of hearing loss are included. Those with other causes of hearing loss and contraindications for HBOT are excluded. The primary outcome is absolute PTA4 after 14 weeks, while secondary outcomes include other measures of audiometric hearing improvement including word recognition score and patient-reported outcomes related to hearing, tinnitus, balance and quality of life. The power analyses indicated a group size of 151 participants to detect a difference in mean PTA4 of at least 10 dB HL at follow-up with 90% power based on an assumed SD of 34 dB HL with a 0.05 significance level.Ethics and dissemination The trial has been approved by the Regional committees for medical and health research ethics (268140), by the Norwegian Medical Products Agency and is registered in the EU Clinical Trials Information System (CTIS, 2024-510798-84-00). User representatives have been involved in the development of the study. The results will be reported according to the Consolidated Standards of Reporting Trials (CONSORT) 2025 guidelines in an international peer-reviewed medical journal as soon as possible after the last visit of the last patient.Trial registration number 2021-002284-22 (primary registration 4 May 2021; initially registered in EU Clinical Trials Register (EudraCT)). From 2024 replaced by EU Clinical Trials Information System (CTIS): 2024-510798-84-00 (primary registration 2 October 2024).", "abstract_shown": true, "affiliations": [ "Department of Otorhinolaryngology and Head and Neck Surgery, Haukeland University Hospital, Bergen, Norway", "Department of Clinical Medicine, University of Bergen, Bergen, Norway", "Department of Otorhinolaryngology, St Olavs Hospital/Trondeim University Hospital, Trondheim, Norway", "Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Faculty of Medicine and Health Sciences, Trondheim, Norway", "Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway", "Department of Anesthesiology, Division of Critical Care, Oslo University Hospital, Oslo, Norway", "Department of Otorhinolaryngology, Innlandet Hospital Trust, Brumunddal, Norway", "Department of Otorhinolaryngology, Sørlandet Hospital Trust, Kristiansand, Norway", "Department of Otorhinolaryngology, Akershus University Hospital, Lørenskog, Norway", "Department of Otorhinolaryngology, Telemark Hospital Trust, Skien, Telemark, Norway", "Faculty of Medicine University of Oslo, Campus Ahus, Oslo, Norway", "Department of Otorhinolaryngology, Helse Førde HF, Førde, Sogn og Fjordane, Norway", "Department of Otorhinolaryngology, Østfold Hospital Trust, Kalnes, Norway", "Department of Otorhinolaryngology, Helse Møre og Romsdal HF, Ålesund, Møre og Romsdal, Norway", "Hyperbaric Medicine Unit, Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway", "Department of Otorhinolaryngology and Head and Neck Surgery, Stavanger University Hospital, Stavanger, Norway" ], "article_type": null, "arxiv": null, "author_total": 21, "authors": [ { "affs": [ 0 ], "name": "Kristina Sture Larsen", "orcid": "0009-0001-7632-5069" }, { "affs": [ 0, 1 ], "name": "Frederik Kragerud Goplen", "orcid": "0000-0002-8022-9483" }, { "affs": [ 2, 3 ], "name": "Haakon Arnesen" }, { "affs": [ 4 ], "name": "Jörg Assmus" }, { "affs": [ 0 ], "name": "Jan Berge", "orcid": "0000-0003-3037-9405" }, { "affs": [ 5 ], "name": "Martin Rygh Braathen", "orcid": "0000-0002-8198-5221" }, { "affs": [ 0 ], "name": "Thomas Evenstad" }, { "affs": [ 6 ], "name": "Matz Elias Kanstad Grimstvedt" }, { "affs": [ 7 ], "name": "Øystein Haugen", "orcid": "0009-0005-4391-0762" }, { "affs": [ 0 ], "name": "Jeanette Hess-Erga", "orcid": "0000-0002-7476-2070" }, { "affs": [ 0 ], "name": "Kathrin Skorpa Nilsen", "orcid": "0009-0005-4274-896X" }, { "affs": [ 0 ], "name": "Mathias Hamlet Næss" }, { "affs": [ 8 ], "name": "Håvard Ottemo Paulsen", "orcid": "0009-0002-5854-6885" }, { "affs": [ 9 ], "name": "Anette Aase Setsaas" }, { "affs": [ 8, 10 ], "name": "Juha Tapio Silvola", "orcid": "0000-0001-7615-096X" }, { "affs": [ 11 ], "name": "Einar Solheim" }, { "affs": [ 12 ], "name": "Carl Jacob Sand Solvåg" }, { "affs": [ 3, 13 ], "name": "Anker Stubberud" }, { "affs": [ 14 ], "name": "Guro Vaagbø" }, { "affs": [ 15 ], "name": "Natascha Wathne" }, { "affs": [ 14 ], "name": "Bernd Müller", "orcid": "0009-0002-4097-6051" } ], "bibtex": "https://research.draconitic.com/paper/2attxnb75nrx9.bib", "cited_by": 0, "doi": "10.1136/bmjopen-2026-121315", "fulltext_url": "https://bmjopen.bmj.com/content/16/11/e121315.full", "id": "2attxnb75nrx9", "issns": [ "2044-6055", "2044-6055" ], "landing_url": "https://bmjopen.bmj.com/lookup/doi/10.1136/bmjopen-2026-121315", "language": "en", "licence": "CC-BY", "licence_label": "CC BY", "licence_source": "journal", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "lcc", "R" ] ], "openalex": null, "pdf_url": null, "pmcid": null, "pmid": null, "published": "2026-11-04", "publisher": "BMJ", "ris": "https://research.draconitic.com/paper/2attxnb75nrx9.ris", "sources": [ { "first_seen": "2026-11-05T00:21:06Z", "native_id": "10.1136/bmjopen-2026-121315", "source": "crossref", "url": "https://bmjopen.bmj.com/lookup/doi/10.1136/bmjopen-2026-121315" }, { "first_seen": "2026-11-06T14:21:08Z", "native_id": "07de685fecd143ea846948ba0daa2962", "source": "doaj", "url": "https://doi.org/10.1136/bmjopen-2026-121315" } ], "subjects": [ { "field": "medicine", "origin": "lcc:R", "subfield": "general" } ], "title": "Study protocol of the SuDHO study: hyperbaric oxygen treatment added to standard care for acute idiopathic sudden sensorineural hearing loss – a multicentre randomised controlled trial", "title_text": "Study protocol of the SuDHO study: hyperbaric oxygen treatment added to standard care for acute idiopathic sudden sensorineural hearing loss – a multicentre randomised controlled trial", "type": "peer-reviewed", "updated_at": "2026-11-07T14:20:54Z", "url": "https://research.draconitic.com/paper/2attxnb75nrx9", "venue": "BMJ Open", "versions": [] }