International Multicenter Registry for Hyperbaric Oxygen Therapy: Results through June 2021.

Introduction: The International Multicenter Registry for Hyperbaric Oxygen Therapy (International Report Registered Identifier DERR1-10.2196/18857) was established in 2011 to capture outcomes and complications data for both Undersea and Hyperbaric Medical Society (UHMS) approved and selected unapproved hyperbaric oxygen (HBO2) therapy indications. Methods: A Research Electronic Data Capture (REDCap) template was designed and distributed to all participating centers for prospective data collection. Centers contributed de-identified demographic, treatment, complications, and outcome data. This report provides summary data on sites and enrollment, as well as pre- and post-treatment data on quality of life (EQ-5D-5L questionnaire), head and neck radiationoutcomes, non-healing wounds (Strauss score), and idiopathic sudden sensorineural hearing loss. Data were analyzed mainly using the Wilcoxon signed-rank test. Results: Twenty-two centers contributed data for 2,880 patients. The most common UHMS-approved indication was delayed radiation injury, followed by enhancement of wound healing, and carbon monoxide poisoning. One hundred and twenty-five patients were treated for non-UHMS approved indications. Quality of life, head and neck radiation symptoms, Strauss wound scores, and hearing were significantly improved after HBO2. Complication rates were low and comparable to previous reports. The registry also offered the ability to analyze factors that affect outcomes, such as smoking and severity of hearing loss. Discussion: The registry accrues prospective data on defined outcomes from multiple centers and allows for analysis of factors affecting outcomes. This registry does not have a control group, which is a limitation. Nevertheless, the registry provides a unique, comprehensive dataset on HBO2 outcomes from multiple centers internationally.

Development of an International, Multicenter, Hyperbaric Oxygen Treatment Registry and Research Consortium: Protocol for Outcome Data Collection and Analysis.

BACKGROUND: Hyperbaric oxygen (HBO2)-oxygen at pressures higher than atmospheric-is approved for 14 indications by the Undersea and Hyperbaric Medical Society. HBO2's main effect is to increase oxygen content in plasma and body tissues, which can counteract hypoxia or ischemia. Laboratory studies show that HBO2 has effects beyond relieving hypoxia (eg, promoting angiogenesis in irradiated tissue, anti-inflammatory effects, radiosensitization of tumors, hypoxia preconditioning, and fungal growth inhibition) and has potential to treat conditions such as inflammatory bowel disease and pyoderma gangrenosum. Lack of consistently collected outcome data on a large cohort of individuals receiving HBO2 therapy limits its use for both established and new indications. A course of therapy often involves 30-40 visits to a hyperbaric chamber, so the number of patients seen at any given center is constrained by chamber capacity. As a result, published HBO2 outcome data tend to be from small case series because few patients with a particular condition are treated at a given center. To solve this problem, a registry that collects and pools data systematically from multiple institutions has been established. OBJECTIVE: The aim of this study is to collect consistent outcome data across multiple hyperbaric centers to assess treatment effectiveness and establish a research consortium. METHODS: A consortium of hyperbaric centers who have agreed to collect consistent outcome data on all patients seen has been assembled. Data are collected at each participating center using Research Electronic Data Capture (REDCap), a web-based, data collection system used frequently for research. Standard outcome measures have been defined for each condition, which are programmed into the REDCap data collection templates. Governance is through a consortium agreement that defines data security, data sharing, publications, liability, and other issues. Centers obtain Institutional Review Board (IRB) and ethics approval to participate, either from their own institutions or by relying on the IRB at the coordinating center at Dartmouth College. Dissemination will occur through a yearly report and by publications based on the data in the registry. RESULTS: Early results from some common indications show significant pretreatment to posttreatment changes. Additional indications and outcome measures are being added using the procedures outlined in the consortium agreement. CONCLUSIONS: The registry collects consistent outcome information for a therapy that needs further study and a stronger evidence base. It also overcomes the challenge of collecting data from an adequate number of patients for both established and emerging indications by combining data collection from multiple centers. The data entry requirements should be within the capabilities of existing staff at any given hyperbaric center. By using REDCap, the registry can be expanded to include detailed information on particular indications and long-term follow-up on selected patients without significantly increasing the basic data entry requirements. Through the registry, a network of enrolled hyperbaric centers has been established that provides the basis for a clinical trial network. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/18857.