Emerging Indications for Hyperbaric Oxygen Treatment: Registry Cohort Study

Abstract

Background: Hyperbaric oxygen (HBO₂) treatment is used across a range of medical specialties for a variety of applications, particularly where hypoxia and inflammation are important contributors. Because of its hypoxia-relieving and anti-inflammatory effects HBO₂ may be useful for new indications not currently approved by the Undersea and Hyperbaric Medical Society. Identifying these new applications for HBO₂ is difficult because individual centers may only treat a few cases and not track the outcomes consistently. The web-based International Multicenter Registry for Hyperbaric Oxygen Therapy captures prospective outcome data for patients treated with HBO₂ therapy. These data can then be used to identify new potential applications for HBO₂, which has relevance for a range of medical specialties.

Objective: Although hyperbaric medicine has established indications, new ones continue to emerge. One objective of this registry study was to identify cases where HBO₂ has been used for conditions falling outside of current Undersea and Hyperbaric Medical Society-approved indications and present outcome data for them.

Methods: This descriptive study used data from a web-based, multicenter, international registry of patients treated with HBO₂. Participating centers agree to collect data on all patients treated using standard outcome measures, and individual centers send deidentified data to the central registry. HBO₂ treatment programs in the United States, the United Kingdom, and Australia participate. Demographic, outcome, complication, and treatment data, including pre- and posttreatment quality of life questionnaires (EQ-5D-5L) were collected for individuals referred for HBO₂ treatment.

Results: Out of 9726 patient entries, 378 (3.89%) individuals were treated for 45 emerging indications. Post-COVID-19 condition (PCC; also known as postacute sequelae of COVID-19; 149/378, 39.4%), ulcerative colitis (47/378, 12.4%), and Crohn disease (40/378, 10.6%) accounted for 62.4% (n=236) of the total cases. Calciphylaxis (20/378, 5.3%), frostbite (18/378, 4.8%), and peripheral vascular disease-related wounds (12/378, 3.2%) accounted for a further 13.2% (n=50). Patients with PCC reported significant improvement on the Neurobehavioral Symptom Inventory (NSI score: pretreatment=30.6; posttreatment=14.4; P<.001). Patients with Crohn disease reported significantly improved quality of life (EQ-5D score: pretreatment=53.8; posttreatment=68.8), and 5 (13%) reported closing a fistula. Patients with ulcerative colitis and complete pre- and post-HBO₂ data reported improved quality of life and lower scores on a bowel questionnaire examining frequency, blood, pain, and urgency. A subset of patients with calciphylaxis and arterial ulcers also reported improvement.

Conclusions: HBO₂ is being used for a wide range of possible applications across various medical specialties for its hypoxia-relieving and anti-inflammatory effects. Results show statistically significant improvements in patient-reported outcomes for inflammatory bowel disease and PCC. HBO₂ is also being used for frostbite, pyoderma gangrenosum, pterygium, hypospadias repair, and facial filler procedures. Other indications show evidence for improvement, and the case series for all indications is growing in the registry.

International registered report identifier (irrid): RR2-10.2196/18857.

Keywords: PASC; PCC; calciphylaxis; facial filler; frostbite; hyperbaric oxygen; hypospadias; infected implanted hardware; inflammatory bowel disease; postacute sequelae of COVID-19; post–COVID-19 condition; pyoderma gangrenosum.

Figure 1

Data entry screen for frostbite injuries. The registry provides different approaches to data entry to make data entry easy and consistent.

Figure 2

Results from the EQ-5D visual analog scale for patients with Crohn disease. A total of 20 patients had complete pretreatment and posttreatment hyperbaric oxygen (HBO2) data. A sensitivity analysis using a best, worst, and average case for missing data shows that the results are significant in all those cases.

Figure 3

Reported fistula discharge pre- and post-HBO2 therapy in patients with Crohn disease who had complete pre- and post-HBO2 data. The sensitivity analyses results are follows: best case (25/33, 76% improved; P<.001), worst case 10/33, 30% improved; P=.33), and average case (18/33, 55% improved; P=.08).

Figure 4

Results on the EQ-5D visual analog scale for patients with ulcerative colitis (UC) who had complete pre- and posthyperbaric oxygen (HBO2) data. The sensitivity analyses results are follows: best case (38/41, 93% improved; P<.001), worst case (19/41, 46% improved; P=.76), and average case (31/41, 76% improved; P=.002).

Figure 5

Results on the bowel questionnaire from the subset of patients with ulcerative colitis (UC) who had complete pre- and posthyperbaric oxygen (HBO2) data. The sensitivity analysis showed the best (38/41, 93%; P<.001) and worst (19/41, 46%; P=.14) cases, indicating that the results are sensitive to missing data.

Figure 6

Results from the Neurobehavioral Symptom Inventory (NSI) for patients treated for post–COVID-19 condition. In the sensitivity analyses, the best (133/149, 89.3% improved; P<.001), worst (111/149, 74.5% improved; P<.001), and average (131/149, 87.9% improved; P<.001) cases all showed significant improvement.