Hyperbaric Oxygen Therapy for Wound Healing: What the Trials Show
Which wounds hyperbaric oxygen helps, what the Cochrane review and diabetic foot ulcer trials found, Medicare's Wagner grade 3 rule and a typical course.
This content is for informational purposes only and does not constitute medical advice. Always consult a healthcare professional. Read full disclaimer
Hyperbaric oxygen therapy (HBOT) can help some hard-to-heal wounds, but not every wound, and never on its own. It is an accepted add-on treatment for selected diabetic foot ulcers, delayed radiation injuries, compromised skin grafts and flaps, necrotising soft-tissue infections and chronic osteomyelitis that has not responded to surgery and antibiotics. For diabetic foot ulcers, the trial results are mixed, so choosing the right patient matters as much as the chamber.
This guide covers which wounds qualify, what the clinical trials actually found, what a course of treatment looks like and who is not a good candidate.
Which Wounds Can a Hyperbaric Chamber Help Heal?
Three reference lists are widely used: the Undersea and Hyperbaric Medical Society (UHMS) in the United States, the European Committee for Hyperbaric Medicine (ECHM), and Medicare's National Coverage Determination 20.29. Here is how they treat the main wound types. For the full list of conditions beyond wounds, see our guide to accepted HBOT indications.
| Wound type | UHMS | ECHM 2016 | Medicare (US) | Evidence in brief |
|---|---|---|---|---|
| Diabetic foot ulcer, Wagner grade 3 or worse | Indication | Type 2 (suggested), Level B | Covered with criteria | Randomised trials disagree; Cochrane found faster healing at 6 weeks but no clear benefit at 1 year |
| Delayed radiation injury (soft tissue and bone) | Indication | Type 1 for jaw osteoradionecrosis, radiation cystitis and proctitis | Covered | Cochrane 2023: 18 trials, low to moderate certainty of benefit |
| Compromised skin grafts and flaps | Indication | Type 2, Level C | Covered (compromised skin grafts) | Mostly small studies |
| Necrotising soft-tissue infections | Indication | Type 1, Level C | Covered | Observational studies only, always alongside surgery |
| Chronic refractory osteomyelitis | Indication | Type 2, Level C | Covered | No randomised trials |
| Pressure ulcers and venous (stasis) ulcers | Only as "selected problem wounds"; best evidence is for diabetic foot ulcers | Type 3 at most, for selected delayed-healing wounds | Not covered | Cochrane found one small venous ulcer trial of 16 people |
ECHM "Type 1" means strongly recommended, "Type 2" suggested and "Type 3" optional. Level A to C describes how strong the supporting evidence is, with Level C resting mainly on expert consensus.
How Does Hyperbaric Oxygen Help Wounds?
Many chronic wounds are short of oxygen. The UHMS indications text notes that oxygen levels around a wound are roughly half those in normal tissue, and that fibroblast growth, collagen deposition, new blood vessel growth and the ability of white blood cells to kill bacteria all depend on oxygen.
During HBOT you breathe close to 100% oxygen at 2 to 3 times normal atmospheric pressure. In a 2011 review, Thom reported that arterial oxygen tension often exceeds 2,000 mmHg during treatment, with 200 to 400 mmHg reaching tissues. Repeated sessions are thought to support new blood vessel growth and infection control over a course of weeks.
Hyperbaric physicians often measure transcutaneous oxygen (TcPO2) on the skin next to the wound before deciding. According to UHMS, a wound oxygen level below about 40 mmHg best identifies wounds suited to HBOT, while wounds that are not hypoxic may not be. The ECHM recommends TcPO2 as the best way to select patients.
Diabetic Foot Ulcers: Who Qualifies?
Medicare criteria
Medicare covers HBOT for diabetic wounds of the lower limbs only when all three of these apply:
- The patient has type 1 or type 2 diabetes and a lower-limb wound caused by diabetes.
- The wound is classified as Wagner grade 3 or higher.
- The patient has failed an adequate course of standard wound therapy.
Standard wound therapy includes checking and correcting blood supply problems, optimising nutrition and blood sugar, removing dead tissue (debridement), moist dressings, off-loading pressure from the foot and treating infection. HBOT is covered only after 30 days of this care with no measurable signs of healing. The wound must then be re-evaluated every 30 days, and treatment stops if there is no measurable healing in any 30-day period. Private insurers may apply different rules; see our guide to HBOT insurance coverage.
European criteria
The ECHM gives similar advice. It suggests HBOT for diabetic foot ulcers of Wagner grade 3 and above that have failed to respond to adequate wound care after four weeks. It also recommends vascular screening first, to see whether blood flow can be restored surgically, and says HBOT should always be part of a multidisciplinary plan, not a stand-alone therapy.
What Do the Diabetic Foot Ulcer Trials Show?
This is where honest answers matter. Three well-known randomised trials reached different conclusions.
| Trial | Patients | Treatment | Main result |
|---|---|---|---|
| HODFU, Sweden (Löndahl 2010) | 94 patients with Wagner grade 2 to 4 ulcers present for over 3 months | 40 sessions at 2.5 ATA for 85 minutes, 5 days a week, versus hyperbaric air (placebo) | Ulcer healed at 1 year in 52% (25 of 48) with HBOT versus 29% (12 of 42) with placebo |
| Canada (Fedorko 2016) | 107 patients with Wagner grade 2 to 4 ulcers of at least 4 weeks | 30 daily 90-minute sessions at 244 kPa (about 2.4 ATA) versus sham | No difference: healed at 12 weeks in 20% with HBOT versus 22% with sham; amputation criteria met by 11 of 49 versus 13 of 54 |
| DAMO2CLES, Netherlands (Santema 2018) | 120 patients with diabetes and an ischaemic leg wound | Standard care with or without HBOT | No significant difference: limb salvage 53 versus 47 patients, wounds healed at 12 months 30 versus 28 |
The Cochrane review of HBOT for chronic wounds (Kranke 2015) pooled 12 trials with 577 participants. For diabetic foot ulcers, five trials with 205 people showed a higher rate of healing at six weeks (risk ratio 2.35), but the benefit was not evident at one year. There was no statistically significant difference in major amputations. The authors said design and reporting flaws in the trials meant they were not confident in the results. In 2020 Cochrane added a note that the review did not comply with its conflict-of-interest policy and that an update was under way.
Why do trials disagree? Patient selection is one likely reason. In DAMO2CLES, 35% of patients in the HBOT group could not complete the planned treatment; those who did had fewer major amputations, although that kind of subgroup finding cannot prove cause and effect. UHMS also notes that the trials it reviewed did not use measured wound hypoxia to choose patients, although hyperbaric physicians routinely use that measurement in practice.
The practical takeaway: HBOT is a reasonable option for a deep diabetic foot ulcer that is not healing despite good wound care and restored blood flow, especially when oxygen testing shows the tissue is hypoxic. It is not a guaranteed way to avoid amputation.
Radiation Wounds and Delayed Radiation Injury
Radiotherapy can damage small blood vessels, and injuries may appear months or years later: non-healing skin wounds, bone death in the jaw (osteoradionecrosis), or damage to the bladder (radiation cystitis) or rectum (radiation proctitis).
- The 2023 Cochrane review of late radiation tissue injury (Lin and colleagues) included 18 studies with 1,071 participants. HBOT may lead to complete resolution or significant improvement (low-certainty evidence) and may greatly reduce wound breakdown after head and neck surgery in irradiated tissue (low-certainty evidence). Pain from jaw osteoradionecrosis improved slightly at 12 months.
- The ECHM strongly recommends HBOT for mandibular osteoradionecrosis, haemorrhagic radiation cystitis and radiation proctitis.
- Preventing jaw osteoradionecrosis before tooth extraction is less clear. The UK HOPON trial randomised 144 patients and gave 30 sessions at 2.4 ATA. Osteoradionecrosis at six months occurred in 6.4% with HBOT and 5.7% without, and the authors concluded HBOT was unnecessary for dental extractions or implants in the irradiated jaw. This trial was published after the 2016 ECHM conference.
Compromised Skin Grafts and Flaps
When a graft or flap is losing its blood supply, HBOT may help the tissue survive. The ECHM suggests HBOT for compromised grafts and flaps and recommends starting as soon as possible after the problem is diagnosed. It also recommends HBOT before and after surgery when the risk is high, for example an irradiated or infected wound bed.
A 2026 systematic review (Carter and colleagues) included 24 studies, 13 of them randomised, with 2,246 patients. The evidence was rated very low to moderate, yet the authors made a strong recommendation for HBOT. The review was funded by UHMS and two authors are paid UHMS consultants, which readers should weigh.
Necrotising Soft-Tissue Infections
Necrotising fasciitis and similar infections are surgical emergencies. Treatment is urgent surgery and antibiotics in hospital; HBOT is an add-on and must never delay surgery. The ECHM recommends HBOT only as part of a protocol combined with immediate surgery and antibiotics.
A 2023 meta-analysis (Huang and colleagues) of retrospective studies covering 49,152 patients, 1,448 of whom received HBOT, found lower mortality in the HBOT group. Because every included study was retrospective, the authors called the evidence weak, and noted that HBOT is not available in all hospitals.
Chronic Refractory Osteomyelitis
This is a bone infection that persists or returns despite surgery and antibiotics. According to StatPearls, no randomised trials have tested HBOT for it. It is considered when standard treatment has failed, typically once a day for 90 to 120 minutes at 2 to 3 ATA alongside antibiotics, and usually 20 to 40 sessions are needed. The ECHM rates it Type 2, Level C.
What Does a Course of HBOT for Wounds Look Like?
- Chamber and pressure. UHMS defines clinical HBOT as treatment in a hard-sided chamber at not less than 2.0 ATA, breathing medical-grade oxygen, typically for 90 to 120 minutes per treatment. The wound trials above used 2.4 to 2.5 ATA. UHMS describes "mild" hyperbaric treatment below 1.5 ATA, typical of soft-shell chambers, as unproven. Compare them in our chamber types guide.
- Frequency. Most conditions need daily treatments for several weeks. Thom's review describes wound protocols of daily 1.5 to 2 hour treatments for 20 to 40 days; the trials above used 30 to 40 sessions.
- Monitoring. Your wound team keeps doing debridement, dressings and off-loading throughout. Under Medicare rules, progress is reviewed every 30 days.
- Side effects. The 2023 Cochrane review found HBOT increased the risk of reduced visual acuity, which is usually temporary, and of ear barotrauma. Read more in our guide to HBOT side effects and safety.
Who Is Not a Candidate for HBOT for Wounds?
HBOT is unlikely to be offered, or covered, if:
- The wound is not on the accepted lists. Medicare does not cover HBOT for pressure (decubitus) ulcers, stasis ulcers or chronic peripheral vascular insufficiency.
- Standard care has not been tried. Both Medicare (30 days) and the ECHM (four weeks) expect proper wound care first.
- Blood flow can be fixed surgically. The ECHM recommends vascular screening and, where needed, revascularisation before HBOT.
- The tissue is not hypoxic, or TcPO2 shows no oxygen response, per UHMS guidance.
- There is a medical contraindication. StatPearls lists untreated pneumothorax (collapsed lung) as the only absolute contraindication. Other conditions, such as COPD, epilepsy or difficulty clearing the ears, need individual assessment.
- Daily attendance is not realistic. The trials above used five sessions a week for six to eight weeks.
Questions to Ask a Wound Care or Hyperbaric Centre
- Does my wound meet UHMS, ECHM or my insurer's criteria, and what grade is it?
- Will you measure TcPO2 before and during treatment?
- Is treatment in a hard-shell chamber at 2.0 ATA or higher, and is the facility accredited?
- How many sessions do you plan, and when will you decide whether it is working?
- Who manages debridement, off-loading and blood sugar while I am in treatment?
Our checklist on how to choose an HBOT clinic has more.
Finding a Hyperbaric Wound Care Centre
As of September 2026, 349 facilities listed on hyperbaric.app are tagged with wound care. You can find hyperbaric clinics near you and check whether they treat medical indications in hard-shell chambers.
Sources
- Kranke P, Bennett MH, Martyn-St James M, Schnabel A, Debus SE, Weibel S. Hyperbaric oxygen therapy for chronic wounds. Cochrane Database of Systematic Reviews. 2015;(6):CD004123.
- Löndahl M, Katzman P, Nilsson A, Hammarlund C. Hyperbaric oxygen therapy facilitates healing of chronic foot ulcers in patients with diabetes. Diabetes Care. 2010;33(5):998-1003.
- Fedorko L, Bowen JM, Jones W, Oreopoulos G, Goeree R, Hopkins RB, O'Reilly DJ. Hyperbaric oxygen therapy does not reduce indications for amputation in patients with diabetes with nonhealing ulcers of the lower limb: a prospective, double-blind, randomized controlled clinical trial. Diabetes Care. 2016;39(3):392-399.
- Santema KTB, Stoekenbroek RM, Koelemay MJW, Reekers JA, van Dortmont LMC, Oomen A, et al. Hyperbaric oxygen therapy in the treatment of ischemic lower-extremity ulcers in patients with diabetes: results of the DAMO2CLES multicenter randomized clinical trial. Diabetes Care. 2018;41(1):112-119.
- Lin ZC, Bennett MH, Hawkins GC, Azzopardi CP, Feldmeier J, Smee R, Milross C. Hyperbaric oxygen therapy for late radiation tissue injury. Cochrane Database of Systematic Reviews. 2023;8(8):CD005005.
- Shaw RJ, Butterworth CJ, Silcocks P, Tesfaye BT, Bickerstaff M, Jackson R, et al. HOPON (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis): a randomized controlled trial of hyperbaric oxygen to prevent osteoradionecrosis of the irradiated mandible after dentoalveolar surgery. International Journal of Radiation Oncology, Biology, Physics. 2019;104(3):530-539.
- Carter MJ, Eckert KA, Fife CE, Gelly HB. Systematic review of comparative studies evaluating hyperbaric oxygen therapy on skin flap and graft surgical indications. Plastic and Reconstructive Surgery Global Open. 2026;14(5):e7750.
- Huang C, Zhong Y, Yue C, He B, Li Y, Li J. The effect of hyperbaric oxygen therapy on the clinical outcomes of necrotizing soft tissue infections: a systematic review and meta-analysis. World Journal of Emergency Surgery. 2023;18(1):23.
- Cooper JS, Hanley ME, Hendriksen S. Hyperbaric treatment of chronic refractory osteomyelitis. StatPearls. Updated 2 June 2025.
- Thom SR. Hyperbaric oxygen: its mechanisms and efficacy. Plastic and Reconstructive Surgery. 2011;127 Suppl 1:131S-141S.
- Gawdi R, Yrastorza J, Cooper JS. Hyperbaric oxygen therapy contraindications. StatPearls. Updated 27 May 2025.
- Mathieu D, Marroni A, Kot J. Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment. Diving and Hyperbaric Medicine. 2017;47(1):24-32.
- Mathieu D, Marroni A, Kot J. Correction to: Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment. Diving and Hyperbaric Medicine. 2017;47(2):131-132.
- Centers for Medicare & Medicaid Services, National Coverage Determination 20.29: Hyperbaric Oxygen Therapy
- Undersea and Hyperbaric Medical Society, Indications for hyperbaric oxygen therapy
This article is for information only and is not medical advice. Whether HBOT is appropriate for a wound should be decided with your wound care team and a qualified hyperbaric physician.