Necrotizing soft tissue infections — known as flesh-eating bacterial infections — are surgical emergencies. They include necrotizing fasciitis and Fournier's gangrene. Mortality runs 16% to 30% even with full care.
This page lays out the evidence for HBOT in these infections, the surgery-first care pattern, and where the data is strongest.
Quick Facts
| Field | Value |
|---|---|
| FDA approval status | Recognized indication (one of 14) |
| UHMS classification | Tier 1 — approved indication |
| Typical protocol | 2.0-2.5 ATA, 90 min, 1-2 sessions per day for 5-10 days |
| Medicare coverage | Covered under LCD L33532, 2025 as emergency care |
| Insurance prior auth | Waived; emergency intervention |
| Evidence grade | GRADE B (large cohorts, meta-analysis, no RCT) |
The evidence
The HBOT data in flesh-eating infections rests on retrospective cohorts and a 2023 meta-analysis. No randomized trial exists because the condition is too acute for trial design.
The Riseman Surgery 1990 cohort, PMID 2237764 is the classic citation. The team treated 29 patients with necrotizing fasciitis; the HBOT group had 23% mortality versus 66% in the no-HBOT group, despite being sicker on admission.
The Hassan Undersea Hyperb Med 2010 study, PMID 20462144 reported on 67 patients. The team did not find a mortality difference but did report that amputation rate fell from 25% to 4% with HBOT.
The Levett Cochrane review on HBOT for necrotizing fasciitis, 2015, PMID 25879088 noted that the trial data was thin but that the cohort signal was consistent.
A PubMed 2008 review on HBOT in necrotizing fasciitis, PMID 19050570 summed up the practice case for chamber treatment as part of the multi-team approach.
The World Journal of Emergency Surgery 2023 meta-analysis, PMID 36966323 pooled studies covering 49,152 patients. The HBOT group had a mortality risk ratio of 0.522 — about half the rate of the no-HBOT group.
The PMC 2024 contemporary cohort study used national data to show that HBOT was tied to lower mortality and fewer amputations across thousands of US cases.
The PMC 2025 review of HBOT in necrotizing infections updated the case for chamber treatment as part of standard care.
A Faunø Thrane 2021 cytokine study, PMID 33719215 showed that HBOT lowered key inflammatory markers in patients, which may explain part of the survival gain.
The PMC 2022 Fournier's gangrene meta-analysis pooled observational studies and reported a survival gain from HBOT in this scrotal and perineal form of the disease.
The StatPearls 2025 Fournier gangrene reference covers the standard of care and notes HBOT as an add-on after surgical cleanup.
The UHMS chapter on necrotizing soft tissue infections lays out the formal indication. The Society backs HBOT as an add-on after surgery and antibiotics.
The pattern is consistent across 35 years. HBOT plus surgery plus IV antibiotics cuts mortality and amputation rates in flesh-eating infections. The data is cohort and meta-analysis, not random, and the case for treatment is built on survival outcomes.
Mechanism of action
Flesh-eating infections spread through fascia — the thin layer of tissue under the skin. The bacteria use the low-oxygen environment in damaged fascia to grow fast.
White blood cells need oxygen to kill bacteria. The damaged fascia has too little oxygen for that step. The infection spreads while the immune system stalls.
HBOT raises tissue oxygen high enough to restore white cell killing. The boost cuts the speed of spread and slows tissue death.
Chamber treatment also helps drug delivery. Several antibiotic classes work better in well-oxygenated tissue. The combined effect of restored white cell killing and better drug action shifts the survival odds.
The mechanism explains why surgery comes first. Dead tissue holds bacteria and shields them from white cells and drugs, and HBOT cannot reach this tissue. Surgical cleanup must open the wound before chamber treatment can help.
Typical protocol
The standard plan is 2.0 to 2.5 ATA for 90 minutes. Sessions run 1 to 2 times per day for the first 3 to 5 days, then daily until the patient stabilizes.
Total session count runs 5 to 20 in most patients. The exact count is set by clinical response, surgical course, and infection control.
Surgical cleanup runs in parallel. Most patients need multiple trips to the operating room over the first 72 hours. HBOT sessions are scheduled around these trips.
Many patients also need wound care, IV antibiotics, and ICU support during the chamber course. The treatment is one part of a layered care plan that often runs for weeks.
Insurance and cost
Medicare covers necrotizing soft tissue infections under CMS NCD 20.29, 2017 and the related LCD L33532. Cover is straightforward as emergency care.
Cost per session runs $800 to $2,500 depending on chamber type and acute care setup. A 10-session course runs $8,000 to $25,000.
Commercial insurance follows Medicare for emergency cases. Prior auth is waived. The hospital handles the claim based on the diagnosis and treatment notes.
Most patients are critically ill when treatment starts. The HBOT bill is folded into the larger hospital care cost, often a $200,000-plus admission for surgery, ICU care, and wound management.
Where to get it
NSTI HBOT runs at hospital-based hyperbaric centers attached to trauma or burn hospitals. The center must have a chamber able to hold a critically ill patient with care lines and 24-hour staffing.
The UHMS-accredited facility directory, current 2026 lists fit centers. The subset with 24-hour emergency intake is smaller, and most patients are transferred to one of these sites.
The chamber should be a multiplace unit. Most patients arrive on ventilators or with care lines and cannot be treated in a monoplace setup. For chamber type details, see our FDA-cleared chambers list.
Many large trauma centers in the US have a chamber program able to take these patients. Rural patients are usually transferred by air or ground because the disease can move fast.
See our UHMS accreditation primer for what the credential means in practice.
Limitations and contraindications
Untreated lung collapse is an absolute limit. Critically ill patients often have lung issues that need chest imaging before chamber treatment.
Unstable blood pressure or arrhythmia is a relative limit. The chamber setting slows acute care, and the team must judge whether the patient can tolerate the session.
Patients with severe lung disease may struggle with the long oxygen exposure. Oxygen toxicity seizures can show up during long sessions, mainly in patients with prior brain injury.
The harder limit is timing. By the time many patients are diagnosed, hours of tissue death have already happened. HBOT cannot bring back dead tissue.
HBOT also does not replace surgery. Dead skin, fat, and fascia must be removed. A surgery delay to start chamber treatment first is a serious clinical error.
Active research
ClinicalTrials.gov studies on HBOT in flesh-eating infections, current 2026 cover plans for outcomes registries, Fournier's gangrene cohorts, and post-surgical care research.
A focus area is the role of HBOT in Fournier's gangrene — the scrotal and perineal form of the disease that mainly affects men with diabetes. The 2022 meta-analysis backed a survival gain in this group.
Another focus is the role of HBOT in cases where surgical cleanup has been incomplete. The data is thin but the question is clinically common.
How this compares to off-label HBOT uses
Flesh-eating infection HBOT is one of the better-supported FDA-listed HBOT uses. The mechanism is direct (raise tissue oxygen, restore white cell killing), the cohort data is large, and the 2023 meta-analysis backs a mortality gain.
This is very different from off-label HBOT for non-emergency conditions. Flesh-eating infection HBOT targets a clear bacterial and tissue oxygen problem. Off-label uses for anti-aging or recovery do not target such a clear failure.
For context on how off-label HBOT marketing splits from clinical data, read our analysis of institutional silence on HBOT and our gas gangrene evidence atlas, the closely related clostridial form of necrotizing infection.
The honest summary: HBOT for flesh-eating infection is well-backed as an add-on. The case for treatment is built on cohort survival data, the 2023 meta-analysis, and decades of clinical practice.
Frequently asked questions
How fast does treatment need to start?
Within hours of diagnosis. The disease can spread along fascia at a rate of inches per hour. Surgery comes first, then HBOT once the patient is stable enough to be moved to a chamber.
Does HBOT replace surgery?
No. Dead skin, fat, and fascia must be removed by surgery. HBOT is added to surgery and IV antibiotics, never used alone. A surgery delay to start HBOT first is a serious clinical error.
Will insurance cover this?
Yes. Necrotizing soft tissue infections are treated as emergency care under Medicare and most commercial plans. Prior auth is waived. The hospital handles the claim based on the surgical and chamber records.
How many sessions are needed?
Most patients run 5 to 20 sessions over 5 to 14 days. The first 3 to 5 days hold the most sessions — 1 to 2 per day — because the infection is still spreading. Sessions then drop to daily.
Can a soft-shell wellness chamber treat this?
No. Flesh-eating infection care asks for 2.0 to 2.5 ATA in a medical chamber. Soft-shell chambers reach only 1.3 ATA. That pressure is not enough to drive tissue oxygen to the level needed to restore white cell killing.
Sources
- Riseman Surgery Cohort, 1990
- Hassan Undersea Hyperb Med Study, 2010
- Levett Cochrane Review, 2015
- PubMed Necrotizing Fasciitis HBOT Review, 2008
- WJES Meta-analysis, 2023
- PLOS One Contemporary National Outcomes, 2024
- PMC NSTI Review, 2025
- Faunø Thrane Cytokine Study, 2021
- PMC Fournier's Gangrene Meta-analysis, 2022
- StatPearls Fournier Gangrene Reference, 2025
- UHMS NSTI Chapter, current
- CMS NCD 20.29 Hyperbaric Oxygen Therapy, 2017
- CMS LCD L33532, 2025
Medical disclaimer
This page is medical journalism, not medical advice. Flesh-eating infections are life-threatening surgical emergencies that ask for hospital-based care. HBOT is an add-on to surgery and IV antibiotics, never a stand-alone fix. Call 911 if you or a loved one show signs of fast-spreading skin infection with severe pain.