Hyperbaric oxygen therapy is an adjunct to emergency surgical debridement and broad-spectrum intravenous antibiotics for necrotizing fasciitis and other necrotizing soft-tissue infections. It enhances neutrophil bactericidal activity in hypoxic tissue, inhibits anaerobic toxin production, and improves antibiotic penetration. Necrotizing soft-tissue infection is one of the 14 conditions for which Health Canada-aligned hospital programmes provide HBOT under provincial health insurance.
Quick Answer
Does HBOT help necrotizing soft tissue infections? Hyperbaric oxygen therapy is an adjunct to emergency surgical debridement and broad-spectrum intravenous antibiotics for necrotizing fasciitis and other necrotizing soft-tissue infections. It enhances neutrophil bactericidal activity in hypoxic tissue, inhibits anaerobic toxin production, and improves antibiotic penetration. Necrotizing soft-tissue infection is one of the 14 conditions for which Health Canada-aligned hospital programmes provide HBOT under provincial health insurance.
Necrotizing soft-tissue infections (NSTIs) are rapidly progressive bacterial infections that destroy skin, subcutaneous tissue, fascia, and sometimes muscle. The category includes necrotizing fasciitis (Type I polymicrobial, Type II monomicrobial Group A Streptococcus, Type III marine Vibrio, Type IV fungal), Fournier's gangrene (perineal/genital), Ludwig's angina (cervical), and craniofacial necrotizing infection. Mortality remains 20 to 40 percent even with optimal modern care, rising to 50 percent or higher when surgical debridement is delayed beyond 24 hours of presentation.
Classic presentation includes pain out of proportion to visible findings, rapidly spreading erythema with poorly demarcated borders, skin discoloration progressing to purple or black, bullae, crepitus from gas-producing organisms, and systemic toxicity (fever, tachycardia, hypotension, leukocytosis, lactic acidosis). The LRINEC score (Laboratory Risk Indicator for Necrotizing Fasciitis) using CRP, white-cell count, hemoglobin, sodium, creatinine, and glucose can support clinical suspicion but does not replace it; a score below 6 does not exclude the diagnosis.
NSTIs follow trauma (penetrating, blunt, or surgical), insect bites, intravenous drug use injection sites, pressure ulcers, and post-operative wounds. Risk factors include diabetes mellitus, immunosuppression, chronic alcohol use, peripheral vascular disease, age over 60, and obesity. The single most important determinant of survival is time from presentation to first surgical debridement; HBOT is added when feasible without delaying surgery.
HBOT addresses NSTIs through four convergent mechanisms.
First, neutrophil bactericidal restoration. The oxygen-dependent oxidative burst that neutrophils use to kill bacteria requires tissue pO2 above 30 mmHg, but necrotic tissue is profoundly hypoxic (pO2 often below 5 mmHg). HBOT at 2.4 ATA can raise tissue pO2 to several hundred mmHg, restoring full neutrophil killing capacity at the wound margin.
Second, anaerobic toxin suppression. Clostridium perfringens alpha-toxin and Group A Streptococcus exotoxin production are inhibited at the elevated oxygen tensions achieved with HBOT. Toxin suppression helps halt the rapid tissue spread that defines NSTIs.
Third, antibiotic synergy. HBOT enhances the activity of aminoglycosides, fluoroquinolones, and certain beta-lactam antibiotics by improving their tissue penetration and oxygen-dependent intracellular accumulation. This is particularly relevant in the hypoxic, edematous wound bed where standard antibiotic delivery is impaired.
Fourth, demarcation and wound preparation. Repeated HBOT helps the surgical team distinguish viable from non-viable tissue at successive debridement procedures, reduces post-debridement edema, and promotes granulation in the wound bed before reconstructive surgery.
Typical Treatment Protocol
The standard adjunctive protocol is recompression to 2.0 to 2.5 ATA on 100 percent oxygen for 90 minutes per session. The first one to two sessions are typically delivered within hours of the index surgical debridement, with twice-daily treatment continuing for the first 24 to 48 hours, then transitioning to once-daily for the remainder of the course. Typical total course is 10 to 30 sessions, guided by clinical response, serial debridement findings, and wound bed status. Therapy is paused or stopped when the wound is clean and granulating, or when reconstructive surgery is scheduled. HBOT is delivered between surgical procedures, NEVER as a substitute for or as a delay to debridement. The sequence is debride first, antibiotics second (broad-spectrum IV with anti-MRSA, anti-anaerobic, and anti-Streptococcus coverage pending culture), HBOT third. If the receiving hyperbaric facility is more than 60 to 90 minutes away from the surgical theatre, transfer for HBOT is considered only after the initial debridement is complete and the patient is hemodynamically stable.
Level B - Moderate Evidence
Supported by controlled studies and clinical evidence
Time-to-first-debridement is the strongest predictor of survival in NSTIs. Mortality rises sharply when surgical debridement is delayed beyond 24 hours of presentation. HBOT is added without delaying surgery.
Retrospective cohort studies and meta-analyses (Wilkinson and Doolette 2004, Soh et al. 2012) suggest adjunctive HBOT is associated with reduced mortality and fewer debridement procedures, though randomised controlled trials are not feasible for ethical reasons in this life-threatening condition.
HBOT restores neutrophil oxygen-dependent killing capacity at tissue oxygen tensions only reachable at 2.0 ATA and above. Normobaric oxygen alone does not achieve this in necrotic tissue.
Anaerobic toxin production by Clostridium perfringens and Group A Streptococcus is inhibited at the elevated oxygen tensions HBOT delivers, helping halt tissue spread.
The standard adjunctive protocol is 2.0 to 2.5 ATA, 90 minutes per session, twice daily for the first 24 to 48 hours, then once daily, for a total course of 10 to 30 sessions guided by wound response.
In Ontario, urgent inter-facility transfer for adjunctive HBOT is coordinated through CritiCall Ontario (1-800-668-4357), which provides 24/7 physician-to-physician triage between the surgical team and the receiving hyperbaric programme.
Highest-evidence-tier studies tagged to this condition in the Canada Hyperbarics research database, ranked by evidence tier (1 = meta-analysis or RCT, 2 = cohort, 3 = case series), most recent first.
Urol Int · 2021 · Systematic Review
Healthcare (Basel) · 2021 · Systematic Review
Infect Dis (Lond) · 2019 · Systematic Review
BMC Ear Nose Throat Disord · 2018 · Systematic Review
Cochrane Database Syst Rev · 2018 · Systematic Review
Studies in our database that include a ClinicalTrials.gov registration. Trial registration is a marker of methodological rigour because the protocol, primary outcome, and analysis plan are deposited before enrolment begins.
Infect Dis Ther · 2025 · Cohort Study · PMID 40613866
European journal of medical research · 2023 · Prospective Study · PMID 37946314
JMIR research protocols · 2022 · Prospective Study · PMID 36427229
BMJ Open · 2017 · Cohort Study · PMID 28982834
BMJ Open · 2015 · Cohort Study · PMID 25967993
Necrotizing soft-tissue infection is a surgical emergency, and the patient's first stop is the operating theatre, not the hyperbaric chamber. After the initial debridement, broad-spectrum IV antibiotics, and stabilisation, the surgical team contacts the hospital hyperbaric programme to coordinate adjunctive HBOT. In Ontario, this is most efficiently done through CritiCall Ontario (1-800-668-4357), which provides 24/7 physician-to-physician triage. In other provinces the call goes directly to the receiving hospital chamber.
The first HBOT session typically begins within hours of the index debridement, often while the patient is still being stabilised in the surgical ICU. In a multiplace chamber, you remain on full critical-care support (ventilator, infusions, monitoring) with a hyperbaric-trained nurse and physician inside the chamber alongside other patients. In a monoplace chamber, the support is delivered through purpose-designed pass-throughs. Pressurisation takes five to ten minutes, the 90-minute treatment phase is on 100 percent oxygen at 2.0 to 2.5 ATA, and decompression takes another five to ten minutes.
Subsequent sessions alternate with serial surgical debridements over the first several days. Most patients require two to four debridements before the wound bed is clean. HBOT continues twice-daily for the first 24 to 48 hours, then transitions to once-daily until the wound is granulating or reconstructive surgery is scheduled. Total course is typically 10 to 30 sessions over two to four weeks. The hyperbaric medicine team, the surgical team, infectious diseases, critical care, and (later) plastic surgery all participate in the multi-disciplinary management. Recovery from severe NSTIs is typically prolonged, with significant rehabilitation needs after the acute treatment phase.
Necrotizing soft-tissue infection is recognised by Health Canada as one of the 14 conditions for which hyperbaric oxygen is the established standard of care. Treatment is delivered at 11 hospital-based hyperbaric programmes across seven provinces (Ontario, Quebec, British Columbia, Alberta, Nova Scotia, Newfoundland, Saskatchewan) on an emergency-priority basis under OHIP, RAMQ, MSP, AHCIP, MSI, MCP, and Saskatchewan Health.
For patients in the six provinces and territories without an in-province hospital programme (Manitoba, New Brunswick, Prince Edward Island, Yukon, Northwest Territories, Nunavut), urgent inter-facility transfer is coordinated through the receiving province's transfer service: CritiCall Ontario (1-800-668-4357) is the standard line for Ontario and northern Manitoba referrals, while western Canadian referrals route through Alberta Health Services or Vancouver Coastal Health depending on geography.
The receiving emergency department must coordinate three things in parallel: immediate surgical debridement at the local hospital, broad-spectrum IV antibiotics, and arrangement of transfer to the nearest hyperbaric programme. HBOT is delivered between debridement procedures; the patient continues to require the surgical team's care throughout. CritiCall Ontario specifically provides 24/7 physician-to-physician triage to coordinate this multi-team handover.
Hyperbaric oxygen therapy for the 14 Health Canada-recognised conditions, including Necrotizing Soft Tissue Infections, is delivered at the 11 hospital hyperbaric programmes located in seven provinces (Ontario, Quebec, British Columbia, Alberta, Nova Scotia, Newfoundland and Labrador, and Saskatchewan). The six provinces and territories without an in-province hospital programme (Manitoba, New Brunswick, Prince Edward Island, Yukon, Northwest Territories, and Nunavut) route patients to the nearest receiving hospital programme. Use the links below for province-specific coverage, referral pathway, and emergency routing details.
Hospital + Private
OHIP (Ontario Health Insurance Plan)
Hospital Only
MSP (Medical Services Plan)
Hospital + Private
Alberta Health / AHCIP
Hospital Only
RAMQ
Disrupted
Saskatchewan Health Authority
No Hospital Chamber
Manitoba Health
Hospital Only
MSI (Medical Services Insurance)
No Hospital Chamber
Medicare NB
Hospital Only
MCP (Medical Care Plan)
Out-of-Province Referral
Health PEI
Out-of-Province Referral
Yukon Health and Social Services
Out-of-Province Referral
NWT Health and Social Services
Out-of-Province Referral
Nunavut Department of Health
For acute or emergency presentations of Necrotizing Soft Tissue Infections, call 911 first. The receiving emergency department coordinates urgent transfer to the nearest hospital hyperbaric programme through the relevant provincial transfer network (CritiCall Ontario at 1-800-668-4357, BC Patient Transfer Network, EHS Nova Scotia, or equivalent). For diving-related emergencies, the Divers Alert Network (DAN) emergency hotline is 1-919-684-9111.
There are no absolute contraindications to adjunctive HBOT in NSTIs given the high mortality of untreated or under-treated disease. The single condition that must be addressed before chamber entry is untreated pneumothorax, which will tension under compression and again under decompression; tube thoracostomy is performed first. HBOT must NOT delay surgical debridement under any circumstance. If transfer to a hyperbaric programme would push the first debridement beyond 12 to 24 hours of presentation, the local team should debride first and consider HBOT as a secondary stage. Severe haemodynamic instability requiring continuous vasopressor titration is a relative contraindication because chamber-side pump titration is more difficult; most modern multiplace chambers accommodate ventilator-dependent and vasopressor-dependent patients with appropriate critical-care support.
Yes, as an adjunct to emergency surgical debridement and broad-spectrum intravenous antibiotics. HBOT enhances neutrophil bactericidal activity in hypoxic tissue, inhibits anaerobic toxin production, and improves antibiotic penetration. It is not a substitute for surgery; the standard sequence is debride first, antibiotics second, HBOT third, with HBOT delivered between debridement procedures.
No. Surgical debridement remains the primary and most critical treatment. Mortality rises sharply when debridement is delayed beyond 24 hours of presentation. HBOT is added when it can be arranged without delaying surgery.
Retrospective cohort studies and meta-analyses suggest adjunctive HBOT is associated with reduced mortality and fewer surgical debridements when added to standard surgical and antibiotic treatment. Randomised controlled trials are not ethically feasible in this life-threatening condition, so the evidence base is observational.
As soon as the patient is hemodynamically stable after the first surgical debridement. The first one to two HBOT sessions are typically delivered within hours of the index debridement, with twice-daily treatment continuing for the first 24 to 48 hours.
Typical course is 10 to 30 sessions at 2.0 to 2.5 ATA on 100 percent oxygen for 90 minutes per session. The first 24 to 48 hours are twice-daily, then transitioning to once-daily. Total course is guided by clinical response, serial debridement findings, and wound bed status.
Yes. Necrotizing soft-tissue infection is recognised by Health Canada and covered as an emergency indication at all 11 hospital-based hyperbaric programmes in Canada under OHIP, RAMQ, MSP, AHCIP, MSI, MCP, and Saskatchewan Health. For patients in provinces without an in-province hospital programme, urgent inter-facility transfer is coordinated through provincial transfer services such as CritiCall Ontario (1-800-668-4357).
No. Surgical debridement comes first. If transfer to a hyperbaric programme would push the first debridement beyond 12 to 24 hours of presentation, the local team should debride first and consider HBOT as a secondary stage after the patient is stabilised.
Fournier gangrene is necrotizing fasciitis of the perineum and external genitalia, more common in men with diabetes or immunosuppression. It is treated the same way: emergency surgical debridement, broad-spectrum IV antibiotics, and adjunctive HBOT at the same protocol (2.0 to 2.5 ATA, 90 minutes per session, twice daily then once daily, total course 10 to 30 sessions).