Physician Referral Guide: Hyperbaric Oxygen for Gas Gangrene

Assessing the patient before referral

While arranging surgical management and hyperbaric assessment, the receiving team should:

• Begin resuscitation and broad-spectrum intravenous antibiotics without delay, using a regimen with clostridial coverage (typically a penicillin plus clindamycin for its anti-toxin effect), narrowed once cultures return.
• Mobilise emergency surgical debridement, which takes precedence over every other step. The treatment sequence is debride first, antibiotics second, HBOT third.
• Obtain plain radiographs or CT of the affected region to document soft-tissue gas and the extent of fascial involvement, recognising that imaging supports but never delays operative exploration.
• Draw blood cultures, a complete blood count, electrolytes, renal function, lactate, creatine kinase, and a coagulation panel, and type and screen for likely operative blood loss.
• Document the wound, the exposure history, and the time of onset, so the hyperbaric team can prioritise the first session relative to the index debridement.

What the evidence supports

The clostridial alpha-toxin produced by *Clostridium perfringens* drives the fulminant tissue destruction characteristic of this infection. The mechanistic rationale for HBOT is well established: alpha-toxin production is inhibited once tissue oxygen tension exceeds roughly 250 mmHg, a threshold reached only at hyperbaric pressures of about 2.8 to 3.0 ATA and not achievable with normobaric oxygen. At these pressures the chamber also restores oxygen-dependent neutrophil bactericidal activity, which requires a tissue oxygen tension above roughly 30 mmHg, and supports clearer demarcation of viable from non-viable tissue to guide subsequent surgical debridement. The Undersea and Hyperbaric Medical Society classifies gas gangrene as an accepted indication.

Randomised controlled trials are not ethically feasible in a rapidly fatal condition where withholding an established adjunct would be untenable, so the human evidence is observational. Retrospective cohort and case-control studies suggest that adjunctive HBOT is associated with reduced mortality and a reduced extent of definitive amputation, although these designs cannot establish causation and are subject to confounding by indication and centre-level differences in surgical care. Mortality remains in the range of 25 to 50 percent even with optimal modern care, which underscores that HBOT is one component of an aggressive combined surgical, antimicrobial, and critical-care response rather than a treatment that stands on its own.

The Canadian referral pathway

Gas gangrene is treated as an emergency at all 11 Canadian hospital-based hyperbaric programmes and is covered by every provincial plan without prior authorisation. Because the priority is rapid surgical source control, the receiving centre should arrange definitive surgery locally where possible and coordinate hyperbaric treatment in parallel.

• Ontario: call CritiCall Ontario at 1-800-668-4357, the single coordination line that connects emergency departments to the Toronto General (UHN), Hamilton General, and The Ottawa Hospital programmes and arranges Ornge transport when needed.
• British Columbia: route to Vancouver General Hospital (Leon Judah Blackmore Pavilion), the only hospital chamber in the province; covered under MSP.
• Alberta: route to Misericordia Community Hospital (Edmonton) or Foothills Medical Centre / Arthur J.E. Child Comprehensive Cancer Centre (Calgary); covered by Alberta Health.
• Quebec: RAMQ covers Hopital du Sacre-Coeur de Montreal and Hotel-Dieu de Levis.
• Provinces and territories without a chamber (Manitoba, New Brunswick, PEI, Yukon, NWT, Nunavut): manage surgical source control locally and arrange inter-provincial air-ambulance referral to the nearest chamber, most commonly Misericordia Edmonton or the Ontario programmes.

The Divers Alert Network 24/7 emergency line at 1-919-684-9111 can also help Canadian emergency departments locate the nearest accepting chamber when local pathways fail. Detailed clinical background is available on the gas gangrene condition page.

How to use the research list below

The list contains every gas gangrene study in the Canada Hyperbarics database that was published in 2020 or later and has a freely available full-text version, each linked directly to that full text. Paywalled and abstract-only studies are excluded, and retracted studies are removed. This is a reference list, not a set of summaries. Counts and the open-access set refresh each quarter.