HBOT Approved Indications in Canada: A Regulatory Guide for Referring Physicians

TL;DR: Hyperbaric oxygen therapy (HBOT) has 14 indications recognised by the Undersea and Hyperbaric Medical Society (UHMS), the international authority whose indications list Canadian hyperbaric centres follow as the clinical standard. This physician guide reviews each recognised indication, summarises the current evidence base, clarifies the distinction between recognised and off-label uses, and outlines referral pathways across Canadian provinces.

Hyperbaric oxygen therapy (HBOT) is a medical treatment in which patients breathe 100% oxygen inside a pressurized chamber at pressures greater than 1 atmosphere absolute (ATA). In Canada, HBOT is regulated as a medical procedure delivered in Health Canada-approved hyperbaric chambers, and its clinical application is guided by the 14 indications recognized by the UHMS. For referring physicians, understanding which conditions carry approved-indication status – and the strength of evidence behind each – is essential for making informed referral decisions and counselling patients appropriately.

According to data retrieved from PubMed, the International Multicenter Registry for Hyperbaric Oxygen Therapy, which captured outcomes from 2,880 patients across 22 centres internationally, found that the most common recognised conditions treated were delayed radiation injury, enhancement of wound healing, and carbon monoxide poisoning (Harlan et al., 2022). Complication rates remained low and comparable to previous reports, reinforcing the safety profile of HBOT when used for approved indications.

Estimated reading time: 10 minutes

What Are the 14 UHMS-Recognised Indications for HBOT?

The Undersea and Hyperbaric Medical Society (UHMS) is the internationally recognized authority on hyperbaric medicine. UHMS maintains a list of 14 indications for HBOT, which serves as the foundation for clinical practice guidelines worldwide – including those followed by Canadian hyperbaric centres. Health Canada’s role is to license the hyperbaric chambers themselves as medical devices; provincial health plans then determine which indications qualify for public coverage.

According to a comprehensive review published in PubMed, UHMS has defined the minimum number of HBOT cycles, dose, and frequency for these 14 absolute indications (Jeyaraman et al., 2023; DOI: 10.1007/s43465-023-00837-2).

The complete list of recognised conditions is as follows:

How Does Health Canada Regulate Hyperbaric Oxygen Therapy?

Health Canada regulates HBOT through its medical device framework. Hyperbaric chambers are classified as Class III or Class IV medical devices, requiring Health Canada licensing before they can be sold or used in clinical practice. The therapy itself is delivered as a medical procedure, meaning it must be prescribed by a physician and administered by trained hyperbaric personnel.

Health Canada does not maintain its own separate list of approved HBOT indications. Instead, Canadian hyperbaric centres follow the recognised conditions as the clinical standard. Provincial health ministries then determine which of these indications qualify for public health insurance coverage – a decision that varies significantly by province.

Key regulatory points for referring physicians:

• Chamber approval: Only Health Canada-licensed chambers may be used for clinical treatment. Verify that the receiving facility operates an approved device.
• Operator certification: Hyperbaric technicians and physicians should hold certification from recognized bodies such as the Canadian Undersea and Hyperbaric Medical Association (CUHMA) or UHMS.
• Off-label use: Conditions not on the UHMS-approved list may be treated at the discretion of the hyperbaric physician, but these are considered off-label and are not covered by provincial health plans.
• Advertising restrictions: Under Health Canada guidelines, clinics cannot advertise HBOT as a cure or treatment for non-approved conditions without appropriate research context and caveats.

Which Indications Have the Strongest Evidence?

Not all 14 UHMS-recognised indications carry the same weight of evidence. For referring physicians, understanding the evidence hierarchy helps prioritize referrals and counsel patients effectively.

Emergency Indications (Strongest Evidence)

Four indications are considered emergencies where HBOT is a primary or critical adjunct treatment:

1. Air or gas embolism – HBOT is the definitive treatment. Recompression reduces bubble size and restores blood flow.
2. Carbon monoxide poisoning – Strong evidence supports HBOT within 24 hours of exposure for reducing delayed neurological sequelae.
3. Decompression sickness – HBOT via recompression is the standard of care, supported by decades of diving medicine evidence.
4. Clostridial myositis (gas gangrene) – HBOT is an important adjunct to surgical debridement and antibiotics, with evidence showing reduced mortality.

Strong Evidence (Cochrane-Reviewed)

Delayed radiation injury has some of the strongest evidence among non-emergency indications. A 2023 Cochrane systematic review analysing 18 randomized controlled trials (1,071 participants) found that HBOT may result in complete resolution or significant improvement of late radiation tissue injury (RR 1.39, 95% CI 1.02–1.89) and may substantially reduce wound dehiscence following head and neck soft tissue surgery (RR 0.24, 95% CI 0.06–0.94). Pain scores in osteoradionecrosis also improved at 12 months (Lin et al., 2023; DOI: 10.1002/14651858.CD005005.pub5).

Enhancement of healing in selected problem wounds – particularly diabetic foot ulcers – is supported by multiple systematic reviews and is one of the most commonly treated indications in Canadian hyperbaric centres.

Moderate Evidence With Guideline Support

Idiopathic sudden sensorineural hearing loss (ISSHL) was added to the recognised conditions in 2014. The American Academy of Otolaryngology–Head and Neck Surgery updated its clinical practice guidelines in 2019, including HBOT as an option combined with steroid therapy within 2 weeks of symptom onset (KAS 9a) or as salvage therapy within 1 month (KAS 9b) (Chandrasekhar et al., 2019; DOI: 10.1177/0194599819859885).

A retrospective study of hyperbaric facilities in Australia and New Zealand found that following the UHMS guideline addition, the proportion of patients treated for ISSHL increased from 3.2% to 12.1% of all hyperbaric cases (P < 0.0009), demonstrating how guideline changes directly influence referral patterns (Sherlock et al., 2021; DOI: 10.28920/dhm51.1.68-71).

What Is the Difference Between Approved and Off-Label HBOT?

Approved (on-label) HBOT refers to treatment for one of the 14 UHMS-recognised indications. These are conditions for which the evidence has been reviewed and accepted by the international hyperbaric medicine community. In Canada, provincial health plans base their coverage decisions on these approved indications.

Off-label (investigational) HBOT refers to treatment for conditions not on the UHMS list. Examples include traumatic brain injury (TBI), post-concussion syndrome, long COVID, autism spectrum disorder, fibromyalgia, and anti-aging applications. While emerging research exists for several of these conditions, they have not yet met the UHMS evidence threshold for approved-indication status.

Key distinctions for referring physicians:

When referring for an off-label indication, physicians should ensure patients understand the investigational nature of the treatment, the cost implications, and the current state of the evidence. Clinics treating off-label conditions should be transparent about the distinction.

How Do Provincial Coverage Policies Affect Referral Decisions?

Provincial health plan coverage for HBOT varies considerably across Canada. This directly affects referral pathways and patient access. The following summarizes the current landscape:

• Ontario (OHIP): Covers HBOT for 14 approved indications at both hospitals and eligible private clinics that may bill OHIP for approved indications. Ontario has the broadest coverage in Canada.
• British Columbia (MSP): Coverage is limited to Vancouver General Hospital (VGH). Private clinics in BC are not covered by MSP – patients pay out of pocket.
• Alberta (AHCIP): Coverage is available at Alberta Health Services hospital clinics in Calgary and Edmonton. Private clinics are covered at CPSA-accredited private facilities under AHCIP.
• Quebec (RAMQ): Hospital-based HBOT is covered. Private clinics are not covered by RAMQ.
• Nova Scotia (MSI): HBOT is available at the QEII Health Sciences Centre in Halifax, covered by MSI. Private clinics are not covered. Wait times can be 1.5 to 2 years.
• Manitoba, Saskatchewan, New Brunswick, Newfoundland and Labrador, PEI: No confirmed provincial coverage for private clinics. Hospital-based services may be available on a case-by-case basis.

Private insurance: Some private insurance plans cover HBOT for approved indications. Encourage patients to check with their insurer before beginning treatment, as pre-authorization is often required.

What Should Referring Physicians Consider Before Making a Referral?

A structured approach to HBOT referral ensures appropriate patient selection and optimal outcomes. Consider the following before referring:

1. Confirm the indication: Is the patient’s condition on the UHMS-approved list? If not, is there sufficient emerging evidence to warrant a referral for off-label treatment?
2. Screen for contraindications: Absolute contraindications include untreated pneumothorax. Relative contraindications include upper respiratory infections, seizure disorders, concomitant use of certain chemotherapy agents (bleomycin, doxorubicin, cisplatin), claustrophobia, and uncontrolled high fever.
3. Assess timing: Several indications are time-sensitive. Carbon monoxide poisoning, air embolism, and decompression sickness require emergency referral. Sudden hearing loss benefits most from treatment initiated within 2 weeks of symptom onset. Delayed radiation injury can be treated electively.
4. Verify facility accreditation: Refer to facilities with Health Canada-approved chambers and CUHMA– or UHMS-certified personnel.
5. Document thoroughly: Include the specific indication, relevant diagnostic workup, prior treatments attempted, and the clinical rationale for HBOT in the referral letter.
6. Discuss coverage: Advise patients on whether their provincial health plan covers HBOT for their specific indication and whether pre-authorization is needed.

How Does the Evidence for Approved Indications Compare Across Conditions?

The strength of evidence varies across the 14 approved indications. The following summary helps referring physicians contextualize the evidence when counselling patients:

Strongest evidence (emergency standard of care):

• Air or gas embolism – definitive treatment
• Decompression sickness – decades of diving medicine evidence
• Carbon monoxide poisoning – multiple RCTs supporting reduced neurological sequelae

Strong evidence (supported by systematic reviews):

• Delayed radiation injury – Cochrane review (18 RCTs, 1,071 participants) showing benefit
• Problem wound healing (diabetic ulcers) – multiple systematic reviews

Moderate evidence (supported by clinical studies and guidelines):

• Idiopathic sudden sensorineural hearing loss – AAO-HNS guideline inclusion
• Necrotizing soft tissue infections – adjunct to surgery, clinical data
• Refractory osteomyelitis – long clinical history, observational data
• Compromised grafts and flaps – perioperative use, clinical evidence
• Crush injuries – time-sensitive, clinical data

Supporting evidence (established clinical practice):

• Gas gangrene – adjunct to surgery, historical evidence
• Intracranial abscess – adjunct role, limited RCT data
• Severe anaemia – bridge to transfusion, case series
• Acute thermal burns – limited but supportive data

Where Can Canadian Physicians Find Accredited Hyperbaric Facilities?

Canada Hyperbarics maintains a comprehensive directory of hyperbaric facilities across Canada, including both hospital-based and private clinics. The conditions page provides detailed information on each approved indication, and the research database offers access to thousands of peer-reviewed studies on HBOT.

Additional resources for referring physicians:

• CUHMA: The Canadian Undersea and Hyperbaric Medical Association provides physician education, certification, and clinical guidelines specific to Canadian practice.
• UHMS: The Undersea and Hyperbaric Medical Society maintains the definitive list of approved indications and publishes clinical practice guidelines.
• Health Canada: The Health Canada medical device database can be used to verify chamber approvals and regulatory compliance.

Frequently Asked Questions

Is HBOT considered a standard medical treatment in Canada?

Yes. HBOT is a recognized medical procedure in Canada when used for recognised conditions and delivered in Health Canada-approved chambers by certified personnel. It is covered by several provincial health plans for approved indications.

How many HBOT sessions are typically required?

The number of sessions varies by indication. Emergency conditions (air embolism, CO poisoning, decompression sickness) may require 1–3 sessions. Chronic conditions such as delayed radiation injury or non-healing wounds typically require 20–40 sessions at 2.0–2.4 ATA, delivered 5 days per week.

Can physicians refer for off-label HBOT indications?

Yes. Physicians may refer patients for off-label HBOT, but should ensure patients are fully informed about the investigational nature of the treatment, the lack of provincial health plan coverage, and the current state of the evidence. The hyperbaric physician assumes clinical responsibility for the treatment decision.

What documentation is needed for an HBOT referral?

A referral letter should include the patient’s diagnosis, relevant imaging and lab results, prior treatments attempted, the specific HBOT indication, and any known contraindications. For coverage purposes, include the corresponding ICD-10 diagnostic code.

Are there age restrictions for HBOT in Canada?

There are no absolute age restrictions. HBOT has been used safely in paediatric patients for approved indications such as carbon monoxide poisoning and necrotizing infections. The decision to treat is based on clinical indication, not age alone.

How quickly should patients be referred for time-sensitive indications?

Emergency indications (air embolism, CO poisoning, decompression sickness, gas gangrene) require immediate referral. Idiopathic sudden sensorineural hearing loss should be referred within 2 weeks of symptom onset for initial therapy, or within 1 month for salvage therapy. Crush injuries benefit from treatment within 4–6 hours.

What is the safety profile of HBOT for approved indications?

According to PubMed, the International Multicenter Registry reported low complication rates across 2,880 patients treated for approved indications. The most common side effects include ear barotrauma (usually mild and preventable with equalization techniques), transient myopia (reversible after treatment ends), and rarely, oxygen toxicity seizures (approximately 1 in 10,000 treatments). The Cochrane review noted an increased risk of temporary reduction in visual acuity with HBOT.

Does HBOT interact with other treatments?

HBOT is generally compatible with most medical treatments. However, certain chemotherapy agents – particularly bleomycin, doxorubicin, and cisplatin – may interact with hyperbaric oxygen. Concurrent use of these agents is a relative contraindication. Always inform the hyperbaric team of the patient’s complete medication list.

Key Takeaways for Referring Physicians

• HBOT has 14 UHMS-recognised indications that Canadian hyperbaric centres and provincial health systems treat as the clinical standard.
• Evidence strength varies by indication – emergency indications and delayed radiation injury carry the strongest evidence.
• Timing matters – several indications are time-sensitive, making prompt referral critical for optimal outcomes.
• Provincial coverage varies significantly – Ontario offers the broadest coverage; other provinces may limit coverage to hospital-based treatment.
• Off-label use requires informed consent – emerging indications may warrant referral, but patients must understand the investigational status and cost implications.
• Verify facility accreditation – refer only to centres with Health Canada-approved chambers and certified hyperbaric personnel.

Canada Hyperbarics provides a free facility directory, condition-specific information, and a research database to support evidence-based referral decisions. For questions about specific clinical scenarios, consult with a CUHMA-certified hyperbaric physician.

This content is for informational purposes only and does not constitute medical advice. Physicians should exercise independent clinical judgement when making referral decisions. Always consult the latest clinical practice guidelines and the patient’s individual circumstances before initiating any treatment. Canada Hyperbarics is an independent educational resource and is not affiliated with any specific hyperbaric clinic.

References

1. Harlan NP, Ptak JA, Rees JR, et al. International Multicenter Registry for Hyperbaric Oxygen Therapy: Results through June 2021. Undersea Hyperb Med. 2022;49(3):275-287. PubMed: 36001560
2. Jeyaraman M, Sami A, Nallakumarasamy A, et al. Hyperbaric Oxygen Therapy in Orthopaedics: An Adjunct Therapy with an Emerging Role. Indian J Orthop. 2023;57(5):748-761. DOI: 10.1007/s43465-023-00837-2
3. Lin ZC, Bennett MH, Hawkins GC, et al. Hyperbaric oxygen therapy for late radiation tissue injury. Cochrane Database Syst Rev. 2023;8(8):CD005005. DOI: 10.1002/14651858.CD005005.pub5
4. Chandrasekhar SS, Tsai Do BS, Schwartz SR, et al. Clinical Practice Guideline: Sudden Hearing Loss (Update). Otolaryngol Head Neck Surg. 2019;161(1_suppl):S1-S45. DOI: 10.1177/0194599819859885
5. Sherlock S, Kelly S, Bennett MH. Hyperbaric oxygen for sudden hearing loss: Influence of international guidelines on practice in Australia and New Zealand. Diving Hyperb Med. 2021;51(1):68-71. DOI: 10.28920/dhm51.1.68-71