How to Refer a Patient for HBOT in Canada: A Physician Guide

TL;DR: Referring a patient for hyperbaric oxygen therapy (HBOT) in Canada involves identifying an approved indication, screening for contraindications, locating an accredited facility, and submitting documentation to the treating hyperbaric physician. This step-by-step guide walks referring physicians through the complete referral pathway – from patient selection to post-treatment follow-up – across all 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). For referring physicians across Canada, understanding when and how to refer patients for HBOT can be the difference between timely intervention and missed therapeutic windows. The Undersea and Hyperbaric Medical Society (UHMS) currently recognises 14 approved indications, and several Canadian provinces offer public coverage for eligible patients. This guide provides a clear, evidence-based referral pathway so you can confidently navigate the process from initial assessment to post-treatment follow-up.

According to PubMed, Samson et al. (2024) note that hyperbaric medicine is a subspecialty many physicians may not encounter frequently, yet identifying conditions that benefit from HBOT – particularly emergency indications – can significantly impact patient outcomes (DOI: 10.1016/j.jemermed.2024.09.009). Canada Hyperbarics maintains a comprehensive directory of accredited facilities across the country to support the referral process.

Estimated reading time: 9 minutes

When Should You Refer a Patient for Hyperbaric Oxygen Therapy?

The first step in the referral process is determining whether your patient has a condition that meets established criteria for HBOT. The UHMS recognises 14 approved indications, and Health Canada aligns closely with these designations. Understanding the distinction between emergency and elective indications is critical for appropriate referral timing.

Step 1: Identify Whether the Condition Is an Approved Indication

The 14 UHMS-approved indications for HBOT are:

1. Air or gas embolism
2. Carbon monoxide poisoning (including suspected cyanide poisoning)
3. Gas gangrene (clostridial myositis and myonecrosis)
4. Crush injury, compartment syndrome, and other acute traumatic ischemias
5. Decompression sickness
6. Enhancement of healing in selected problem wounds (diabetic foot ulcers, chronic non-healing wounds)
7. Exceptional blood loss anaemia (when transfusion is not an option)
8. Intracranial abscess
9. Necrotising soft tissue infections
10. Refractory osteomyelitis
11. Delayed radiation injury (soft tissue and bony necrosis)
12. Compromised grafts and flaps
13. Acute thermal burn injury
14. Idiopathic sudden sensorineural hearing loss

As documented by Harlan et al. (2020) in the development of an international hyperbaric treatment registry, these 14 indications form the evidence-based foundation for HBOT referrals, though outcome data collection across multiple centres continues to strengthen the evidence base (DOI: 10.2196/18857).

Step 2: Determine Urgency – Emergency vs. Elective Referral

Referral urgency varies significantly by indication. Based on PubMed literature, Samson et al. (2024) identify seven conditions requiring emergency transfer to a hyperbaric facility:

For sudden sensorineural hearing loss (SSNHL), timing is particularly critical. A meta-analysis by Rhee et al. (2018) published in JAMA Otolaryngology demonstrated that HBOT combined with standard medical therapy produced significantly higher complete hearing recovery rates (OR 1.61; 95% CI 1.05–2.44), with greater benefit observed in patients with severe-to-profound hearing loss and when HBOT was initiated as early salvage treatment (DOI: 10.1001/jamaoto.2018.2133). This underscores the importance of timely referral – delays beyond 2 weeks reduce treatment efficacy.

How Do You Screen a Patient Before Referring for HBOT?

Step 3: Screen for Absolute and Relative Contraindications

Before initiating a referral, screen your patient for contraindications. The hyperbaric physician will conduct their own assessment, but pre-screening helps avoid unnecessary referrals and delays.

Absolute contraindications:

• Untreated pneumothorax
• Concurrent use of bleomycin (risk of pulmonary toxicity)
• Concurrent use of cisplatin (impairs wound healing response)
• Concurrent use of disulfiram (blocks protective superoxide dismutase activity)
• Concurrent use of doxorubicin (cardiotoxicity risk under pressure)
• Concurrent use of mafenide acetate (inhibits carbonic anhydrase, increases CO₂ toxicity risk)

Relative contraindications requiring specialist assessment:

• Upper respiratory infection or sinusitis (barotrauma risk)
• Seizure disorder (oxygen toxicity threshold)
• Claustrophobia (particularly for monoplace chambers)
• Chronic obstructive pulmonary disease with CO₂ retention
• History of spontaneous pneumothorax
• High fever
• Pregnancy (relative – may be used for carbon monoxide poisoning)
• Congenital spherocytosis
• Heart failure

Regarding heart failure, a Canadian retrospective cohort study by Schiavo et al. (2024) from Toronto General Hospital examined 23 patients with pre-existing heart failure who underwent elective HBOT. The study found that patients with heart failure can receive HBOT safely after optimisation of heart failure therapy and fluid restriction, though ongoing surveillance is warranted due to HBOT’s hemodynamic effects including increased afterload and decreased cardiac output (DOI: 10.1371/journal.pone.0293484). This finding is particularly relevant for Canadian physicians, as it suggests that a heart failure diagnosis should prompt specialist assessment rather than automatic exclusion.

What Is the Step-by-Step Referral Process in Canada?

Step 4: Locate an Accredited Hyperbaric Facility

Canada has hyperbaric facilities in most major centres, though availability varies significantly by province. Use the Canada Hyperbarics facility directory to find accredited centres near your patient.

Key considerations when selecting a facility:

• Accreditation: Look for facilities accredited by the Canadian Undersea and Hyperbaric Medical Association (CUHMA) or affiliated with a hospital programme
• Chamber type: Monoplace chambers treat one patient at a time; multiplace chambers treat several patients simultaneously and allow attendants inside – relevant for critically ill patients
• Emergency availability: Not all centres accept emergency referrals 24/7 – confirm availability for urgent cases
• Provincial coverage: Determine whether your patient’s treatment may be publicly funded (see coverage section below)

Step 5: Prepare Referral Documentation

A complete referral package accelerates the process and reduces delays. Include the following:

1. Referral letter stating the clinical indication, treatment history to date, and specific reason for HBOT referral
2. Relevant diagnostic imaging (wound photographs, CT/MRI for radiation injury or osteomyelitis, audiogram for SSNHL)
3. Laboratory results (complete blood count, HbA1c for diabetic wounds, coagulation studies as relevant)
4. Current medication list (particularly noting any drugs with known interactions – bleomycin, cisplatin, disulfiram, doxorubicin, mafenide acetate)
5. Comorbidity summary (cardiac history, pulmonary status, seizure history, anxiety/claustrophobia)
6. Previous wound care documentation (for chronic wound referrals – evidence of failed conventional therapy strengthens the case for HBOT)

For more information about the conditions treated with HBOT and the supporting evidence base, refer your patients to the Canada Hyperbarics conditions resource.

Step 6: Submit the Referral

Most Canadian hyperbaric facilities accept referrals via:

• Fax referral – still the most common method in Canadian healthcare
• Electronic referral – available at some hospital-based programmes through provincial e-referral systems
• Direct physician-to-physician consultation – recommended for emergency or time-sensitive cases (carbon monoxide poisoning, decompression sickness, SSNHL)

Expected timelines after referral submission:

What Provincial Coverage Options Exist for HBOT Referrals?

Step 7: Understand Provincial Funding Pathways

Public coverage for HBOT varies significantly across Canadian provinces. Understanding these pathways helps you set appropriate expectations with patients and may influence your choice of receiving facility.

For a complete breakdown of provincial coverage, visit the Canada Hyperbarics coverage guide. Patients without public coverage should also explore private insurance options – many extended health benefit plans include HBOT when prescribed by a physician for an approved indication.

What Should Physicians Know About HBOT Treatment Protocols?

Step 8: Understand What Happens After Referral

Once your referral is accepted, the hyperbaric facility typically follows this process:

1. Initial consultation: The hyperbaric physician reviews the referral, examines the patient, and confirms the indication
2. Pre-treatment assessment: Chest X-ray (to rule out occult pneumothorax), tympanic membrane examination, blood glucose check for diabetic patients
3. Treatment plan: Protocol selection based on indication – typically 2.0–2.4 ATA for 90–120 minutes per session
4. Treatment course: Most elective protocols involve 20–40 sessions (one daily, five days per week); emergency protocols may require fewer but more intensive sessions
5. Ongoing communication: The hyperbaric physician provides progress reports to you as the referring physician at regular intervals

Standard treatment parameters by common indication:

How Should Referring Physicians Manage Post-Treatment Follow-Up?

Step 9: Coordinate Post-Treatment Care

Your role as the referring physician continues after HBOT is complete:

• Review the discharge summary from the hyperbaric facility, including treatment response and any complications
• Continue wound care or condition management – HBOT is adjunctive therapy, not a standalone treatment
• Monitor for treatment response – wound healing improvements may continue for weeks after the last session due to ongoing angiogenesis
• Document outcomes – recording treatment response supports future referral decisions and contributes to the evidence base
• Consider re-referral if the patient had a partial response and may benefit from additional sessions

Frequently Asked Questions About HBOT Referrals

Can I refer a patient for HBOT for an off-label indication?

Yes, but with important caveats. Some conditions – such as traumatic brain injury, long COVID, and PTSD – are under active investigation but are not yet UHMS-approved. Patients may access HBOT for these conditions through private clinics on a self-pay basis or through clinical trials. As the referring physician, clearly document that the referral is for an emerging indication and ensure the patient understands the evidence limitations. Visit the Canada Hyperbarics research database for the latest evidence on emerging indications.

Does my patient need a physician referral to access HBOT?

In Canada, clinical HBOT requires a physician referral. Hospital-based programmes universally require referral. Most private clinics also require a physician referral or medical prescription, particularly for insurance billing purposes. Direct-to-consumer “mild” hyperbaric chambers (operating at lower pressures with ambient air) are a different category and are not the same as clinical HBOT.

How quickly should I refer for sudden hearing loss?

As soon as possible. Evidence suggests the greatest benefit occurs when HBOT is initiated within the first 2 weeks of symptom onset. Rhee et al. (2018) found that HBOT as a salvage treatment with a prolonged duration of at least 1,200 minutes showed the greatest benefit. Contact the nearest hyperbaric facility by phone for urgent consultation.

What if there is no hyperbaric facility in my province?

Out-of-province referrals are possible. Contact your provincial health authority about interprovincial coverage policies. For emergency indications, arrangements can often be expedited. Private air ambulance services can facilitate transfer for critical cases. The Canada Hyperbarics facility directory lists all known facilities nationally.

Is HBOT safe for my elderly patient with heart failure?

Based on PubMed research, a 2024 Canadian study from Toronto General Hospital found that patients with heart failure – including those with preserved ejection fraction – can receive HBOT safely after optimisation of heart failure therapy and fluid restriction, though ongoing surveillance is warranted. Discuss the case directly with the hyperbaric physician during referral.

What documentation does the hyperbaric facility need from me?

At minimum: a referral letter with the clinical indication, relevant imaging and lab results, current medication list (especially noting bleomycin, cisplatin, disulfiram, doxorubicin, or mafenide acetate), and a comorbidity summary. Wound photographs and treatment history are essential for chronic wound referrals.

Are there professional development resources for learning more about HBOT?

Yes. The Canadian Undersea and Hyperbaric Medical Association (CUHMA) offers education and certification programmes. The Undersea and Hyperbaric Medical Society (UHMS) provides the Certified Hyperbaric Technologist (CHT) and board certification pathways. Both organisations hold annual conferences with CME credits. Visit the Canada Hyperbarics about page for additional resources and regulatory information.

Key Takeaways for Referring Physicians

• 14 UHMS-approved indications form the evidence-based foundation for HBOT referrals in Canada
• Emergency indications (carbon monoxide poisoning, decompression sickness, gas embolism) require immediate referral – contact the hyperbaric facility by phone
• Time-sensitive conditions like sudden sensorineural hearing loss benefit from referral within 2 weeks of onset
• Screen for contraindications before referring – particularly untreated pneumothorax and concurrent drug interactions
• Provincial coverage varies widely – Ontario (OHIP) offers the broadest coverage; other provinces vary from hospital-only to no public coverage
• Include complete documentation with your referral to avoid delays: referral letter, imaging, labs, medication list, comorbidity summary
• HBOT is adjunctive – maintain your role in ongoing patient management during and after treatment

Canada Hyperbarics is Canada’s independent information resource for hyperbaric oxygen therapy. For more clinical resources, explore our conditions directory, research database, and FAQ section.

This content is for informational purposes only and does not constitute medical advice. Physicians should exercise clinical judgement in all patient care decisions. Always consult the most current clinical guidelines and the treating hyperbaric physician for patient-specific recommendations.