TL;DR: A robust patient screening protocol is the foundation of safe hyperbaric oxygen therapy. This guide walks Canadian clinic owners through building a step-by-step screening system, from initial intake questionnaires and absolute contraindication checks to pre-treatment assessments, documentation standards, and ongoing monitoring. Following these steps helps protect patients, satisfy Health Canada requirements, and reduce adverse events at your facility.
Patient screening for hyperbaric oxygen therapy (HBOT) is a systematic process designed to identify individuals who may be at increased risk of adverse events during pressurised oxygen treatment. For Canadian clinic owners and operators, a well-structured screening protocol is not optional – it is a regulatory and ethical necessity that directly affects patient outcomes, staff safety, and your facility’s accreditation standing.
According to a 2026 narrative review published in Cureus, HBOT safety is “favourable when typical regimens are used (2.0-2.5 ATA for 60-90 minutes, 20-40 sessions), with mostly mild, reversible adverse events” (DOI: 10.7759/cureus.102116). However, these favourable safety outcomes depend on proper patient selection and rigorous pre-treatment screening. A survey of 98 hyperbaric centres published in Respiratory Medicine found that screening practices vary significantly between facilities, and that the prevalence of pulmonary barotrauma was extremely low (0.00045%) when screening protocols were followed (DOI: 10.1016/j.rmed.2008.03.012).
This how-to guide from Canada Hyperbarics provides a practical, step-by-step framework you can adapt for your own clinic. Whether you operate a monoplace or multiplace chamber facility, these steps will help you establish a screening protocol that meets Canadian regulatory standards and aligns with Undersea and Hyperbaric Medical Society (UHMS) best practices.
What Are the Key Steps in Building an HBOT Patient Screening Protocol?
An effective screening protocol follows a logical sequence from first contact through to treatment initiation. Each step filters for different risk factors and builds a complete clinical picture of the patient. The following seven steps outline a comprehensive screening framework suitable for Canadian hyperbaric clinics of any size.
Step 1: Design a Standardised Intake Questionnaire
Your intake form is the first layer of screening. It should capture the patient’s complete medical history before they ever enter the chamber. Key sections to include:
- Referring physician information and reason for referral
- Current medications – particularly bleomycin, cisplatin, doxorubicin, disulfiram, and mafenide acetate, which may interact with HBOT
- Surgical history – especially recent ear, sinus, or thoracic surgery
- Respiratory history – asthma, COPD, pneumothorax, emphysema, or pulmonary blebs
- Cardiac history – congestive heart failure, pacemakers, or recent cardiac events
- Diabetes status and current blood glucose management
- Pregnancy status (for patients of childbearing age)
- Claustrophobia history or anxiety disorders
- History of seizures or epilepsy
- Previous HBOT experience and any adverse reactions
Keep the form in both English and French to serve patients across all Canadian provinces. Store completed forms securely in compliance with PIPEDA (Personal Information Protection and Electronic Documents Act) requirements.
Step 2: Screen for Absolute Contraindications
Absolute contraindications are conditions where HBOT must not be administered under any circumstances. Your protocol must include a hard stop at this stage. The universally recognised absolute contraindication is:
- Untreated pneumothorax – air trapped in the pleural space can expand during decompression, causing tension pneumothorax, a life-threatening emergency
Additional conditions that most clinical guidelines treat as absolute contraindications include:
- Certain chemotherapy agents (bleomycin within the past 6-12 months due to risk of pulmonary toxicity)
- Untreated or unstable seizure disorders (oxygen toxicity can lower seizure threshold)
When an absolute contraindication is identified, document the finding, notify the referring physician, and do not proceed with treatment. This must be a non-negotiable policy in your standard operating procedures.
Step 3: Evaluate Relative Contraindications
Relative contraindications require a risk-benefit analysis by the treating hyperbaric physician. These conditions do not automatically disqualify a patient but require additional assessment, monitoring, or protocol modification. Common relative contraindications include:
| Relative Contraindication | Risk | Mitigation Strategy |
|---|---|---|
| Upper respiratory infection | Ear/sinus barotrauma | Delay treatment until resolved |
| Uncontrolled asthma or COPD | Air trapping, barotrauma | Pulmonary function testing, slow compression |
| Congestive heart failure (NYHA III-IV) | Pulmonary oedema | Cardiology clearance, oxygen monitoring |
| Claustrophobia | Panic, early termination | Anxiolytics, gradual exposure, companion in multiplace |
| History of seizures (controlled) | Oxygen-induced seizures | Lower treatment pressure, air breaks |
| Insulin-dependent diabetes | Hypoglycaemia during treatment | Pre-treatment glucose check, snack protocol |
| Pregnancy | Theoretical foetal risk | Proceed only for life-threatening indications (e.g., CO poisoning) |
| Implanted devices (pacemakers) | Device malfunction under pressure | Manufacturer clearance for pressure tolerance |
| Pulmonary blebs or bullae | Pulmonary barotrauma | CT screening, careful decompression rate |
A study surveying 98 HBOT centres worldwide found that 66.3% of facilities accepted patients with pulmonary blebs or bullae after appropriate screening, and X-ray was the most widely used screening tool for patients with a history of lung disease (Toklu et al., 2008). This demonstrates that relative contraindications do not automatically exclude patients but require documented clinical decision-making.
Step 4: Conduct the Pre-Treatment Physical Assessment
Before the first treatment session, a qualified hyperbaric physician or trained clinical staff member should conduct a focused physical examination. This assessment should include:
- Otoscopic examination – check for tympanic membrane integrity, active ear infection, or eustachian tube dysfunction
- Respiratory assessment – auscultation, oxygen saturation measurement, and chest X-ray if clinically indicated
- Blood glucose measurement – for diabetic patients, ensure glucose is within safe range (typically 5.0-15.0 mmol/L) before entering the chamber
- Blood pressure and heart rate – to identify uncontrolled hypertension or cardiac concerns
- Visual acuity baseline – myopic shift is a known reversible side effect of prolonged HBOT courses
- Neurological baseline – particularly for patients being treated for brain injury or neurological conditions
- Pregnancy test – for patients of childbearing age where status is uncertain
Document all findings in the patient’s chart. This baseline data is essential for monitoring treatment response and identifying adverse events early.
How Should Canadian Clinics Handle Pre-Session Safety Checks?
Beyond the initial screening, every treatment session requires its own pre-session safety check. This is a separate process from the intake screening and must be completed before every chamber pressurisation.
Step 5: Implement a Pre-Session Checklist
Create a standardised pre-session checklist that your chamber operators and nursing staff complete before each treatment. The checklist should verify:
- Patient identity confirmed (two-identifier system)
- No prohibited items entering the chamber – lighters, matches, electronic devices, petroleum-based products, synthetic fabrics, hearing aids, or any ignition source
- Patient wearing approved cotton garments provided by the facility
- Current symptoms reviewed – no active cold, sinus congestion, fever, or ear pain
- Blood glucose checked (diabetic patients)
- Ability to equalise ear pressure confirmed – patients must demonstrate Valsalva or Frenzel manoeuvre
- Medication review – confirm no new medications since last session
- Informed consent reviewed and on file
- Chamber safety equipment verified – fire suppression system active, communication system functional, emergency abort procedure reviewed with patient
A 2025 scoping review in Diving and Hyperbaric Medicine examining emergency scenarios during HBOT found that “safety protocols, including oxygen level and equipment specifications, vary between monoplace and multiplace hyperbaric chambers, influencing the feasibility of in-chamber emergency response” (Nohl et al., 2025). Your pre-session checklist should account for the specific chamber type at your facility.
What Documentation Standards Should Your Clinic Follow?
Step 6: Establish Documentation and Record-Keeping Standards
Thorough documentation protects your patients, your staff, and your clinic. Every element of the screening and treatment process must be recorded. Your documentation system should include:
- Initial screening form with physician signature and date
- Contraindication assessment documenting the clinical decision for each identified risk factor
- Informed consent signed by the patient, covering risks (barotrauma, oxygen toxicity, visual changes, claustrophobia), benefits, and alternatives
- Pre-session checklists for every treatment session
- Treatment logs recording pressure, duration, oxygen concentration, and any incidents
- Adverse event reports – any barotrauma, oxygen toxicity symptoms, hypoglycaemia, anxiety episodes, or equipment malfunctions
- Ongoing assessment notes – periodic reassessment at defined intervals (typically every 10-20 sessions)
Research published in Frontiers in Medicine reviewing HBOT adverse events found that common complications include “mild barotrauma, tinnitus, headache, and claustrophobia,” all of which “resolved upon discontinuation of HBOT, and no severe adverse reactions were documented” (Fang et al., 2025). Tracking these events systematically enables your clinic to identify patterns, refine screening criteria, and demonstrate safety outcomes during audits.
Retain all records for a minimum of 10 years, consistent with provincial health record retention requirements. Digital records should be encrypted and backed up, and physical records stored in a secure, fire-resistant location.
How Do You Build Ongoing Monitoring Into Your Safety Protocol?
Step 7: Create an Ongoing Monitoring and Reassessment Schedule
Screening is not a one-time event. Patients undergoing extended treatment courses (20-40+ sessions) require periodic reassessment. Build the following into your protocol:
- Every session – pre-session symptom check, vital signs for at-risk patients
- Every 10 sessions – physician review of treatment progress, reassessment of contraindications, blood glucose trends (diabetic patients)
- Every 20 sessions – visual acuity recheck (myopic shift monitoring), comprehensive physical reassessment
- End of treatment – final assessment, outcome documentation, referral back to referring physician with treatment summary
For patients with approved clinical conditions such as diabetic wounds or radiation injury, treatment courses may extend over months. Ongoing monitoring ensures that new contraindications are caught early and that treatment remains appropriate throughout the care episode.
What Training Should Staff Complete Before Administering Screening?
Your screening protocol is only as effective as the people implementing it. All clinical staff involved in patient screening and chamber operation should hold appropriate certification. In Canada, the Canadian Undersea and Hyperbaric Medical Association (CUHMA) provides guidance on training standards for hyperbaric personnel.
Key training requirements include:
- Hyperbaric safety officer certification – at least one staff member per shift
- Contraindication recognition – all clinical staff must be able to identify absolute and relative contraindications
- Emergency response procedures – fire safety, chamber abort procedures, and basic life support in the hyperbaric environment
- Equipment operation and maintenance – familiarity with your specific chamber system
- Ongoing continuing education – annual refresher training on screening protocols and emergency procedures
Consider having your screening protocol reviewed by a CUHMA-affiliated hyperbaric physician annually. For facilities seeking accreditation, both CUHMA and UHMS accreditation processes evaluate the quality and consistency of patient screening documentation. You can find accredited hospitals and regulated facilities across Canada on the Canada Hyperbarics directory.
Frequently Asked Questions About HBOT Patient Screening
What is the most important contraindication to screen for before HBOT?
Untreated pneumothorax is the only universally recognised absolute contraindication to HBOT. Air trapped in the pleural space can expand during decompression, potentially causing tension pneumothorax. All patients must be screened for current or recent pneumothorax before beginning treatment.
How often should screening be repeated during a treatment course?
Pre-session symptom checks should occur before every treatment. A comprehensive physician reassessment is recommended every 10-20 sessions, depending on the patient’s condition and risk factors. Visual acuity should be rechecked every 20 sessions to monitor for myopic shift.
Can patients with pacemakers receive hyperbaric oxygen therapy?
Many modern pacemakers and implantable cardiac devices are rated for use at specific pressures. Your clinic should obtain written documentation from the device manufacturer confirming the pressure tolerance of the specific model. Most devices are rated to at least 3.0 ATA, which exceeds standard HBOT treatment pressures of 2.0-2.5 ATA.
What should clinic owners include in the informed consent for HBOT?
Informed consent should cover the nature of the treatment, expected benefits for the patient’s specific condition, potential risks (middle ear barotrauma, sinus barotrauma, oxygen toxicity seizures, temporary myopia, claustrophobia), alternatives to HBOT, and the right to withdraw consent at any time. Include specific risks relevant to the patient’s medical history.
Does Health Canada regulate patient screening for hyperbaric chambers?
Health Canada regulates hyperbaric chambers as Class III medical devices under the Medical Devices Regulations. While Health Canada does not prescribe specific screening protocols, facilities must demonstrate safe operation as part of their medical device licence obligations. Both CUHMA and UHMS accreditation standards include detailed requirements for patient screening and documentation.
What are the most common adverse events during HBOT?
According to PubMed-indexed research, the most commonly reported adverse events are middle ear barotrauma, sinus pain, headache, tinnitus, and claustrophobia. These are generally mild and resolve when treatment is paused or discontinued. Oxygen toxicity seizures are rare, occurring in approximately 1-3 per 10,000 treatments, and resolve quickly once the patient breathes normal air.
What Resources Can Help You Develop Your Protocol?
Canadian clinic owners do not need to build a screening protocol from scratch. Several authoritative resources provide templates and guidelines:
- CUHMA – Canadian clinical practice guidelines and accreditation standards
- UHMS – International guidelines, approved indications list, and facility accreditation criteria
- Health Canada Medical Devices Bureau – Regulatory requirements for hyperbaric chamber licensing and operation
- Canada Hyperbarics Research Library – over 11,000 indexed studies with summaries, searchable by condition and study type
Review your protocol annually, update it when new evidence emerges, and ensure every staff member has access to the current version. A well-implemented screening protocol is your clinic’s first line of defence against preventable adverse events.
This content is for informational purposes only and does not constitute medical advice. Clinic owners and operators should consult with qualified hyperbaric medicine professionals and legal advisors when developing clinical protocols. Always follow current Health Canada regulations and provincial health authority requirements for your jurisdiction.