Long COVIDRECLAIM-HBOTNCT06452095
Recovering From COVID-19 Lingering Symptoms Adaptive Integrative Medicine Trial - Effect of Hyperbaric Oxygen Therapy for the Treatment of Post COVID Condition
A study testing Hyperbaric Oxygen therapy in people with Long COVID and Post Acute Sequelae of COVID-19, run by University Health Network, Toronto at 1 site in Canada.
Trial summary
The RECLAIM study platform will be used to explore whether the use of Hyperbaric Oxygen therapy (HBOT) improves the symptoms of post covid cognitive dysfunction. Hyperbaric oxygen therapy is a well-established medical treatment. HBOT promotes healing by delivering a high concentration of oxygen into the body. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Long COVID, Post Acute Sequelae of COVID-19, Post-COVID-19 Condition
- What is being tested?
- Hyperbaric Oxygen therapy
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 120 participants
- Where
- 1 siteCanada
- Study dates
- 1 Jan 2026to 31 Dec 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥18 years;
- Positive COVID-19 test by nasopharyngeal swab RT-PCR (reverse transcription polymerase chain reaction) test, antibody or antigen tests at least 3 months prior to randomization; OR Presumed COVID-19 assessed by the site investigator (no positive COVID-19 test) with acute illness after October 15, 2019.
- Patients should be treated with standard of care therapies (as discussed in the study manual) for at least 4 weeks prior to entry into trial.
- Lingering COVID-19 symptoms beyond 3 months from onset of acute COVID and symptoms have lasted at least 2 months. The onset of COVID is considered the earliest of two dates: the date of positive test or the date of first symptoms;
- Lingering symptoms from COVID-19 present at the time of randomization. "Lingering symptoms of Long COVID" must include self-reported cognitive dysfunction symptoms.
- Female patients of childbearing potential (as assessed by the overseeing Investigator) who are sexually active must agree to practice true abstinence or use effective methods of contraception while on study treatment. Effective methods of contraception must be discussed and approved by the overseeing Investigator.
- Must be able to provide informed consent and both willing and able to comply with study requirements.
- A confirmed ability to travel to one of the three sites where HBOT or sham can be administered.
Who cannot join
- Patients who had mechanical ventilation or extracorporeal membrane oxygen (ECMO) for COVID-19;
- Current end-organ failure, organ transplantation, or current hospitalization in acute care hospital;
- Contraindications to all of the study interventions;
- Co-enrolment in another interventional trial (co-enrolment in an observational study is permitted);
- Currently pregnant or breastfeeding.
- Pneumothorax
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- Poorly controlled seizure disorder
- Chronic sinusitis
- Chronic or acute otitis media
- Major ear drum trauma.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Andrew Janes, MSc contact
Canada1 site, 1 recruiting
- Recruiting
University Health Network
Toronto, Ontario, M5G 2C4
Doris Liu-Yee, RN, Doris.Lui-Yee@uhn.ca
Angela M Cheung, MD, PhD, CCD
About this study
Official title: RECLAIM: Recovering From COVID-19 Lingering Symptoms Adaptive Integrative Medicine Trial - Effect of Hyperbaric Oxygen Therapy for the Treatment of Post COVID Condition (RECLAIM-HBOT)
The RECLAIM study platform will be used to explore whether the use of Hyperbaric Oxygen therapy (HBOT) improves the symptoms of post covid cognitive dysfunction.
Hyperbaric oxygen therapy is a well-established medical treatment. HBOT promotes healing by delivering a high concentration of oxygen into the body. This high level of oxygen has a number of known benefits, such as growth of new blood vessels, as well as regulating immune and inflammation responses. It helps protect the brain and other nervous tissue from inflammation. HBOT may also have antiviral effects.
Read more
Collectively, it has the potential to target the underlying mechanisms believed to play a critical role in the development of Long COVID.
Many individuals with Long COVID complain of fatigue, brain fog, muscle aches and other symptoms. There is evidence to suggest that these symptoms may be a problem with the blood vessels, resulting in abnormal delivery of oxygen to tissues. Thus, our group is investigating whether HBOT improves post-COVID cognitive dysfunction.
Read the detailed description
This is a Sub-Protocol to the Core Clinical Study Protocol titled: REcovering from COVID19 Lingering symptoms Adaptive Integrative Medicine (RECLAIM),
- Being tested
- Hyperbaric Oxygen therapy
- Medical subject headings
- Post-Acute COVID-19 Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hyperbaric Oxygen therapyDevice
The SECHRIST INDUSTRIES mono-place Hyperbaric Chambers OR Sigma Series mono-place Hyperbaric Chambers
| Study group | Role | What they receive |
|---|---|---|
| Hyperbaric oxygen therapy | Experimental | HBOT GROUP will have HBOT with 100% oxygen for 90 min, once daily, five times a week for 8 consecutive weeks. This will be given at a slightly higher pressure than normal air pressure (2 times regular air pressure) Receives: Device: Hyperbaric Oxygen therapy |
| Hyperbaric oxygen sham | Sham comparator | CONTROL GROUP will have sham treatment, which will look and feel like HBOT, but will not have high enough oxygen concentration for any therapeutic or health benefit. Sham treatment with 21% oxygen (the amount of oxygen normally present in the air) for 90 min, once daily, five times a week for 8 consecutive weeks. This will be given at standard atmospheric pressure (1.03 ATA). The air pressure will vary slightly to mimic the feeling of HBOT. Receives: Device: Hyperbaric Oxygen therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Simple reaction time [SRT] task from the TestMyBrain (TMB) Digital Neuropsychology Toolkit
On-line survey tool
Measured: Baseline/Start of intervention to two months
Verbal paired associates [VPA] task from the TestMyBrain (TMB) Digital Neuropsychology Toolkit
On-line survey tool
Measured: Baseline/Start of intervention to two months
Secondary outcomes (14)
Symptoms scale
Three point Likert scale assessing how bothersome symptoms are on a weekly basis for two months then monthly until end of study, as reported by the participant: to provide a granular, detailed picture of the symptom trajectory.
Measured: Baseline/start of intervention weekly to 2 months, then once monthly to 6 months.
Symptom Checklist
Symptom Checklist (adapted from the De Paul Symptom Questionnaire (DSQ2), the World Health Organization Global COVID-19 Clinical Platform's Post COVID-19 CRF and the Symptom Burden Questionnaire for Long COVID): to track symptom trajectory.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Six Minute Walking Test (6MWT) with oximetry
Subjects walk as far as they can in six minutes while receiving maximum encouragement. It is simple to execute, inexpensive, standardized and gives a tangible measure of functional exercise capacity. It has been validated in many different populations. The 6MWT will be conducted according to American Thoracic Society standards.
Measured: Baseline/start of intervention and 2 months.
SF-36
The self-administered SF-36 evaluates eight health concepts: physical functioning, role functioning-physical, bodily pain, general health, vitality, social functioning, role functioning-emotional, and mental health. Previous studies have used this instrument in many different populations and it takes approximately 15 minutes to complete.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
TestMyBrain cognitive testing
TestMyBrain was developed as a tool to collect large, population-based samples for understanding the relationship between cognition, emotion, social functioning, and health. This test battery includes:
TMB Verbal Paired Associates (Concrete), TMB Digit Span - Backward, TMB Digit Span - Forward, TMB Choice Reaction Time, TMB Simple Reaction Time, TMB Gradual Onset Continuous Performance Task. The test battery will take about 20 minutes to complete and will assess: verbal, episodic and working memory, attention, processing speed, basic psychomotor response speed, and cognitive control.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Post COVID19 functional status scale
The post-COVID-19 functional status (PCFS) scale focuses on relevant aspects of daily life during follow-up after the infection. The scale is intended to help users become aware of current functional limitations in COVID-19 patients, whether or not as a result of the specific infection, and to objectively determine this degree of disability. The scale is ordinal, has 6 steps ranging from 0 (no symptoms) to 5 (death), and covers the entire range of functional outcomes by focusing on limitations in usual duties/activities either at home or at work/study, as well as changes in lifestyle. The PCFS demonstrates good construct validity.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Reintegration to Normal Living Index (RNLI)
This short self-administered assessment tool will determine the degree to which participants reintegrate into normal social activities such as recreation, mobility in the community and interaction in family and other relationships. This tool has been validated in community living adults with mobility limitations.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
The Fatigue Scale
The Fatigue Scale was adapted from the De Paul Symptom Questionnaire (DSQ2)'s 38 questions assessing medical history of Myalgic Encephalitis/Chronic Fatigue Syndrome (ME/CFS), comorbidities, medications, impact on quality of life and daily activities, etc.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Brief Fatigue inventory
The self-administered Brief Fatigue Inventory is composed of 9 items evaluated on a 10-point scale, assessing severity of fatigue and impact of fatigue on daily life. It takes approximately 2-3 minutes to complete.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Post-Exertional Malaise
The self-administered DPEMQ is comprised of three sections assessing post-exertional malaise (PEM): (i) onset and triggers of PEM (9 questions), (ii) consequences and symptoms (14 questions), (iii) duration, recovery and pacing (7 questions).
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Mental Health - General Anxiety Assessment Form (GAD-7)
The GAD-7 is a valid and efficient tool for screening for generalized anxiety disorder and assessing its severity in clinical practice and research. It is an easy-to-use, self-administered patient questionnaire that can be completed in minutes.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Mental Health - Patient Health Questionnaire (PHQ-9)
The PHQ-9 is a validated, multipurpose instrument for screening, diagnosing, monitoring and measuring the severity of depression. It incorporates Diagnostic and Statistical Manual 1V (DSM-IV) depression diagnostic criteria with other leading major depressive symptoms into a brief self-report tool. The PHQ-9 is brief and useful in clinical practice.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Dyspnea
Assessed using the Borg Dyspnea scale. This short assessment tool assesses perceived shortness of breath on exertion using a 10 point scale as assessed by the patient.
Measured: Baseline/start of intervention to 1, 2 months 3 and 6 months
Blood samples
Blood samples will be used in correlative studies using advanced multi-omic and machine learning techniques to better understand our results so as to identify phenotypes that will benefit from specific therapies
Measured: Baseline/start of intervention and 2 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2024
- Study start1 Jan 2026
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Long COVIDStudies of the same condition, open and under way.
- More trials run by University Health Network, TorontoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- RECLAIM is a Canada-wide phase ll/lll, prospective, adaptive randomized controlled platform trial that is intended to study various interventions for patients with long COVID. Interventional arms may be discontinued based on interim analysis results and new interventions may be selected and included as part of the platform as the trial progresses. As such, the protocol and consent documents are a modular design. The HBOT arm includes: * Master Protocol and informed consent documents: Contain information applicable to the whole platform. * HBOT Sub-Protocol: Contain additional information, specific to the HBOT interventional arm.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Health Network, Toronto
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Angela M Cheung, MD, PhD, Study director, University Health Network, TorontoRita Katznelson, MD, Principal investigator, University Health Network, Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06452095
- Sponsor's protocol ID
- 21-6203-HBOT
- Acronym
- RECLAIM-HBOT
- Status last verified
- Feb 2026
- First submitted
- 7 Jun 2024
- Last updated
- 23 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 23 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- RECLAIM: Recovering From COVID-19 Lingering Symptoms Adaptive Integrative Medicine Trial - Effect of Hyperbaric Oxygen Therapy for the Treatment of Post COVID Condition (RECLAIM-HBOT)
- ClinicalTrials.gov ID
- NCT06452095
- Acronym / sponsor ID
- RECLAIM-HBOT / 21-6203-HBOT
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- University Health Network, TorontoUniversity, hospital or other
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 11 Jun 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The RECLAIM study platform will be used to explore whether the use of Hyperbaric Oxygen therapy (HBOT) improves the symptoms of post covid cognitive dysfunction.
Hyperbaric oxygen therapy is a well-established medical treatment. HBOT promotes healing by delivering a high concentration of oxygen into the body. This high level of oxygen has a number of known benefits, such as growth of new blood vessels, as well as regulating immune and inflammation responses. It helps protect the brain and other nervous tissue from inflammation. HBOT may also have antiviral effects.
Collectively, it has the potential to target the underlying mechanisms believed to play a critical role in the development of Long COVID.
Many individuals with Long COVID complain of fatigue, brain fog, muscle aches and other symptoms. There is evidence to suggest that these symptoms may be a problem with the blood vessels, resulting in abnormal delivery of oxygen to tissues. Thus, our group is investigating whether HBOT improves post-COVID cognitive dysfunction.
Detailed description
This is a Sub-Protocol to the Core Clinical Study Protocol titled: REcovering from COVID19 Lingering symptoms Adaptive Integrative Medicine (RECLAIM),
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- RECLAIM is a Canada-wide phase ll/lll, prospective, adaptive randomized controlled platform trial that is intended to study various interventions for patients with long COVID. Interventional arms may be discontinued based on interim analysis results and new interventions may be selected and included as part of the platform as the trial progresses. As such, the protocol and consent documents are a modular design. The HBOT arm includes: * Master Protocol and informed consent documents: Contain information applicable to the whole platform. * HBOT Sub-Protocol: Contain additional information, specific to the HBOT interventional arm.
| Arm | Type | Receives |
|---|---|---|
| Hyperbaric oxygen therapy | Experimental | Device: Hyperbaric Oxygen therapyHBOT GROUP will have HBOT with 100% oxygen for 90 min, once daily, five times a week for 8 consecutive weeks. This will be given at a slightly higher pressure than normal air pressure (2 times regular air pressure) |
| Hyperbaric oxygen sham | Sham comparator | Device: Hyperbaric Oxygen therapyCONTROL GROUP will have sham treatment, which will look and feel like HBOT, but will not have high enough oxygen concentration for any therapeutic or health benefit. Sham treatment with 21% oxygen (the amount of oxygen normally present in the air) for 90 min, once daily, five times a week for 8 consecutive weeks. This will be given at standard atmospheric pressure (1.03 ATA). The air pressure will vary slightly to mimic the feeling of HBOT. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Age ≥18 years;
- Positive COVID-19 test by nasopharyngeal swab RT-PCR (reverse transcription polymerase chain reaction) test, antibody or antigen tests at least 3 months prior to randomization; OR Presumed COVID-19 assessed by the site investigator (no positive COVID-19 test) with acute illness after October 15, 2019.
- Patients should be treated with standard of care therapies (as discussed in the study manual) for at least 4 weeks prior to entry into trial.
- Lingering COVID-19 symptoms beyond 3 months from onset of acute COVID and symptoms have lasted at least 2 months. The onset of COVID is considered the earliest of two dates: the date of positive test or the date of first symptoms;
- Lingering symptoms from COVID-19 present at the time of randomization. "Lingering symptoms of Long COVID" must include self-reported cognitive dysfunction symptoms.
Key exclusion criteria (10 listed)
- Patients who had mechanical ventilation or extracorporeal membrane oxygen (ECMO) for COVID-19;
- Current end-organ failure, organ transplantation, or current hospitalization in acute care hospital;
- Contraindications to all of the study interventions;
- Co-enrolment in another interventional trial (co-enrolment in an observational study is permitted);
- Currently pregnant or breastfeeding.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hyperbaric Oxygen therapyThe SECHRIST INDUSTRIES mono-place Hyperbaric Chambers OR Sigma Series mono-place Hyperbaric Chambers | Device | Hyperbaric oxygen sham, Hyperbaric oxygen therapy |
Primary outcome
Simple reaction time [SRT] task from the TestMyBrain (TMB) Digital Neuropsychology Toolkit
Time frame: Baseline/Start of intervention to two months
On-line survey tool
Verbal paired associates [VPA] task from the TestMyBrain (TMB) Digital Neuropsychology Toolkit
Time frame: Baseline/Start of intervention to two months
On-line survey tool
14 secondary outcomes
Symptoms scale
Time frame: Baseline/start of intervention weekly to 2 months, then once monthly to 6 months.
Symptom Checklist
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Six Minute Walking Test (6MWT) with oximetry
Time frame: Baseline/start of intervention and 2 months.
SF-36
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
TestMyBrain cognitive testing
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Post COVID19 functional status scale
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Reintegration to Normal Living Index (RNLI)
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
The Fatigue Scale
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Brief Fatigue inventory
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Post-Exertional Malaise
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Mental Health - General Anxiety Assessment Form (GAD-7)
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Mental Health - Patient Health Questionnaire (PHQ-9)
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Dyspnea
Time frame: Baseline/start of intervention to 1, 2 months 3 and 6 months
Blood samples
Time frame: Baseline/start of intervention and 2 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Feb 2026.
- Individual participant dataSharing planned: Undecided
Related trials for Long COVID
Not yet recruitingPhase 1
Phase I Open-Label Safety Trial of Pembrolizumab for Neurological Post- Acute Sequelae of SARS-CoV-2 (PD1-PASC I)
Post-Acute COVID-19 Syndrome
Recruiting
Whole-body Cryotherapy in Those With Chronic Fatigue: A Feasibility Study
ME/CFS, Fibromyalgia (FM)
Not yet recruitingPhase 3
The Study of Brave-LC LDN Treatment Trial
Post-acute COVID-19 Syndrome
Active, not recruitingObservational study
Epigenetic Changes in Long COVID Patients
Long COVID-19 Syndrome, Long COVID Symptoms
Enrolling by invitationPhase 2
Immunotherapy for Neurological Post-Acute Sequelae of SARS-CoV-2
Systemic Inflammation, Neuroinflammation
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Andrew Janes, MSc contact
Angela M Cheung, MD, PhD study director
University Health Network, Toronto
Rita Katznelson, MD principal investigator
University Health Network, Toronto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hyperbaric Oxygen therapy in people with Long COVID and Post Acute Sequelae of COVID-19, run by University Health Network, Toronto at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 23 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact RECLAIM CONTACT RECLAIM contact line (1-866-673-2524, reclaim@uhn.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Simple reaction time [SRT] task from the TestMyBrain (TMB) Digital Neuropsychology Toolkit (time frame: Baseline/Start of intervention to two months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Feb 2026.