Hyperbaric Oxygen TherapyMICROHBNCT03980210
Effect of Hyperbaric Oxygen Therapy on Microcirculation
A study testing Hyperbaric oxygen therapy in people with Hyperbaric Oxygen Therapy, run by University Hospital, Lille at 1 site in France.
Trial summary
Previous studies shoes that hyperoxia alters microcirculation.The investigators hypothesize that hyperbaric may restore microcirculation integrity. This hypothesis is supported by a recent study in rabbits, but no data exists for humans. Read more about this study
- Who is it for?
- Ages 18 to 64 yearsHealthy volunteers can take part
- Conditions the study is for
- Hyperbaric Oxygen Therapy
- What is being tested?
- Hyperbaric oxygen therapy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteFrance
- Study dates
- 14 Jun 2019to 25 Jul 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 to 64 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- To provide a medical certificate of fitness to dive (< 1 year)
- Consent given for study participation
- French health insurance affiliated
Who cannot join
- Temporary or definitive contra-indication to dive
- Pregnancy or < 18 years of age
- Precedent dive < 24 hours
- Under a legal protection measure
- Medical history of a disease known to alter microcirculation
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of Hyperbaric Oxygen Therapy on Healthy Volunteers Microcirculation
Previous studies shoes that hyperoxia alters microcirculation.The investigators hypothesize that hyperbaric may restore microcirculation integrity. This hypothesis is supported by a recent study in rabbits, but no data exists for humans.
The study will expose fifteen healthy volunteers to a succession of different fraction of inspired oxygen and barometric pressure and assess microcirculatory and macrocirculatory changes via sidestream dark field videomicroscopy, near-infrared spectroscopy, Laser Doppler, transthoracic echocardiography and bio-impedancemetry at every step.
Read the detailed description
Microcirculation alterations and hyperoxia are known to alter ICU-patients' prognostic.
Studies have shown that hyperoxia alters healthy volunteers' microcirculation, whereas hyperbaric oxygen therapy is commonly used to facilitate cicatrization. There seems to be a paradox. A recent study in rabbits has given some evidences that hyperbaria may restore microcirculation integrity, but to date, there is no such evidences in human.
To study hyperoxia and hyperbaric induced changes in micro and macrocirculation, fifteen healthy volunteers will be exposed to successive variations of inspired oxygen fraction and barometric pressure according to a predefine sequence so that only one parameter will change from a condition to the next one :
- FiO2 0.21 - 1 ATA
- FiO2 1 - 1 ATA
- FiO2 1 - 2.5 ATA
- FiO2 0.21 - 2.5 ATA
- FiO2 0.21 - 1 ATA
At each time, and after a 30 minutes period of exposure, measures will be made using SDF-microscopy, Laser Doppler and NIRS to assess microcirculation.
As previously described, macrocirculation can modify microcirculation due to a mechanism called hemodynamic coherence.
Hence, the investigators planned to assess macrocirculation changes at every step of the protocol using bioimpedancemetry and transthoracic echocardiography.
Each volunteer will be his own control, using the first measurements (condition 1. FiO2 0.21 - 1 ATA) as reference.
- Conditions
- Hyperbaric Oxygen Therapy
- Being tested
- Hyperbaric oxygen therapy
- Keywords
- Hyperbaric oxygen therapy, Normobaric oxygen therapy, Hyperoxia, Sidestream dark field videomicroscopy, Microcirculation
- Medical subject headings
- Hyperoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hyperbaric oxygen therapyProcedure or surgery
- FiO2 0.21 - 1 ATA
- FiO2 1 - 1 ATA
- FiO2 1 - 2.5 ATA
- FiO2 0.21 - 2.5 ATA
- FiO2 0.21 - 1 ATA
| Study group | Role | What they receive |
|---|---|---|
| Hyperbaric oxygen therapy | Experimental | Successive changes in fraction of inspired oxygen and barometric pressure (ATA: Atmosphere absolute)
Five successive steps:
1. FiO2 0.21 - 1 ATA
2. FiO2 1 - 1 ATA
3. FiO2 1 - 2.5 ATA
4. FiO2 0.21 - 2.5 ATA
5. FiO2 0.21 - 1 ATA Receives: Procedure: Hyperbaric oxygen therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in proportion of perfused vessel (PPV)
Proportion of perfused vessel assessed by Sidestream dark field microscopy on the sublingual mucosa
Measured: 30 minutes after hyperbaric hyperoxia exposure (FiO2 1 - 2.5 ATA)
Secondary outcomes (5)
Changes in proportion of perfused vessel (PPV)
Proportion of perfused vessel assessed by Sidestream dark field microscopy on the sublingual mucosa
Measured: 30 minutes after FiO2 1 - 1 ATA exposure
Changes in proportion of perfused vessel (PPV)
Proportion of perfused vessel assessed by Sidestream dark field microscopy on the sublingual mucosa
Measured: 30 minutes after FiO2 0.21 - 2.5 ATA exposure
Changes in hyperemic reaction after a vaso-occlusion test
Area under curve assessed by near-infrared spectroscopy
Measured: 30 minutes after FiO2 1 - 2.5 ATA exposure
Changes in area of hyperaemia after a vaso-occlusion test
Area under curve assessed by Laser-Doppler
Measured: 30 minutes after FiO2 1 - 2.5 ATA exposure
Validation of cardiac output assessed by bioimpedancemetry under hyperbaric condition
Comparison with transthoracic echocardiography
Measured: 30 minutes after FiO2 1 - 2.5 ATA exposure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jun 2019
- Study start14 Jun 2019
- Primary completion25 Jul 2019
- Study completion25 Jul 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Hyperbaric Oxygen TherapyStudies of the same condition, open and under way.
- 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Lille
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Thibault Duburcq, MD, Principal investigator, University Hospital, Lille
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03980210
- Sponsor's protocol ID
- 2018_63
- Other IDs
- 2019-A00053-54
- Acronym
- MICROHB
- Status last verified
- Jan 2026
- First submitted
- 15 May 2019
- Last updated
- 8 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Cousin N, Goutay J, Girardie P, Favory R, Drumez E, Mathieu D, Poissy J, Parmentier E, Duburcq T. Effects of high oxygen tension on healthy volunteer microcirculation. Diving Hyperb Med. 2022 Dec 20;52(4):260-70. doi: 10.28920/dhm52.4.260-270.
PubMed 36525683
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Hyperbaric Oxygen Therapy on Healthy Volunteers Microcirculation
- ClinicalTrials.gov ID
- NCT03980210
- Acronym / sponsor ID
- MICROHB / 2018_63
- Conditions
- Hyperbaric Oxygen Therapy
- Keywords
- Hyperbaric oxygen therapy, Normobaric oxygen therapy, Hyperoxia, Sidestream dark field videomicroscopy, Microcirculation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- University Hospital, LilleUniversity, hospital or other
- Study start
- 14 Jun 2019 (actual)
- Primary completion
- 25 Jul 2019 (actual)
- Study completion
- 25 Jul 2019 (actual)
- First posted
- 10 Jun 2019 (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.
Previous studies shoes that hyperoxia alters microcirculation.The investigators hypothesize that hyperbaric may restore microcirculation integrity. This hypothesis is supported by a recent study in rabbits, but no data exists for humans.
The study will expose fifteen healthy volunteers to a succession of different fraction of inspired oxygen and barometric pressure and assess microcirculatory and macrocirculatory changes via sidestream dark field videomicroscopy, near-infrared spectroscopy, Laser Doppler, transthoracic echocardiography and bio-impedancemetry at every step.
Detailed description
Microcirculation alterations and hyperoxia are known to alter ICU-patients' prognostic.
Studies have shown that hyperoxia alters healthy volunteers' microcirculation, whereas hyperbaric oxygen therapy is commonly used to facilitate cicatrization. There seems to be a paradox. A recent study in rabbits has given some evidences that hyperbaria may restore microcirculation integrity, but to date, there is no such evidences in human.
To study hyperoxia and hyperbaric induced changes in micro and macrocirculation, fifteen healthy volunteers will be exposed to successive variations of inspired oxygen fraction and barometric pressure according to a predefine sequence so that only one parameter will change from a condition to the next one :
- FiO2 0.21 - 1 ATA
- FiO2 1 - 1 ATA
- FiO2 1 - 2.5 ATA
- FiO2 0.21 - 2.5 ATA
- FiO2 0.21 - 1 ATA
At each time, and after a 30 minutes period of exposure, measures will be made using SDF-microscopy, Laser Doppler and NIRS to assess microcirculation.
As previously described, macrocirculation can modify microcirculation due to a mechanism called hemodynamic coherence.
Hence, the investigators planned to assess macrocirculation changes at every step of the protocol using bioimpedancemetry and transthoracic echocardiography.
Each volunteer will be his own control, using the first measurements (condition 1. FiO2 0.21 - 1 ATA) as reference.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Hyperbaric oxygen therapy | Experimental | Procedure: Hyperbaric oxygen therapySuccessive changes in fraction of inspired oxygen and barometric pressure (ATA: Atmosphere absolute) Five successive steps: 1. FiO2 0.21 - 1 ATA 2. FiO2 1 - 1 ATA 3. FiO2 1 - 2.5 ATA 4. FiO2 0.21 - 2.5 ATA 5. FiO2 0.21 - 1 ATA |
Who may qualify
- Ages
- 18 to 64 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- To provide a medical certificate of fitness to dive (< 1 year)
- Consent given for study participation
- French health insurance affiliated
Key exclusion criteria (5 listed)
- Temporary or definitive contra-indication to dive
- Pregnancy or < 18 years of age
- Precedent dive < 24 hours
- Under a legal protection measure
- Medical history of a disease known to alter microcirculation
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 therapy1. FiO2 0.21 - 1 ATA 2. FiO2 1 - 1 ATA 3. FiO2 1 - 2.5 ATA 4. FiO2 0.21 - 2.5 ATA 5. FiO2 0.21 - 1 ATA | Procedure or surgery | Hyperbaric oxygen therapy |
Primary outcome
Changes in proportion of perfused vessel (PPV)
Time frame: 30 minutes after hyperbaric hyperoxia exposure (FiO2 1 - 2.5 ATA)
Proportion of perfused vessel assessed by Sidestream dark field microscopy on the sublingual mucosa
5 secondary outcomes
Changes in proportion of perfused vessel (PPV)
Time frame: 30 minutes after FiO2 1 - 1 ATA exposure
Changes in proportion of perfused vessel (PPV)
Time frame: 30 minutes after FiO2 0.21 - 2.5 ATA exposure
Changes in hyperemic reaction after a vaso-occlusion test
Time frame: 30 minutes after FiO2 1 - 2.5 ATA exposure
Changes in area of hyperaemia after a vaso-occlusion test
Time frame: 30 minutes after FiO2 1 - 2.5 ATA exposure
Validation of cardiac output assessed by bioimpedancemetry under hyperbaric condition
Time frame: 30 minutes after FiO2 1 - 2.5 ATA exposure
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jan 2026.
- Results publication: PubMed 36525683Cousin N, Goutay J, Girardie P, Favory R, Drumez E, Mathieu D, Poissy J, Parmentier E, Duburcq T. Effects of high oxygen tension on healthy volunteer microcirculation. Diving Hyperb Med. 2022 Dec 20;52(4):260-70. doi: 10.28920/dhm52.4.260-270.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Thibault Duburcq, MD principal investigator
University Hospital, Lille
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 Hyperbaric Oxygen Therapy, run by University Hospital, Lille at 1 site in France.
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 3 inclusion and 5 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: finished, as of the sponsor's last update on 8 Jan 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 France. 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. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in proportion of perfused vessel (PPV) (time frame: 30 minutes after hyperbaric hyperoxia exposure (FiO2 1 - 2.5 ATA)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03980210, which also lists 1 linked publication.
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 8 Jan 2026.