An interventional study of Hyperbaric oxygen therapy in Hyperbaric Oxygen Therapy, sponsored by University Hospital, Lille. Completed at 1 site in France. Open to participants aged 18 Years to 64 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-08.
Sponsored by University Hospital, Lille · Not applicable, Interventional, and Basic science
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.
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 :
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.
115 studies on the registry are indexed under Hyperoxia; 13 are open to participants now.
This study's enrollment of 15 is below the median of 48 across 82 interventional studies indexed under Hyperoxia.
Browse Hyperoxia studies →University Hospital, Lille is the lead sponsor of 631 studies on the registry; 142 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
Procedure: Hyperbaric oxygen therapy
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
Changes in proportion of perfused vessel (PPV)
Proportion of perfused vessel assessed by Sidestream dark field microscopy on the sublingual mucosa
Time frame: 30 minutes after hyperbaric hyperoxia exposure (FiO2 1 - 2.5 ATA)
Changes in proportion of perfused vessel (PPV)
Proportion of perfused vessel assessed by Sidestream dark field microscopy on the sublingual mucosa
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 30 minutes after FiO2 1 - 2.5 ATA exposure
Validation of cardiac output assessed by bioimpedancemetry under hyperbaric condition
Comparison with transthoracic echocardiography
Time frame: 30 minutes after FiO2 1 - 2.5 ATA exposure
Plan to share: No
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