Obstructive Sleep Apnea (OSA)NCT07062770
Assessment of Circuit Rebreathing During CPAP Therapy
A study testing Continuous positive airway pressure (CPAP) and Mask exhaust port flow in people with Obstructive Sleep Apnea (OSA), run by Brigham and Women's Hospital at 1 site in United States.
Trial summary
The goal of this research is to better understand how different CPAP mask designs affect airflow and rebreathing of exhaled carbon dioxide (CO₂) during sleep in individuals with obstructive sleep apnea (OSA). Read more about this study
- Who is it for?
- Ages 21 to 70 years
- Conditions the study is for
- Obstructive Sleep Apnea (OSA)
- What is being tested?
- Continuous positive airway pressure (CPAP) and Mask exhaust port flow
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 13 participants
- Where
- 1 siteUnited States
- Study dates
- 27 May 2025to 1 Dec 2025
- 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 21 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Moderate to severe OSA (AHI>20)
- Self-reported CPAP users or have previously used CPAP
- Self-reported holding pressure of maximum 13 cmH2O (if known)
- Age: 21-70
- BMI: 18-40 kg/m2
Who cannot join
- Self-reported severe mouth-breathing
- Requirement for nocturnal supplemental oxygen or other ventilatory support
- Severe cardiovascular or pulmonary disease
- Any unstable or acute medical condition
- Any additional sleep disorder, including insomnia, except for OSA.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Brigham and Women's Hospital
Boston, Massachusetts, 02115
Atqiya Aishah, PhD, 857 396 3808, aaishah@bwh.harvard.edu
Scott A Sands, PhD, 617 278 0911, sasands@bwh.harvard.edu
About this study
Official title: Assessment of Circuit Rebreathing During Continuous Positive Airway Pressure (CPAP) Therapy
The goal of this research is to better understand how different CPAP mask designs affect airflow and rebreathing of exhaled carbon dioxide (CO₂) during sleep in individuals with obstructive sleep apnea (OSA).
Read the detailed description
To understand the existence and severity of circuit rebreathing during treatment with continuous positive airway pressure (CPAP) using different sizes of the exhaust ports in individuals with obstructive sleep apnea (OSA).
Flow-adjusted end-tidal oxygen (PetO2) and carbon dioxide (PetCO2) will be assessed to determine the magnitude of hypoxic load during both wakefulness and sleep. To systematically assess these conditions, the conditions were defined as follows:
- 5A: 35 L/s exhaust flow with 5 cmH₂O PAP
- 5B: 23 L/s exhaust flow with 5 cmH₂O PAP
- 5C: 18 L/s exhaust flow with 5 cmH₂O PAP
- 5D: 13 L/s exhaust flow with 5 cmH₂O PAP
- 5E: 8 L/s exhaust flow with 5 cmH₂O PAP
- 0P: 35 L/s exhaust flow with 0 cmH₂O PAP
- 10A: 35 L/s exhaust flow with 10 cmH₂O PAP
- 10B: 23 L/s exhaust flow with 10 cmH₂O PAP
- 10C: 18 L/s exhaust flow with 10 cmH₂O PAP
- 10D: 13 L/s exhaust flow with 10 cmH₂O PAP
- 10E: 8 L/s exhaust flow with 10 cmH₂O PAP Primary endpoint is to evaluate the effect of exhaust flow on flow-adjusted average inspired oxygen fraction (FiO₂) during (1) wakefulness and (2) sleep between 5B vs. 5D.
- Conditions
- Obstructive Sleep Apnea (OSA)
- Being tested
- Continuous positive airway pressure (CPAP), Mask exhaust port flow
- Keywords
- Obstructive sleep apnea
- Medical subject headings
- Sleep Apnea, Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Continuous positive airway pressure (CPAP)Device
Subjects will be administered either 0, 5 or 10 cmH2O
Mask exhaust port flowOther
Subjects will be administered varying levels of exhaust flow: 35, 23, 18, 13 and 8 L/s
| Study group | Role | What they receive |
|---|---|---|
| 5 cmH2O with 35L/s | Experimental | 35 L/s exhaust flow with 5 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 5 cmH2O with 23L/s | Experimental | 23 L/s exhaust flow with 5 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 5 cmH2O with 18L/s | Experimental | 18 L/s exhaust flow with 5 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 5 cmH2O with 13L/s | Experimental | 13 L/s exhaust flow with 5 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 5 cmH2O with 8L/s | Experimental | 8 L/s exhaust flow with 5 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 0 cmH2O with 35L/s | Placebo comparator | 35 L/s exhaust flow with 0 cmH₂O PAP Receives: Other: Mask exhaust port flow |
| 10 cmH2O with 35L/s | Experimental | 35 L/s exhaust flow with 10 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 10 cmH2O with 23L/s | Experimental | 23 L/s exhaust flow with 10 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 10 cmH2O with 18L/s | Experimental | 18 L/s exhaust flow with 10 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 10 cmH2O with 13L/s | Experimental | 13 L/s exhaust flow with 10 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
| 10 cmH2O with 8L/s | Experimental | 8 L/s exhaust flow with 10 cmH₂O PAP Receives: Device: Continuous positive airway pressure (CPAP); Other: Mask exhaust port flow |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in flow-adjusted average inspired oxygen fraction (FiO₂) during wake.
Difference in FiO2 between 23L/s vs 13L/s exhaust flow at 5 cmH2O PAP.
Measured: through study completion, an average of 1 year
Change in flow-adjusted average inspired oxygen fraction (FiO₂) during sleep.
Difference in FiO2 between 23L/s vs 13L/s exhaust flow at 5 cmH2O PAP.
Measured: through study completion, an average of 1 year
Secondary outcomes (1)
Impact on hypoxic burden during sleep.
Difference in hyboxic burden between 23L/s vs 13L/s exhaust flow at 5 cmH2O PAP.
Measured: through study completion, an average of 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jul 2025
- Study start27 May 2025
- Primary completion1 Dec 2025 (estimated)
- Study completion1 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obstructive Sleep Apnea (OSA)Studies of the same condition, open and under way.
- More trials run by Brigham and Women's HospitalThe 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
- Other
- Allocation
- Randomised
- Intervention model
- Sequential
- Model description
- Subjects will perform 1 in-lab sleep study visit consisting of an evening wake session followed by an overnight sleep study. Subjects will receive randomized sequences of 11 conditions (varying in exhaust flow and PAP levels) during the evening and sleep portions of the night.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 13 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Brigham and Women's Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Sleep Res, Inc.
- Responsible party
- Principal investigator, Atqiya Aishah, Ph.D., Brigham and Women's Hospital
- Investigators
- Atqiya Aishah, PhD, Principal investigator, Harvard Medical School & Brigham and Women's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07062770
- Sponsor's protocol ID
- 2025P000798
- Status last verified
- Jul 2025
- First submitted
- 27 May 2025
- Last updated
- 14 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: Deidentified subject data will be available upon request.
Study at a glance
From the registry record, last updated by the sponsor on 14 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Circuit Rebreathing During Continuous Positive Airway Pressure (CPAP) Therapy
- ClinicalTrials.gov ID
- NCT07062770
- Acronym / sponsor ID
- 2025P000798
- Conditions
- Obstructive Sleep Apnea (OSA)
- Keywords
- Obstructive sleep apnea
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 13 participants (estimated)
- Lead sponsor
- Brigham and Women's HospitalUniversity, hospital or other
- Collaborators
- Sleep Res, Inc.
- Study start
- 27 May 2025 (actual)
- Primary completion
- 1 Dec 2025 (estimated)
- Study completion
- 1 Dec 2025 (estimated)
- First posted
- 14 Jul 2025 (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 goal of this research is to better understand how different CPAP mask designs affect airflow and rebreathing of exhaled carbon dioxide (CO₂) during sleep in individuals with obstructive sleep apnea (OSA).
Detailed description
To understand the existence and severity of circuit rebreathing during treatment with continuous positive airway pressure (CPAP) using different sizes of the exhaust ports in individuals with obstructive sleep apnea (OSA).
Flow-adjusted end-tidal oxygen (PetO2) and carbon dioxide (PetCO2) will be assessed to determine the magnitude of hypoxic load during both wakefulness and sleep. To systematically assess these conditions, the conditions were defined as follows:
- 5A: 35 L/s exhaust flow with 5 cmH₂O PAP
- 5B: 23 L/s exhaust flow with 5 cmH₂O PAP
- 5C: 18 L/s exhaust flow with 5 cmH₂O PAP
- 5D: 13 L/s exhaust flow with 5 cmH₂O PAP
- 5E: 8 L/s exhaust flow with 5 cmH₂O PAP
- 0P: 35 L/s exhaust flow with 0 cmH₂O PAP
- 10A: 35 L/s exhaust flow with 10 cmH₂O PAP
- 10B: 23 L/s exhaust flow with 10 cmH₂O PAP
- 10C: 18 L/s exhaust flow with 10 cmH₂O PAP
- 10D: 13 L/s exhaust flow with 10 cmH₂O PAP
- 10E: 8 L/s exhaust flow with 10 cmH₂O PAP Primary endpoint is to evaluate the effect of exhaust flow on flow-adjusted average inspired oxygen fraction (FiO₂) during (1) wakefulness and (2) sleep between 5B vs. 5D.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Single blind (participant)
- Number of arms
- 11
- Model description
- Subjects will perform 1 in-lab sleep study visit consisting of an evening wake session followed by an overnight sleep study. Subjects will receive randomized sequences of 11 conditions (varying in exhaust flow and PAP levels) during the evening and sleep portions of the night.
| Arm | Type | Receives |
|---|---|---|
| 5 cmH2O with 35L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow35 L/s exhaust flow with 5 cmH₂O PAP |
| 5 cmH2O with 23L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow23 L/s exhaust flow with 5 cmH₂O PAP |
| 5 cmH2O with 18L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow18 L/s exhaust flow with 5 cmH₂O PAP |
| 5 cmH2O with 13L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow13 L/s exhaust flow with 5 cmH₂O PAP |
| 5 cmH2O with 8L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow8 L/s exhaust flow with 5 cmH₂O PAP |
| 0 cmH2O with 35L/s | Placebo comparator | Other: Mask exhaust port flow35 L/s exhaust flow with 0 cmH₂O PAP |
| 10 cmH2O with 35L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow35 L/s exhaust flow with 10 cmH₂O PAP |
| 10 cmH2O with 23L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow23 L/s exhaust flow with 10 cmH₂O PAP |
| 10 cmH2O with 18L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow18 L/s exhaust flow with 10 cmH₂O PAP |
| 10 cmH2O with 13L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow13 L/s exhaust flow with 10 cmH₂O PAP |
| 10 cmH2O with 8L/s | Experimental | Device: Continuous positive airway pressure (CPAP), Other: Mask exhaust port flow8 L/s exhaust flow with 10 cmH₂O PAP |
Who may qualify
- Ages
- 21 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Moderate to severe OSA (AHI>20)
- Self-reported CPAP users or have previously used CPAP
- Self-reported holding pressure of maximum 13 cmH2O (if known)
- Age: 21-70
- BMI: 18-40 kg/m2
Key exclusion criteria (5 listed)
- Self-reported severe mouth-breathing
- Requirement for nocturnal supplemental oxygen or other ventilatory support
- Severe cardiovascular or pulmonary disease
- Any unstable or acute medical condition
- Any additional sleep disorder, including insomnia, except for OSA.
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 |
|---|---|---|
| Continuous positive airway pressure (CPAP)Subjects will be administered either 0, 5 or 10 cmH2O | Device | 10 cmH2O with 13L/s, 10 cmH2O with 18L/s, 10 cmH2O with 23L/s, 10 cmH2O with 35L/s, 10 cmH2O with 8L/s, 5 cmH2O with 13L/s, 5 cmH2O with 18L/s, 5 cmH2O with 23L/s, 5 cmH2O with 35L/s, 5 cmH2O with 8L/s |
| Mask exhaust port flowSubjects will be administered varying levels of exhaust flow: 35, 23, 18, 13 and 8 L/s | Other | 0 cmH2O with 35L/s, 10 cmH2O with 13L/s, 10 cmH2O with 18L/s, 10 cmH2O with 23L/s, 10 cmH2O with 35L/s, 10 cmH2O with 8L/s, 5 cmH2O with 13L/s, 5 cmH2O with 18L/s, 5 cmH2O with 23L/s, 5 cmH2O with 35L/s, 5 cmH2O with 8L/s |
Primary outcome
Change in flow-adjusted average inspired oxygen fraction (FiO₂) during wake.
Time frame: through study completion, an average of 1 year
Difference in FiO2 between 23L/s vs 13L/s exhaust flow at 5 cmH2O PAP.
Change in flow-adjusted average inspired oxygen fraction (FiO₂) during sleep.
Time frame: through study completion, an average of 1 year
Difference in FiO2 between 23L/s vs 13L/s exhaust flow at 5 cmH2O PAP.
1 secondary outcome
Impact on hypoxic burden during sleep.
Time frame: through study completion, an average of 1 year
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 14 Jul 2025.
- Individual participant dataSharing planned: Yes. Deidentified subject data will be available upon request.
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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.
Atqiya Aishah, PhD principal investigator
Harvard Medical School & Brigham and Women's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Continuous positive airway pressure (CPAP) and Mask exhaust port flow in people with Obstructive Sleep Apnea (OSA), run by Brigham and Women's Hospital at 1 site in United States.
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 5 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: looking for participants now, as of the sponsor's last update on 14 Jul 2025. 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 United States. 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 Atqiya Aishah, PhD (857 396 3808, aaishah@bwh.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in flow-adjusted average inspired oxygen fraction (FiO₂) during wake. (time frame: through study completion, an average of 1 year). 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 14 Jul 2025.