Assessment of Circuit Rebreathing During CPAP Therapy
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Continuous positive airway pressure (CPAP), Mask exhaust port flow.
- Who it may be relevant to
- Registry conditions: Obstructive Sleep Apnea (OSA). Basic parameters: 21 years — 70 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Assessment of Circuit Rebreathing During Continuous Positive Airway Pressure (CPAP) Therapy
Overview
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.
Interventions
- Device Continuous positive airway pressure (CPAP)
Subjects will be administered either 0, 5 or 10 cmH2O - Other Mask exhaust port flow
Subjects will be administered varying levels of exhaust flow: 35, 23, 18, 13 and 8 L/s
Primary outcome measures
- Change in flow-adjusted average inspired oxygen fraction (FiO₂) during wake. [Time frame: through study completion, an average of 1 year]
- Change in flow-adjusted average inspired oxygen fraction (FiO₂) during sleep. [Time frame: through study completion, an average of 1 year]
Secondary outcome measures (1)
- Impact on hypoxic burden during sleep. [Time frame: through study completion, an average of 1 year]
Eligibility criteria
Inclusion criteria
- 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
Exclusion criteria
- 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.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Sequential
- Masking
- Single blind
- Primary purpose
- Other
Study locations
United States · 1 center
- Brigham and Women's Hospital — Boston
Identifiers
NCT: NCT07062770 · 2025P000798