Brigham Research Institute (BRI) - Brigham and Women's Hospital

Assessment of Circuit Rebreathing During CPAP Therapy

Purpose

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).

Condition

Obstructive Sleep Apnea (OSA)

Eligibility

Eligible Ages: Between 21 Years and 70 Years
Eligible Sex: All
Accepts Healthy Volunteers: No

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.

Study Design

Phase: N/A
Study Type: Interventional
Allocation: Randomized
Intervention Model: Sequential Assignment
Intervention 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.
Primary Purpose: Other
Masking: Single (Participant)
Masking Description: The exhaust flow and PAP level conditions will be blinded for the participant.

Arm Groups

Arm	Description	Assigned Intervention
Experimental 5 cmH2O with 35L/s	35 L/s exhaust flow with 5 cmH₂O PAP	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
Experimental 5 cmH2O with 23L/s	23 L/s exhaust flow with 5 cmH₂O PAP	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
Experimental 5 cmH2O with 18L/s	18 L/s exhaust flow with 5 cmH₂O PAP	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
Experimental 5 cmH2O with 13L/s	13 L/s exhaust flow with 5 cmH₂O PAP	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
Experimental 5 cmH2O with 8L/s	8 L/s exhaust flow with 5 cmH₂O PAP	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
Placebo Comparator 0 cmH2O with 35L/s	35 L/s exhaust flow with 0 cmH₂O PAP	Other: Mask exhaust port flow Subjects will be administered varying levels of exhaust flow: 35, 23, 18, 13 and 8 L/s
Experimental 10 cmH2O with 35L/s	35 L/s exhaust flow with 10 cmH₂O PAP	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
Experimental 10 cmH2O with 23L/s	23 L/s exhaust flow with 10 cmH₂O PAP	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
Experimental 10 cmH2O with 18L/s	18 L/s exhaust flow with 10 cmH₂O PAP	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
Experimental 10 cmH2O with 13L/s	13 L/s exhaust flow with 10 cmH₂O PAP	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
Experimental 10 cmH2O with 8L/s	8 L/s exhaust flow with 10 cmH₂O PAP	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

Recruiting Locations

Brigham and Women's Hospital
Boston 4930956, Massachusetts 6254926 02115

Contact:
Atqiya Aishah, PhD
857 396 3808
aaishah@bwh.harvard.edu

More Details

Status: Recruiting
Sponsor: Brigham and Women's Hospital

Study Contact

Atqiya Aishah, PhD
857 396 3808
aaishah@bwh.harvard.edu

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.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.