Assessment of Circuit Rebreathing During CPAP Therapy

Launched by BRIGHAM AND WOMEN'S HOSPITAL · Jul 10, 2025

Keywords

ClinConnect Summary

This study is looking at how different designs of CPAP masks affect the way air flows and how much exhaled carbon dioxide (CO₂) might be breathed back in during sleep for people with obstructive sleep apnea (OSA). OSA is a condition where breathing stops and starts during sleep, and CPAP machines help keep the airway open by providing steady air pressure through a mask. The researchers want to understand which mask designs work best to keep the air fresh and safe throughout the night.

People who might join this study are adults aged 21 to 70 who have moderate to severe OSA and have used a CPAP machine before. Participants should have a body weight within a healthy to moderately high range (BMI between 18 and 40) and not have other serious health problems like severe lung or heart disease. If you join, you can expect to try different CPAP masks while researchers check how air flows and how much CO₂ is rebreathed during sleep. This study is currently looking for volunteers, and your participation can help improve CPAP mask designs for better comfort and safety in the future.

Gender

ALL

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.