Distribution of Ventilation, Respiratory Drive and Gas Exchange: Measurements and Monitoring
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Pulmonary Disease
- Sponsor
- University of California, San Diego
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Distribution of ventilation
- Status
- Enrolling By Invitation
- Last Updated
- last year
Overview
Brief Summary
Respiratory physiology involves a complex interplay of elements including control of breathing, respiratory drive, pulmonary mechanics, distribution of ventilation and gas exchange. Body position may also play an important role in respiratory mechanics. While effective methods exist for measuring these variables, they are typically measured in isolation rather than in combination. In pulmonary disease, decreasing mechanical stress and strain and optimizing transpulmonary pressure or the distending pressure across the lung, minimizing overdistention and collapse are central to clinical management. Obesity has a significant impact on pulmonary mechanics and is a risk factor for obstructive sleep apnea (OSA). However, our understanding of these elements is limited even in the general population. The investigators plan to use various validated methods to assess control of breathing, respiratory drive, distribution of ventilation and gas exchange to obtain a better understanding of underlying physiologic signatures in patients with and without obesity and the role of posture/position, with a secondary analysis comparing participants with and without obstructive sleep apnea.
Investigators
Alex Pearce
Principal Investigator
University of California, San Diego
Eligibility Criteria
Inclusion Criteria
- •18 years or older
- •Non-smokers
Exclusion Criteria
- •\<18 years old
- •Significant history of pulmonary disease
- •Chest wall, anatomical, physical abnormalities, skin integrity issues precluding placement of electrode belt in direct contact with skin
- •Skin integrity issues precluding placement of nose clips, or transcutaneous carbon dioxide monitoring
- •Inability to form a seal around a mouthpiece
- •Known esophageal strictures, webs, or varices (if esophageal manometry to be included)
- •Known platelet count \< 100,000 (if esophageal manometry to be included)
- •On therapeutic anticoagulation (if esophageal manometry to be included)
- •Known multidrug resistant (MDR) pulmonary infection
- •Non-English language speakers
Outcomes
Primary Outcomes
Distribution of ventilation
Time Frame: 3 hours
Change in regional ventilation distribution (ventral/dorsal) measured through electrical impedance tomography (EIT)
Respiratory drive
Time Frame: 3 hours
Respiratory drive will also be assessed by measurement of occlusion pressure (cm H2O) at 100 ms (P0.1) after the initiation of an inspiratory effort against a closed circuit.
Secondary Outcomes
- Pulmonary mechanics(3 hours)
- Dead space fraction(3 hours)
- Ventilatory ratio(3 hours)