Pulmonary DiseaseNCT05462600
Distribution of Ventilation, Respiratory Drive and Gas Exchange: Measurements and Monitoring
An observational study of Pulmonary Disease and Respiratory System Abnormalities, run by University of California, San Diego at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Pulmonary Disease, Respiratory System Abnormalities, OSA
- What is being tested?
- Position change
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Jul 2022to 30 Dec 2026
- Phase
- Observational
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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Investigators will enroll 20 subjects with BMI 18.5-24.9 and 20 subjects with BMI 25 or more. The detailed inclusion criteria for subjects are listed below.
Who may be able to join
- 18 years or older
- Non-smokers
Who cannot join
- <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)
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- 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
- Chronic hypoxemic respiratory failure
- Confirmed or suspected intracranial bleed, stroke, edema
- Active implants (i.e. implantable electronic devices such as pacemakers, cardioverter defibrillators or neurostimulators) or if device compatibility is in doubt
- Pregnant or lactating patients as safety and efficacy for use of EIT in such cases has not been verified
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
University of California San Diego Health
La Jolla, California, 92037
About this study
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.
- Being tested
- Position change
- Medical subject headings
- Lung Diseases, Respiratory System Abnormalities, Respiratory Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Position changeOther
Distribution of ventilation, respiratory drive, pulmonary mechanics and gas exchange will be measured in 3 unique positions: prone, head of bed (HOB) flat (i.e. 0 degrees) and HOB elevated (i.e. 30 degrees).
| Study group | Role | What they receive |
|---|---|---|
| BMI>24.9 kg/m2 | Not described Receives: Other: Position change | |
| BMI 18-24.9 kg/m2 | Not described Receives: Other: Position change |
What is being measured
The primary outcome is the main question the study is designed to answer.
Distribution of ventilation
Change in regional ventilation distribution (ventral/dorsal) measured through electrical impedance tomography (EIT)
Measured: 3 hours
Respiratory drive
Respiratory drive differences will be measured by mean desaturation (change from baseline percent oxygen saturation) following breath-hold maneuvers
Measured: 3 hours
Respiratory drive
Respiratory drive differences will be assessed by the duration of maximal breath-hold (seconds)
Measured: 3 hours
Respiratory drive
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.
Measured: 3 hours
Secondary outcomes (3)
Pulmonary mechanics
Pulmonary mechanics will be measured by transpulmonary pressure (cmH2O)obtained from esophageal manometry (transpulmonary pressure= airway pressure- esophageal pressure)
Measured: 3 hours
Dead space fraction
Dead space fraction will be calculated by partial pressure arterial/transcutaneous CO2 (PCO2) minus partial pressure of CO2 in mixed expired gas divided by the partial pressure of arterial/transcutaneous CO2
Measured: 3 hours
Ventilatory ratio
Ventilatory ratio will be calculated as measured minute ventilation multiplied by the measured partial pressure of PCO2 divided (transcutaneous) by the predicted minute ventilation based on ideal body weight multiplied by the ideal PaCO2
Measured: 3 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Jul 2022
- Study start19 Jul 2022
- Primary completion30 Dec 2026 (estimated)
- Study completion30 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pulmonary DiseaseStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, San Diego
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Alex Pearce, University of California, San Diego
- Investigators
- Alex Pearce, Principal investigator, University of California, San Diego
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05462600
- Sponsor's protocol ID
- 801980
- Status last verified
- Jun 2024
- First submitted
- 30 Jun 2022
- Last updated
- 11 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided