Healthy ParticipantsNCT01893697
The Influence of Posture on Airway Diameter, Resistance and Airflow Distribution in Healthy Subjects
An observational study of Healthy Participants, run by University Hospital, Antwerp at 1 site in Belgium.
Trial summary
FRI could give the opportunity to investigate the possible effect of a lateral posture on airway diameter and airflow distributions. This physiological study in healthy subjects may help to identify the role of positioning as an aid in airway clearance techniques for patients with respiratory diseases. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Participants
- What is being tested?
- HRCT scan in a specific postural position
- How many people
- 5 participants
- Where
- 1 siteBelgium
- Study dates
- Apr 2013to Sep 2014
- Phase
- Observational
- Are there results?
- None posted in the registry
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 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Healthy subjects
Who may be able to join
- Men or female patients age > 18
- No respiratory disease in the days prior to the enrollment
- Able to perform a lung function tests
- Motivated to participate.
- Written informed consent from the subject prior to the participation
Who cannot join
- Serious co-morbidity which would interfere with the examinations
- One or multiple CT scans of the chest during the last year.
- Deformities or complications preventing patients to maintain side lying position during the scanning procedure
Trial locations and contacts
1 site in 1 country.
About this study
FRI could give the opportunity to investigate the possible effect of a lateral posture on airway diameter and airflow distributions. This physiological study in healthy subjects may help to identify the role of positioning as an aid in airway clearance techniques for patients with respiratory diseases.
Read the detailed description
Many respiratory diseases require a physiotherapeutic treatment that focusses on clearance of excessive mucus from the airways.
The underlying physiological hypothesis why those mucus clearance techniques are effective is based on the development of an optimal expiratory airflow velocity that applies shearing forces on the mucus at the inner surface of the airway. These shearing forces eventually lead to displacement of mucus to the central airways were it could be evacuated.To accomplish optimal velocity with the same expiratory airflow, it is necessary to decrease the airway diameter and hence increase in the airflow velocity. In other words, the airway diameter and resistance are important factors to take into account in mucus clearance techniques.
In many mucus clearance techniques, postural position is used to facilitate this clearance. Clinical trials in patients with chronic obstructive pulmonary disease (COPD) and cystic fibrosis where they combined clearance techniques with different postural positions showed to be effective.
The influence of posture has been evaluated in the lateral decubitus position and resulted in a greater clearance of mucus in the depended lung. The authors suggested that this may be due to a better deflation of the depended lung that is favored by 3 forces: gravity, mediastinum weight and pressure of abdominal viscera on the infra lateral lung. Deflation of this lung leads not only to a decrease in lung volume, but also results in a decrease in airway diameter. Nevertheless, it is not known to what extend this decrease in diameter occurs in a lateral position. Furthermore, an optimal expiratory flow must be retained in the underlying lung at lower lung volumes. These regional changes in the underlying lung cannot be measured by for example classic lung function tests since these test are not sensitive enough. Indeed, Washko et. al. found no significant changes of overall residual volume (RV), total lung capacity (TLC) and vital capacity (VC) between the different positions in healthy subject.
However, Functional respiratory imaging (FRI) is able to assess the regional changes in healthy subjects. This 3D imaging technique in combination with computational fluid dynamics (CFD) is accurate in calculating regional changes such as airway diameter, volume and resistance. In addition, repetitive FRI measures are able to assess lobar expansion, which is an indirect measure of airflow distribution in a specific part of the lung.
- Conditions
- Healthy Participants
- Being tested
- HRCT scan in a specific postural position
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
HRCT scan in a specific postural positionOther
HRCT Scan taken in supine and lateral position
| Study group | Role | What they receive |
|---|---|---|
| Healthy Participants | HRCT scan in a specific postural position Receives: Other: HRCT scan in a specific postural position |
What is being measured
The primary outcome is the main question the study is designed to answer.
Functional Respiratory Imaging
A low dose 3D spiral high resolution computed tomography (HRCT) scan will be taken on 2 volumes TLC and functional residual capacity (FRC) in both supine and lateral decubitus position. Image post processing is performed to look at local changes in airway or lobar volume [liter] and airway resistance [kiloPascal.seconds/liter] distribution in the lung
Measured: 1 study visit (1 day)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jul 2013 (estimated)
- Study startApr 2013
- Primary completionSep 2014
- Study completionSep 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Healthy ParticipantsStudies of the same condition, open and under way.
- More trials run by University Hospital, AntwerpThe sponsor's other registered studies.
- 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
- Case crossover
- Time perspective
- Prospective
- Enrolment
- 5 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Antwerp
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Wilfried De Backer, University Hospital, Antwerp
- Investigators
- Wilfried De Backer, MD PhD, Principal investigator, University Hospital, Antwerp
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01893697
- Sponsor's protocol ID
- RESPT_2013_01
- Status last verified
- May 2015
- First submitted
- 27 Jun 2013
- Last updated
- 28 May 2015
- Results posted
- No
- Data monitoring committee
- No
Publications
Ides KM, De Backer WA, Lanclus M, Leemans G, Dierckx W, Lauwers E, Vissers D, Steckel J, De Backer JW. The effect of posture on airflow distribution, airway geometry and air velocity in healthy subjects. BMC Pulm Med. 2022 Dec 15;22(1):477. doi: 10.1186/s12890-022-02276-5.
PubMed 36522658
Study at a glance
From the registry record, last updated by the sponsor on 28 May 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Influence of Posture on Airway Diameter, Resistance and Airflow Distribution in Healthy Subjects
- ClinicalTrials.gov ID
- NCT01893697
- Acronym / sponsor ID
- RESPT_2013_01
- Conditions
- Healthy Participants
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 5 participants (actual)
- Lead sponsor
- University Hospital, AntwerpUniversity, hospital or other
- Study start
- Apr 2013
- Primary completion
- Sep 2014 (actual)
- Study completion
- Sep 2014 (actual)
- First posted
- 9 Jul 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
FRI could give the opportunity to investigate the possible effect of a lateral posture on airway diameter and airflow distributions. This physiological study in healthy subjects may help to identify the role of positioning as an aid in airway clearance techniques for patients with respiratory diseases.
Detailed description
Many respiratory diseases require a physiotherapeutic treatment that focusses on clearance of excessive mucus from the airways.
The underlying physiological hypothesis why those mucus clearance techniques are effective is based on the development of an optimal expiratory airflow velocity that applies shearing forces on the mucus at the inner surface of the airway. These shearing forces eventually lead to displacement of mucus to the central airways were it could be evacuated.To accomplish optimal velocity with the same expiratory airflow, it is necessary to decrease the airway diameter and hence increase in the airflow velocity. In other words, the airway diameter and resistance are important factors to take into account in mucus clearance techniques.
In many mucus clearance techniques, postural position is used to facilitate this clearance. Clinical trials in patients with chronic obstructive pulmonary disease (COPD) and cystic fibrosis where they combined clearance techniques with different postural positions showed to be effective.
The influence of posture has been evaluated in the lateral decubitus position and resulted in a greater clearance of mucus in the depended lung. The authors suggested that this may be due to a better deflation of the depended lung that is favored by 3 forces: gravity, mediastinum weight and pressure of abdominal viscera on the infra lateral lung. Deflation of this lung leads not only to a decrease in lung volume, but also results in a decrease in airway diameter. Nevertheless, it is not known to what extend this decrease in diameter occurs in a lateral position. Furthermore, an optimal expiratory flow must be retained in the underlying lung at lower lung volumes. These regional changes in the underlying lung cannot be measured by for example classic lung function tests since these test are not sensitive enough. Indeed, Washko et. al. found no significant changes of overall residual volume (RV), total lung capacity (TLC) and vital capacity (VC) between the different positions in healthy subject.
However, Functional respiratory imaging (FRI) is able to assess the regional changes in healthy subjects. This 3D imaging technique in combination with computational fluid dynamics (CFD) is accurate in calculating regional changes such as airway diameter, volume and resistance. In addition, repetitive FRI measures are able to assess lobar expansion, which is an indirect measure of airflow distribution in a specific part of the lung.
Study design
- Observational model
- Case crossover
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Healthy Participants | – | Other: HRCT scan in a specific postural positionHRCT scan in a specific postural position |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Healthy subjects
Key inclusion criteria (5 listed)
- Men or female patients age > 18
- No respiratory disease in the days prior to the enrollment
- Able to perform a lung function tests
- Motivated to participate.
- Written informed consent from the subject prior to the participation
Key exclusion criteria (3 listed)
- Serious co-morbidity which would interfere with the examinations
- One or multiple CT scans of the chest during the last year.
- Deformities or complications preventing patients to maintain side lying position during the scanning procedure
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| HRCT scan in a specific postural positionHRCT Scan taken in supine and lateral position | Other | Healthy Participants |
Primary outcome
Functional Respiratory Imaging
Time frame: 1 study visit (1 day)
A low dose 3D spiral high resolution computed tomography (HRCT) scan will be taken on 2 volumes TLC and functional residual capacity (FRC) in both supine and lateral decubitus position. Image post processing is performed to look at local changes in airway or lobar volume [liter] and airway resistance [kiloPascal.seconds/liter] distribution in the lung
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2015.
- Derived from this study: PubMed 36522658Ides KM, De Backer WA, Lanclus M, Leemans G, Dierckx W, Lauwers E, Vissers D, Steckel J, De Backer JW. The effect of posture on airflow distribution, airway geometry and air velocity in healthy subjects. BMC Pulm Med. 2022 Dec 15;22(1):477. doi: 10.1186/s12890-022-02276-5.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Wilfried De Backer, MD PhD principal investigator
University Hospital, Antwerp
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Healthy Participants, run by University Hospital, Antwerp at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 May 2015. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Functional Respiratory Imaging (time frame: 1 study visit (1 day)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01893697, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 May 2015; AzTrials last refreshed its copy on 7 Nov 2026.