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Impulse Oscillometry and Airway Inflammation in Chronic Obstructive Pulmonary Disease

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ClinicalTrials.gov Identifier: NCT00677560
Recruitment Status : Unknown
Verified May 2008 by Imperial College London.
Recruitment status was:  Not yet recruiting
First Posted : May 14, 2008
Last Update Posted : May 14, 2008
Sponsor:
Information provided by:
Imperial College London

Brief Summary:

Spirometry is a useful clinical tool for the assessment and monitoring of lung disease, however, it does not provide information on peripheral airways resistance. On the contrary, impulse oscillometry (IOS) may provide information not only on airway resistance (Rrs) but also on the elastic properties of the lung (Xrs).

Even though patients with asthma may show some reduction of the caliber of the small airways these changes are more a feature of patients with COPD. We hypothesize that IOS measurements may detect these differences and provide different resistance profiles for asthma and COPD.


Condition or disease
Asthma COPD

Detailed Description:

Background

Spirometry is a useful clinical tool for the assessment and monitoring of obstructive lung disease but provides no information on the underlying mechanisms causing obstruction. The role of an increase in airflow resistance can be assessed by body plethysmography, but this technique requires elaborate equipment, a skilled operator and considerable subject co-operation. A much simpler technique, impulse oscillometry (IOS) provides a more extensive assessment of pulmonary mechanics. With IOS small volume oscillations are applied at the mouth during ordinary tidal breathing; the instantaneous pressure/flow signal produced by the imposed oscillations (impedance ,Zrs) is analyzed into its in-phase (resistance, Rrs) and out-of-phase (reactance, Xrs) components. Because Rrs is measured over a range of frequencies, IOS has the potential to distinguish between large and small airway resistance. Changes in Xrs have been less studied, but there are suggestions that these also may distinguish between different types of airflow obstruction.

Objectives

The main objective of this study is to investigate the ability of IOS to measure small airway disease by providing different impedance profiles for patients with asthma and COPD. Even though patients with asthma may show some reduction of the calibre of the small airways these changes are more a feature of patients with COPD. We hypothesize that the frequency dependent changes of IOS resistances will enable us to identify patients with COPD where we expect low frequency impedance to be higher compared to patients with asthma. Furthermore, in view of the increased lung compliance which characterizes COPD patients we expect reactance, an IOS measurement which reflects lung elastance, to be elevated compared to asthmatic subjects.

Another objective of this study is to investigate the relationship between small airway resistance and inflammation. The measurement of exhaled nitric oxide (FENO), a marker of inflammation, at multiple exhalation flow rates allows the partitioning of NO produced in the central airways from that generated in the more peripheral lung. We will investigate the relationship between the levels of peripheral airway NO and small airway resistance as assessed by IOS and plethysmography. Furthermore, we would like to measure bronchial blood flow (Qaw) which also is a marker of inflammation and may play a role in the narrowing of the small airways


Study Type : Observational
Estimated Enrollment : 105 participants
Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Impulse Oscillometry and Airway Inflammation in Chronic Obstructive Pulmonary Disease
Study Start Date : August 2008

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Lung Diseases
U.S. FDA Resources

Group/Cohort
1
Asthma
2
COPD
3
Normal subjects



Primary Outcome Measures :
  1. Airway resistance [ Time Frame: cross sectional ]

Secondary Outcome Measures :
  1. inflammation [ Time Frame: cross sectional ]


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
patients will be recruited from outpatient clinics
Criteria

Inclusion Criteria:

  • male or female, aged between 18-70 years;
  • volunteers who are able to give written informed consent Patients meeting the diagnostic criteria for asthma or COPD

Exclusion Criteria:

  • upper respiratory tract infection within the previous 28 days
  • any history or evidence of renal, cardiovascular, gastrointestinal or hepatic disease
  • any history and evidence of neuropsychiatric disease
  • treatment with antibiotics within 4 weeks prior to the study
  • alcohol, drug abuse or any other condition associated with poor compliance
  • breast feeding
  • pregnancy
  • are unable to provide written informed consent

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00677560


Contacts
Contact: Paolo Paredi, MD, PhD 44-20-7351-8051 p.paredi@imperial.ac.uk
Contact: Sergei Kharitonov, MD, PhD 44-20-7351-8066 s.kharitonov@imperial.ac.uk

Locations
United Kingdom
Airway Disease Section, National Heart and Lung Institute, Imperial College
London, United Kingdom, SW3 6LY
Sponsors and Collaborators
Imperial College London
Investigators
Principal Investigator: Paolo Paredi, MD, PhD Airway Disease Section, National Heart and Lung Institute, Imperial College, London
Study Director: Sergei A Kharitonov, MD, PhD Airway Disease Section, National Heart and Lung Institute, Imperial College, London
Study Chair: Peter J Barnes, Prof Airway Disease Section, National Heart and Lung Institute, Imperial College, London
Study Chair: Neil Pride, Prof Airway Disease Section, National Heart and Lung Institute, Imperial College, London
Study Chair: Michael Goldman, Prof Airway Disease Section, National Heart and Lung Institute, Imperial College, London

Responsible Party: P Paredi, Imperial College, London
ClinicalTrials.gov Identifier: NCT00677560     History of Changes
Other Study ID Numbers: 08/H0709/2
First Posted: May 14, 2008    Key Record Dates
Last Update Posted: May 14, 2008
Last Verified: May 2008

Keywords provided by Imperial College London:
resistance
reactance
inflammation

Additional relevant MeSH terms:
Lung Diseases
Inflammation
Lung Diseases, Obstructive
Pulmonary Disease, Chronic Obstructive
Respiratory Tract Diseases
Pathologic Processes