Mechanism(s)of Airflow Limitation in Moderate-severe Persistent Asthma
Information source: Gelb, Arthur F., M.D.
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Asthma
Intervention: budesonide/formoterol (Drug); fluticasone/salmeterol (Drug); mometasone/formoterol (Drug); Prednisone (Drug)
Phase: Phase 4
Status: Recruiting
Sponsored by: Gelb, Arthur F., M.D. Official(s) and/or principal investigator(s): Arthur F Gelb, MD, Principal Investigator, Affiliation: Arthur F Gelb Medical Corporation
Overall contact: Arthur F Gelb, MD, Phone: 562-633-2204, Email: afgelb@msn.com
Summary
The purpose of this study is to evaluate the site and mechanisms responsible for expiratory
airflow limitation in chronic, treated, non-smoking, stable asthmatics with moderate to
severe persistent expiratory airflow obstruction. Treatment will include inhaled
corticosteroids and long acting beta2agonists and long acting muscarinic antagonists. We are
interested in determining whether the large and/or small airways are the predominant site of
airflow limitation. We are also interested in determining whether intrinsic small airways
obstruction and/or loss of lung elastic recoil is responsible for expiratory airflow
limitation and to what extent may be attributed to loss of lung elastic recoil vs decreased
airway conductance in peripheral airways. We are also interested to evaluate the role of
varying doses of inhaled corticosteroids to suppress large and small airway inflammation
using exhaled nitric oxide as surrogate markers of inflammation. For comparison purposes,
spirometry and measurements of exhaled nitric oxide will also be obtained if possible during
a naturally occurring exacerbation of asthma. High resolution thin section CT of the lung
will also be obtained. Analysis will evaluate integrity of the lung parenchyma as to absence
and or presence of emphysema and extent of emphysema using voxel quantification. We will
also investigate optical coherence tomography to detect clinically unsuspected emphysema. We
will also obtain autopsy material when available in asthmatics who expire
Clinical Details
Official title: Evaluation of Mechanism(s)Limiting Expiratory Airflow in Chronic, Stable Asthmatics Who Are Non-smokers
Study design: Observational Model: Cohort, Time Perspective: Prospective
Primary outcome: use exhaled nitric oxide as a surrogate marker of large airway vs small airway/lung inflammation following various doses of inhaled corticosteroidsdetermine site of airflow limitation, whether predominantly large and /or small airways using expiratory flow volume curves obtained before and after asthmatics breathe a 80% helium-20% oxygen gas mixture investigate the mechanisms that limit expiratory airflow: intrinsic airway obstruction vs loss of lung elastic recoil
Secondary outcome: dynamic hyperinflationEvaluate large and small airways and lung parenchyma in autopsied asthmatics and look for unsuspected emphysema Optical Coherence Tomography
Detailed description:
Results will be evaluated during exacerbation and when stable following treatment.
Eligibility
Minimum age: 10 Years.
Maximum age: 95 Years.
Gender(s): Both.
Criteria:
Inclusion Criteria:
- Current non-smoking (<10 pack yr smoking history)
- Stable, treated asthmatics
- Age 12-95 yr
- post 180ug albuterol by MDI: FEV 1/FVC < 70% and FEV 1 <80% predicted
Exclusion Criteria:
- Pregnancy
Locations and Contacts
Arthur F Gelb, MD, Phone: 562-633-2204, Email: afgelb@msn.com
Arthur F Gelb Medical Corporation, Lakewood, California 90712, United States; Recruiting Arthur F Gelb, MD, Principal Investigator
Additional Information
Related publications: Gelb AF, Zamel N. Unsuspected pseudophysiologic emphysema in chronic persistent asthma. Am J Respir Crit Care Med. 2000 Nov;162(5):1778-82. Gelb AF, Licuanan J, Shinar CM, Zamel N. Unsuspected loss of lung elastic recoil in chronic persistent asthma. Chest. 2002 Mar;121(3):715-21. Gelb AF, Gutierrez CA, Weisman IM, Newsom R, Taylor CF, Zamel N. Simplified detection of dynamic hyperinflation. Chest. 2004 Dec;126(6):1855-60. Gelb AF, Flynn Taylor C, Shinar CM, Gutierrez C, Zamel N. Role of spirometry and exhaled nitric oxide to predict exacerbations in treated asthmatics. Chest. 2006 Jun;129(6):1492-9. Gelb AF, Taylor CF, Nussbaum E, Gutierrez C, Schein A, Shinar CM, Schein MJ, Epstein JD, Zamel N. Alveolar and airway sites of nitric oxide inflammation in treated asthma. Am J Respir Crit Care Med. 2004 Oct 1;170(7):737-41. Epub 2004 Jun 30. Gelb AF, Zamel N, Krishnan A. Physiologic similarities and differences between asthma and chronic obstructive pulmonary disease. Curr Opin Pulm Med. 2008 Jan;14(1):24-30. Review.
Starting date: October 2007
Last updated: March 13, 2015
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