Mechanism(s) of Airflow Limitation During Exacerbation of Asthma
| Status: | Recruiting |
|---|---|
| Conditions: | Asthma |
| Therapuetic Areas: | Pulmonary / Respiratory Diseases |
| Healthy: | No |
| Age Range: | 10 - 80 |
| Updated: | 4/2/2016 |
| Start Date: | October 2007 |
| End Date: | June 2016 |
| Contact: | Arthur F Gelb, MD |
| Email: | afgelb@msn.com |
| Phone: | 562-633-2204 |
Evaluation of Mechanism(s)Limiting Expiratory Airflow in Chronic, Stable Asthmatics Who Are Non-smokers
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. The investigators are interested in
determining whether the large and/or small airways are the predominant site of airflow
limitation. The investigators are also interested in determining whether intrinsic small
airways obstruction and/or loss of lung elastic recoil is responsible for expiratory airflow
limitation. The investigators 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.
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. The investigators are interested in
determining whether the large and/or small airways are the predominant site of airflow
limitation. The investigators are also interested in determining whether intrinsic small
airways obstruction and/or loss of lung elastic recoil is responsible for expiratory airflow
limitation. The investigators 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.
In addition we will also obtain above studies in asthmatics during naturally occuring
exacerbation of asthma and following treatment. If available, results of lung function
studies including measurements of lung elastic recoil will be compared to pathologic
analyses of formalin fixed, air inflated lungs obtained at autopsy in asthmatics who die
from asthma related or non-asthma related death. This kind of lung structure-function study
will provide potential mechanism(s) to explain the loss of lung elastic recoil in acute and
chronic asthmatics who are non-smokers. We will also obtain voxel quantification of high
resolution thin section CT of lung obtained without IV contrast. Also, we will use
fiberoptic bronchoscopy to obtain optical coherence tomography in stable asthmatics with
mild to moderate to severe expiratory airflow limitation to assess integrity of the lung
parenchyma.
exacerbation of asthma and following treatment. If available, results of lung function
studies including measurements of lung elastic recoil will be compared to pathologic
analyses of formalin fixed, air inflated lungs obtained at autopsy in asthmatics who die
from asthma related or non-asthma related death. This kind of lung structure-function study
will provide potential mechanism(s) to explain the loss of lung elastic recoil in acute and
chronic asthmatics who are non-smokers. We will also obtain voxel quantification of high
resolution thin section CT of lung obtained without IV contrast. Also, we will use
fiberoptic bronchoscopy to obtain optical coherence tomography in stable asthmatics with
mild to moderate to severe expiratory airflow limitation to assess integrity of the lung
parenchyma.
Inclusion Criteria:
- Current non-smoking (<10 pack yr smoking history)
- Stable, treated asthmatics
- Age 10-80 yr
- post 180ug albuterol by MDI: FEV 1/FVC < 70% and FEV 1 <80% predicted
Exclusion Criteria:
- Pregnancy
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