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Printable Handouts
Navigable Slide Index
- Introduction
- Pathophysiology of asthma - common wisdom
- Talk outline
- Airflow limitation/obstruction
- Forced expiratory vital capacity maneuver (1)
- Forced expiratory vital capacity maneuver (2)
- Spirometry (1)
- Spirometry (2)
- FEV1
- Uses of spirometry in asthma
- The flow-volume loop (1)
- The flow-volume loop (2)
- The flow-volume loop (3)
- Cross sectional variance for FEV1 and FVC
- Spirometry is age, race and gender dependent
- Spirometry (3)
- The FEV1/FVC falls with age
- Accelerated decline in lung function in asthma (1)
- Accelerated decline in lung function in asthma (2)
- Asthma severity and initiating treatment in youths
- Levels of asthma control
- The heterogeneous airways
- What is a small airway ?
- Resistance generation
- Narrowing of parallel airways
- Obstruction of parallel airways
- Retrograde catheter
- Retrograde catheter study
- Peripheral airway resistance
- Time of the day influence on peripheral resistance
- Lung volumes
- Hyperinflation defends the FEV1
- Am chest tightness correlates with RV
- Closing volume/capacity
- Imaging modalities to evaluate small airways
- MRI + hyperpolarized 3He (1)
- Enhanced lung deposition with small particle size
- Effect of particle size on FEV1
- Reversibility
- Spirometry (4)
- Significant bronchodilator response
- Bronchodilator responsiveness variability
- Bronchodilator response flow volume loops
- Patterns of responses
- Isovolume shift
- Best index of a bronchodilator effect (1)
- Best index of a bronchodilator effect (2)
- Best index of a bronchodilator effect (3)
- Bronchodilator response is airway opening
- MRI + hyperpolarized 3He (2)
- Assumption: fall in FEV1 is due to "remodeling"
- Mechanisms of airway obstruction
- Airway remodeling: friend or foe?
- Periodicity of airflow limitation
- Asthmatic peak flow diary data
- Airways hyper-responsiveness and PEF variability
- Asthma: temporal periodicity
- Forced oscillations test (FOT) (1)
- Forced oscillations test (FOT) (2)
- Resistance differences
- Airways hyper-responsiveness (1)
- Airways hyper-responsiveness (2)
- Airway hyper-responsiveness correlations
- Why perform an airways challenge test?
- Bronchial provocation tests
- Antigen-induced airway hyper-responsiveness
- Exercise induced bronchospasm
- Bronchoprovocation and severity
- Inhibition of deep inspirations
- Therapy guide through bronchoprovocation
- Time courses of improvement in asthma
- Summary (1)
- Control of airway caliber and patency
- Summary (2)
- Heterogeneity of reversibility
- Summary (3)
- The signal is the noise
- Summary (4)
- Acknowledgements and dedication
Topics Covered
- Physiology of asthma, a syndrome defined by lung dysfunction
- Airflow limitation
- Small airways
- Reversibility of airflow limitation
- Periodicity and variability of airflow limitation
- Airways hyperresponsiveness
Links
Series:
Categories:
Therapeutic Areas:
Talk Citation
Irvin, C.G. (2022, May 16). Physiology of asthma and involvement of small airways [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved October 14, 2024, from https://doi.org/10.69645/NJEY1331.Export Citation (RIS)
Publication History
Financial Disclosures
- Prof. Charles G. Irvin, Grant/Research Support (Principal Investigator): NIH, American Lung Association.
Update Available
The speaker addresses developments since the publication of the original talk. We recommend listening to the associated update as well as the lecture.
- Full lecture Duration: 70:02 min
- Update Interview Duration: 12:47 min
A selection of talks on Clinical Practice
Transcript
Please wait while the transcript is being prepared...
0:00
Hello. My name is Charlie Irvin.
I'm a professor of medicine
and I'm also a professor of physiology and biophysics
here at the University of Vermont,
and I'm the Director of the Vermont Lung Center.
Today's lecture is on the
Physiology of Asthma and the Involvement of the Small Airways.
0:18
This diagram presents the common wisdom of the pathophysiology of asthma.
That is that asthma or the asthmatic has narrowed airways due to
smooth muscle contraction and accumulation of mucus within the airway lumen.
As we'll learn in this lecture,
this is far from the facts and many asthmatics and
the physiological changes that characterize the asthmatic are complex and varied.
0:44
This is the outline for the presentation today.
Asthma is a syndrome.
It's a syndrome that's characterized by airway inflammation and
a particular set of lung function abnormalities that are shown here.
Airflow limitation refers to the ability to bronchodilator,
periodicity of airflow limitation and airways hyper-responsiveness.
And it's these four topics that I'm going to be discussing,
because asthma is, after all,
defined by the physiological dysfunction,
so it's at this point, we do not have a biomarker or some other aspect of
the pathology that absolutely characterizes this particular syndrome and disease.
So let's first turn and discuss airflow limitation.
1:31
Airflow limitation or obstruction can be measured with a variety of techniques.
I will be discussing it at various points within this lecture.
Spirometry with the classic measurement of FEV1 and FVC.
And that's where we'll begin.
Flow volume loops, which are measurements of flow versus volume.
Other measurements of airflow limitation including
sGAW or conductance with the body with plethysmograph,
forced oscillations, peak flow recordings,
and the measurement of lung volume.