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Updated: Jul 13, 2026
13:28
Methodology for Sputum Induction and Laboratory Processing
Published on: December 17, 2017
Maximum expiratory flow rates in induced bronchoconstriction in man.
The Journal of Clinical Investigation
|June 1, 1969
Summary
Maximum expiratory flow-volume (MEFV) and partial expiratory flow-volume (PEFV) curves detect airway changes. Measurements at constant lung inflation are sensitive indicators of airway caliber changes, crucial for assessing bronchodilator effectiveness.
Area of Science:
- Pulmonary Physiology
- Respiratory Medicine
Background:
- Bronchoconstriction and bronchodilation significantly impact airflow dynamics.
- Standard pulmonary function tests may not fully capture subtle airway caliber changes.
Purpose of the Study:
- To compare the sensitivity of different expiratory flow-volume curve measurements in detecting airway caliber changes.
- To evaluate the utility of measurements at constant lung inflation for assessing airway responses to constrictor and dilator drugs.
Main Methods:
- Evaluation of maximum expiratory flow-volume (MEFV) and partial expiratory flow-volume (PEFV) curves.
- Administration of bronchoconstrictor and bronchodilator drugs.
- Measurement of maximum flow at constant lung inflation, peak expiratory flow rate, 1-second forced expiratory volume, and slope of the effort-independent portion of MEFV curves.
Main Results:
- Maximum flow measurements at constant lung inflation demonstrated larger changes than peak expiratory flow rate or 1-second forced expiratory volume following constriction and dilation.
- Flow rate changes on PEFV curves were generally greater than on MEFV curves.
- Decreased maximum flow rates were attributed to small airway narrowing, not altered lung static recoil force.
Conclusions:
- Measurements of maximum expiratory flow rates at constant lung inflation offer a sensitive and objective method for assessing airway caliber changes.
- This method remains valid even when total lung capacity is altered during treatment, providing a reliable tool for evaluating airway responses.
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