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Phase-Resolved Functional Lung MRI for Pulmonary Ventilation and Perfusion (V/Q) Assessment
Published on: August 9, 2024
Bronchodilatation and the inspiratory flow volume curve
R Reddy1, T Cook, M F Tenholder
1Department of Medicine, University of Tennessee, Memphis, USA.
Chest
|November 1, 1996
Summary
Forced inspiratory vital capacity (FIVC) can confirm bronchodilator responsiveness in spirometry. A change in FIVC, alongside FEV1 and FVC, indicates improved lung function after medication.
Area of Science:
- Pulmonary Medicine
- Respiratory Physiology
Background:
- Spirometry, a standard pulmonary function test, includes inspiratory flow-volume curves.
- These curves can help identify upper airway obstructions.
Purpose of the Study:
- To evaluate changes in inspiratory parameters during bronchodilator challenge testing.
- To determine if inspiratory parameters correlate with bronchodilator responsiveness.
Main Methods:
- Analyzed peak inspiratory flow (PIF), forced inspiratory flow at 50% (FIF50), and forced inspiratory vital capacity (FIVC).
- Assessed 145 patients undergoing bronchodilator challenge testing (beta-agonist inhaler).
- Used American Thoracic Society criteria for spirometry acceptability.
Main Results:
- Fifty-five patients showed bronchodilator responsiveness (≥12% or 200-mL change in FEV1/FVC).
- Forced inspiratory vital capacity (FIVC) was the only inspiratory parameter consistently correlating with bronchodilator responsiveness.
- Reduced air trapping correlated with FIVC changes.
Conclusions:
- Forced inspiratory vital capacity (FIVC) serves as a reliable indicator of bronchodilator responsiveness.
- FIVC changes provide additional confirmation of improved lung function post-bronchodilator.
- Inspiratory flow-volume curves offer valuable insights beyond standard expiratory spirometry.
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