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Updated: Aug 11, 2026
06:11
Employing the Forced Oscillation Technique for the Assessment of Respiratory Mechanics in Adults
Published on: February 9, 2022
[CHARACTERISTICS OF ASTHMA PATIENTS WITH A FORCED EXPIRATORY VOLUME IN ONE SECOND/FORCED VITAL CAPACITY OF LESS THAN
Shinobu Osanai1, Yoshinori Minami1, Takaaki Sasaki1
1Division of Respiratory Medicine and Neurology, Department of Internal Medicine, Asahikawa Medical University.
Arerugi = [Allergy]
|August 10, 2026
Summary
Asthma patients with persistent low FEV1/FVC ratios after bronchodilator inhalation (BDI) show preserved responsiveness, particularly in forced vital capacity (FVC). These individuals exhibit more severe airflow obstruction but respond well to bronchodilators.
Area of Science:
- Pulmonology
- Respiratory Medicine
- Clinical Investigation
Background:
- Investigating asthma patients with persistent airflow obstruction post-bronchodilator inhalation (BDI).
- Focusing on the forced expiratory volume in one second to forced vital capacity ratio (FEV1/FVC) below 70% after BDI.
Purpose of the Study:
- To analyze clinical characteristics and BDI responsiveness in asthma patients with a post-BDI FEV1/FVC <70%.
- To compare these patients with those achieving a post-BDI FEV1/FVC ≥70%.
Main Methods:
- Retrospective observational study of 130 asthma patients.
- Analysis of airway reversibility tests and medical records.
- Comparison of two groups based on post-BDI FEV1/FVC ratio (≥70% vs. <70%).
Main Results:
- The group with post-BDI FEV1/FVC <70% (O group) had higher peripheral blood eosinophils and lower baseline %FEV1 and %FVC.
- Despite lower baseline lung function, the O group showed greater absolute and relative increases in FEV1 and FVC after BDI.
- The O group had a higher proportion of patients meeting airway reversibility criteria.
Conclusions:
- Asthma patients with post-BDI FEV1/FVC <70% have more severe obstructive ventilatory impairment.
- Bronchodilator responsiveness is preserved in this group, with notable FVC improvement.
- This suggests a distinct phenotype within asthma management.
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