Potentiality of impulse oscillometry to evaluate bronchodilator reversibility in untreated adult patients with newly diagnosed asthma

Sep 29, 2026

Identifying positive bronchodilator reversibility (BDR) supports asthma diagnosis, yet forced expiration required for spirometry is not feasible for all patients. Impulse oscillometry (IOS) measures lung mechanics during quiet tidal breathing without patient effort. This retrospective study examined IOS performance for evaluating BDR in untreated adult patients with newly diagnosed asthma (UAPNDS), using pretreatment and post-salbutamol IOS and spirometry data.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages7

Reading Time18 min

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Abstract

Background

Methods

Results

Conclusion

Keywords

1. INTRODUCTION

J Chin MedAssoc Original article Potentiality of impulse oscillometry to evaluate bronchodilator reversibility in untreated adult patients with newly diagnosed asthma Yi-Han Hsiaoa,b,c, Yu-Jung Lind, Tien-Hsin Jengd, Kang-Cheng Sua,b,e, Hsin-Kuo Kob,f, Sheau-Ning Yangg, Diahn-Warng Perngb,c,* , Yu Ru Koua,b,h,* aDepartment and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC; bSchool of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC; cDivision of General Chest Medicine, Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; dDepartment of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; eDivision of Clinical Respiratory Physiology, Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; fDivision of Respiratory Therapy, Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; gDepartment of Pharmacy, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; hCardiovascular and Mitochondria Related Diseases Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan, ROC Abstract Background: Identifying positive bronchodilator reversibility (BDR) helps the diagnosis of asthma. However, not all patients can adequately perform the forced expiration during the spirometry test. An alternative test is required. Impulse oscillometry (IOS) is an effort-independent technique that enables the measurement of lung mechanics during quiet tidal breathing. We investigated the potentiality of IOS to evaluate BDR in untreated adult patients with newly diagnosed asthma (UAPNDS) . Methods: All UAPNDS (aged 20–80 years) who never smoke and underwent IOS and spirometry before and after salbutamol inhalation at their initial visit to the hospital from March 22, 2017, to December 31, 2019, were identified. A total of 323 patients were enrolled. Data from the medical record, including demographic characteristics, laboratory examination, spirometric data, and IOS parameters, were retrospectively reviewed. The associations of parameters with the positive BDR and the performance of parameters in predicting the positive BDR were evaluated by statistical methods. Results: Patients (n = 323) had a median age of 64 years and were mostly female (67 .5%) . Several variables, including serum total immunoglobulin level, blood eosinophil counts, blood eosinophil percentage (%), and two IOS parameters, were found to be different between the positive (n = 93) and negative BDR (n = 230) groups. Multivariate logistic regression analyses after adjustment by cofactors revealed that the percentage change of the area under the reactance curve between 5 Hz and resonant frequency [ΔAx (%)] after salbutamol inhalation was the only independent factor for the positive BDR. The area under the receiver operating characteristic curve of ΔAx (%) in predicting the positive BDR was 0.614 (p = 0.0013), and its optimal cutoff value was −53 .8%(sensitivity, 39.78% and specificity, 80.43%) . Conclusion: In addition to spirometry, ΔAx (%), an IOS parameter, may serve as a novel indicator to evaluate BDR in UAPNDS. Keywords: Asthma; Bronchodilator reversibility; Impulse oscillometry; Spirometry 1. INTRODUCTION Asthma is a chronic inflammatory airway disease characterized by respiratory symptoms due to airway obstruction that is often *Address correspondence. Dr. Diahn-Warng Perng, Department of Chest Medicine, Taipei Veterans General Hospital, 201, Section 2, Shi-Pai Road, Taipei 112, Taiwan, [ROC. E-mail address: dwperng@vghtpe.gov.tw](ROC. E-mail address: dwperng@vghtpe.gov.tw) (D.-W. Perng); Dr. Yu Ru Kou, Department and Institute of Physiology, College of Medicine, National Yang Ming Chiao Tung University, 155, Section 2, Linong Street, Taipei 112, Taiwan, [ROC. E-mail address: yrkou@nycu.edu.tw](ROC. E-mail addres

FAQs

Why is bronchodilator reversibility (BDR) important for asthma diagnosis?

Positive BDR helps support the diagnosis of asthma. It is assessed using bronchodilator testing, which traditionally relies on spirometry-based measures.

What challenge limits the use of spirometry for assessing BDR?

Spirometry requires effort-dependent forced expiration and patient cooperation, which can be inadequate in populations such as children, elderly patients, or those with respiratory muscle weakness.

Which IOS parameter showed independent association with positive BDR after salbutamol?

The percentage change of the area under the reactance curve between 5 Hz and resonant frequency (ΔAx (%)) after salbutamol inhalation was the only independent factor associated with positive BDR.

Sep 29, 2026

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