Comparative Study Of Impulse Oscillometry And Spirometry In Patients With Asthma Visiting A Tertiary Health Care Hospital

Abstract

Introduction

The mechanical properties of lungs play a crucial role in respiratory health. However, these properties are disrupted in diseased states, such as asthma, which influence airflow regulation. Techniques such as spirometry are commonly used to assess the mechanical properties of the airways. In this regard, impulse oscillometry (IOS) is increasingly being recognized as a non-invasive technique. This study aimed to evaluate the diagnostic and prognostic utility of IOS in patients with asthma, as well as to explore the correlation between IOS and spirometry variables.

Material and methods This cross-sectional study included 50 patients with asthma, who were recruited from the Department of Respiratory Medicine at Sri Lalithambigai Medical College and Hospital from February to March 2023. The patients met the criteria of the ethical committee. Patients with physician-diagnosed asthma and those who discontinued the use of short-acting and long-acting bronchodilators and sustained-release theophylline 6 h, 12 h, and 24 h before the test, respectively, were included in the study. Patients with exacerbated asthma in the 3 months preceding the study and those with other apparent respiratory illnesses were excluded. All the patients had their spirometry (FVC, FEV1, and FEV1/FVC) and IOS (R5, R20, and X5) measures recorded. The IOS results were compared to those obtained by spirometry.

Results The average age of the participants in our study was 46 years, with a standard deviation of 15 years. Male patients comprised 67% of the participants. Among patients with asthma, the sensitivity for R20 (the most indicative value of IOS measurements in the asthma group) was 82%. We observed a correlation between the IOS measures R5, R20, and X5 with the spirometry measure FEV1 among patients with asthma. Additionally, R5 and R20 demonstrated a significant correlation with FVC in patients with asthma.

Conclusion As significant correlations were observed between the IOS and spirometry measures, we infer that IOS can be used as a complementary test to spirometry for long-term follow-up and could be clinically beneficial.

Categories Respiratory medicine, diagnosis and testing