Abstract
Introduction: Asthma is a common, heterogeneous disease that is characterized by chronic airway inflammation and variable expiratory airflow limitation. Current guidelines use spirometric measures for asthma assessment. This systematic review aimed to assess the use of tests of small airways function to diagnose asthma.
Methods: Standard systematic review methodology was used and a range of electronic databases was searched (Embase, MEDLINE, CINAHL, CENTRAL, Web of Science, DARE). Studies that used physiological small airways function tests to diagnose asthma in adults with no restrictions on language or date were included. The risk of bias and quality assessment tools used were AHRQ tool for cross-sectional studies and QUADAS-2 for diagnostic test accuracy (DTA) studies.
Results: 7072 studies were identified and 10 studies met the review criteria. 7 included oscillation techniques and 5 included maximal mid-expiratory flow (MMEF). Studies were small and of variable quality. In oscillation, total resistance (R5) was higher in asthmatic compared to control and reactance was lower. Predicted percentage of MMEF in asthmatic was lower than controls in all studies and lower than predicted FEV1. R5 showed 69-72% sensitivity and 61-86% specificity.
Conclusion: Small airways tests were found to be different in patients with asthma, showing more limitation in resistance, reactance and lower predicted values in MMEF. Further studies are needed to assess the effectiveness of these tests on a larger scale using different indices reported from the tests such as the difference between inhalation and exhalation in oscillation techniques and how demographics and comorbidities alter results.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 3205.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020