The Role of Impulse Oscillometry in Evaluating Disease Severity and Predicting the Airway Reversibility in Patients With Bronchiectasis

Abstract

BackgroundImpulse oscillometry (IOS) can be used to evaluate airway impedance in patients with obstructive airway diseases. Previous studies have demonstrated that IOS parameters differ between patients with bronchiectasis and healthy controls. This study aims to explore the usefulness of IOS in assessing disease severity and airway reversibility in patients with bronchiectasis.MethodSeventy-four patients with non-cystic fibrosis bronchiectasis who visited our Respiratory Medicine outpatient clinic were consecutively recruited. Spirometry, plethysmography and IOS tests were performed. Patients were stratified into mild, moderate and severe disease according to Reiff, Bhalla, BSI, FACED, and BRICS scores. Airway reversibility was measured by bronchodilation test (BDT) and the result was classified as positive or negative. ROC curves of IOS parameters were used to assess the usefulness of IOS parameters in predicting airway reversibility. Correlations between the IOS, spirometric lung function and bronchiectasis severity parameters were analyzed.ResultsMany IOS parameters, such as airway resistance at 5 Hz (R5), small airways resistance (R5–R20), total airway reactance (X5), resonance frequency (Fres), total airway impedance at 5 Hz (Z5), and peripheral resistance (Rp) increased in patients with bronchiectasis who presented a moderate to severe severity as categorized by the FACED, BSI and Reiff scores. Large airway resistance (R20) and central resistance (Rc) were not significantly different among groups with different bronchiectasis severity. The difference between R5 and R20 (R5-R20) showed 81.0% sensitivity, and 69.8%specificity in predicting the airway reversibility in bronchiectasis with AUC of 0.794 (95%CI, 0.672–0.915).ConclusionIOS measurements are useful indicators of bronchiectasis severity and may be useful for predicting the airway reversibility.

Quantitative CT Metrics for the Prediction of Therapeutic Effect in Asthma

“…In addition, the reactance indices X5 and Fres significantly increase in moderate to severe asthma patients compared to those with mild disease. It is because the Fres is a sensitive indicator to airway obstruction, at which point the forces of inertia and capacitance are equal [ 10 , 33 ]. Likewise, the reactance indices X5 reflect the physical properties of the lung parenchyma and its ability to expand and facilitate alveolar filling in peripheral airways [ 34 ].…”

“…Combined with traditional spirometry, IOS may increase the clinical recognition of some airway diseases in the early stage. In fact, we have proved the usefulness of IOS in evaluating and predicting disease severity in bronchiectasis [ 10 ].…”

Usefulness of impulse oscillometry in predicting the severity of bronchiectasis

“…The detection of changes in the bronchi and reduced lung elasticity observed in bronchiectasis renders IOS a suitable tool for assessing its severity. Several previous studies have explored IOS parameters in assessing bronchiectasis severity, with some highlighting correlations between resonance frequency (Fres) and FACED scores [24], whereas others noted associations between FACED scores and peripheral resistance than X5 or Fres [25]. Despite these promising ndings, uncertainties remain, warranting further investigation.…”

Bronchiectasis Assessment in Primary Ciliary Dyskinesia: A Non-Invasive Approach Using Forced Oscillation Technique

“…Previous studies on patients with non-PCD bronchiectasis have reported a strong correlation between FOT parameters and the severity of bronchiectasis disease [ 25 ]. Another study highlighted that total breath reactance at 5 Hz (X 5 ) could effectively differentiate between healthy subjects and patients with obstructive pulmonary diseases [ 21 ].…”

“…According to the findings of Tan C. et al, bronchiectasis severity scores exhibited positive correlations with various FOT parameters, including R 5 , R 5 -R 20 , resonance frequency, airway impedance at 5 Hz, peripheral resistance, and negative correlation with X 5 [ 25 ]. In our study, we utilized the multi-frequency mode of FOT to measure pulmonary resistance and reactance at frequencies 5-11-19 Hz.…”