Impulse Oscillometry in COPD Exacerbation

Deniz Bilici41 enrolled

Overview

This study aimed to evaluate small airway function during ECOPD and recovery periods using IOS. In this prospective single-center study, patients with ECOPD underwent evaluation of their pulmonary functions using IOS and spirometry during exacerbation and recovery (6-12 weeks after exacerbation). The patients were divided into two groups: mild exacerbations and (moderate and severe) exacerbations based on ROME criteria.A total of 41 patients were initially enrolled, with 38 completing the study. This study reveals that IOS can be easily used in ECOPD, and IOS parameters that reflect small airways (R5-R20, AX, and Fres) are correlated with FEV1% and the severity of dyspnea. Additionally, IOS parameters significantly improve during recovery, except for R20. Further research is necessary on its application in the functional assessment of patients with COPD exacerbations.

Study Type

OBSERVATIONAL

Enrollment

Conditions

COPD Exacerbation COPD

Interventions

Impulse OscillometryDIAGNOSTIC_TEST

Impulse Oscillometry (IOS) is a simple, non-invasive, effort-independent method that uses sound waves to detect airway changes quickly. It only requires the patient to breathe normally to assess lung function by measuring both resistance and reactance of the airways. 6,7 These features of IOS suggest it may be a useful test for assessing patient respiratory function during exacerbation periods when airway resistance, airflow limitation, and respiratory muscle weakness further impair breathing.

Eligibility

Sex: ALL

Medical Language ↔ Plain English

Inclusion Criteria: * patients who were consecutively admitted to the emergency department or pulmonology outpatient clinic of our hospital with a diagnosis of ECOPD, as defined by the GOLD 2023 Report Exclusion Criteria: * Patients diagnosed with pneumonia, pulmonary embolism, heart failure, pleural effusion, or pneumothorax were excluded. * Patients who were unable to perform spirometry during exacerbation or had a forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ratio of ≥ 0.70 were also excluded.

Outcomes

Primary Outcomes

Physiological parameter of IOS in COPD exacerbation period

We investigated descriptive parameters of impulse oscillometry during copd exacerbation period to use in clinical setting in the future. The parameters for assessing airway resistance, including resistance at 5 Hz (R5), which indicates total airway resistance; resistance at 20 Hz (R20), representing the resistance of large airways; and the difference between resistance at 5 Hz and 20 Hz ( R5-R20 ). The parameters that assess reactance are X5, which measures peripheral elastic resistance at 5 Hz; AX, the area under the reactance curve between 5 Hz and the resonant frequency, reflecting the elastic properties of the lung; and Fres, the oscillation frequency at which reactance is zero. In the exacerbation of copd period FEV1% was correlated with all IOS parameters except R20, and BORG was correlated with IOS parameters except R20 and X5. Furthermore, IOS parameters reflecting the small airways (R5-R20, X5, AX, Fres) also showed strong intercorrelations.

Time frame: from baseline

Secondary Outcomes

Comparison of parameter of IOS in COPD exacerbation period to stable period (approximately 6 weeks later)

Thirty-eight patients were re-evaluated during the recovery period. Significant improvements were observed in R5, R5-R20, AX, and Fres during recovery. No differences were observed in IOS parameters based on the severity of exacerbation.

Time frame: 6 weeks later from the baseline

Comparison and correlations of IOS and pulmonary function test parameters in recovery period of COPD patient

We investigated correlation of IOS parameters such as R5, R5-R20, X5, AX, and Fres with pulmonary function test paramteres such as FEV1%, FVC%, FEV1/FVC We measured these parameters both in exacerbation and recovery periods of same patients and compared the results of two tests measurements