Diaphragm Ultrasound is an Imaging Biomarker that Distinguishes Exacerbation Status from Stable Chronic Obstructive Pulmonary Disease

Abstract

Background: Evaluating the diaphragm muscle in chronic obstructive pulmonary disease (COPD) is important. However, the role of diaphragm ultrasound (DUS) in distinguishing the exacerbation status of COPD (AECOPD) is not fully understood. We set this study to evaluate the role of DUS as a biomarker for distinguishing the AECOPD. Methods: COPD patients who underwent DUS were enrolled between March 2020 and November 2020. The diaphragm thickening fraction (TF max ) and diaphragm excursion (DE max ) during maximal deep breathing were measured. Patients were divided into exacerbation and stable groups. Demographics, lung function, and DUS findings were compared between the two groups. Receiver operating characteristic curve and univariate/multivariate logistic regression analyses were performed. Results: Fifty-five patients were enrolled. The exacerbation group had a lower body mass index (BMI) (20.9 vs 24.2, p = 0.003), lower TF max (94.8 ± 8.2% vs 158.4 ± 83.5%, p = 0.010), and lower DE max (30.8 ± 11.1 mm vs 40.5 ± 12.5 mm, p = 0.007) compared to stable group. The areas under the TF max (0.745) and DE max (0.721) curves indicated fair results for distinguishing AECOPD. The patients were divided into low and high TF max and DE max groups based on calculated cut-off values. Low TF max (odds ratio [OR] 8.40; 95% confidence interval [CI] 1.55-45.56) and low DE max (OR 11.51; were associated with AECOPD after adjusting for age, sex, BMI, and lung functions. Conclusion: DUS showed the possibility of an imaging biomarker distinguishing AECOPD from stable status.

The 2023 Core Content of advanced emergency medicine ultrasonography

“…In COPD assessment, thoracic ultrasound offers valuable information on lung hyperinflation, diaphragmatic excursion, and disease severity, assisting in treatment decisions, and therapy monitoring. [85][86][87] POCUS is strongly supported by evidence for assessing hernia, cholecystitis, and diverticulitis. Its integration into clinical practice improves patient care through timely and accurate diagnoses, leading to better outcomes.…”

MRI-assessed diaphragmatic function can predict frequent acute exacerbation of COPD: a prospective observational study based on telehealth-based monitoring system

“…A further study showed that DD has high specificity and sensitivity in predicting NIV failure in AECOPD patients and may help identify patients who need NIV therapy and be helpful in predicting the duration of hospitalization [ 58 ]. A recent study explored the value of diaphragm markers for distinguishing AECOPD from stable COPD [ 18 ], which is a step forward in the role of the diaphragm between AECOPD.…”

“…During severe AECOPD, progressive development of dynamic hyperinflation causes a change in the geometry of the chest wall and diaphragm, with impaired lung function [ 16 , 17 ]. Another study confirmed that lower diaphragm thickening fraction (DTF max ) and diaphragm excursion (DE max ) during maximal deep breathing were associated with AECOPD, which leads to the possibility of an imaging biomarker distinguishing AECOPD from stable status [ 18 ]. The impairment of diaphragmatic function may be one of the main pathophysiological mechanisms in COPD that seems related to acute exacerbation [ 19 ] .…”

Two-dimensional shear wave elastography: a new tool for evaluating respiratory muscle stiffness in chronic obstructive pulmonary disease patients

“…3 ). Similar to the measurement method of An [ 22 ], the diaphragm excursion (DE) and diaphragm thickening fraction (TF) were measured at tidal inspiration and at maximal deep inspiration. Pulmonary function tests were performed in accordance with the standards of the European Respiratory Society [ 23 ], and the FEV 1 , forced vital capacity (FVC), FEV 1 /FVC, inspiratory capacity (IC), functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC) and RV/TLC were recorded.…”