Sonographic examination of respiratory muscles at chronic obstructive lung disease exacerbation and evaluation of the relationship wi̇th the clinical severi̇ty of exacerbati̇on

In this study, our aim is to examine the thickening fraction of the parasternal intercostal and diaphragm respiratory muscles as an indirect indicator of the increased load of respiratory muscles in patients with COPD exacerbation and to determine the its relationship between clinical severity of exacerbation. Our study was conducted prospectively between 01.09.2019-24.03.2020 in Abant Izzet Baysal University Chest Diseases and Radiology Departments. A total of 159 patients who were over 50 years of age, with a diagnosis of COPD known according to GOLD criteria, and with a complaint of COPD exacerbation to the hospital, were evaluated sonographically. Of the patients, 63 had mild, 63 had moderate and 33 had severe exacerbation. Parasternal intercostal and pectoralis majör muscle thickening fractions were found to be significantly higher in moderate and severe exacerbations compared to mild exacerbations, while the diaphragm muscle thickening fraction was significantly lower (p<0.001). In the severe and moderate exacerbation groups, the parasternal intercostal and pectoralis majör muscle thickening fractions were found to be significantly higher in severe exacerbations than in the moderate exacerbations (p <0.001), but however, there was no significant difference in diaphragm muscle thickening fraction between these two groups. In addition, there was a significant negative correlation between the clinical severity of COPD exacerbation and respiratory muscle thickness and FEV1 (%expected) (p <0.001). A significant negative correlation was found between the number of exacerbations in the last 1 year and FEV1 (% expected) and muscle thickness (p <0.001). As a result, as the clinical severity of exacerbation increases, the thickening fractions in the parasternal intercostal and pectoralis majör muscles increase, but in the diaphragm, on the contrary, it decreases. Assessment of respiratory muscles by ultrasonography, without the risk of ionizing radiation, can provide useful information in the assessment of COPD exacerbation, characterizing the group of COPD patients at risk of experiencing severe exacerbation, and it can be a reliable and reproducible biomarker in patient follow-up. It can also create new opportunities to evaluate the function of respiratory muscles and response to treatments in COPD patients. Keywords: Respiratory muscle ultrasonography, COPD exacerbation, thickening fraction in parasternal intercostal and diaphragm muscles