Thoracic Ultrasound for Acute Dyspnea in Interstitial Lung Disease

Background: Lung ultrasound (LUS) can be used at follow-up for patients with stable interstitial lung disease (ILD). LUS could also help guide the diagnosis of etiology for acute respiratory episodes. Methods: We conducted a prospective, one-center, observational study including patients with ILD hospitalized in the pulmonology unit or in the intensive care unit of the Tours University Hospital for acute dyspnea. LUS was performed at admission and then at a follow-up visit in the six months following discharge. We compared the number of B-lines between the two LUSs. We also compared the features of the first LUS between the different etiologies responsible for increased dyspnea. Results: Of 24 patients, 16 had acute ILD exacerbation (67%), 6 had pulmonary infections (25%) and 2 had acute heart failure (8%). LUS was feasible in all patients and always showed lung sliding, pleural irregularities and B-lines. There were pleural effusions in four cases (17%) and pulmonary consolidations in two cases (8%). Seven patients had A-lines in at least one thoracic space on the initial LUS. We found a significant decrease in the number of B-lines at follow-up (76; IQR, [59-86.75]) compared to admission (86.5; IQR, [71.5-94.5]) (p-value = 0.02). There was a trend of more A-lines in patients with infection (1 [0.25-1.75]) compared to AE-ILD (0 [0-0]). Conclusions: Following an episode of acute dyspnea in patients with ILD, LUS shows a decrease in the number of B-lines. Patients with ILD and concurrent pulmonary infection may have more A-lines than patients with AE-ILD.