ABSTRACT
Study Objectives: Subpleural consolidations and B-lines are common lung ultrasound (LUS) patterns seen in patients infected with COVID-19. The aim of this study is to describe how each LUS pattern correlates with patient vital signs and inflammatory biomarkers. Methods: This is a retrospective analysis of adult patients who presented to a large urban tertiary emergency department between May 1, 2020 and June 30, 2020. Patients were included in the study if they 1) presented with a respiratory chief complaint;2) met systemic inflammatory response syndrome (SIRS) criteria;3) were confirmed to have COVID-19 diagnosed by PCR;and 4) had point-of-care LUS performed and recorded in our imaging storage database. All clinical data was reviewed using the hospital's electronic medical records. The study was approved through the Institutional Review Board (IRB). All LUS images were obtained by emergency medicine physicians during the patient's emergency department course and were considered adequate if they included a minimum of 4 lung fields (bilateral anterior and posterior fields). Images were reviewed by ultrasound fellowship trained emergency physicians who were blinded to patient clinical outcome data. Images were assessed for subpleural consolidations, B-lines, and merging B-lines. LUS patterns were measured against patient vital signs (temperature, heart rate, respiratory rate, SpO2) and inflammatory biomarkers (CRP, D-Dimer, Ferritin, LDH, Procalcitonin) that were collected on initial hospital presentation. Linear correlations were performed using Pearson's r coefficient. Statistical analysis was completed with SPSS. Statistical significance was set at p< 0.05. Results: A total of 39 patients were included in the study. There were 33 men and 6 women ranging in age between 23 and 77 years old with a mean age of 49 years. Conclusions: Subpleural consolidations were found to have a positive correlation with increasing respiratory rate (p=0.046) and ferritin levels (p=0.0016). An increasing percentage of intercostal spaces with B-lines and confluent B-lines had a positivenegative correlation with ferritin levels (SpO2 (p=0.0021).016, 0.034). LUS did not correlate with inflammatory biomarkers. Lastly, merging B-lines were found to have a positive correlation with D-Dimer (p= 0.013) and ferritin levels (p=0.0015). Subpleural consolidations, B-lines, and mergingconfluent B-lines appear to correlate with elevated ferritin, a marker that has been associated with severe COVID-19 disease. Additionally, subpleural consolidations were found to correlate with worse clinical and respiratory status. These LUS patterns may be manifestations of more severe lung injury and systemic pathophysiological processes that take place over the course of a COVID-19 infection., specifically SpO2. However, furthersurprisingly these common LUS findings did not correlate with inflammatory lab values, which some studies suggest may have prognostic value for patients with COVID. Our study has limitations. This study specifically was limited to only patient's that had a recorded LUS image in our storage database. Therefore, many patients with covid may have been excluded. Our study highlights that there is a potential role for US in the assessment of disease severity. Further investigation is needed to determine prognostication of these LUS patterns.