Feasibility of using point-of-care lung ultrasound for early triage of COVID-19 patients in the emergency room

Abstract

Purpose Diagnostic value of point-of-care lung ultrasound (POCUS) in detection of coronavirus disease (COVID-19) in an emergency setting is currently unclear. In this study, we aimed to compare diagnostic performance, in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, of POCUS lung, chest CT, and RT-PCR for clinically suspected COVID-19 infections in patients submitting to the emergency room (ER). Material and methods This retrospective study enrolled 93 patients with a suspected COVID-19 infection, admitted to the ER between March 28th and April 20th, 2020. Test subjects showed one or more symptoms of an acute respiratory infection, for which consequent COVID-19 testing was achieved using POCUS lung, chest CT, and RT-PCR. CT images were analyzed by 2 radiologists blinded to RT-PCR results. POCUS lung was performed by three emergency medical doctors, and reports were analyzed by the researcher, blinded to clinical information, US imaging, CT, and RT-PCR test results. Results Compared with RT-PCR, POCUS lung demonstrated outstanding sensitivity and NPV (93.3% and 94.1% respectively) while showing poor values for specificity, PPV, and accuracy (21.3%, 19.2%, and 33.3% respectively). In contrast, similar inquiries using chest CT as index test, excellent sensitivity, specificity, NPV, and accuracy (80.0%, 86.7%, 95.6%, and 85.6%, respectively) were reported, beside a moderate value for PPV (54.5%). Conclusion POCUS may provide early ER triage with a useful, rapid, low-threshold, and safe screening tool in evaluating possible COVID-19 infections. Due to limited specificity, suggestive POCUS lung findings should be confirmed with RT-PCR or chest CT.

Point-of-care lung ultrasound assessment for risk stratification and therapy guiding in COVID-19 patients: a prospective noninterventional study

“…Given the extensive lung involvement in COVID-19 patients, LUS may have some potential utility in the management of acutely ill patients [15,16]. Some studies have reported an improvement in lung involvement assessment in COVID-19 by using LUS in the context of ED and ICU [17,18], but we only have found two prospective studies analyzing the prognostic value of LUS during the first pandemic wave of COVID-19 (March & April 2020) [19]. The first included 80 patients (17 outpatients, 42 hospitalized and 21 with orotracheal intubation or death), initially admitted to ED.…”

Echocardiography, Lung Ultrasound and Cardiac Magnetic Resonance Findings in COVID-19: A Systematic Review

“…LUS demonstrated remarkable sensitivity and negative predictive value (NPV) among reviewed studies, with sensitivity ranging from 68% to 93.3% and a NPV ranging from 52%to 94.1% [78,80,82,87], suggesting the utility of LUS as a screening test to rule out COVID-19 lung infection. Data regarding specificity, positive predictive value (PPV) and diagnostic accuracy has been conflicting, with some studies demonstrating values as low as 21.3%, 19.2% and 33.3% for specificity, PPV and diagnostic accuracy, respectively [87], while others demonstrating higher values up to 92.9%, 84.6% and 93.3% for specificity, PPV and diagnostic accuracy, respectively [78]. Lu W et al demonstrated higher sensitivity and NPV of LUS in patients with moderate disease (77.8% and 88.9%, respectively) with both values reaching 100% in patients with severe disease.…”

Low Dose Chest CT and Lung Ultrasound for the Diagnosis and Management of COVID-19

“…Asymptomatic patients with positive COVID-19 RT-PCR showed pathological LUS findings in 22% of cases, including numerous B lines and pulmonary consolidation in a LUS allows a rapid diagnosis of COVID-19 pneumonia and a triage of patients within only 2-3 min in the ED with excellent sensitivity and negative predictive value in comparison to chest CT (93.3% and 94.1%, respectively) [47]. Furthermore, it is a radiation-free technique that may be a valuable alternative to CT scan for the diagnosis of pneumonia in pregnant women and paediatric settings [40].…”