Diagnostic yield of point-of-care ultrasound imaging of the lung in patients with COVID-19.

Gil-Rodrigo, Adriana; Llorens, Pere; Martínez-Buendía, Carmen; Luque-Hernández, María-José; Espinosa, Begoña; Ramos-Rincón, José Manuel

OBJECTIVES To assess the diagnostic yield of point-of-care ultrasound imaging in patients suspected of having noncritical severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection but no apparent changes on a chest radiograph. MATERIAL AND METHODS Cross-sectional analysis of a case series including patients coming to an emergency department in March and April 2020 with mild-moderate respiratory symptoms suspected to be caused by SARS-CoV-2. A point-of-care ultrasound examination of the lungs was performed on all participants as part of routine clinical care. Ultrasound findings were compared according to the results of SARS-CoV-2 test results. RESULTS Fifty-eight patients with a median (interquartile range) age of 44.5 (34-67) years were enrolled; 42 (72.4%) were women. Twenty-seven (46.5%) had confirmed SARS-CoV-2 infection. Ultrasound findings were consistent with interstitial pneumonia due to coronavirus disease 2019 (COVID-19) in 33 (56.9%). Most were in cases with testconfirmed COVID-19 (100% vs 22.2% of cases with no confirmation; P < .001). The most common ultrasound findings in confirmed COVID-19 cases were focal and confluent B-lines in the basal and posterior regions of the lung (R1, 85.2%; R2, 77.8%; L1, 88.9%; and L2, 88.9%) and associated pleural involvement (70.4%, 70.4%, 81.5%, and 85.2%, respectively). The sensitivity of point-of-care ultrasound in the diagnosis of COVID-19 was 92.6% (95% CI, 75.7%-99.1%). Specificity was 85.2% (95% CI, 66.3%-95.8%); positive predictive value, 75.8% (95% CI, 59.6%- 91.9%); negative predictive value, 92% (95% CI, 74.0%-99.0%); and positive and negative likelihood ratios, 6.2 (95% CI, 6.0-6.5) and 0.1 (95% CI, 0.1-0.1), respectively. CONCLUSION Point-of-care lung ultrasound could be useful for the diagnosis of noncritical SARS-CoV-2 infection when chest radiographs are inconclusive.