Lung Ultrasound in the Emergency Department for Early Identification of COVID-19 Pneumonia.

Background Coronavirus disease 2019 (COVID-19) is a pandemic overwhelming the health care systems worldwide. Lung ultrasound (LUS) use has been proposed to identify suspected COVID-19 patients and direct them to the isolation area in the emergency department (ED) or to discharge them for outpatient treatment. Objective Our aim was to retrospectively investigate the use of LUS in the ED to identify COVID-19 pneumonia (CP). Methods We performed a retrospective single-center study including all patients accessing the ED who underwent LUS examination for suspicion of COVID-19 during the initial outbreak. Demographics, clinical parameters, laboratory values, imaging features, and outcome variables were collected. The receiver operating characteristic (ROC) curve was used to evaluate diagnostic accuracy. Results A total of 41% patients were COVID-19-positive; 67% of them were diagnosed with CP. The ROC curve of the LUS score showed an area under the curve of 0.837 (95% CI 0.75-0.92) and with a cutoff value ≥3 identified 28 of 31 patients with CP and 11 of 15 without (sensitivity 90%, 95% CI 74-97%; specificity 75%, 95% CI 56-76%). LUS in combination with nasopharyngeal swab has a sensitivity of 100% (95% CI 74-97%) and a specificity of 61% (95% CI 44-67%). Conclusions LUS is a promising technique for early identification of CP in patients who accessed the ED in an active epidemic time. The LUS score shows a sensitivity of 90% for CP, allowing to quickly direct patients with COVID-19 to the ED isolation area or to discharge them for outpatient treatment.