Lung Ultrasound Score in Evaluating the Severity of Coronavirus Disease 2019 (COVID-19) Pneumonia

The purpose of this study is to observe the potential of lung ultrasound in evaluating the severity of coronavirus disease 2019 (COVID-19) pneumonia. Lung ultrasound was performed in ten zones of the patients' chest walls. The features of the ultrasound images were observed, and a lung ultrasound score (LUS) was recorded. The ultrasound features and scores were compared between the refractory group (PaO(2)/FiO(2) ≤ 100 mm Hg or on extracorporeal membrane oxygenation) and the non-refractory group. The prediction value of the LUS was studied by receiver operating characteristic (ROC) curve analysis. In total, 7 patients were enrolled in the refractory group and 28 in the non-refractory group. B-line patterns and shred signs were the most common signs in all patients. Patients in the refractory group had significantly more ground-glass signs (median 6 [interquartile range {IQR}, 2.5–6.5] vs. median 0 [IQR, 0–3]), consolidation signs (median 1 [IQR, 1–1.5] vs. median 0 [IQR, 0–3]) and pleural effusions (median 5 [IQR, 1.5–6] vs. median 0 [IQR, 0–0.25]). The LUS was significantly higher in the refractory group (33.00 [IQR 27.50–34.00] vs. 25.50 [IQR 22.75–30.00]). The ROC of the LUS showed a cutoff score of 32 with a specificity of 0.893 and a sensitivity of 0.571 in diagnosing refractory respiratory failure among patients. In COVID-19 patients, lung ultrasound is a promising diagnostic tool in diagnosing patients with refractory pneumonia.