To estimate the characteristics and value of lung ultrasonography of patients with coronavirus disease 2019 (COVID-19) for clinical practice.

The bedside pulmonary ultrasound and related clinical data of 26 patients with COVID-19 admitted to Public Health Clinical Center of Chengdu from January 23rd to February 25th, 2020 were analyzed, retrospectively. Pathological pulmonary ultrasound features such as "B-line" , consolidation and "white lung" in 10 scan areas of the patients’ double lungs were analyzed. The patients were divided into moderate group (13 cases) and critical group (including 4 severe cases and 9 critical cases) according to diagnosis and treatment protocol of COVID-19 (trial version 6) of National Health Commission of China, and the baseline data, lung CT and pulmonary ultrasound characteristics between the two groups were compared. The consistency of lung CT and lung ultrasound in diagnosing lung consolidation and pleural effusion were analyzed by Kappa test, and the consistency ratio was also calculated. The pulmonary ultrasound and CT scores of each patient’s pulmonary lesion severity were performed, and Pearson correlation analysis between the pulmonary ultrasound and CT scores was performed.

Among the 26 patients with COVID-19, 14 males and 12 females, with an average age of (48.25 ± 16.43) years old. The incidences of pulmonary ultrasound showing "B-line" , consolidation and "white lung" were 92.3% (24/26), 69.2% (18/26) and 46.2% (12/26), respectively. The numbers of patients with lung consolidation and multiple lung consolidation in critical group were significantly higher than those of moderate group [12 (92.3%) vs. 4 (30.8%): P = 0.004; 9 (69.2%) vs. 2 (15.4%): P = 0.015]. "White lung" was only found in critical group (12/13, 92.3%). The pulmonary ultrasound score in critical group was also significantly higher than that in moderate group (18.62 ± 5.35) vs. (4.46 ± 1.71): t =-9.089, P < 0.001). Pulmonary ultrasound and lung CT showed good consistency between lung consolidation and pleural effusion (progressive P < 0.001, consistency ratio > 0.8). There was a good correlation between lung ultrasound score and CT score in evaluating the severity of lung injury (r = 0.985, P < 0.001).

Lung consolidation and "white lung" were typical pulmonary sonographic features in patients with severe and critical COVID-19 in lung ultrasonography. This study confirmed that pulmonary ultrasound was a reliable technique to reflect the severity of lung injury of patients with COVID-19.