A 36-year-old man presented to our fever clinic on 13 February 2020 in Nanchong, Sichuan, China, with a dry cough, headache, asthenia and fever, which had started 10 days previously. He denied any recent travel, but reported a history of contact with a family member from Wuhan, China (who had not been diagnosed with SARS-CoV-2 infection), which was considered a high-risk area for COVID-19 infection by the Chinese health authorities at the time.
The patient did not have any chronic medical problems and was a non-smoker. The physical examination revealed that body temperature of 38.2 C, respiratory rate of 20 breaths per minute, pulse of 105 beats per minute, blood pressure of 109/71 mmHg, and his oxygen saturation was 91% in room air. The thoracic CT image (Figure 1(a) and (b)) showed bilateral lesions, patchy, also confluent and ground glass with the mixed consolidation. Blood tests showed lymphocytopenia, thrombocytopenia and high levels of lactate dehydrogenase (LDH) and other inflammatory markers. A nasopharyngeal swab sample was collected and tested for SARS-CoV-2. The test result was positive. The patient was isolated and was provided with symptomatic support and antiviral treatment (recombinant human interferon, lopinavir/ritonavir oral solution, diammonium glycyrrhizinate injection and methylprednisolone).
The ethics committee of North Sichuan Medical College approved this study. Informed consent was obtained before the LUS procedure. The LUS examinations were performed using a portable device (Mindray/UMT-500, China) with a 5-MHz convex probe. Settings were set to penetration mode with a low center frequency and a single focus zone at the level of pleura, and compound scan technology was used in the diagnosis of consolidation. In order to reduce the exposure risk, only one emergency department (ED) physician (Y.C.) entered the isolation room, observing all the standard preventive measures for respiratory, droplet and contact isolation provided by the National Health Commission of the People's Republic of China for the COVID-19 outbreak. The ultrasound probe was enclosed in a sterile, plastic probe cover. The patient was scanned in the supine position following the LUS examination method described in a previous study. Each hemithorax was divided into six regions using three longitudinal lines (parasternal, anterior and posterior axillary) and two axial lines (one above the diaphragm and the other 1 cm above the nipples). The ultrasound device was sterilized in a dedicated area and put enclosed in a new sterile plastic bag at the end of the procedure.
During the hospitalization, the patient conducted a total of four ultrasound examinations, which were first, fifth, tenth, and fifteenth days of admission, respectively. The LUS was performed by the same ED physician using the same ultrasound device. The specific LUS findings for this patient were the interstitial-alveolar damage showing bilateral, diffuse pleural line abnormalities, subpleural consolidations, white lung areas and thick, irregular vertical artifacts (Figure 1(c)-(h)). When the patient recovered from the SARS-CoV-2 infection, LUS images showed a normal pleural line with A-lines regularly reverberating (Figure 1(i) and (j)). Detailed report of LUS findings at each examination are shown in Table 1.