Lung Ultrasound in COVID-19 era
April 14, 2020Co-opted Member – Tania Elger
May 5, 2020
Ultrasound findings in COVID-19 pneumonia
AUTHORS:
Dr. Soccorsa Sofia, Dr. Michele Spampinato
Emergency Department, Local Health Unit, Bologna, Italy
Image.1: Region R1, day 1, normal A-lines corresponding to normal chest CT findings (see Image 2).
Image.2: Normal chest CT findings in region R1
Image.3: Region R2, day 1, coalescent vertical artifacts erasing the A-lines. The vertical artifacts indicate a non-ventilated area of subpleural pulmonary parenchyma. Please note the sharp demarcation.
Image.4: Region R3, day 1, ring down artifact (thin arrow) appearing from a small subpleural consolidation (thick arrow).
Image.5: Region R3, day 1, non-confluent vertical artifacts indicating non-ventilated lung (arrows).
Image.6: Region L3, day 1, broad vertical artifacts below pleural thickening sharply demarcated from the normally ventilated lung parenchyma.
Image.7: CT image, day 1, corresponding to the previous ultrasound images. The small ground glass areas in L3 corresponds to the subpleural artifacts on LUS.
Image.8: Chest CT (day 2) confirming the lung consolidation. There is also “crazy paving” sign and ground glass opacities.
Video 1: Lung consolidation in the basal segment of the lower right lobe after patient deterioration (day 2).
1Clinical history
A 30-year-old man presents to the emergency department (ED) due to syncope. For the last 10 days he had had fever, cough and dyspnea. At the ED his peripheral oxygen saturation was 86%, BP 130/80, HR 88bpm, RR 20 /min and his temperature 37.4°C. He was given oxygen via a mask. Chest CT was performed and later lung ultrasound (LUS) was performed in 12 areas longitudinal/oblique views using a convex array probe followed by a linear array probe for details (figure 1).
The patient tested positive for SARS-COV-2. On day 2 after admission the patient’s condition deteriorated, and he was transferred to the ICU. Another chest CT was performed. We show the ultrasound and CT images with corresponding legends (image 1-7 + video 1) and discuss the findings in relation to the diagnostic work-up of COVID-19 pneumonia.
2Discussion
Most patients with COV-2 related disease present with fever, cough, muscle pain, chest discomfort and later dyspnea. More rarely sore throat and intestinal symptoms may be present. 81% of infections are mild (flu-like symptoms); 13.8% of patients develop severe disease including pneumonia and shortness of breath, usually about one week after symptom onset; 4.7% are critical and suffer from respiratory failure, septic shock and multiorgan failure; and in 2.5-7.8% of cases (depending on country and available data) the infection is fatal. The risk of death increases in older patients.
On imaging, initial lesions are usually peripheral because SARS-COV-2 attacks the small distal airways. Several reports have described the findings in chest CT. Most commonly few, small, segmental ground glass opacities are seen peripherally and basal. These may deteriorate to become bilateral and multisegmental and finally consolidation and/or ARDS.
Most common LUS signs are: vertical pleurogenic artifacts with varying degree of intensity (from few to confluent). These alternate with clear demarcation to A-lines in the same area, especially in the mid- and upper lung. Pleural thickening, sometimes marked, due to the presence of numerous, small subpleural consolidations. Lobar or translobar consolidations of large size and minimal pleural effusions. The LUS features match with the site and kind on CT.
LUS is an examination, which can be carried out bedside. It may provide early information of presence of diffuse multifocal pneumonia (as in COVID-19) and its deterioration (enlarging consolidations). By doing LUS in cases with COVID-19 pneumonia, transport of patients through the hospital and unnecessary exposure of staff and other patients is avoided.
Similar LUS signs as the ones described have been observed in other kinds of viral epidemic pneumonia. If they, individually or in combination, have some specificity for COVID-19 pneumonia it should be established with further appropriate studies.
3References
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