Lung Ultrasound Findings In Covid-19 Respiratory Disease And Correlation To Disease Severity

Lung ultrasonography has emerged as a promising imaging modality during the COVID-19 pandemic with potential use in triage, diagnosis, prognosis and disease progression.

This retrospective observational cohort study carried out in a busy urban Emergency Department in the United Kingdom provides a systematic analysis of lung ultrasound findings (pleural irregularities, B-lines, consolidations, pleural effusions) in SARS-CoV-2 positive patients and correlates these findings to disease severity as defined by oxygen-deficiency based on the Berlin Criteria for ARDS.

Our results show that wide B-lines, as well pleural irregularities and subpleural consolidations are frequent findings in COVID-19 disease. Lung abnormalities occur bilaterally, interspersed with normal lung, and without significant predilection for specific lung areas. Wide B-lines are a strong feature in COVID-19 infection. We also describe a finding of small localised peri-pleural effusions in 8.3% (95% C.I. 5.9-10.8%) of lung zones.

Disease severity correlates strongly to the frequency of abnormal ultrasound findings. Irregular pleura and subpleural consolidations increase from 40% (95% C.I. 33.3-46.1%) and 27.7% (C.I.95% 21.8-33.5%) of zones affected in mild disease to 85.7% (C.I.95% 79.8-91.7%) and 66.2% (C.I.95% 58.1-74.2%) in severe disease. Wide B-lines increase from 15.6% (C.I.95% 10.9-20.4%) to 45.1% (C.I.95% 36.7-53.6%). There is an inverse correlation to the amount of normal lung seen, decreasing from 57.1% (C.I.95% 50.6-63.6%) to 6% (C.I.95% 2.0-10.1%) of lung zones.

These results contribute to a more thorough understanding of the lung changes in COVID-19 pneumonia and enhance the evidence base for the application of ultrasound in triage, diagnosis, treatment, and prognosis in SARS-CoV-2 infection.