Utility of Lung Ultrasound in COVID-19: A Systematic Scoping Review

Lung ultrasound (LUS) has an established evidence base and has proven useful in previous viral epidemics. An understanding of the utility of LUS in COVID-19 is crucial to determine its most suitable role based on local circumstances. A scoping review was thus undertaken to explore the utility of LUS in COVID-19 and guide future research. 33 studies were identified which represent a rapidly expanding evidence base for LUS in COVID-19. The quality of the included studies was relatively low. However LUS appears to be a highly sensitive and fairly specific test for COVID-19 in all ages and in pregnancy and is almost certainly more sensitive than CXR. The precise diagnostic accuracy of LUS may be influenced by various factors including disease severity, pre-existing lung disease, scanning protocol, operator experience, disease prevalence and the reference standard. High quality research is needed in various fields including: diagnostic accuracy in undifferentiated patients; triage and prognostication; monitoring progression and guiding interventions; persistence of residual LUS findings; inter-observer agreement; and the role of contrast-enhanced LUS.