The utility of lung ultrasound in COVID-19: A systematic scoping review

Introduction: 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. Method: Online databases, specialist websites and social media platforms were searched to identify studies that explore the utility of LUS in COVID-19. Case reports and recommendations were excluded. Findings: In total, 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 certainly appears to be a highly sensitive and fairly specific test for COVID-19 in all ages and in pregnancy. Discussion: There may be LUS findings and patterns that are relatively specific to COVID-19; however, specificity may also be influenced by factors such as disease severity, pre-existing lung disease, operator experience, disease prevalence and the reference standard. Conclusion: LUS is almost certainly more sensitive than chest radiograph for COVID-19 and has several advantages over computed tomography and real-time polymerase chain reaction. High-quality research is needed into various aspects of LUS including: diagnostic accuracy in undifferentiated patients; triage and prognostication; monitoring progression and guiding interventions; the persistence of residual LUS findings; inter-observer agreement and the role of contrast-enhanced LUS.