CLUE: COVID-19 lung ultrasound in emergency department.

Lung ultrasound (LUS) plays a critical role in the SARS-CoV-2 pandemic. Evidence is mounting on its utility to diagnose, assess the severity and as a triage tool in the ED. Sonographic features correlate well to computed tomography (CT) chest findings and a bedside LUS performed by a trained clinician along with clinical examination, could be an alternative to chest X-ray and CT chest in these highly infectious patients. In this article, we have described a step-by-step approach to LUS in COVID patients and the CLUE (COVID-19 LUS in the ED) protocol, which involves an anatomical parameter, the severity of lung changes, objectively scored using the validated LUS scoring system and a physiological parameter, oxygen requirement. We believe this CLUE protocol can help risk-stratify patients presenting to ED with suspected COVID-19 and aid clinicians in making appropriate disposition decisions.