Combatting COVID-19: is ultrasound an important piece in the diagnostic puzzle?

The current COVID-19 pandemic is causing diagnostic and risk stratification difficulties in Emergency Departments (ED) worldwide. Molecular tests are not sufficiently sensitive, and results are usually not available in time for decision making in the ED. Chest x-ray (CXR) is a poor diagnostic test for COVID-19, and computed tomography (CT), while sensitive, is impractical as a diagnostic test for all patients. Lung ultrasound (LUS) has an established role in the evaluation of acute respiratory failure and has been used during the COVID-19 outbreak as a decision support tool. LUS shows characteristic changes in viral pneumonitis, and while these changes are not specific for COVID-19, it may be a useful adjunct during the diagnostic process. It is quick to perform and repeat and may be done at the bedside. The authors believe that LUS can help to mitigate uncertainty in undifferentiated patients with respiratory symptoms. This review aims to provide guidance regarding indications for LUS, describe the typical sonographic abnormalities seen in patients with COVID-19 and provide recommendations around the logistics of performing LUS on patients with COVID-19 and managing the infection control risk of the procedure. The risk of anchoring bias during a pandemic and the need to consider alternative pathologies are emphasised throughout this review. LUS may be a useful point-of-care test for emergency care providers during the current COVID-19 pandemic if used within a strict framework that governs education, quality assurance and proctored scanning protocols.