Small droplet emission in exhaled breath during different breathing manoeuvres: Implications for clinical lung function testing during COVID‐19

Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the setting is a major concern for infection prevention. In particular concern has been for small droplets (typically ≤5 microns), which have been shown to contain virus1, as well remaining airborne for longer, potentially increased spread2. Modelling has shown particular of particles once exhaled during movement and exercise3, but increases in exhaled mass are less well established, and likely to vary depending on breathing pattern. function testing (PFTs) is essential to respiratory medicine, and COVID-19 has had implications4. International guidance highlights PFTs as an aerosol generating, but to date the varying response of different breathing manoeuvres have not been (see supplemental figure). The use of in-line filters are standard of care in many lung labs, reducing the risk of viral and bacterial contamination. [Opening paragraph]