TY - JOUR T1 - Placing a mask on COVID-19 patients during high-flow nasal cannula therapy reduces aerosol particle dispersion JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00519-2020 VL - 7 IS - 1 SP - 00519-2020 AU - Jie Li AU - James B. Fink AU - Ahmad A. Elshafei AU - Laurel M. Stewart AU - Hannah J. Barbian AU - Sara H. Mirza AU - Lena Al-Harthi AU - David Vines AU - Stephan Ehrmann Y1 - 2021/01/01 UR - http://openres.ersjournals.com/content/7/1/00519-2020.abstract N2 - High-flow nasal cannula (HFNC) has been shown to improve oxygenation and reduce the need for intubation for hypoxaemic patients [1]. A retrospective study reported the effectiveness of HFNC to improve oxygenation of COVID-19 patients [2]. The transmission route of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus remains controversial [3], and concerns persist of potentially increased virus transmission when using HFNC among COVID-19 patients [3–5]. Computational fluid dynamics simulations reported that wearing a surgical/procedure mask over HFNC may reduce aerosol droplet dispersion [6]. However, how far those results translate in vivo among infected patients is unknown. Furthermore, the infectious potential of dispersed aerosol droplets is uncertain. Thus, we aimed to investigate the amount of aerosol particles and their size distribution in the vicinity of COVID-19 patients during conventional nasal cannula and HFNC therapy with and without a mask, as well as virus detection in environmental air samples taken during HFNC therapy. Our hypotheses were HFNC would generate similar or lower particle concentrations than conventional oxygen therapy and placing a mask over HFNC would reduce particle concentrations.Wearing a surgical/procedure mask over high-flow nasal cannula (HFNC) reduces aerosol particle concentrations in the patients’ vicinity. Wearing a mask over HFNC should be encouraged to reduce risks of aerosol transmission. #COVID19 https://bit.ly/2HLg5cE ER -