The following is the summary of “Characterization of SARS-CoV-2 Aerosols Dispersed During Noninvasive Respiratory Support of Patients With COVID-19” published in the January 2023 issue of Respiratory Care January by Ramsey, et al.

High-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) were essential components of respiratory therapy during the COVID-19 pandemic. It is unclear how much these treatments contribute to the production and spread of infectious respiratory aerosols. This research aimed to describe the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) aerosol from COVID-19 patients receiving NRS therapy.  Nearly all of the 31 COVID-19 patients who were getting NRS therapy (mainly HFNC) had air samples taken using one of several distinct aerosol collection instruments. 

Filters were used to capture aerosols for testing for SARS-CoV-2 RNA. A second set of measurements were taken in an aerosol chamber with healthy adult individuals using respiratory treatment devices in a controlled, repeatable environment. About 50 aerosol samples were taken from people undergoing HFNC or NIV therapy, and 6 samples were acquired from people who were not undergoing NRS. Only 4 out of 56 aerosol samples tested positive for SARS-CoV-2 RNA; these samples were all collected in close proximity to the individual utilizing a high air flow scavenger mask. 

Aerosol dispersion did not rise noticeably from baseline in the chamber measurements performed with healthy patients using respiratory treatment equipment. Researchers conclude that there is a low likelihood of detecting SARS-CoV-2-containing aerosols in the vicinity of COVID-19 patients undergoing NRS treatments in a clinical setting. These findings, along with controlled chamber data demonstrating that the use of HFNC and NIV devices was not related with increased aerosol dispersion, suggest that clinical use of NRS treatments does not result in increased aerosol dispersion.

Source: rc.rcjournal.com/content/68/1/8