Effects of saline nebulization on SARS-CoV-2 RNA spreading and exhaled bio-aerosol particles in COVID-19 patients

Background: Nebulized therapy is the mainstay for treating obstructive airway diseases, but there is heightened concern about the potential risk for SARS-CoV-2 transmission during nebulization in COVID-19 patients. Aim: To investigate the effects of 0.9% saline nebulization on SARS-CoV-2 RNA spreading in 11 COVID-19 patients (five females, mean age 62.45 +/- 9.31 years); also to ascertain whether saline nebulization changed the number of exhaled bio-aerosol particles in six out of the 11 patients. Methods: Air samples were collected using suction pumps equipped with 0.45 mm PTFE filters and positioned around the patient's bed. Exhaled particles were quantified by using an optical particle counter. Findings: At baseline (i.e. before nebulization) SARS-CoV-2 was detected more frequently in the pumps close to the patient than in those far away. After saline nebulization, the detection of SARS-CoV-2 in the pumps close to the patient was comparable to that observed at baseline. In the pumps far from the patient, saline nebulization slightly, but not significantly, increased SARS-CoV-2 RNA detection compared to baseline. Overall, no significant changes in the SARS-CoV-2 RNA detection were observed after saline nebulization. At baseline, exhaled particle emission varied among patients, with two of them showing higher emission of particles than the remaining patients. Saline nebulization induced a marked decrease in exhaled particles in the two patients who displayed high emission at baseline, whereas no changes were observed in the remaining patients. Saline nebulization did not significantly change SARS-CoV-2 RNA spreading. Conclusion: Saline nebulization does not significantly increase SARS-CoV-2 spreading. (c) 2024 The Authors. Published by Elsevier Ltd on behalf of The Healthcare Infection Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).