Rajiv Dhand, MD, FCCP, FACP, FAARC, FRSM, ATSF
Division of Pulmonary and Critical Care Medicine
Professor and Wahid T. Hanna, MD Endowed Chair of Medicine
Associate Dean of Clinical Affairs
Graduate School of Medicine
University of Tennessee Health Science Center, Knoxville, TN
INTRODUCTION
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the global pandemic of coronavirus disease 2019 (COVID-19), has afflicted more than 245 million people worldwide and caused more than 5 million deaths (1). COVID-19 primarily affects the respiratory tract and infected persons generate respiratory droplets and aerosols containing the virus that transmit the infection to susceptible hosts (2). Patients with COVID-19 need inhaled therapies, either for pre-existing respiratory diseases or because of new onset respiratory distress and hypoxemia in patients with no previous pulmonary problems. Aerosolized therapies increase particle concentrations in the vicinity of patients receiving such treatments (3, 4). Inhalers (pMDIs, DPIs and SMIs) have a very low risk of contamination and the risk of spreading infection with those devices is largely due to “bioaerosols” generated by the patient during breathing, speaking, coughing or sneezing (2,5,6). In contrast, nebulizers, especially those that are operated continuously, release “fugitive emissions” that could remain in the indoor environment (7, 8) (Figure 1).