Introduction: Bioaerosols significantly contribute to infection transmission. Nebulization increases the degree of fugitive aerosols and is limited in use during the COVID-19 pandemic. However, nebulized medications may be an important part of treatment and a transmission risk when infectious bioaerosols are present. Allowing for nebulized medication delivery while mitigating environmental contamination permits safe transport and in-hospital treatment without airflow restrictions. Using a novel device, preliminary data assessing the efficacy of nebulized DNA and environmental fugitive aerosols are presented. Methods: A novel device was 3D printed and attached to a simple facemask on a manikin. The vacuum port of the device was attached to the wall suction. Reprogramming a cough assist machine, bioaerosol was pushed/pulled through the pulmonary tree of a manikin while nebulized medical aerosol was ‘inhaled’. Distinct DNA-coated 1 micrometer spheres were nebulized from the manikin’s lungs and face mask medication port at a rate of 8L/min. Sampling sites included air sampling at 50 L/min, the face mask surface, and an inline filter to capture scavenged and lung DNA. Standard cycle threshold detection curves were obtained for each DNA oligo used. Results: Sampling comparing DNA delivery with and without a mouthpiece demonstrated a 6-fold higher ‘medication DNA’ uptake with a mouthpiece. Similarly, a 16-fold reduction in scavenged ‘medication DNA’ into the vacuum system occurred with a mouthpiece. More than 99% of the nebulized DNA was scavenged with and without a mouthpiece without reaching the environment. Conclusion: Using a model to simulate the generation of inspiratory and expiratory pressures, this device, in combination with commonly available transport and hospital equipment, was successful in preventing environmental contamination when nebulizing solutions coated with DNA. It is important to add a mouthpiece when concurrently administering nebulized medications to maximize medication availability to the lungs. Future studies should reproduce these results and discuss a generalizable model to test medication delivery and environmental impact.
Zeger et al. (Sun,) studied this question.