Size- and Time-Dependent Aerosol Removal from a Protective Box during Simulated Intubation and Extubation Procedures

Because the SARS-CoV-2 virus primarily spreads through droplets and aerosols, a protective box could provide adequate protection by shielding medical professionals during the intubation and extubation procedures from generated droplets and aerosols. In this study, size- and time-dependent aerosol concentrations were measured inside and outside the protective box in the particle size ranging from 14 nm to 20 μm during simulated intubation and extubation procedures. An improved protective box with active ventilation was designed based on a plastic bag with armholes covered with latex sheets that utilizes a supportive frame. Coughing during the intubation and extubation procedure was simulated using an aerosol generator which dispersed the aerosol powder into the protective box. During the intubation and extubation procedure, the concentration of particles increased inside the protective box but, due to the high negative airflow, quickly dropped to background levels. The particle concentration of all measured particle sizes decreased within the same time frame. No leakage of particles was observed through the armhole openings. The presented protective box design provides excellent protection against generated droplets and aerosols. The decrease in concentration does not depend on the particle size. Outside the box, particle concentration did not change with time.