Abstract View
Real-Time Space-Resolved Monitoring of Aerosol Distribution in Operating Rooms and Intensive Care Units
KAITLYN GLENN, Jiayang He, Robert Rochlin, Abhyjot Pandher, Ching-Hsuan Huang, Joelle Segovia, Bailey Deck, Selina Teng, James Hecker, Igor Novosselov, University of Washington
Abstract Number: 525
Working Group: Infectious Aerosols in the Age of COVID-19
Abstract
Many infection diseases, including Covid-19, can spread by aerosols. In hospital environments such as operating rooms (ORs) and Intensive Care Units (ICUs), it is critical to assess the persistence of potentially infectious aerosols to minimize their effect on patients and staff. Medical facilities do not assess the fate of aerosols generated by an infected person or particles generated during medical procedures, as both time and space resolution measurement of aerosol concentration is required. We deploy a monitoring network of 16-20 low-cost particle sensors per room in four ORs and four ICUs to map the movement and size of particles with a time resolution of ten seconds. Monitors are placed around the bed and room at various heights and distances between 2-6 feet apart and outside the room at a nursing station to record the concentration passing through each point. Mimicking aerosol generation by a patient, we nebulize saline solution to create NaCl particles that act as tracers for potentially infectious aerosols. We could draw several conclusions from the experiments performed at the University of Washington Medical Center. (i) Operating rooms are very effective at exchanging air and may require less than a third of the time that is currently recommended by the guidelines for infectious disease control. Typically, the aerosol concentration returns to the baseline within 5 minutes after aerosolization is terminated. (ii) Often, medical equipment blocks the air vents, which contributes to reduced airflow and increase exfiltration of potentially infectious aerosol from the OR into the hallway. (iii) Negative pressure ICUs are more effective at removing the aerosol particles and require up to one-third less time to clear the aerosol loading than positive pressure ICUs. The sensor network approach can be used to optimize the HVAC system and to understand the spread of infectious diseases in hospitals.