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Effectiveness of a Negative Pressure Airway Chamber in Reducing the Exposure of Healthcare Providers to Aerosol Generating Medical Procedures
ALBERTO BALDELLI, Kevin Heieis, Steven Rogak, Andrew Poznikoff, Matthias Görges, Robert Purdy, The University of British Columbia
Abstract Number: 99
Working Group: Infectious Aerosols in the Age of COVID-19
Abstract
Aerosols carry airborne viruses, such as SARS-CoV-2; this is a concern for healthcare providers (HCP) when working in close proximity to patients undergoing aerosol-generating medical procedures. The negative pressure airway chamber (NPAC), a Plexiglas enclosure fitted securely over a patient’s head and shoulders with applied high-volume suction, was developed to shield HP from airborne particles generated while performing airway manipulation tasks at induction of anesthesia. Results from both a physical simulation study on baseline performance and a trial with human participants during simulated clinical use are presented.
The NPAC efficacy in trapping aerosols was investigated using a manikin in a regular hospital room with minimal ventilation. When applied to a manikin emitting 10 lpm of saline aerosols (median dried size ~ 1 µm), the NPAC reduced particulate matter concentrations (PM) at the HCP location by an average of 89 ± 5%, when compared to its absence. When performing common anesthetic tasks: preoxygenation, bag-mask ventilation and high flow oxygen therapy, the levels of PM at the HCP location never exceed the baseline (no aerosol source). Removing the chamber after performing these tasks was also shown to not cause a surge in PM at the HCP location.
With ethical approval and informed consent, a within-subject, block-randomized, study comparing intubation of a manikin with and without the NPAC was conducted. Simulated intubation trials involved: a) an aerosol generator being started and the HCP placing their hands and arms into the attached NPAC sleeves and gloves, b) bag-mask ventilation for 3 min, c) termination of aerosol generation, d) mask removal and airway instrumentation with an endotracheal tube, e) auscultation following removal of the NPAC. PM were reduced 84% for the overall clinical trials; PM peaks while performing bag-mask ventilation and auscultation were reduced by 82%.