key: cord-0838585-iiaz3b66 authors: Sinnige, Jante S.; Kooij, Fabian O.; van Schuppen, Hans; Hollmann, Markus W.; Sperna Weiland, Nicolaas H. title: Protection of healthcare workers during aerosol-generating procedures with local exhaust ventilation date: 2021-03-20 journal: Br J Anaesth DOI: 10.1016/j.bja.2021.02.032 sha: 2e8f11cfbea4b3c2b15e495deea65d3b915d9366 doc_id: 838585 cord_uid: iiaz3b66 nan (SARS-CoV-1), performing tracheal intubation and noninvasive ventilation is associated with viral transmission to healthcare workers. 1 Medical interventions, in particular related to airway management, are classified as aerosol-generating procedures. 2 To protect healthcare workers during aerosol-generating procedures, the emphasis has been on wearing personal protective equipment (PPE). 3 Although this is an important measure, eliminating pathogens from room air is a superior intervention according to the US Center for Disease Control and Prevention. 4 Air exchange rate is important to decrease aerosol concentrations, but adequate room ventilation is absent in many hospital environments. 5 We explored local exhaust ventilation (LEV), an engineering technique used to reduce airborne particle concentration by capturing contaminants or fumes directly at their source. 6 Because positioning of the extraction hood is an operator-dependent process, we included different hood positions to determine if this influences aerosol extraction. We hypothesised, that LEV reduces aerosol concentration and distribution during a simulated aerosol-generating procedure. The experiments were performed in a resuscitation room in the emergency department of our academic teaching hospital (Appendix 1). Room ventilation consisted of a neutral pressure hierarchy towards the hallway and an air exchange rate of 24 changes h -1 . We simulated a tracheal intubation setting by positioning a mannequin (ALS Simulator, Laerdal, Stavanger, Norway) supine on the patient bed. Two particle counters ( This was necessary because people shed aerosols and particle counters are unable to distinguish these from nebulised saline. To approximate a real-world situation with turbulent airflow, we performed the experiment in a room equipped with a mixing-type ventilation system. Secondly, aerosols from normal saline were used, not from SARS-CoV-2. We do not expect that this influenced the results, because the aerodynamic diameter of SARS-CoV-2 aerosols is similar to the aerosols we employed. Aerosol generating procedures and risk of transmission of acute respiratory infections to healthcare workers: A systematic review Aerosol-generating procedures and infective risk to healthcare workers from SARS-CoV-2: the limits of the evidence COVID-19: Guidance for the remobilisation of services within health and care settings -Infection prevention and control recommendations Infection Control in Healthcare Personnel: Infrastructure and Routine Practices for Occupational Infection Prevention and Control Services Recommendations Only The Influence of room ventilation settings on aerosol clearance and distribution Local exhaust ventilation for the control of welding fumes in the construction industry -A literature review Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals Aerosol boxes and barrier enclosures for airway management in COVID-19 patients: a scoping review and narrative synthesis The aerosol box for intubation in coronavirus disease 2019 patients: an in-situ simulation crossover study Impact of an aerosol box on time to tracheal intubation: systematic review and meta-analysis The authors declare no competing interests. Funding Support was provided solely from institutional and/or departmental sources. The authors thank Marco Scholten for technical assistance with the measurements.