RT Journal Article SR Electronic T1 Airborne infection risk during open-air cardiopulmonary resuscitation JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 673 OP 678 DO 10.1136/emermed-2021-211209 VO 38 IS 9 A1 Talib Dbouk A1 Silvia Aranda-García A1 Roberto Barcala-Furelos A1 Antonio Rodríguez-Núñez A1 Dimitris Drikakis YR 2021 UL http://emj.bmj.com/content/38/9/673.abstract AB Aim Cardiopulmonary resuscitation (CPR) is an emergency procedure where interpersonal distance cannot be maintained. There are and will always be outbreaks of infection from airborne diseases. Our objective was to assess the potential risk of airborne virus transmission during CPR in open-air conditions.Methods We performed advanced high-fidelity three-dimensional modelling and simulations to predict airborne transmission during out-of-hospital hands-only CPR. The computational model considers complex fluid dynamics and heat transfer phenomena such as aerosol evaporation, breakup, coalescence, turbulence, and local interactions between the aerosol and the surrounding fluid. Furthermore, we incorporated the effects of the wind speed/direction, the air temperature and relative humidity on the transport of contaminated saliva particles emitted from a victim during a resuscitation process based on an Airborne Infection Risk (AIR) Index.Results The results reveal low-risk conditions that include wind direction and high relative humidity and temperature. High-risk situations include wind directed to the rescuer, low humidity and temperature. Combinations of other conditions have an intermediate AIR Index and risk for the rescue team.Conclusions The fluid dynamics, simulation-based AIR Index provides a classification of the risk of contagion by victim’s aerosol in the case of hands-only CPR considering environmental factors such as wind speed and direction, relative humidity and temperature. Therefore, we recommend that rescuers perform a quick assessment of their airborne infectious risk before starting CPR in the open air and positioning themselves to avoid wind directed to their faces.All data relevant to the study are included in the article or uploaded as supplemental information. All data relevant to the study are included in the article.