Aerosol Exposure During Surgical Tracheotomy in SARS-CoV-2 Positive Patients

Shock. 2020 Sep 9. doi: 10.1097/SHK.0000000000001655. Online ahead of print.

Abstract

Introduction: Since December 2019, the novel coronavirus SARS-CoV-2 has been spreading worldwide. Since the main route of infection with SARS-CoV-2 is probably via contact with virus-containing droplets of the exhaled air, any method of securing the airway is of extremely high risk for the health care professionals involved. We evaluated the aerosol exposure to the interventional team during a tracheotomy in a semi-quantitative fashion. In addition, we present novel protective measures.

Materials and methods: To visualize the air movements occurring during a tracheotomy, we used a breathing simulator filled with artificial fog. Normal breathing and coughing were simulated under surgery. The speed of aerosol propagation and particle density in the direct visual field of the surgeon were evaluated.

Results: Laminar air flow (LAF) in the OR reduced significantly the aerosol exposure during tracheostomy. Only 4.8 ± 3.4% of the aerosol was in contact with the surgeon. Without LAF, however, the aerosol density in the inspiratory area of the surgeon is ten times higher (47.9 ± 10.8%, p < 0.01). Coughing through the opened trachea exposed the surgeon within 400ms with 76.0 ± 8.0% of the aerosol - independent of the function of the LAF. Only when a blocked tube was inserted into the airway, no aerosol leakage could be detected.

Discussion: Coughing and expiration during a surgical tracheotomy expose the surgical team considerably to airway aerosols. This is potentially associated with an increased risk for employees being infected by airborne transmitted pathogens. Laminar airflow in an operating room leads to a significant reduction in the aerosol exposure of the surgeon and is therefore preferable to a bedside tracheotomy in terms of infection prevention. Ideal protection of medical staff is achieved when the procedure is performed under endotracheal intubation and muscle relaxation.