Aerosol exposure during surgical tracheotomy with and without laminar air flow

Introduction In the context of the current SARS-CoV-2 pandemic, aerosol generating activities have moved into focus. In the field of ENT surgery, one such activity is tracheotomy. The aim of this study was to clarify the aerosol exposure during tracheotomy. Material and method To simulate the air flow during a tracheotomy an airway model filled with artificial fog was developed. With the help of a projector the dispersion of the fog was visualized and video documented for further evaluation. The evaluation was performed with and without a laminar airflow system. Results Without LAF the aerosol was only slowed down by gravity. Approximately 50% of the aerosol volume reached the face of the surgeon. With LAF the aerosol rose about 40 cm upwards for about 1.6 seconds. During this ascent was noticeably slowed down. Afterwards, the flow was reversed to a large extent and began sinking. Nevertheless, approx. 4.8 ± 3.4% of the aerosol volume reached the surgeon's face. Discussion Although the LAF systems mandatory in German operating theatres considerably reduce the amount of aerosol that reaches the surgeon's face, a relevant measurable proportion still was detected in front of the surgeon's face mask. Wherever possible the protective measures in the context of a surgical tracheotomy should include performing the tracheotomy under a laminar air flow.