Risk of Aerosolization and Droplet Formation in Patients with Tracheostomy
COVID-19 can spread by direct contact, droplet, and likely also aerosolization.[4,8,9] Aerosolization refers to the process by which small particles are formed and dispersed in the air.[10] It is important to distinguish aerosolization from droplet formation, which refers to the process by which fluids in the form of large droplets come into direct contact with another person thereby causing infection. In contrast to droplets, aerosolized SARS-CoV-2 does not require personal contact with the source patient and has been shown to remain viable in the air for upwards of three hours.[4] For this reason, procedures or patient groups with increased risk of aerosolization may significantly increase viral transmission.[11,12] Some common procedures known to lead to aerosolization include intubation, tracheotomy, airway suctioning, nebulizer treatments, manipulation of oxygen masks, and non-invasive positive pressure ventilation.[13,14]
It remains unclear exactly how much and how often patients with tracheostomy and TL are aerosolizing. The amount likely differs based on unique patient factors. Based on data from the 2013 SARS-CoV-1 outbreak and early data from the current COVID-19 pandemic, it is likely that patients with fresh tracheostomy or TL are at significantly higher risk of spreading viral particles compared to other patients given high rates of aerosolizing procedures and equipment, including suctioning requirements, nebulizer treatments, open stomas, and open humidification with trach collar.[11,15,16] In addition to the risk of aerosolization, there is also an increased risk of droplet formation given frequent productive coughing in recent surgical patients. Given the increased risk of aerosolization and droplet formation in conjunction with the high rates of undocumented infections and asymptomatic carriers, precautions for all patients with tracheostomy and TL may be indicated.[17]