The authors of a new study on limiting aerosolization and occupational exposures to COVID-19 outlined methods to interrupt disbursement of the novel coronavirus. They also made several recommendations for consideration.
“Methods for prevention of respiratory viral infections depend upon their propensity to be carried in respiratory droplets or as fine droplet nuclei (airborne transmission),” the authors stated. “The respiratory transmission of SARS-CoV-2 virus that causes COVID-19 is mainly by respiratory droplets. Respiratory transmission of this virus via aerosols has not been definitively established, but is possible under certain circumstances.” These include aerosol-generating procedures (AGPs) such as intubation and bronchoscopy.1
“[AGPs] generate potential infectious bioaerosols by provoking coughs and are associated with increased infection rates among employees working in healthcare,” the authors reported. “In contrast, AGPs such as oxygen therapy, use of humidified high-flow nasal cannula, noninvasive ventilation, and manual ventilation via mask are less about ‘generating’ bioaerosols and more about ‘dispersing’ aerosols farther away from the patient.”
The paper’s recommendations, consistent with Centers for Disease Control and Prevention guidelines, include:
- Avoid procedures that irritate airways and provoke violent coughing. Reduce the exposure to infectious aerosol. The authors stated that “rapid sequence intubation is preferable because bioaerosol production is reduced by inhibiting patients’ breathing efforts and coughing with neuromuscular blockade and deep sedation.”
- Stay six feet away from infected patients when possible, especially if the patient coughs or sneezes. Increasing air exchange frequency also helps reduce the bioaerosol concentration in the room air.
- “Institute barriers to filter virus or reduce virus dispersion, e.g., by placing a filter at the exhalation port of the mechanical ventilator or connecting a filter to the oxygen mask,” the authors noted.
- Place a surgical mask on spontaneously breathing patients, or use tissue to cover the mouth or nose, especially when the patient is coughing, sneezing, or talking.
- “Open systems with high-velocity gas flow, such as a vented NIV mask, should be avoided,” the authors recommended. “Likewise, when invasive ventilation circuits need disconnection, such as changing an in-line suction catheter or switching ventilators, the endotracheal tube might be clamped and the ventilator turned off before disconnection.”
- Practice good hand hygiene and respiratory hygiene, including use of personal protective equipment such as N95 respirators.
- Dhand R, Li J. Coughs and sneezes: Their role in transmission of respiratory viral infections, including SARS-CoV-2. Am J Respir Crit Care Med 2020; doi: 10.1164/rccm.202004-1263PP. [Online ahead of print.]