Aerosol generation during endonasal instrumentation in the clinic setting

ABSTRACT

Background: The potential risk for transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) duringendoscopic endonasal instrumentation has been described in recent anecdotal reports. Additionally, recent simulations incadaveric models have demonstrated aerosol generation during power endonasal instrumentation. Endonasal proceduresare commonly performed in the outpatient clinic setting, and with a potential for aerosol generation, these procedures maypose a potential exposure risk to clinic staff. Objective: To provide a greater understanding of aerosol generation and exposure risk during endoscopic endonasalinstrumentation in the outpatient clinic setting. Methods: Using an optical particle sizer, airborne particles concentrations in particles per cubic foot (p/ft ) were measuredduring 30 nasal endoscopies in the outpatient clinic setting. Aerosol measurements were collected within an 18-inch radiusfrom the patient's head during 11 different diagnostic nasal endoscopies and 19 different nasal endoscopies with suctionand mechanical debridement. To identify any particle effect from endonasal instrumentation, airborne particles measuring0.3, 0.5, 1.0, 2.5, 5.0, and 10.0 microns (μm) in diameter were recorded at distinct time points throughout diagnostic anddebridement endoscopies. To account for the effects of native patient breathing on aerosol concentrations, all endoscopymeasurements were compared to aerosol concentrations measured prior to procedure initiation. Results: Compared to preprocedure aerosol levels, no significant increase in mean aerosol concentrations was measuredduring diagnostic nasal endoscopies. However, compared to preprocedure aerosol levels, a statistically significant increasein mean particle concentrations was measured during cold instrumentation at 2,462 p/ft (95% CI 837-4,088;p = 0.005).The use of suction instrumentation was also associated with a statistically significant increase in mean particleconcentrations at 2,973 p/ft (95% CI 1,419-4,529;p = 0.001). In total, greater than 99% of all measured particles wereless than 2.5 μm in diameter, with comparable particle size distributions observed during all forms of endonasalinstrumentation. Conclusion: When measured with an optical particle sizer, diagnostic nasal endoscopy with a rigid endoscope is notassociated with increased particle aerosolization in patients for which sinonasal debridement is not indicated. In patientsneeding sinonasal debridement, the use of cold and suction instrumentation was associated with increased particle aerosolization. The observed generation of airborne particles, especially sub-micrometer aerosols, during endonasaldebridement may increase exposure risk for clinic staff to SARS-CoV-2 compared to patient native breathing. Appropriatepersonal protective equipment use and patient screening should be utilized for all office-based endonasal procedures.