Aerosol Generation during Endoscopic Sinonasal Surgery

Background: Recent anecdotal reports have described a potential transmission risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during endoscopic endonasal surgery due to suspected aerosol generation. Additionally, recent cadaveric simulations have demonstrated aerosol generation patterns during powered endonasal instrumentation. As hospitals adapt daily operations to minimizing exposure risk to coronavirus disease 2019 (COVID-19), a better understanding of endoscopic endonasal surgical techniques and generation of potentially infectious aerosolized particles will enhance the safety of operating room staff and learners.

Objective: To provide greater understanding of possible SARS-CoV-2 exposure risk during endonasal surgeries by quantifying increases in airborne particle concentrations during endoscopic sinonasal surgery.

Methods: Aerosol concentration samples were collected in an outpatient surgery center during endoscopic endonasal surgeries on COVID-19 status-negative patients. Using an optical particle sizer, sample concentrations of airborne particles per cubic foot (p/ft³) measuring 0.3, 0.5, 1.0, 2.5, 5, and 10 microns in diameter were recorded throughout ten different surgeries at six time points: (1) before patient entered the OR, (2) before pre-incision timeout during OR setup, (3) during cold instrumentation with suction, (4) during microdebrider use, (5) during drill use, (6) at the end of the case prior to extubation. Measurements were collected at the operator position (within an 18-inch radius from operative site), the circulating nurse position (average distance of 10.8 feet from the operative site), and anesthesia provider position (average distance of 8.2 feet from the operative site). Additional control testing was conducted with the microdebrider to assess for instrument generated aerosols. Two-sided t-tests were used to estimate the mean difference (MD) and 95% confidence intervals (CI) for particle concentration at different points during the procedures with a Sidak correction to adjust for multiple comparisons. A significance level of p < 0.05 was used for all testing.

Results: Compared to pre-procedure aerosol concentrations, a significant increase in airborne particle concentration was measured at the surgeon position during microdebrider use with a mean increase of 225 p/ft³ (95% CI: 101.5–349.7; p < 0.004). Cold instrumentation with suction use was associated with a nonsignificant increase in airborne particles with a mean increase of 77 p/ft³ (95% CI: −71.73 to 225.1 p < 0.93). There was no statistically significant difference in particle concentration measured at the anesthesia or circulator position during any form of instrumentation.

Conclusion: Microdebrider use during endonasal surgery in a standard operating room is associated with a statistically significant increase in airborne particle concentrations compared to pre-procedure levels. Fortunately, this increase in aerosol concentration is localized to the operating surgeon, with no detectable increase in aerosol particles at other OR positions. Further investigation is needed with more comprehensive particle detection systems to understand aerosol generation during endonasal sinus surgeries; however, these preliminary findings regarding aerosol exposure risk are reassuring for operating room staff beyond the operator position.

Publication History

Article published online:
12 February 2021