key: cord-0818497-hl96i9kd
authors: Bleier, Benjamin S.
title: Reply to: Endonasal drilling may be employed safely in the COVID‐19 era
date: 2020-06-07
journal: Int Forum Allergy Rhinol
DOI: 10.1002/alr.22640
sha: 541d2c2a21fd8437530e39829ca39d59a17f829c
doc_id: 818497
cord_uid: hl96i9kd

nan

To the Editor, I would like to thank our respected colleagues Drs. Snyderman and Gardner for their letter to the editor regarding our study "Endonasal instrumentation and aerosolization risk in the era of COVID-19: simulation, literature review, and proposed mitigation strategies 1 ." In their letter the authors describe a study in which they performed a 4-handed skull base surgical approach in two cadaver heads irrigated with a fluorescein solution using a 60k rpm coarse diamond bur and an 8 Fr suction. The endpoint of this study was examination of the field and surgeon PPE using a UV light. The authors describe that they observed no evidence of droplets with some contact contamination and concluded they were unable to replicate our findings.

In order to provide a comprehensive response, we would like to direct the authors of the letter to our follow-up study by Workman et al entitled "Airborne Aerosol Generation During Endonasal Procedures: Risks and Recommendations. 2 " In this study we repeated the cadaver drilling conditions using a 10Fr suction, through biting forceps, a suction microdebrider, a suction irrigating 12k drill, 70k 4mm diamond and cutting burs, as well as a cautery device. Our endpoints were airborne aerosol production quantified using an optical particle sizer sensitive to particles less than 10 microns. This study confirmed the findings of our original study in that use of the suction, hand actuated instruments, and microdebrider did not produce detectable particles. However, all drill conditions and cautery produced thousands to tens of thousands of airborne aerosols within only 30 seconds. Of note we did find a definitive benefit to the simultaneous application of suction during drilling which appears commensurate with the reported findings from the Pittsburgh group.

These results confirm that the application of drills and cautery, procedures common to endonasal skull base approaches, pose a highly significant risk of aerosol production. The author would point out that the methodology Snyderman and Gardner describe differed from our original study both in surgical technique and the use of a much less sensitive and strictly qualitative method of droplet detection. Consequently, their findings cannot be called a lack of replication but rather a companion data set under independent conditions with independent results. On the other hand, our follow up study 2 suggests that the concomitant application of suction while drilling does confer a benefit which seems to be consistent with the Pittsburgh findings.

Endonasal instrumentation and aerosolization risk in the era of COVID-19: simulation, literature review, and proposed mitigation strategies

Airborne Aerosol Generation During Endonasal Procedures in the Era of COVID-19: Risks and Recommendations

Ultimately, the author is generally in full agreement with Drs. Snyderman and Gardner in their closing thoughts. While we have identified a series of risk factors germane to the operative team during endonasal surgery, we concur that there are both source control and provider PPE strategies which can be utilized to enable these surgeries to continue in a safe manner.