Is Office Laryngoscopy an Aerosol‐Generating Procedure?

Abstract

Objectives/Hypothesis: The aims of this work were 1) to investigate whether office laryngoscopy is an aerosolgenerating procedure with an optical particle sizer (OPS) during clinical simulation on healthy volunteers, and 2) to critically discuss methods for assessment of aerosolizing potentials in invasive interventions. Study Design: Prospective quantification of aerosol and droplet generation during clinical simulation of rigid and flexible laryngoscopy. Methods: Two healthy volunteers were recruited to undergo both flexible and rigid laryngoscopy. An OPS was used to quantify aerosols and droplets generated for four positive controls relative to ambient particles (speech, breathing, /e/ phonation, and /ae/ phonation) and for five test interventions relative to breathing and phonation (flexible laryngoscopy, flexible laryngoscopy with humming, flexible laryngoscopy with /e/ phonation, rigid laryngoscopy, and rigid laryngoscopy with /ae/ phonation). Particle counts in mean diameter size range from 0.3 to >10 μm were measured with OPS placed at 12 cm from the subject's nose/mouth. Results: None of the laryngoscopy interventions (n = 10 each) generated aerosols above that produced by breathing or phonation. Breathing (n = 40, 1-3 μm, P = .016) and /ae/ phonation (n = 10, 1-3 μm, P = .022; 3-5 μm. P = .083; >5 μm, P = .012) were statistically significant producers of aerosols and droplets. Neither speech nor /e/ phonation (n = 10 each) were associated with statistically significant aerosols and droplet generation. Conclusions: Using OPS to detect droplets and aerosols, we found that office laryngoscopy is likely not an aerosolgenerating procedure. Despite its prior use in otolaryngological literature, an OPS has intrinsic limitations. Our study should be complemented with more sophisticated methods of droplet distribution measurement.

Respiratory Particle Emission During Voice Assessment and Therapy Tasks in a Single Subject

“…Workman et al found that speech generated significantly more particles than panting, while Rameau et al found that speech did not generate significantly more particles than breathing. 1 , 28 Similar to the current study, both studies looked at a limited particle range of 1–10 μm, and sample sizes were small (N = 2). The small sample size in our study and others do not allow for capturing the notable intersubject variability of particle emission that has previously been established.…”

“… 14 , 30 , 31 Thus, we were able to measure only a narrow segment of the particle size spectrum for respiration and phonation. Other studies within the otolaryngology literature have similarly examined this same range of particle size, 1 , 28 and future studies should examine a larger range of particle size in order to develop a comprehensive understanding of particle generation. Though our particle counter measured particles as small as 0.3 μm, only particles between 1 and 10 μm were analyzed.…”

AHNS endocrine surgery section consensus statement on nasopharyngolaryngoscopy and clinic reopening during COVID‐19: How to get back to optimal safe care

“…Recent studies among healthy controls have demonstrated significant airborne aerosol production may occur during nasal endoscopy, talking, and sneezing. Data vary between studies depending on the experimental setup and equipment used and not all studies show laryngoscopy interventions generate aerosols above that produced by breathing or phonation 17 . The most common method used to reduce sneezing, namely topical nasal anesthesia and decongestion spray, also produced a significant number of aerosols 18 .…”

“…Data vary between studies depending on the experimental setup and equipment used and not all studies show laryngoscopy interventions generate aerosols above that produced by breathing or phonation. 17 The most common method used to reduce sneezing, namely topical nasal anesthesia and decongestion spray, also produced a significant number of aerosols. 18 Studies employing episodic stresses such as sneeze have shown that surgical masks are vulnerable to leakage from dynamic changes in both pressure and air velocity.…”

International Registry of Otolaryngologist‒Head and Neck Surgeons with COVID‐19

“…None of the references mention higher rates of infection among otolaryngologists in Italy. Second, the true aerosol-generating potential of otolaryngology practice and procedures remains controversial, [3][4][5][6][7] as do early reports of potential super-spreader events putatively attributed to endoscopic endonasal procedures. 8 Finally, the authors highlight 6 "instructional cases" and out-line "takeaway lessons," based on the description of these events.…”