Airborne aerosol olfactory deposition contributes to anosmia in COVID-19.

INTRODUCTION: Olfactory dysfunction (OD) affects a majority of COVID-19 patients, is atypical in duration and recovery, and is associated with focal opacification and inflammation of the olfactory epithelium. Given recent increased emphasis on airborne transmission of SARS-CoV-2, the purpose of the present study was to experimentally characterize aerosol dispersion within olfactory epithelium (OE) and respiratory epithelium (RE) in human subjects, to determine if small (sub 5µm) airborne aerosols selectively deposit in the OE. METHODS: Healthy adult volunteers inhaled fluorescein-labeled nebulized 0.5-5µm airborne aerosol or atomized larger aerosolized droplets (30-100µm). Particulate deposition in the OE and RE was assessed by blue-light filter modified rigid endoscopic evaluation with subsequent image randomization, processing and quantification by a blinded reviewer. RESULTS: 0.5-5µm airborne aerosol deposition, as assessed by fluorescence gray value, was significantly higher in the OE than the RE bilaterally, with minimal to no deposition observed in the RE (maximum fluorescence: OE 19.5(IQR 22.5), RE 1(IQR 3.2), p<0.001; average fluorescence: OE 2.3(IQR 4.5), RE 0.1(IQR 0.2), p<0.01). Conversely, larger 30-100µm aerosolized droplet deposition was significantly greater in the RE than the OE (maximum fluorescence: OE 13(IQR 14.3), RE 38(IQR 45.5), p<0.01; average fluorescence: OE 1.9(IQR 2.1), RE 5.9(IQR 5.9), p<0.01). CONCLUSIONS: Our data experimentally confirm that despite bypassing the majority of the upper airway, small-sized (0.5-5µm) airborne aerosols differentially deposit in significant concentrations within the olfactory epithelium. This provides a compelling aerodynamic mechanism to explain atypical OD in COVID-19.

Aerosolization During Common Ventilation Scenarios.

Otolaryngologists are at increased risk for exposure to suspected aerosol-generating procedures during the ongoing coronavirus disease 2019 (COVID-19) pandemic. In the present study, we sought to quantify differences in aerosol generation during common ventilation scenarios. We performed a series of 30-second ventilation experiments on porcine larynx-trachea-lung specimens. We used an optical particle sizer to quantify the number of 1- to 10-µm particles observed per 30-second period (PP30). No significant aerosols were observed with ventilation of intubated specimens (10.8 ± 2.4 PP30 vs background 9.5 ± 2.1, P = 1.0000). Simulated coughing through a tracheostomy produced 53.5 ± 25.2 PP30, significantly more than background (P = .0121) and ventilation of an intubated specimen (P = .0401). These data suggest that undisturbed ventilation and thus intubation without stimulation or coughing may be safer than believed. Coughing increases aerosol production, particularly via tracheostomy. Otolaryngologists who frequently manage patient airways and perform tracheostomy are at increased risk for aerosol exposure and require appropriate personal protective equipment, especially during the ongoing COVID-19 pandemic.

Telemedicine Services Provided to Medicare Beneficiaries by Otolaryngologists Between 2010 and 2018.

IMPORTANCE: Clinicians are increasingly adopting telemedicine in an effort to expand patient access and efficiently deliver care. However, the extent to which otolaryngologists provide telemedicine services is unclear. OBJECTIVE: To characterize recent trends in the use of telemedicine by otolaryngologists to deliver care to Medicare beneficiaries. DESIGN, SETTING, AND PARTICIPANTS: A retrospective cross-sectional analysis was conducted between January 1, 2010, and December 31, 2018, using publicly available Medicare Physician/Supplier Procedure Summary data on physicians practicing in the field of otolaryngology and benchmark specialties (dermatology and psychiatry) that provided telemedicine services to Medicare beneficiaries. MAIN OUTCOMES AND MEASURES: Primary outcomes were the mean annual number of telemedicine services delivered per active physician and mean annual payment per active physician for these services. Secondary outcomes included the number, setting, and complexity of telemedicine services. RESULTS: Between 2010 and 2018, otolaryngologists provided 2127 total telemedicine services (7 unique service types) to Medicare beneficiaries and received $88 574 in total payment for these services. During this period, the mean number of telemedicine services increased at a compound annual growth rate (CAGR) of 11.0%, and the mean Medicare payment per otolaryngologist increased at a CAGR of 21.8%. In comparison, telemedicine use during this period generally increased at a higher rate in the fields of dermatology (mean number of services per active physician at CAGR of 13.0%; mean Medicare payment per active physician at CAGR of 12.5%) and psychiatry (mean number of services per active physician at CAGR of 25.8%; mean Medicare payment per active physician at CAGR of 26.6%). In 2018, outpatient evaluation and management visits accounted for most telemedicine services provided (337 of 353 [95.5%]) and the payments received ($17 542.13 of $18 470.47 [95.0%]) by otolaryngologists. In contrast, physicians in other specialties also provided substantial portions of telemedicine services in the inpatient (psychiatry, 18 403 of 198 478 [9.3%]; dermatology, 231 of 1034 [22.3%]) and skilled nursing facility settings (psychiatry, 14 690 of 198 478 [7.4%]; dermatology, 46 of 1034 [4.4%]). CONCLUSIONS AND RELEVANCE: This study suggests that the extent to which otolaryngologists used telemedicine to deliver care to Medicare beneficiaries between 2010 and 2018 was rare. Although there was relative growth in the use of telemedicine by otolaryngologists during this period, absolute growth remained low. Policy makers and provider organizations should support otolaryngologists in the adoption of telemedicine technologies, especially while coronavirus disease 2019 (COVID-19) viral suppression efforts necessitate prolonged restriction of physical clinic throughput.

CARES Act Provider Relief Fund Aid to Otolaryngologists in Small Practices.

The COVID-19 pandemic has placed unprecedented financial strain on otolaryngologists. Otolaryngologists employed by small practices may be particularly vulnerable to the effects of ongoing losses because these organizations often have limited financial reserves. We performed a retrospective cross-sectional analysis of federal direct aid provided to small practices (defined as ≤15 clinicians) employing otolaryngologists, using the Centers for Medicare and Medicaid Services Physician Compare National Downloadable File and the Department of Health and Human Services (HHS) Provider Relief Fund database. As of June 18, 2020, the HHS had allocated nearly $80 million to 966 (88.9%) of 1087 small practices employing 2455 otolaryngologists. The median amount of aid per clinician was $7909 (interquartile range, $4409-$12,710). These findings suggest that the majority of small practices have received direct aid through the HHS Provider Relief Fund, but aid amounts have thus far been modest relative to the fixed costs of practice.

Suction mitigation of airborne particulate generated during sinonasal drilling and cautery.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has significantly impacted endonasal surgery, and recent experimentation has demonstrated that sinonasal drilling and cautery have significant propensity for airborne particulate generation immediately adjacent to the surgical field. In the present investigation, we assessed nasopharyngeal suctioning as a mitigation strategy to decrease particulate spread during simulated endonasal surgical activity. METHODS: Airborne particulate generation in the 1-µm to 10-µm range was quantified with an optical particle sizer in real-time during cadaveric-simulated anterior and posterior endonasal drilling and cautery conditions. To test suction mitigation, experiments were performed both with and without a rigid suction placed in the contralateral nostril, terminating in the nasopharynx. RESULTS: Both anterior (medial maxillary wall and nasal septum) and posterior (sphenoid rostrum) drilling produced significant particulate generation in the 1-µm to 10-µm range throughout the duration of drilling (p < 0.001) without the use of suction, whereas nasopharyngeal suction use eliminated the detection of generated airborne particulate. A similar effect was seen with nasal cautery, with significant particle generation (p < 0.001) that was reduced to undetectable levels with the use of nasopharyngeal suction. CONCLUSION: The use of nasopharyngeal suctioning via the contralateral nostril minimizes airborne particulate spread during simulated sinonasal drilling and cautery. In the era of COVID-19, this technique offers an immediately available measure that may increase surgical safety.

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

OBJECTIVE: In the era of SARS-CoV-2, the risk of infectious airborne aerosol generation during otolaryngologic procedures has been an area of increasing concern. The objective of this investigation was to quantify airborne aerosol production under clinical and surgical conditions and examine efficacy of mask mitigation strategies. STUDY DESIGN: Prospective quantification of airborne aerosol generation during surgical and clinical simulation. SETTING: Cadaver laboratory and clinical examination room. SUBJECTS AND METHODS: Airborne aerosol quantification with an optical particle sizer was performed in real time during cadaveric simulated endoscopic surgical conditions, including hand instrumentation, microdebrider use, high-speed drilling, and cautery. Aerosol sampling was additionally performed in simulated clinical and diagnostic settings. All clinical and surgical procedures were evaluated for propensity for significant airborne aerosol generation. RESULTS: Hand instrumentation and microdebridement did not produce detectable airborne aerosols in the range of 1 to 10 µm. Suction drilling at 12,000 rpm, high-speed drilling (4-mm diamond or cutting burs) at 70,000 rpm, and transnasal cautery generated significant airborne aerosols (P < .001). In clinical simulations, nasal endoscopy (P < .05), speech (P < .01), and sneezing (P < .01) generated 1- to 10-µm airborne aerosols. Significant aerosol escape was seen even with utilization of a standard surgical mask (P < .05). Intact and VENT-modified (valved endoscopy of the nose and throat) N95 respirator use prevented significant airborne aerosol spread. CONCLUSION: Transnasal drill and cautery use is associated with significant airborne particulate matter production in the range of 1 to 10 µm under surgical conditions. During simulated clinical activity, airborne aerosol generation was seen during nasal endoscopy, speech, and sneezing. Intact or VENT-modified N95 respirators mitigated airborne aerosol transmission, while standard surgical masks did not.