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1 Title: Application of a modified endoscopy face mask for flexible laryngoscopy during the 2 COVID-19 pandemic 3 4 Authors: Vishal Narwani, MD,1 Nikita Kohli, MD,1 Michael Lerner, MD1 5 6 Affiliations: 7 1Division of Otolaryngology, Department of Surgery, Yale School of Medicine, New Haven, 8 CT 9 10 Corresponding Author: 11 Vishal Narwani 12 Division of Otolaryngology 13 Department of Surgery 14 Yale School of Medicine 15 333 Cedar St 16 New Haven, CT, 06510 17 E-mail: [email protected] 18 19 Keywords: COVID-19, flexible laryngoscopy, diagnostic flexible laryngoscopy, DFL, aerosol 20 generating procedure, AGP, otolaryngology 21 22 Conflicts of Interest: None disclosed 23 Funding: None 24 25 Authorship Contributions: 26 Vishal Narwani Co-wrote and edited manuscript 27 Nikita Kohli Co-wrote and edited manuscript 28 Michael Lerner Originated idea, co-wrote and edited manuscript
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This manuscript has been accepted for publication in Otolaryngology-Head and Neck Surgery. This manuscript has been accepted for publication in Otolaryngology-Head and Neck Surgery.
29 Abstract 30 Diagnostic flexible laryngoscopy (DFL) is a critical tool in the armamentarium of an 31 otolaryngologist. However, in the midst of the COVID-19 pandemic, DFL represents a high- 32 risk procedure for both patients and otolaryngologists due to the risk of aerosolization. In cases 33 where DFL is required, either in COVID-19-positive patients or in patients with unknown 34 COVID-19 status, we describe the use of a modified endoscopy face mask as an adjunct to 35 personal protection equipment to reduce occupational transmission of COVID-19 while 36 performing DFL. Our modified endoscopy mask provides an additional barrier against the 37 transmission of airborne pathogens. The modified endoscopy face mask may also serve as a 38 useful tool for otolaryngologists as they return to performing more aerosol generating 39 procedures in the outpatient setting. 40 41 42 43 44 45 46 47 Introduction
48 The 2019 novel coronavirus disease (COVID-19), declared as a global pandemic on
49 March 11, 2020 by the World Health Organization, presents extraordinary challenges to
50 healthcare systems around the world, impacting both patients and healthcare workers.1
51 Amongst the medical community, otolaryngologists are particularly at high risk of
52 occupational exposure to COVID-19, given the nature of head and neck examinations, where
53 the SARS-CoV-2 is prevalent in high concentrations,2 and due to commonly performed
54 aerosol-generating procedures .3 Diagnostic flexible laryngoscopy (DFL) is a critical tool in
55 the armamentarium of an otolaryngologist that aids in the visualization of the nasal cavity,
56 larynx and pharynx. However, in the midst of the COVID-19 pandemic, DFL represents a high-
57 risk procedure for both patients and otolaryngologists, reserved for critical cases where
58 findings may alter management. Furthermore, as the pandemic evolves and medical facilities
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59 resume non-emergent services in the future, there is a need to determine how to perform DFL
60 safely.
61 In cases where DFL is required, either in COVID-19-positive patients or in patients
62 with unknown COVID-19 status, we describe the use of a modified endoscopy face mask as
63 an adjunct to personal protection equipment (PPE) to reduce occupational transmission of
64 COVID-19 while performing DFL.
65 Methods
66 Supplies and Equipment
67 To simulate outpatient DFL, an airway simulation manikin (Laerdal SimMan Manikin,
68 Laerdal Inc. Wappingers falls, NY) seated upright on a clinic exam chair was used. An adult
69 endoscopy face mask (VBM medical, Sulz am Neckar, Germany), originally designed to allow
70 fiberoptic nasotracheal intubation through a 5mm port with simultaneous ventilation,4 was
71 modified to enable the passage of a standard flexible laryngoscope by fashioning a 3 mm slit
72 using a scalpel. The endoscopy face mask was then secured on the manikin using a face mask
73 harness (Rusch Medical, Wayne, PA) and attached to a hook ring. A heat and moisture
74 exchanger with bacterial and viral filter (McKesson Corporation, Irving, TX) was attached to
75 the inferior mount of the face mask (Figures 1-3).
76 A 3.5mm flexible distal-chip laryngoscope (Pentax Medical, Montvale, NJ) was easily
77 passed through its 5mm port. With the 5mm port plugged, the scope was also passed through
78 the modified 3mm slit with minimal resistance, achieving a tighter seal. The scope was able to
79 be maneuvered without difficulty through the mask and reach the subglottis with ease, with
80 only 5 cm of dead space between the face mask and the patient.
81
82 Discussion
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83 Otolaryngologists are exceptionally susceptible to iatrogenic transmission of COVID-
84 19, given the high viral load of SARS-CoV-2 in the upper airway of infected patients.
85 Otolaryngologists are exposed to exhaled pathogens during routine examination of the nasal
86 passages, oral cavity, and oropharynx, and particularly more during endoscopy and other
87 AGPs, where gagging, coughing, and sneezing are common events. Aerosolized COVID-19
88 particles may remain airborne for up to 3 hours, and may survive on surfaces for much longer.5
89 Recommendations have been published in the otolaryngology literature, advocating to perform
90 flexible laryngoscopy only in critical cases and when findings may have an immediate impact
91 on patient management; consideration of pre-procedure COVID-19 testing; use of powered,
92 air-purifying respirator (PAPR) or N95 mask in addition to PPE by the provider and use of
93 surgical masks by the patient.6,7 Awareness of these practices are key to reduce aerosolization
94 risks to health care workers. In the event flexible laryngoscopy is required, either in the setting
95 of patients with known COVID-19, unknown COVID-19 status, or high-risk patients who test
96 negative on PCR, given the significant false negative rate of current RT-PCR assay for
97 COVID-19,8 we advocate the use of the modified endoscopy mask described in this
98 communication.
99 Endoscopy masks are easy-to-use and widely available in centers with endoscopy
100 suites. While it may not provide a complete, 100% air-tight seal, the combination of the
101 modified endoscopy mask and heat and moisture exchanger with viral filter, allows for an
102 additional barrier for transmission of airborne pathogens, and a useful adjunct to PPE. The
103 modified endoscopy face mask also allows for flexible laryngoscopy to be performed in
104 patients who require ventilation, such as in COVID-19 intubated patients, while minimizing
105 aerosolization of airborne pathogens. Additional strategies that mitigate droplet transmission
106 of the virus including the use of anesthetic gels, hand hygiene, and laryngoscope disinfection,
107 previously described in literature should also be employed.6,7 A recent article by Workman et
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108 al studied the aerosolization of particles from powered-instrumentation during nasal endoscopy
109 in a cadaver model using a surgical mask and a modified surgical ‘VENT mask’, modified with
110 the addition of an internal and external surgical glove through which the endoscope passes.
111 The group showed that aerosols were reduced by both the standard surgical mask and ‘VENT
112 mask’ in a simulated sneezing event.9 We believe our modified endoscopy face mask provides
113 an improved barrier to the transmission of aerosols since a tighter seal is achieved, decreasing
114 potential aerosol escape.
115
116 Conclusion
117 Flexible laryngoscopy is an essential procedure in otolaryngology which poses a high
118 occupational risk of transmission of COVID-19. Current recommendations include limiting
119 DFL to critical cases. In the event that DFL is required, either in patients with COVID-19,
120 unknown COVID-19 status or high risk patients who test negative on PCR, we advocate the
121 use of our modified endoscopy face mask alongside PPE, to serve as an additional barrier
122 against viral transmission. The modified endoscopy face mask may also serve as a useful tool
123 for otolaryngologists as they return to performing more aerosol generating procedures in the
124 outpatient setting.
125
126 127 References 128 1. World Health Organization. Coronavirus disease (COVID-19) outbreak. 129 https://www.who.int/westernpacific/emergencies/covid-19. Accessed April 24, 2020. 130 131 2. Zou L, Ruan F, Huang M, et al. SARS-CoV-2 viral load in upper respiratory specimens of 132 infected Patients. N Engl J Med. 2020;382(12):1177-1179. 133 134 3. Chan JYK, Wong EWY, Lam W. Practical Aspects of Otolaryngologic clinical services 135 during the 2019 novel Coronavirus epidemic: an experience in Hong Kong. JAMA 136 Otolaryngol Head Neck Surg 2020;348:1967-1976. 137 138 4. Patil VU. Concerning the complications of the Patil-Syracuse Mask. Anesth Analg. 139 1993;76(5):1165-1166.
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140 141 5. ALNAP. Handbook of COVID-19 Prevention and Treatment. https://www.alnap.org/help- 142 library/handbook-of-covid-19-prevention-and-treatment. Accessed April 26, 2020. 143 144 6. Balakrishnan K, Schechtman S, Hogikyan ND, et al. COVID-19 pandemic: what every 145 otolaryngologist–head and neck surgeon needs to know for safe airway management 146 [published online April 14, 2020] Otolaryngol Head Neck Surg. 147 148 7. Rameau A, Young VN, Amin MR, et al. Flexible laryngoscopy and COVID-19 [published 149 online April 21, 2020] Otolaryngol Head Neck Surg. 150 151 8. Yu P, Zhu J, Zhang Z, et al. A familial cluster of infection associated with the 2019 novel 152 coronavirus indicating potential person-to-person transmission during the incubation period 153 [published online February 18, 2020] J Infect Dis. 154 155 9. Workman AD, Welling DB, Carter BS, et al. Endonasal instrumentation and aerosolization 156 risk in the era of COVID-19: simulation, literature review, and proposed mitigation strategies 157 [published online April 3, 2020] Int Forum Allergy Rhinol. 158 159 160 161 162 163 164 165 166 167 168 Figures 169 170 Figure 1: Equipment required for the modified endoscopy face mask. From left to right, adult 171 endoscopy face mask with 5mm endoscopy port, hook ring, heat and moisture exchanger with 172 bacterial and viral filter, face mask harness, #10 or #15 scalpel (not pictured). 173 174 175 Figure 2: Creation of a 3mm slit in the central silicone membrane of the endoscopy face mask 176 with a #10 scalpel, to allow passage of the flexible fiberoptic laryngoscope. 177 178 179 Figure 3A: In-office set up for flexible fiberoptic laryngoscopy, with modified endoscopy face 180 mask, secured with face mask harness B Flexible fiberoptic laryngoscopy at the level of the 181 vocal folds, utilizing a modified endoscopy face mask and a heat and moisture exchanger with 182 bacterial and viral filter 183 184 185 186 187 188 189
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