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Title: Airway Management for Endoscopic Laryngotracheal Stenosis Surgery During COVID-1

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Authors: Andrew D.P. Prince, BA1, Benjamin H. Cloyd, MD, MIPH2, Norman D. Hogikyan, 3

MD3,4, Samuel A. Schechtman MD2, Robbi A. Kupfer, MD3 4

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Affiliations 6

1 University of Michigan Medical School, Ann Arbor, MI, USA 7

2Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, Michigan, 8

USA 9

3Department of Otolaryngology–Head & Neck Surgery, University of Michigan Medical School, 10

Ann Arbor, Michigan, USA 11

4Center for Bioethics & Social Sciences in Medicine, University of Michigan, Ann Arbor, 12

Michigan, USA 13

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Corresponding Author: 15

Robbi A. Kupfer, MD 16

Department of Otolaryngology—Head & Neck Surgery, University of Michigan Medical School 17

1904 Taubman Center, 1500 E. Medical Center Dr., SPC 5312 18

Ann Arbor, MI 48109-5312 19

Phone: 734-936-7633, Fax: 734-936-9625, Email: rkupfer@med.umich.edu 20

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Keywords: Otolaryngology; COVID-19; laryngotracheal stenosis; subglottic stenosis; laryngeal 22

stenosis; tracheal stenosis; airway management 23

Complete Manuscript Click here to access/download;Complete Manuscript;Stenosisairway management during COVID-19.docx

This manuscript has been accepted for publication in Otolaryngology-Head and Neck Surgery.

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Authorship Contributions: 24

Robbi Kupfer Conceptual design, drafting and review of the manuscript, final approval, 25

and agreement to be accountable 26

Andrew Prince Conceptual design, drafting and review of the manuscript, final approval, 27

and agreement to be accountable 28

Benjamin Cloyd Conceptual design, drafting and review of the manuscript, final approval, 29

and agreement to be accountable 30

Norman Hogikyan Conceptual design, drafting and review of the manuscript, final approval, 31

and agreement to be accountable 32

Samuel Schechtman Conceptual design, drafting and review of the manuscript, final approval, 33

and agreement to be accountable 34

Funding: None 35

COI: None 36

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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.

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Abstract 38

The novel coronavirus disease 2019 (COVID-19) pandemic presents unique challenges for 39

surgical management of laryngotracheal stenosis. High viral concentrations in the upper 40

aerodigestive tract, the ability of the virus to be transmitted by asymptomatic carriers and 41

through aerosols, and the need for open airway access during laryngotracheal surgery create a 42

high-risk situation for airway surgeons, anesthesiologists, and operating room personnel. While 43

some surgical cases of laryngotracheal stenosis may be deferred, patients with significant airway 44

obstruction or progressing symptoms often require urgent surgical intervention. We present best 45

practices from our institutional experience for surgical management of laryngotracheal stenosis 46

during this pandemic including preoperative triage, intraoperative airway management, and 47

personal protective measures. 48

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Introduction 50

The novel coronavirus disease 2019 (COVID-19) outbreak was designated a pandemic by the 51

World Health Organization on March 11, 2020.1 Global spread has occurred at an alarming rate. 52

High viral concentration in the upper aerodigestive tract, the possibility of transmission by 53

asymptomatic carriers, and aerosolization during airway procedures contribute to a high risk of 54

occupational exposure among otolaryngologists.2 55

Efforts to reduce non-essential procedures to minimize patient and provider risk have heightened 56

the need for procedure prioritization and management protocols for patients with time-sensitive 57

conditions. While surgical treatment of severe laryngotracheal stenosis (LTS) is essential to 58

prevent devastating consequences including respiratory failure and death, published guidance for 59

management during the COVID-19 crisis does not exist. 60

Treatment of LTS commonly includes endoscopic surgery to dilate the airway. Intraoperative 61

management requires open access to the airway, often utilizing techniques implicated in viral 62

transmission including jet ventilation, spontaneous ventilation, trans-nasal humidified rapid-63

insufflation ventilatory exchange (THRIVE), and/or laser excision.3,4 Operations employing 64

standard airway management techniques for LTS are thus highly aerosolizing and should be 65

avoided at this time. We present alternative airway management techniques to minimize 66

aerosolization and discuss patient triage and safety measures. 67

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Preoperative Evaluation and Triage 69

During COVID-19, LTS surgery should be performed when delay poses significant risk to the 70

patient. Evaluation during COVID-19 may involve initial phone or video triage to ascertain 71

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severity of LTS symptoms including dyspnea or stridor. Patients who have had prior procedures 72

can often provide insights into the acuity of their symptoms. When circumstances require 73

visualization of the larynx, office visits with laryngoscopy should be conducted with appropriate 74

airborne precautions.5 Given current public health mandated mobility restrictions, scheduling 75

surgery without in-person examination can be considered for patients with known history of 76

recurrent stenosis. 77

Shared decision making between the patient and surgeon about whether to proceed with surgery 78

is paramount. Triage discussions must also involve departmental and operating room leadership 79

in the setting of pandemic-related resource limitations. Appropriate timing should be considered, 80

as a controlled LTS surgery may save emergency resources and possibly pose less viral 81

transmission risk to health care providers and patients than an emergent procedure. 82

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Preoperative Testing and Personal Protective Equipment (PPE) 84

Preoperative testing for asymptomatic patients has the potential to provide reassurance to 85

proceed with surgery if negative; however, testing resources are limited and may not be 86

available. Furthermore, a single negative test may be misleading.6 Current guidelines at our 87

institution are therefore to wear full airborne precautions PPE and mitigate occupational 88

exposures (Table 1) during high risk aerosol generating procedures without requirement for 89

preoperative COVID-19 testing. 90

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Laryngotracheal Stenosis Endoscopic Surgical Protocol During COVID-19 92

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Development of an airway management plan for LTS surgery always mandates close 93

coordination of care amongst surgeon and anesthesiologist, and this need is amplified during the 94

COVID-19 pandemic due to recommended modifications in standard techniques. Individual 95

patient factors must also be considered, including comorbidities, degree and nature of stenosis, 96

and surgical access via direct laryngoscopy. The protocol outlined in Table 2 for patients 97

requiring subglottic stenosis surgical intervention at our institution during the COVID-19 crisis 98

was developed collaboratively by otolaryngology along with head and neck anesthesiology 99

colleagues. 100

The key principle guiding pandemic-related modifications in airway management is mitigation 101

of viral aerosolization, which is achieved by using closed systems when possible, rapid sequence 102

induction (RSI), neuromuscular blockade, and avoiding bag-mask ventilation.7 Prolonged awake 103

preoxygenation for five minutes can extend apnea time and reduce need for bag masking. Direct 104

laryngoscopy, telescopic bronchoscopy, dilation, and intubation are performed by the surgeon 105

immediately following RSI. Patients selected through triage are likely to have severe stenosis, 106

requiring immediate dilation to allow for safe intubation. Our protocol utilizes intubation with 107

5.0 cuffed microlaryngeal tracheal tube (Medtronic, Minneapolis, MN) with an outer diameter of 108

6.9 mm; therefore, dilation is performed prior to intubation if the stenosis is narrower than this 109

diameter. 110

Once intubation is accomplished, surgery proceeds with intermittent apnea using closed-loop 111

communication between the surgeon and anesthesiologist to ensure ventilation is held any time 112

the cuff is deflated, circuit is disconnected, or tube is removed. Neuromuscular blockade is 113

maintained throughout the case to minimize upper respiratory response. Laser is avoided due to 114

risk of virus aerosolization. 115

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Extubation can also lead to aerosolization due to coughing, gagging, and endotracheal tube 116

removal. Similar to the rest of the procedure, we recommend minimizing the number of 117

personnel present and continuing to utilize full airborne precautions PPE. Use of glycopyrrolate 118

may help to minimize secretions, while intravenous lidocaine, opioids, sedatives, and topical 119

lidocaine applied to the larynx and trachea at the conclusion of the surgical procedure may 120

attenuate laryngeal and cough reflex at extubation.8 Aerosolization barriers may also be 121

considered, although we are not currently using these devices at our institution.9 122

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Laryngeal Mask Airway (LMA) Considerations 124

For patients with inadequate direct laryngoscopy access or known difficult laryngoscopy, airway 125

dilation can be accomplished over a guidewire using flexible bronchoscopy through a 126

supraglottic airway (i.e. LMA). While this technique is an invaluable tool in select cases, risk of 127

aerosolization is thought to be higher with LMA than with endotracheal intubation10 and 128

therefore we recommend using this technique with caution during the COVID-19 pandemic. 129

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Conclusion 131

Surgical management of LTS presents unique challenges during the COVID-19 pandemic 132

requiring careful consideration of patient triage and protocols that minimize patient and provider 133

risk. Close collaboration between otolaryngology and anesthesiology teams is essential to safely 134

navigate these difficult airways while mitigating risk of viral aerosolization. 135

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Acknowledgments: None 138

References 139

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https://www.who.int/emergencies/diseases/novel-coronavirus-2019/events-as-they-141

happen. Accessed April 17, 2020. 142

2. Cheng X, Liu J, Li N, et al. Otolaryngology Providers Must Be Alert for Patients with 143

Mild and Asymptomatic COVID-19. Otolaryngol Head Neck Surg. 144

2020:194599820920649. 145

3. Hui DS. Severe acute respiratory syndrome (SARS): lessons learnt in Hong Kong. J 146

Thorac Dis. 2013;5 Suppl 2:S122-126. 147

4. Garden JM, O'Banion MK, Bakus AD, Olson C. Viral disease transmitted by laser-148

generated plume (aerosol). Arch Dermatol. 2002;138(10):1303-1307. 149

5. Rameau A, Young VN, Amin MR, Sulica L. Flexible Laryngoscopy and COVID-19. 150

Otolaryngol Head Neck Surg. 2020:194599820921395. 151

6. Beeching NJ, Fletcher TE, Beadsworth MBJ. Covid-19: testing times. Bmj. 152

2020;369:m1403. 153

7. Balakrishnan K, Schechtman S, Hogikyan ND, Teoh AYB, McGrath B, Brenner MJ. 154

COVID-19 Pandemic: What Every Otolaryngologist-Head and Neck Surgeon Needs to 155

Know for Safe Airway Management. Otolaryngol Head Neck Surg. 156

2020:194599820919751. 157

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This manuscript has been accepted for publication in Otolaryngology-Head and Neck Surgery.

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8. Clivio S, Putzu A, Tramer MR. Intravenous Lidocaine for the Prevention of Cough: 158

Systematic Review and Meta-analysis of Randomized Controlled Trials. Anesth Analg. 159

2019;129(5):1249-1255. 160

9. Brown S, Patrao F, Verma S, Lean A, Flack S, Polaner D. Barrier System for Airway 161

Management of COVID-19 Patients. Anesthesia & Analgesia. 9000;Publish Ahead of 162

Print. 163

10. COVID-19 and Anesthesia FAQ. Anesthesia Patient Safety Foundation. 164

https://www.apsf.org/covid-19-and-anesthesia-faq/. Published 2020. Accessed April 23, 165

2020. 166

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Table 1. Mitigation of Occupational Exposures During Airway Surgery 168

Principle Implementation

Airborne precautions PPE

All personnel in OR should wear gown, gloves, and PAPR or fit-tested N95

mask and full face shield (eye protection)

Providers should be trained in appropriate donning and doffing procedures

Optimize personnel Procedures should be performed expeditiously by experienced providers with the

fewest assistants and trainees possible

Room air clearance Room air clearance times should be followed to ensure aerosolized virus has

cleared prior to room entry by OR turnover personnel

Minimize virus

aerosolization

Airway management should include closed circuits when possible utilizing

intermittent apnea and avoiding bag-mask ventilation

Use of laser should be avoided

Cough should be mitigated upon emergence from anesthesia

Abbreviation: PPE, personal protective equipment; PAPR, powered air-purifying respirator

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Table 2. Laryngotracheal Stenosis Surgical Protocol in COVID-19 171

Protocol Step Implementation

Rapid Sequence Induction

Awake preoxygenation with 100% FiO2 for 5 minutes followed by rapid

sequence induction

Avoid bag-mask and laryngeal mask ventilation

Direct Laryngoscopya Assess degree of laryngotracheal stenosis with rigid telescope

Initial Dilation

Dilate stenosis with balloon or rigid dilators prior to intubation if airway

diameter less than outer diameter of ETTb

Surgeon should be familiar with relative diameters of: lumen of chosen

laryngoscope, available dilators, and outer diameter of ETTc

Initial Closed System with

ETT Intubation

Tracheal intubation with small cuffed ETT

ETT loaded over rigid telescope may mitigate risk of false passage

Once intubated ventilate with 100% FiO2 to preoxygenate before apneic

interventions

Laryngoscope Suspension

Hold ventilation before disconnecting ETT and removing laryngoscope if closed

laryngoscope used for intubation

Reconnect circuit before reinserting and suspending laryngoscope

Intermittent Apnea

Proceed with procedures that can be done while intubated, e.g. steroid

injection/mitomycin application

Intermittently extubate for balloon dilation/biopsy/excision

Stop ventilation during end expiration prior to extubation

Maintain neuromuscular blockade throughout the surgery

ETT can be replaced directly through the operative laryngoscope between apneic

interventions

Extubation Administer glycopyrrolate during procedure to minimize secretions

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Apply topical lidocaine to larynx and trachea upon completion of surgical

procedure

Intravenous lidocaine, opioids, sedatives at time of extubation to attenuate

laryngeal and cough reflexes

a May use closed operating laryngoscope or anesthesia laryngoscope blade

b Outer diameter of 5.0 cuffed microlaryngeal tracheal tube is 6.9 mm

c A 28-French Jackson laryngeal dilator (Pilling/Teleflex, Morrisville, NC) has an outer diameter 9.3 mm and can be

passed through a standard (male) Ossoff-Pilling laryngoscope (Pilling/Teleflex, Morrisville, NC)

Abbreviation: FiO2, fraction of inspired oxygen; ETT, endotracheal tube; THRIVE, trans-nasal humidified rapid-

insufflation ventilatory exchanges

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This manuscript has been accepted for publication in Otolaryngology-Head and Neck Surgery.

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