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\begin{document}

\title{Conservation of personal protective equipment for head and neck cancer
surgery during~ COVID-19 pandemic~~~}



\author[1]{Velda Ling Yu Chow MD, MS}%
\affil[1]{University of Hong Kong Li Ka Shing }%


\vspace{-1em}



  
  \date{May 19, 2024}


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\textbf{AUTHORS}

Velda Ling Yu Chow MD, MS,~Jimmy Yu Wai Chan MD, MS, PhD,~Valerie Wai
Yee Ho MD,~George Chung Ching Lee MD, BDS,~Melody Man Kuen Wong
MD,~Stanley Thian Sze Wong BSc, PhD,~Wei Gao, BSc, MSc, PhD

\textbf{CORRESPONDING AUTHOR}

Velda Ling Yu Chow MD, MS

Division of Head and Neck Surgery

Department of Surgery

University of Hong Kong Li Ka Shing Faculty of Medicine

Queen Mary Hospital

ADDRESS FOR CORRESPONDANCE AND REPRINT

Division of Head and Neck Surgery

Department of Surgery

University of Hong Kong Li Ka Shing Faculty of Medicine

Queen Mary Hospital

102 Pokfulam Road,

Hong Kong SAR, China

Telephone: +852 2255 2208

Fax: +852 2819 3780

E-mail: vlychow@gmail.com

\textbf{DISCLOSURE}

No financial disclosure. This paper is not based on previous
communication to a society or meeting

\textbf{RUNNING TITLE}

Conserve PPE for head and neck surgery during COVID-19

\textbf{KEY WORDS}

Conservation, PPE, Face shield, Head and neck cancer, COVID-19

\textbf{ABSTRACT}

\textbf{Background}

COVID-19 pandemic has led to a global shortage of personal protective
equipment (PPE). This study aims to stratify face shield needs when
performing head and neck cancer surgery.

\textbf{Methods}

Fifteen patients underwent surgery between 01 March 2020 and 09 April
2020. Operative diagnosis and procedure; droplet count and distribution
on face shields were documented.

\textbf{Results}

Forty-five surgical procedures were performed for neck nodal metastatic
carcinoma of unknown origin (n=3); carcinoma of tonsil (n=2), tongue
(n=2), nasopharynx (n=3), maxilla (n=1) and laryngo-pharynx (n=4).
Droplet contamination was 57.8\%, 59.5\%, 8.0\% and 0\% for operating,
first and second assistant surgeons, and scrub nurse respectively.
Droplet count was highest and most widespread during osteotomies. No
droplet splash was noted for transoral robotic surgery.

\textbf{Conclusion}

Face shield is not a mandatory adjunctive PPE for all head and neck
surgical procedures and health care providers. Judicious use helps to
conserve resources during such difficult times.

\textbf{INTRODUCTION}

SARS-CoV-2 virus is the causative agent of the coronavirus disease 2019
(COVID-19) pandemic. Since it's outbreak, health care systems around the
world are faced with unprecedented challenges with priorities of care
and resources being shifted to combat COVID-19.

With limited resources during the COVID-19 pandemic, the major
challenges that we head and neck cancer surgeons face are patient
selection and timing of treatment, whilst preventing transmission of
virus to health care providers and patients {[}1{]}. Majority of head
and neck cancer patients are elderly with multiple co-morbidities and
poor respiratory reserve from chronic tobacco use, predisposing them to
SARS-CoV-2 contraction and COVID-19 related mortality. However, if left
untreated, tumours in the upper aerodigestive tract may impair essential
functions such as breathing and swallowing, tumors may progress and
metastasise, eventually leading to mortality.

SARS-CoV-2 is found in high abundance in the upper aerodigestive tract
mucosa, particularly the nasopharynx {[}2{]}. Patients may be
asymptomatic at the time of presentation {[}3{]}. There is currently no
accurate way of diagnosis - polymerase chain reaction (PCR) testing for
nucleic acid sequence homology in nasopharyngeal and throat swabs may be
negative early in the course of disease {[}4{]}. The virus is known to
be transmitted via close contact, droplet and aerosols from aerosol
generating procedures (AGP) such as tracheotomy {[}5{]}. Hence as head
and neck surgeons, we are at great risk of becoming infected when
treating head and neck cancer patients.

Ideally full barrier protection should be advocated when treating
unknown, suspected and confirmed COVID-19 patients in order to avoid
disease transmission to health care providers. Such personal protective
equipment (PPE) includes gloves, goggles, face shield and gowns, as well
as items filtering facepiece respirators such as N95 or powered
air-purifying respirator (PAPR) hoods and aprons {[}6{]}.

However, as the number of confirmed cases increases globally, resources
including PPE becomes scarce. As of 12 April 2020, there are 1695096
confirmed cases spanning 215 countries of which Hong Kong accounts for
1005 patients {[}7-8{]}. In Queen Mary Hospital, The University of Hong
Kong, the Division of Head and Neck Surgery has undergone a 50\%
reduction in head and neck cancer operations since March 2020 as a
result of diminished supplies of PPE in particular N95 respirator and
face shields.

In view of global PPE shortage, we look at strategies to optimise PPE
availability, which includes minimising the need for PPE in health care
settings and ensuring rational and appropriate use of PPE.

This study aims to stratify face shield needs when performing head and
neck cancer surgery with the aim of conserving PPE during the COVID-19
pandemic.

\textbf{MATERIALS AND METHODS}

All patients who underwent surgery for head and neck cancer in the
Division of Head and Neck Surgery of the Department of Surgery, The
University of Hong Kong at Queen Mary Hospital and Gleneagles Hong Kong
Hospital between 01 March 2020 and 09 April 2020 were included.

All patients underwent comprehensive work-up for tumour staging
including clinical and endoscopic examination of the upper aerodigestive
tract, and ultrasonography of the neck +/- fine needle aspiration for
cytology of suspected neck nodal metastasis with full barrier
protection. Magnetic resonance imaging +/- whole-body positron emission
tomography scans were also performed for tumour staging.

Admission to head and neck surgical ward was only allowed (1) on
declaring absence of travel history 14 days prior to surgery, (2)
absence of close contact with confirmed cases, and (3) tympanic body
temperature \textless{}37.5 degrees Celsius taken at ward entrance. On
admission, routine bloods including white cell count and chest X-ray
were checked. As recommended by Centre for Health Protection in Hong
Kong (CHP) and Queen Mary Hospital Infection Control Unit, PCR would
only be tested for febrile and symptomatic patients +/- radiological
changes on chest X-ray.

All operations were performed by a consultant surgeon and two assistants
who have completed their fellowship in head and neck surgery. Skin
incisions and tracheotomies were performed using scalpel knife.
Reciprocating and oscillating saws were used for maxillary swing and
manubrial resection respectively. Monopolar and bipolar diathermy was
used for tissue dissection and haemostasis.

Full barrier protection was adopted by all three surgeons and one scrub
nurse. The face shield used was a piece of optically clear, latex free
plastic film imported from China measuring 32cm in length and 22cm in
width with foam forehead cushion and elastic strap. It covered a full
face length from forehead to neck, with outer edges of the face shield
reaching bilateral ears. It had anti-fog and anti-glare properties with
no hearing restrictions.

The face shield of each surgeon and scrub nurse was removed after each
procedure. Each face shield was put against a white background with 12
grids measuring 7cm x 7cm each to facilitate counting at maximal
magnification (Figure 1). The number and size of droplets splashed was
counted for each face shield using the surgical microscope Leica M720
0H5 (Leica Microsystems GmbH, Germany) (Figure 2). Droplet distribution
per face shield was plot on a separate sheet with the same grid as that
used in Figure 1 (Figure 3). Each of the 12 grids were labelled 1 to 12
(Figure 4). Counting and plotting of droplets splashed were performed by
a surgeon who did not participate in the operation. The face shields
were discarded once counting was complete.

Operative diagnosis and procedure; size, average number and distribution
of droplets on face shield for each party were documented.

\textbf{RESULTS}

Fifteen patients with no clinical evidence of COVID-19 underwent
operations for head and neck cancer: 3 patients with metastatic squamous
cell carcinoma of unknown primary underwent examination under
anaesthesia, transoral robotic (TORS) tonsillectomy and tongue base
mucosectomy and modified radical neck dissection; 2 patients underwent
radical tonsillectomy, modified radical neck dissection, free
anterolateral thigh flap reconstruction and tracheostomy for tonsillar
carcinoma; 2 patients with carcinoma of the tongue underwent glossectomy
and selective neck dissection followed by free anterolateral thigh flap
reconstruction and tracheostomy; 1 patient underwent total laryngectomy
for recurrent carcinoma of larynx; 3 patients with recurrent
pharyngo-esophageal carcinoma underwent total laryngectomy (n=3),
circumferential pharyngectomy (n=3) and cervico-esophagectomy after
manubrial resection (n=1), followed by reconstruction with free jejunal
flap (n=3); 3 patients with recurrent nasopharyngeal carcinoma underwent
tracheostomy followed by maxillary swing nasopharyngectomy, 1 patient
required selective neck dissection and free vastus lateralis flap
coverage of exposed internal carotid artery; 1 patient with carcinoma of
maxilla underwent tracheostomy, total maxillectomy, selective neck
dissection and free anterolateral thigh flap reconstruction. (Table 1)

There were a total of 45 procedures of which 26 involved mucosa along
the upper aerodigestive tract. There were 12 procedures which involved
manipulation of the airway including temporary tracheostomy (n=8) and
laryngectomy (n=4). Operating surgeon and scrub nurse were involved in
all surgical procedures (n=45). First assistant was involved in all but
tracheostomy operations (n=37). Second assistant was not involved in
TORS, tracheostomy and free flap harvest procedures (n=25). Overall
droplet size ranged from 0.3mm to 3.0 mm. Percentage of procedures with
droplet contamination was 57.8\% for the operating surgeon (n=26),
59.5\% for the first assistant (n=22) and 8.0\% for the second assistant
(n=2). No droplets were noted on all face shields of the scrub nurse
(n=45).

Average droplet count was highest for procedures involving osteotomies
such as maxillectomy (n=1), maxillary swing (n=3) and manubrial
resection (n=1). Droplet spread was more widespread (zones 2-12) for
maxillectomy procedures (n=4), involving face shields of the operating,
first and second assistant surgeons.

Non-osteotomy surgical procedures involving mucosa of the nasopharynx
(n=3), oropharynx (n=5), oral cavity (n=2), laryngo-pharyngeal apparatus
(n=4), and trachea (n=8) yielded minimal droplet count on face shields
of the operating surgeon and first assistant, affecting zones 6-11 which
were over the lower half of the face. There was one droplet splash at
zone 2 of the first assistant during nasopharyngectomy, corresponding to
upper half of the face. No droplet splash was noted on the second
assistant's face shield. No droplet splash was documented on face
shields of the operating surgeon and first assistant for TORS.

Average droplet count from non-mucosal, non-osteotomy related surgical
procedures such as neck dissection (n=9) and free flap harvest (n=9) was
minimal on both the operating surgeon's and first assistant's face
shields, mainly affecting zones 6, 7, 10 and 11 which were concentrated
on the lower half of the face. One drop was noted in zone 6 of the
second assistant's face shield during modified radical neck dissection.

\textbf{DISUCSSION}

The current global stockpile of PPE is insufficient due to the rapidly
increasing number of infected patients world-wide. In view of global PPE
shortage, strategies have been formulated to optimise PPE availability
include minimising the need for PPE in health care settings, and
ensuring rational and appropriate use of PPE {[}9{]}.

In Queen Mary Hospital, attempts at minimising PPE need include reducing
the volume of head and neck patients undergoing outpatient clinic and
endoscopy service by 60\%, and operations by 50\%; and the number of
healthcare providers within endoscopy suites and operating theatre.

Based on current evidence, SARS-CoV-2 is transmitted between people
through close contact and droplets. Airborne transmission may occur
during AGP and support treatments including tracheal intubation,
non-invasive ventilation, tracheotomy, cardiopulmonary resuscitation,
manual ventilation before intubation, and bronchoscopy. Despite concerns
of aerosolisation of blood through the use of energy device,
manipulation of upper aerodigestive tract mucosa and resection of
tumours in the upper aerodigestive tract are not classified as AGP
{[}9-12{]}. According to World Health Organisation (WHO), droplet and
contact precautions with the use of medical masks, eye protection, cap,
gown and gloves are sufficient for regular care of COVID-19 patients.
Respirators such as N95 or PAPR are advocated for AGP {[}9,13{]}.

There is currently no universal standard for face and/or eye protection
from biohazards. Face shield is usually in the form of an optically
clear plastic film which covers the forehead to neck and both sides of
the face up to the ears. Due to the lack of a good facial seal
peripherally, face shields are usually used as an adjunctive PPE which
acts to provide additional physical barrier against splashes, sprays,
and spatter of body fluids {[}14{]}. However, the use of face shield
hinders the use of a head-light when performing head and neck surgery.
Prolonged use can give rise to fogging, carbon dioxide retention
especially when combined with respirator, and impaired communication.

Centres for Disease Control and Prevention (CDC) Standard Precautions
guidelines for prevention of transmission of infectious agents includes
the use of face shields (with a medical/surgical face mask) when sprays,
splashes, or splatter are anticipated {[}15{]}.~The effectiveness of
face shields in preventing the transmission of viral respiratory
diseases is unknown {[}16{]}. With the use of goggles and appropriate
respiratory protection device, we re-evaluate the need for face shield
in performing head and neck cancer surgical procedures.

In an attempt to conserve face shield and other PPE consumption, we
minimised the number of health care providers during operation: all
tracheostomy (n=8) was performed by the operating surgeon alone.
Furthermore, second assistant was not involved in TORS and free flap
harvest procedures. Only the operating surgeon and scrub nurse was
involved in all 45 surgical procedures.

From our study, the percentage of procedures with droplet contamination
was 57.8\% for the operating surgeon , 59.5\% for the first assistant
and 8.0\% for the second assistant. No droplets were noted on all face
shields of the scrub nurse. In view of 0\% contamination rate, face
shield is not necessary for the scrub nurse for all non-AGP.

Droplet count was highest and most widespread with procedures involving
osteotomies such as maxillectomy, maxillary swing and manubrial
resection. Other than blood, irrigation fluid also contributed to the
number of droplets. Vibrations of saw blade caused droplets to be
dispersed over a large area during osteotomy, as reflected by the
distribution on the surgeon and 2 assistants' face shields (Figure 3,
Table 1). This can be minimised by controlled irrigation and vigilant
suction to minimise the amount of irrigation fluid and blood
accumulating around the saw blade. Operation by an experienced surgeon
would also help to reduce blood loss and shorten procedure time. Face
shield should be provided for the operating, first and second assistant
surgeons during osteotomy related procedures.

Non-osteotomy surgical procedures involving mucosa of the upper
aerodigestive tract yielded minimal droplet count on face shields of the
operating surgeon and first assistant, affecting zones 6-11 which were
centred over the lower half of the face. There was one droplet splash at
zone 2 of the first assistant during nasopharyngectomy, corresponding to
the first assistant's eye-level. No droplet splash was noted on the
second assistant's face shield. Abiding by CDC, WHO and CHP guidelines,
face shield should be used by all surgeon(s) for AGP including
tracheostomy and laryngectomy. For non-AGP, face shield for second
assistant may not be warranted. Given the low droplet count on face
shields of the operating surgeon and first assistant, one could argue
against the need for face shield as an adjunctive PPE to goggles and
adequate respiratory device for the aforementioned procedures which are
non-aerosol-generating.

For TORS, docking was performed by the operating surgeon prior to
commencement of surgery. In order to prevent droplet splash the
following steps have been taken: (1) ensure that the cuff of the
endotracheal tube was inflated with no evidence of air leak (2) Fr 16
Nelaton suction catheter was placed through the remaining nostril down
to the level of the oropharynx for suctioning of saliva prior to docking
and also of blood and diathermy smoke and aerosols during the operation.
There were no droplets noted on the operating surgeon's face shield
during docking and none noted on the first assistant's face shield after
the operation. Hence face shield is not necessary for the operating and
assistant surgeons when performing TORS.

Average droplet count from non-mucosal, non-osteotomy related surgical
procedures such as neck dissection and free flap harvest was minimal on
both the operating surgeon's and first assistant's face shields, mainly
affecting the lower half of the face. One drop was noted in the lower
half of the second assistant's face shield during modified radical neck
dissection. Given the low droplet count and low risk of aerosol
generation of such procedures, one could argue against the routine use
of a face shield as an adjunctive PPE for all surgeons when resources
are low during the COVID-19 pandemic.

Given proper eye protection and adequate respiratory device, results
from our preliminary study suggested that face shield as an adjunctive
PPE was not mandatory for all head and neck surgical procedures. The
following recommendations can be made when performing head and neck
cancer surgery in an attempt to conserve PPE during the COVID-19
pandemic: (1) All operations are to be performed by an experienced
surgeon assisted by specialists in the field of head and neck surgery in
order to minimise operation time and droplet contamination. (2) Number
of surgeons should be kept at a minimum for all procedures not limiting
to AGP. (3) Face shield is advocated for operating and assistant
surgeons for procedures involving osteotomies. (4) Conforming to CDC,
WHO and CHP guidelines, face shield should be worn by surgeon(s)
performing AGP in unknown, suspected and confirmed cases. (5) For
non-AGP involving mucosa of the upper aerodigestive tract, face shield
can be provided to the operating and first assistant surgeon if
resources allow. (6) Routine use of a face shield as adjunctive PPE is
not necessary for all parties when performing TORS and all non-AGP,
non-mucosal and non-osteotomy related procedures. (7) Scrub nurse could
be spared of using a face shield for all non-AGP. (8) If resources
allow, all patients to be operated on can be quarantined in hospital 14
days prior to surgery, followed by 2 sets of PCR tests performed 24
hours apart. This would further ensure that patients are COVID-19 free
prior to operation whereby we can revert to standard droplet
precautions. Larger scale studies with more patients, procedures and
operating surgeons is warranted to justify such recommendations. Other
means to conserve PPE for instance the role and efficacy of N95
respirator versus medical masks in preventing viral transmission is
beyond the scope of this study.

\textbf{CONCLUSION}

During the COVID-19 pandemic, it is our collective responsibility to
conserve PPE when treating head and neck cancer patients whilst
preventing viral transmission to health care providers. Reduction in
patient volume, limiting the number of health care providers and
judicious use of PPE are ways to minimise wastage. Practices and
recommendations made in this document are intended to support safe
clinical practice and efficient use of resources during this challenging
time.

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\end{enumerate}

\textbf{LEGEND FOR FIGURES}

\textbf{Figure 1.}

\textbf{}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/HED-20-0538-COVID-19-PPE-Figure-1/HED-20-0538-COVID-19-PPE-Figure-1}
\caption{{This is a caption
{\label{327663}}%
}}
\end{center}
\end{figure}

Face shield placed on white background with grid prior to droplet count
with surgical microscope.

\textbf{Figure 2.}

\textbf{}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/HED-20-0538-COVID-19-PPE-Figure-2/HED-20-0538-COVID-19-PPE-Figure-2}
\caption{{This is a caption
{\label{570320}}%
}}
\end{center}
\end{figure}

Two blood-stained droplets viewed under surgical microscope at 7.8x
magnification.

\textbf{Figure 3.}

\textbf{}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/HED-20-0538-COVID-19-PPE-Figure-3/HED-20-0538-COVID-19-PPE-Figure-3}
\caption{{This is a caption
{\label{660222}}%
}}
\end{center}
\end{figure}

Plots of droplet splash and distribution with red marker based on face
shield of operating surgeon during manubrial resection.

\textbf{Figure 4.}

\textbf{}

\textbf{Hosted file}

\verb`HED-20-0538_COVID-19_PPE_Figure_4-_.docx`  available at \url{https://authorea.com/users/312328/articles/443229-conservation-of-personal-protective-equipment-for-head-and-neck-cancer-surgery-during-covid-19-pandemic}

Labelling of grids from 1-12.

\textbf{LEGEND FOR TABLE}

\textbf{Table 1.}

\textbf{}

\textbf{Hosted file}

\verb`HED-20-0538_COVID-19_PPE_Table_1.docx`  available at \url{https://authorea.com/users/312328/articles/443229-conservation-of-personal-protective-equipment-for-head-and-neck-cancer-surgery-during-covid-19-pandemic}

Operating procedures, droplet count and distribution by zone for
operating surgeon, 1\textsuperscript{st} and
2\textsuperscript{nd}assistant surgeon and scrub nurse.

\selectlanguage{english}
\FloatBarrier
\end{document}

