PPE for Airway Procedures
Otolaryngologists are commonly involved in AGPs requiring open or
endoscopic airway instrumentation, including tracheostomy, direct
laryngoscopy with interventions, and endotracheal intubation. A
systematic review meant to assess the relative risk of transmission of
SARS-CoV1 during a spectrum of AGPs found endotracheal intubation (odds
ratio [OR]=6.6) and tracheostomy (OR=4.2) to be among the
highest-risk procedures.15 On April 2, the American
Academy of Otolaryngology (AAO) released an updated position statement
recommending against elective tracheostomy within the first 2-3 weeks
following intubation, in patients with high-pressure ventilatory
requirements, and in patients without COVID-19
testing.16 Moreover, there is little existing evidence
suggesting a definitive overall survival benefit associated with early
tracheostomy among critically-ill patients.17 As such,
the theoretical remaining benefits of early, elective tracheostomy (e.g.
laryngotracheal morbidity) must be carefully weighed against the known
risk of SARS-CoV2 transmission during tracheotomy procedures, when the
option to bide time until viral clearance or ventilatory independence
occurs. However, if patient circumstances (e.g. bulky head and neck
tumor) necessitate a tracheostomy or elective tracheostomy is performed,
appropriate PPE is strictly necessary.
PPE for tracheostomy procedures should abide by airborne-level
precautions, which include an N95 mask with eye protection or PAPR,
surgical cap, long-sleeved waterproof surgical gowns, gloves, and
shoe/leg covers to prevent tracking. Some groups, cultivating their
experience from treatment of either SARS-CoV1 or SARS-CoV2 patients,
have advocated for enhanced PPE during high-risk, airway procedures,
such as tracheostomy, including full face-shields or helmets with full
face coverage and double gloves, or concomitant N95 and PAPR
use.18,19 Other important considerations include 1)
possibility of performing open tracheostomy in a negative-pressure room
in the intensive care unit, to minimize unnecessary ventilatory circuit
manipulation for patient transport; 2) complete muscular paralysis, when
permitted (i.e. not awake tracheostomy), during the procedure to
minimize coughing with an open airway; 3) minimization of electrocautery
to mitigate the potential transmission of aerosolized virions through
smoke20, and, 4) use of a closed tracheal suction
system with a viral filter. While percutaneous tracheostomy can be
considered as an alternative to intraoperative open tracheostomy, there
may be similar, if not more significant, risk of aerosolization given
the need for bronchoscopy and serial instrumentation of the airway for
dilation.21 If awake tracheostomy cannot be avoided,
additional unique considerations include adequate local anesthesia to
prevent patient movement during the procedure, and a patient surgical
facemask, with low-flow oxygen administration via nasal cannula, if
necessary, to reduce large droplet transmission with coughing. Routine
tracheostomy tube exchanges should be delayed in COVID-19 patients to
limit airway manipulation; instead, simple cuff deflation should be
considered to reduce mucosal irritation and facilitate phonation. If
exchange is performed, standard airborne-level PPE (N95, eye protection
or full faceshields, surgical gown, and gloves) should be donned by
participating providers, including nurses and respiratory therapists.
Though specific guidelines have not been formulated for suspension
microlaryngoscopy, the procedure exposes the distal airway with positive
pressure ongoing (albeit with a seal created by the endotracheal tube
cuff), and involves instrumentation of the respiratory mucosa. Given the
CDC’s current characterization of intubation and bronchoscopy as
“high-risk” procedures (i.e. either aerosolizing or associated with
poor control of respiratory secretions), airborne precautions should be
strongly considered for suspension microlaryngoscopy if surgery cannot
be delayed (e.g. laryngeal cancer with marginal endoscopic
resectability).22 Use of laser is common during
microlaryngoscopic procedures; the risk of human papilloma virus (HPV)
transmission has been studied in this setting. A study by Kunachack et
al. found that no viable HPV virions could be cultured from CO2 laser
plume.23 Another study by Ferenczy et al. found HPV
DNA in the prefilter section of the smoke evacuator used to clear the
surgical field of the laser plume; the inner, postfilter sections of the
smoke evacuator, however were devoid of viral DNA.24While iatrogenic inoculation of the surgeon is not a widely reported
phenomenon in the treatment of HPV related disease, it is unclear if
empirical measures, including use of a smoke evacuator with a
high-efficiency filter, or prior research concerning HPV would be
applicable to SARS-CoV2. Lastly, jet ventilation should be avoided, if
possible, given the procedure’s high applied pressure without an
inflated cuff as a barrier to aerosolized virions. (Table 1)
Unless the otolaryngologist is required in the operating room during
endotracheal intubation of COVID-positive or suspicious patients (e.g.
if the risk of a surgical airway is high), only anesthesia providers
should be present during intubation with appropriate PPE donned. A
statement issued by the American Society of Anesthesiologists
recommended standard airborne-level PPE (N95 respiratory with eye
protection or facial protection covering the sides of the face versus
PAPR, waterproof gown, and gloves) be worn by providers present during
intubations for patients with confirmed or suspected
COVID-19.25 Additional recommendations for the
intubating provider include use of videolaryngoscopy to allow for
greater distance between the provider and the patient and prompt
inflation of the endotracheal tube cuff after passage through the vocal
cords to create a seal before initiation of positive pressure
ventilation.