Problem to be addressed. The overwhelming scale and severity of the Coronavirus Disease
2019 (COVID-19) pandemic has presented a serious threat to the health of frontline health
care workers (HCWs). Aerosol-generating medical procedures (AGMPs), such as
bag-valve-mask (BVM) ventilation, endotracheal intubation (ETI), and cardiopulmonary
resuscitation (CPR) are commonly required for critically ill COVID-19 patients. AGMPs
produce airborne particles, contributing to the disproportionately high risk of infection
amongst HCWs working in acute care areas. Strategies to mitigate HCWs exposure to and
infection from COVID-19 are required to maintain the integrity of the healthcare
workforce. To minimize HCW exposure during AGMPs, aerosol box devices have been developed
to provide a physical barrier between the patient and the HCW, with the intent of
shielding HCWs from disease particles.

The aerosol box, and its various different adaptations, have been implemented by
hospitals around the world for managing critically ill patients with COVID-19. Studies to
date have demonstrated that aerosol box use potentially reduces spread of aerosolized
particles, but its use is also associated with technical challenges. Studies to date have
focused primarily on the task of ETI, without any evidence describing the impact of
aerosol box use on chest compressions (CC). Furthermore, most studies suffer from small
sample sizes, provided minimal (or no) training on aerosol box use, recruited individuals
(and not resuscitation teams) as participants, failed to quantify the degree of
contamination on providers, or failed to measure airborne particle counts. The study team
recently completed a multicenter randomized trial comparing aerosol box vs. no box use
and demonstrated delayed time to intubation with aerosol box use. However, the study was
done in a limited context (short procedure, airway team of 2 providers, CC not measured),
thus making generalizability to team-based resuscitative care questionable. To date,
there have been no single or multicenter studies concurrently evaluating the effect of
aerosol box use on CPR quality, airborne particle concentration, and HCW contamination
during team-based resuscitative care. As a consequence, it is still unknown if aerosol
boxes are effective in protecting HCWs, and if aerosol box use negatively impacts care
during cardiopulmonary arrest.

The importance and relevance of simulation-based aerosolization studies is highly
dependent upon the use of a realistic model for aerosolization. Several groups have
reported aerosolization devices in the form of cough simulation devices ranging from
hand-held syringes, nasal atomizers, spray guns, bag-valve masking and more advanced air
flow-based devices to simulate cough. Unfortunately, none of these cough simulators were
designed for user-controlled settings of respiratory mechanics (eg. respiratory rate,
volume, flow) while also allowing for performance of intubation and chest compressions.
This study represents the first aerosol box study to use an aerosolization device
comprised of a respiratory simulator allowing for control of respiratory mechanics that
closely mimic those of a real patient, while concurrently allowing performance of AGMPs.

Our study will provide evidence to: (a) evaluate if use of an aerosol box adversely
affects time to completion and quality of critical resuscitation tasks; and (b) determine
if aerosol boxes are effective in reducing airborne particle counts and provider
contamination during team-based cardiac arrest resuscitation. Our long-term goal is to
provide empiric evidence to enhance HCW safety while delivering high quality care during
cardiopulmonary resuscitation. This will be accomplished by creating a cardiac arrest
scenario within a controlled simulated clinical environment, as conducting a similar
study on real patients would be fraught with challenges and risks.

Why is a trial needed now? New COVID-19 variants, variable uptake of immunizations, and
waning immunity amongst the immunized population contribute to the persistent threat of
the COVID-19 pandemic. We've learned how quickly the pandemic can change course, and how
it is important to plan for future pandemics caused by different viruses. Now, more than
ever, it is critical to identify strategies to protect healthcare workers from infection.
HCW infection has led to workforce shortages that negatively impact patient outcome.
Aerosol boxes have been used in some parts of the world to protect HCWs during the
pandemic, but existing evidence gaps have prevented its widespread adoption. A better
understanding of particle dispersion patterns, HCW contamination patterns, and impact on
clinical task performance during resuscitative care will help to inform international
cardiac arrest guidelines.

How will the results of this trial be used? Research assessing strategies to mitigate HCW
risks of contamination are critical to maintaining a viable healthcare workforce during
the pandemic. The proposed study provides further evidence informing the potential use of
aerosol boxes during simulated cardiopulmonary arrest. The research will be the first to
provide a quantitative measure of airborne particles and HCW contamination patterns in
conjunction with clinically important outcome measures. In combination, these metrics
provide key information that will inform clinical practice, institutional airway
management and cardiac arrest policies. Through partnerships (e.g. Heart and Stroke
Foundation of Canada) and longitudinal engagement of key local and national public health
agency stakeholders, the results of this study will be shared with policymakers to enable
evidence-based adaptations to clinical protocols. Existing partnerships within the
International Network for Simulation-based Pediatric Innovation, Research and Education
(INSPIRE network) will enable rapid dissemination of aerosol box training material across
all continents if results are positive. As an author on international COVID-19 and
cardiac arrest resuscitation guidelines, the PI will engage stakeholders to ensure
results inform future International Liaison Committee on Resuscitation (ILCOR) guidelines
for or against use of the aerosol box.

Trial design. A prospective, randomized controlled trial will be conducted across five
sites in North America. Simulation-based research confers the advantage of answering
research questions without risk of harm to HCWs or patients. Three participants will be
recruited to play the roles of airway provider, and two CPR providers in the management
of a simulated, critically ill COVID-19 patient. CPR providers will be trained to provide
CPR coaching to each other. Two trained research assistants will participate in the
resuscitation team as a team leader and bedside nurse/airway assistant and perform these
roles in a standardized manner. Team leaders will not provide any guidance or coaching on
CPR quality. Participants will be randomized by team into either the control arm (i.e. no
aerosol box) or the intervention arm (i.e. use of aerosol box) (Figure 1). Following
randomization, all participants will view a short video orienting them to the simulated
clinical environment. Intervention arm teams will view an additional 5-minute video
orienting them to the design of the aerosol box and including expert-modeled
demonstration of strategies for optimal airway management and delivery of CPR. This
includes how to move the patient within the aerosol box to optimize delivery of CPR. The
training video will be filmed in English and French to permit viewing across all study
sites. After viewing the video, participants will work in teams to practice intubation
and CPR (with aerosol box in place) for a maximum of 15 minutes, providing them
opportunity to coordinate their movements to optimize efficiency. After each procedure,
they will receive feedback from a local airway and aerosol box expert (i.e. site
investigator). Control arm teams will also have opportunity to practice intubation and/or
CPR for 15 min (without aerosol box). After orientation and training, teams will
participate in two sequential simulation scenarios. The order of scenario delivery will
be randomized to eliminate scenario order as a potential confounder. At the end of the
entire session, participants will receive an educational debriefing to discuss
performance issues, infection control measures, and technical skills using a
blended-method approach to debriefing. The Investigators elected not to use a cross-over
study design because of insufficient washout time (between scenarios) and the potential
carry-over effects of learning from the prior scenario influencing performance in the
subsequent scenario.