Preliminary Clinical Evaluation of a Novel Airborne Pathogen Containment Device Design: Randomized Open-label Equivalence Trial of Patient Safety and Acceptability During Endotracheal Intubation.

Background and Rationale Pandemic spread of COVID-19 presents an unprecedented challenge for health care systems around the world. A highly infectious respiratory virus with long incubation, asymptomatic transmission and environmental stability, SARS-CoV-2 places health care workers (HCWs) at risk of contracting the infection and transmitting it to patients. The early problems with personal protective equipment (PPE) supply have led to a renewed urgency to develop a number of different layers of mitigation. Together, these would offer equitable protection and rational supply management. Central to PPE use are questions related to the type (droplets, aerosol or contact) and magnitude (viral load) of the risk in specific situations. Given the unprecedented transmissibility of the newer variants, there is an interest in further mitigating potential exposure. This would be particularly relevant for procedures that limit ability to apply source control such as masking the infectious individual.

Transmission of SARS-CoV-2 is currently understood to occur primarily by respiratory droplets (> 20 microns in diameter), aerosols (< 5 microns) and direct mucosal contact with respiratory secretions. While aerosolization during aerosol generating medical procedures (AGMP) is still a significant focus of infection control protocols, it is increasingly clear that physiologic aerosolization is at least as important. Aerosols containing viral particles can remain suspended and viable in the air for up to 3 hours under experimental conditions. They can be carried by airstream and, when inhaled, be deposited into the lungs as deep as the alveoli. In the setting of perioperative care, AGMPs are administration of oxygen by high-flow nasal cannula, non-invasive positive pressure ventilation, endotracheal intubation and extubation. To minimize aerosol contamination of the facility, Canadian Anesthesiologists' Society and American Society of Anesthesiologists recommend that airway management should ideally be performed in a negative pressure room, while avoiding direct flow of pressurized gas into the patient's airway. This is achieved by limiting flow rate during preoxygenation, ensuring deep muscle relaxation to avoid cough, applying a HEPA filter to the endotracheal tube and inflating the tracheal cuff prior to connecting the ventilator circuit. Very few operating rooms in Canada (and worldwide) are built as isolation rooms. Furthermore, the risk to HCWs who are in the immediate vicinity of the source, performing the procedure, is however, minimally mitigated by these measures.

The ability to apply source control and contain the spread of aerosol at the time of AGMP including extubation would ensure timely patient care without compromising HCW safety and with minimal risk of facility contamination. Several improvised passive intubation shields or boxes have been reported, with significant limitations that make them likely ineffective and potentially harmful. The research proposed in this application builds on our original device design that has addressed the shortcomings of aerosol boxes. This study will provide much needed knowledge about safe clinical use to build on the research team's simulation trials (research funded by the IWK Research Foundation Project Grant).

The device is designed to: (1) be simple and intuitive to use (2) be portable and rapidly deployed (3) provide ergonomic operator access (4) contain the spread of aerosols (5) permanently trap contaminants while minimizing the risk of aerosol resuspension during removal and room cleaning (6) be easily and safely disposed of and (7) inexpensive. Previous testing of the ease of use, potential safety implications and the impact on facility contamination has provided evidence that informs clinical evaluation in this study. Study findings may extend to health system management, public health response, decision-making and planning within and across jurisdictions in Canada and internationally.

This equivalence trial will aim to determine whether intubation with the flexible, disposable, active aerosol containment device is similar to intubation without the enclosure device with respect to intubation times, secondary safety endpoint and exploratory endpoints representing patient and anesthesiologist experiences and perceptions.