Impact of Aerosol Box Use During Cardiopulmonary Arrest: A Multicenter Study

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.