Impact of aerosol box on intubation during COVID-19: a simulation study of normal and difficult airways

PURPOSE: Patients with coronavirus disease (COVID-19) are at risk of requiring mechanical ventilation, and concerns of protecting healthcare workers during aerosol-generating medical procedures has led to the design of the aerosol box. METHODS: We conducted a randomized crossover mannequin-based simulation study to compare airway management with and without the aerosol box. Thirty-five anesthesiology participants and three critical care participants with more than 50 intubations with videolaryngoscopes were recruited. There were four airway simulations with and without the aerosol box (normal, pharyngeal swelling, cervical spine rigidity, and tongue edema). Each participant intubated the mannequin in eight consecutive simulations. The primary outcome of the study was time to intubation. Secondary outcomes included intubation attempts, optimization maneuvers, and personal protective equipment breaches. RESULTS: Mean (standard deviation [SD]) time to intubation overall with the box was 30.9 (23.0) sec, while the time to intubation without the box was 25.1 (12.2) sec (mean difference, 5.8; 95% confidence interval [CI], −2.9 to 14.5). For the normal airway scenario, the mean (SD) time to intubation was 18.6 (3.5) sec for no box and 20.4 (3.3) sec for box (mean difference, 1.8; 95% CI, 0.2 to 3.4). During difficult airway scenarios only, the time to intubation was 34.4 (25.6) sec with the aerosol box and 27.3 (13.2) sec without the aerosol box (mean difference, 7.1; 95% CI, −2.5 to 16.7). There were more intubation attempts, personal protective equipment breaches, and optimization maneuvers during use of the aerosol box. CONCLUSIONS: In this mannequin-based simulation study, the use of the aerosol box increased the time to intubation in some contexts but not others. Further studies in a clinical setting should be conducted to make appropriate modifications to the aerosol box to fully elicit its efficacy and safety prior to implementation in airway guidelines for managing patients with COVID-19.