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

Abstract

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. Résumé Objectif Les patients atteints de la maladie a`coronavirus (COVID-19) courent le risque d'avoir besoin de ventilation me´canique, et les inquie´tudes quant a`la protection des travailleurs de la sante´pendant les interventions me´dicales ge´ne´rant des ae´rosols ont motive´la conception d'une boıˆte pour contenir les ae´rosols. Méthode Nous avons re´alise´une e´tude de simulation croise´e randomise´e sur des mannequins afin de comparer

Comparison of the Efficiency and Usability of Aerosol Box and Intubation Tent on Intubation of a Manikin Using Personal Protective Equipment: A Randomized Crossover Study

“…This corroborates the findings of other manikin studies ( 24 , 27 , 28 ). The median total intubation time in the aerosol box scenario was 30.9 s in our study, which is similar to that reported by Fong et al., but shorter than the time reported by Begley et al.…”

Impact of an aerosol box on time to tracheal intubation: systematic review and meta-analysis

“…Multiple factors, such as increased procedural difficulty, lack of experience, and cognitive overload for the proceduralist, may prolong TTI. 4 , 5 Although a mean delay of 4 s may seem negligible in the overall intubation time sequence, it is important to consider that simulated studies do not fully capture the influence human factors can play in real-life situations. This prolonged TTI should be considered in the context of critically ill patients with COVID-19, where risk of hypoxaemia can be higher, underpinning the importance of minimising apnoea time amongst these patients.…”

Anesthesia care for coronavirus disease (COVID-19) patients: Results from a survey evaluating opinions of American Society of Anesthesiologists (ASA) members

“…A variety of barrier devices (e.g., cover box, or plastic tent) have been suggested to prevent aerosols and droplets from reaching the operator’s face 7 ; one third of respondents expressed being neutral and less than 50% seemed to agree/strongly agree with their use; although we do not know how many of respondents actually tried these devices, it is possible that most perceived the use of intubation boxes to be cumbersome in challenging cases, or that knowledge surrounding the fact that their manipulation may actually redirect aerosolized particles trapped under the shield had already emerged at the time of our survey. [8] , [9] , [10]…”