RESUMEN
OBJECTIVE: The efficacy of previously developed respiratory barrier enclosures to limit healthcare workers' exposure to aerosols from COVID-19 patients remains unclear; in addition, the design of these devices is unsuitable for transportation or other emergency procedures. Therefore, we developed a novel negative pressure respiratory isolator to improve protection from patient-generated aerosols and evaluated its protective effect in conversion to systemic isolator. METHODS: This in vitro study simulated droplets by nebulizing 1% glycerol + 99% ethanol solution. We performed cardiopulmonary resuscitation (CPR) and converted a respiratory barrier enclosure into a systemic isolator with a respiratory barrier as well as a respiratory barrier with negative pressure generator (NPG), which were compared with control and room air. During the procedure, particles were counted for 30 seconds and the count was repeated 10 times. RESULTS: During CPR, the total number of particles in the respiratory barrier with NPG (280,529; interquartile range [IQR], 205,263-359,195; P=0.970) was similar to that in the control (308,789; IQR, 175,056-473,276). Using NPG with a respiratory barrier reduced the number of particles to 27,524 (IQR, 26,703- 28,905; P=0.001). Particle number during conversion of the respiratory barrier into a systemic isolator was also lower than in the control (25,845; IQR, 19,391- 29,772; P=0.001). CONCLUSION: The novel isolator was converted to a systemic isolator without air leakage. The aerosol-blocking effect of the isolator was quantified using a particle counter during CPR. Further studies comparing the barrier effect of isolators within various pressure differentials are warranted.
RESUMEN
OBJECTIVE: This study aimed to introduce a novel negative pressure aerosol box (Carrycure Isolator) and to test its efficiency and limitations, with the hope of suggesting improvements and further directions. METHODS: A novel aerosol box (Carrycure Isolator) was invented. A single-center, randomized, crossover simulation study of 28 emergency medicine physicians was designed. Three trials of each participant using an intubation manikin were conducted, including intubation without the aerosol box (trial A), intubation with the aerosol box (trial B), and intubation with the aerosol box after familiarization (trial C). The primary endpoint was the time to intubation. The secondary endpoints were first-attempt success, number of attempts, percentage of glottic opening score, and Cormack-Lehane view. Collected data were statistically analyzed for their significance. RESULTS: The median times to intubation of trials A, B, and C were 30.5 (interquartile range [IQR], 28.0-40.0 seconds), 59.0 (IQR, 50.0-75.5 seconds), and 34.0 seconds (IQR, 30.5-47.0 seconds), respectively. Post hoc analysis showed that the time to intubation in trial B was significantly longer than that in trial A (P<0.05), while that the time to intubation in trial C was significantly shorter than that in trial B (P<0.05). RESULTS: concerning secondary endpoints showed similar patterns. Participants reported performing intubation with Carrycure Isolator to be relatively difficult, necessitating significant arm movement and view restrictions while increasing their time to intubation. CONCLUSION: Physicians took a longer time to intubate a manikin using the Carrycure Isolator, a novel negative pressure aerosol box. However, the time was improved after a period of familiarization.
