VACuum INtubation (VACcIN) box restricts the exhaled air dispersion generated by simulated cough: description and simulation-based tests of an innovative aerosolization protective prototype

Abstract

The COVID-19 pandemic has caused personal protective equipment shortages worldwide and required healthcare workers to develop novel ways of protecting themselves. Anesthesiologists in particular are exposed to increased risks of contamination when performing interventions such as airway manipulations. We developed and tested an aerosolization protective device which contains aerosols around the patient’s airway and helps eliminate particles using negative pressure. This intubation box is a polymethyl methacrylate prism with openings for gloves, integrated suction and ventilation connectors. We conducted a randomised controlled series of tests to detect 0.5 µm particles after a simulated cough inside the intubation box, using a high-fidelity simulation mannequin. Setting and main outcome : We measured particle concentrations inside the box with and without suction turned on, in both negative and positive pressure operating rooms. We also obtained particle concentrations outside our box and compared them to non-airtight barrier devices. One minute following simulated cough, the mean number of particles per cubic foot in our box with suction on is around 45% that with the suction off (1,462,373 vs 3,272,080, P < 0.0001) in the negative pressure room, and four times lower than with the suction off (760,380 vs 3,088,700, P < 0.0001) in the positive pressure room. After a simulated cough inside the box, particles can be detected in front of the anesthesiologist’s face with a non-airtight device, while none are detected when our box is sealed and its suction turned on. The use of our negative pressure intubation box prevents contamination of surroundings and increases particle elimination, regardless of room pressure.

Efficiency, limitations, and familiarization of a novel negative pressure aerosol box for intubation: a simulation-based randomized crossover study

“…16 Previous studies on negative pressure aerosol boxes or vacuum-assisted aerosol boxes have proven their efficacy by showing reduced particles during intubation of a manikin. 19,20 Our previous study with Carrycure Isolator also proved its efficacy by showing a reduction of particles outside Carrycure Isolator during simulated AGMPs performed on a manikin. 12 To test Carrycure Isolator's efficiency, we measured the time to intubation along with the other secondary outcomes mentioned above.…”

“…Efficacy represents the ability to contain aerosol inside the box, usability refers to the user experience, and efficiency is indicated by the time to intubation [ 16 ]. Previous studies on negative pressure aerosol boxes or vacuum-assisted aerosol boxes have proven their efficacy by showing reduced particles during intubation of a manikin [ 19 , 20 ]. Our previous study with the Carrycure Isolator also proved its efficacy by showing a reduction of particles outside the Carrycure Isolator during simulated AGMPs performed on a manikin [ 12 ].…”

Aerosol Box Use in Reducing Health Care Worker Contamination During Airway Procedures (AIRWAY Study)

“…A plastic drape extending from the top of the box down to the patient’s chest prevents spread of aerosols . Suction tubing at the head of the aerosol box was added, as prior studies have demonstrated that continuous suction decreases airborne particle exposure . Wall suction was set at 200 mm Hg, measured to generate a negative airflow of approximately 50 L/min.…”

“… 15 , 17 , 28 Suction tubing at the head of the aerosol box was added, as prior studies have demonstrated that continuous suction decreases airborne particle exposure. 20 , 28 , 29 , 30 , 31 Wall suction was set at 200 mm Hg, measured to generate a negative airflow of approximately 50 L/min.…”