Aerosol boxes decrease aerosol exposure only in depressurized rooms during aerosol-generating procedures in a simulation study

Purpose The aim of this study was to compare aerosol exposure with or without an aerosol box in a pressurized/depressurized room during aerosol-generating procedures using an experimental model. Methods Cake flour (aerosol model) was expelled from an advanced life support training mannequin. The primary outcome measure was the number of 0.3-10 mu m-sized particles at three locations corresponding to the physician, medical staff, and environmental aerosol exposure levels. The aerosol dispersion was visualized using a high-resolution video. The number of expelled particles was measured after artificial coughing during simulated tracheal intubation and extubation in four situations, with or without an aerosol box in a pressurized or depressurized room (<= 2.5 Pa). Results The particles arising from tracheal intubation at the three positions in the four groups differed significantly in size (p < 0.05). The sizes of particles arising from extubation at the physicians' and medical staff's faces in the four groups differed significantly in size (p < 0.05). Post hoc analysis showed that the counts of all particles at the three positions were significantly lower in the depressurized room with an aerosol box than in the pressurized room without an aerosol box during tracheal intubation (p < 0.05 at three positions) and extubation (p < 0.05) at the physician's and medical staff's positions). Visual assessments supported these results. Conclusion The aerosol box decreased the exposure of the aerosol to the physician, medical staff, and environment during aerosol-generating procedures in the depressurized room only.