Development and validation of a patient face-mounted, negative-pressure antechamber for reducing exposure of healthcare workers to aerosolized particles during endonasal surgery

Abstract

OBJECTIVE The authors developed a negative-pressure, patient face-mounted antechamber and tested its efficacy as a tool for sequestering aerated particles and improving the safety of endonasal surgical procedures. METHODS Antechamber prototyping was performed with 3D printing and silicone-elastomer molding. The lowest vacuum settings needed to meet specifications for class I biosafety cabinets (flow rate ≥ 0.38 m/sec) were determined using an anemometer. A cross-validation approach with two different techniques, optical particle sizing and high-speed videography/shadowgraphy, was used to identify the minimum pressures required to sequester aerosolized materials. At the minimum vacuum settings identified, physical parameters were quantified, including flow rate, antechamber pressure, and time to clearance. RESULTS The minimum tube pressures needed to meet specifications for class I biosafety cabinets were −1.0 and −14.5 mm Hg for the surgical chambers with (“closed face”) and without (“open face”) the silicone diaphragm covering the operative port, respectively. Optical particle sizing did not detect aerosol generation from surgical drilling at these vacuum settings; however, videography estimated higher thresholds required to contain aerosols, at −6 and −35 mm Hg. Simulation of surgical movement disrupted aerosol containment visualized by shadowgraphy in the open-faced but not the closed-faced version of the mask; however, the closed-face version of the mask required increased negative pressure (−15 mm Hg) to contain aerosols during surgical simulation. CONCLUSIONS Portable, negative-pressure surgical compartments can contain aerosols from surgical drilling with pressures attainable by standard hospital and clinic vacuums. Future studies are needed to carefully consider the reliability of different techniques for detecting aerosols.