Surgically generated aerosol and mitigation strategies: combined use of irrigation, respirators and suction massively reduces particulate matter aerosol

Abstract

Background: Aerosol is a health risk to theatre staff. This laboratory study quantifies the reduction in particulate matter aerosol concentrations produced by electrocautery and drilling when using mitigation strategies such as irrigation, respirator filtration and suction in a lab environment to prepare for future work under live OR conditions.

Methods: We combined one aerosol-generating procedure (monopolar cutting or coagulating diathermy or high-speed diamond- or steel-tipped drilling of cadaveric porcine tissue) with one or multiple mitigation strategies (instrument irrigation, plume suction and filtration using an FFP3 respirator filter) and using an optical particle counter to measure particulate matter aerosol size and concentrations.

Results: Significant aerosol concentrations were observed during all aerosol-generating procedures with concentrations exceeding 3 × 10⁶ particles per 100 ml. Considerable reductions in concentrations were observed with mitigation. In drilling, suction, FFP3 filtration and wash alone respectively reduced aerosol by 19.3-31.6%, 65.1-70.8% and 97.2 to > 99.9%. The greatest reduction (97.38 to > 99.9%) was observed when combining irrigation and filtration. Coagulating diathermy reduced concentrations by 88.0-96.6% relative to cutting, but produced larger particles. Suction alone, and suction with filtration reduced aerosol concentration by 41.0-49.6% and 88.9-97.4% respectively. No tested mitigation strategies returned aerosol concentrations to baseline.

Conclusion: Aerosol concentrations are significantly reduced through the combined use of filtration, suction and irrigation. Further research is required to characterise aerosol concentrations in the live OR and to find acceptable exposure limits, and in their absence, to find methods to further reduce exposure to theatre staff.

Keywords: Aerosol; Filtration; Mitigation; Surgical smoke.

Fig. 1

Aerosol particle size distribution for experimental condition using the ‘Precision’ Burr, plotted with a (a) standard scale and a (b) logarithmic scale. Error bars represent 1 S.E.M. Particle counts are per 100 ml. Particle sizes are reported as diameter (µm)

Fig. 2

Aerosol particle size distribution for experimental condition using the ‘Diamond’ Burr comparing with equivalent conditions obtained using the ‘Precision’ burr, plotted with a (a) standard scale and a (b) logarithmic scale. Error bars represent 1 S.E.M. Particle counts are per 100 ml. Particle sizes are reported as diameter (µm)

Fig. 3

Aerosol particle size distribution for experimental condition using cutting and coagulating monopolar electrocautery, plotted with a (a) standard scale and a (b) logarithmic scale. Error bars represent 1 S.E.M. Particle counts are per 100 ml. Particle sizes are reported as diameter (µm)