Aerosolization risk during endoscopic transnasal surgery: a prospective qualitative and quantitative microscopic analysis of particles spreading in the operating room

OBJECTIVE The coronavirus disease 2019 (COVID-19) pandemic represents the greatest public health emergency of this century. The primary mode of viral transmission is droplet transmission through direct contact with large droplets generated during breathing, talking, coughing, and sneezing. However, the virus can also demonstrate airborne transmission through smaller droplets (< 5 μm in diameter) generated during various medical procedures, collectively termed aerosol-generating procedures. The aim of this study was to analyze droplet contamination of healthcare workers and splatter patterns in the operating theater that resulted from endoscopic transnasal procedures in noninfected patients. METHODS A prospective nonrandomized microscopic evaluation of contaminants generated during 10 endoscopic transnasal procedures performed from May 14 to June 11, 2020, in the same operating theater was carried out. A dilution of monosodium fluorescein, repeatedly instilled through nasal irrigation, was used as a marker of contaminants generated during surgical procedures. Contaminants were collected on detectors worn by healthcare workers and placed in standard points in the operating theater. Analysis of number, dimensions, and characteristics of contaminants was carried out with fluorescence microscopy. RESULTS A total of 70 samples collected from 10 surgical procedures were analyzed. Liquid droplets and solid-tissue fragments were identified as contaminants on all detectors analyzed. All healthcare workers appeared to have been exposed to a significant number of contaminants. A significant degree of contamination was observed in every site of the operating room. The mean (range) diameter of liquid droplets was 4.1 (1.0-26.6) μm and that of solid fragments was 23.6 (3.5-263.3) μm. CONCLUSIONS Endoscopic endonasal surgery is associated with the generation of large amounts of contaminants, some of which measure less than 5 μm. All healthcare workers in the surgical room are exposed to a significant and similar risk of contamination; therefore, adequate personal protective equipment should be employed when performing endoscopic endonasal surgical procedures.