The effect of a portable HEPA-filtered body exhaust system on airborne microbial contamination in a conventional operating room.

Abstract

To study the effect of a portable HEPA-filtered air exhaust system (Stackhouse Freedom Surgical Helmet System) on airborne microbial contamination in a modern conventional operating room. Microbial air sampling was done with a two-stage Anderson sampler at the wound site during 46 total joint replacements. All operations were performed by the same surgeon in the same operating room at a large community hospital. In 18 cases done without air exhaust hoods, the number of bacterial and fungal colony-forming units (CFU) ranged from 0.6 to 11.7 (mean, 3.6). Air sampling during 28 operations with the operating team in air exhaust hoods revealed a mean of 3.6 CFU (range, 0 to 11.4). Bacterial CFU averaged 3.4 without hoods and 3.2 with exhaust hoods. Coagulase-negative staphylococci were the most common isolates (48% of isolates with hood, 55% without hood). No infections occurred. We concluded that these air exhaust hoods did not lower airborne microbial contamination detectable with this air sampling method, as compared to standard head cover and mask, in a modern conventional operating room.