Experimental evaluation of the efficacy of sanitation procedures in operating rooms

Background There remains much debate on how to define an adequate sanitation protocol in hospital environments. Methods The efficacy of a sanitation protocol in the operating room (OR) of a modern hospital was evaluated by measuring bacterial load on different types of finishing materials of all internal surfaces (ie, walls, floors, and furnishings). Samples were obtained before cleaning and over the subsequent 24 hours. A total of 2124 microbiological samples were collected using RODAC plates and sterile swabs. Results The data demonstrate a very significant postsanitation reduction of bacterial load on floors and furnishings; however, no significant data on walls were obtained, because of the low levels of initial contamination (1.50 to 5.98 cfu/100 cm2 ). The increase in postsanitation bacterial load over time was greater on smooth materials than on porous materials, on which a further reduction in contamination was seen. The study outcomes were confirmed by simulation experiments in which different materials were contaminated with a predetermined bacterial load and then subjected to the sanitation protocol. These simulation experiments were carried out both in vitro and in an eddy-flux testing room that simulated a full-scale OR similar (in terms of architectonic systems) to a real setting. Conclusion Our data demonstrate that the spatial (vertical/horizontal) disposition of materials affects the initial contamination level, which is always much lower on vertical surfaces than on horizontal ones. Moreover, postsanitation bacterial load recovery is dependent on the physical properties of the surface.