[Optimum utilization of the ventilation system to reduce airborne bacteria in operating rooms]

In 4 operating theatres with 4 different air-conditioning equipments, the number of bacteria per m3 circulating air in the neighbourhood of the open wound has been investigated. The testing has been performed on comparable aseptic operations. The worst results were obtained in 2 conventional theatres, equipped with a modern-up-to-date air-conditioning. The number of bacteria was ranging between 230 and 270 per m3. A much better results was obtained in a theatre, equipped with a so-called germ-stop-wall, dividing the theatre into 2 sections, separating the surgical team and the open wound completely from the anaesthesist and other staff. With this arrangement, 45 germs per m3 were found. The best result with no bacteria at all is present in a vertical flow-enclosure with an exchange rate of 32 per hour. According to our 10-year experience, for aseptic surgery sterile air techniques should be adopted to improve asepsis and to decrease the risk of postoperative infection.