[Investigations on the concentration of air-borne germs in conventionally air-conditioned operating theaters (author's transl)].

The factors influencing the concentration of air-borne bacteria during operations have been analysed. It was found that the concentration of air-borne bacteria depended primarily on the number of persons present in the operating theater, the air exchange rate per hour and the room volume. Persons with sterile dress were found to have much less influence than did persons with unsterile dress. A formula describing the relationship between the average concentration of air-borne germs in operating theaters, the number of persons in sterile and unsterile dress, the air exchange rate and the room volume was derived. In a total of 142 operations, the formula has been found to give reliable estimates of the concentration of air-borne germs. This equation can be used for testing whether or not the concentration of air-borne bacteria in an operating theater is within acceptable limits which have been defined.