Environmental bacteriology in the unidirectional (vertical) operating room

C. O. Bechtol

An integrated body exhaust/clean air operating room system was evaluated in terms of the microbiologic and particulate contamination control it afforded. The clean air unit was of a vertical unidirectional airflow design and employed high-efficiency particulate air filters to provide air low in both microbes and particulates. The body exhaust portion of the system was composed of an exhaust tube the surgeon's mask, a transparent plastic faceplate, and a microbe-retentive surgical gown and hood. Measurements were made of airborne and surface contamination at the wound site and of microbial burden levels associated with the surgical team. Sampling techniques were designed to parallel those used in a previous study of a horizontal flow/body exhaust system so as to provide comparative data on the effect of airflow configuration on wound site contamination. The data showed the vertical flow room to exhibit significantly lower (P less than .05) contamination levels than the horizontal flow enclosure. Surgical lights, draping techniques, and personnel and material positoning unobstructive to the airstream were judged to the prime factors in reducing wound site contamination.