Operating Room and Hospital Air Environment

One method of preventing surgical-site infection is lowering intraoperative environmental contamination. The authors sought to evaluate their hospital's operating room (OR) contamination rate and compare it with the remainder of the hospital. They tested environmental contamination in preoperative, intraoperative, and postoperative settings for a total joint arthroplasty patient. A total of 190 air settle plates composed of trypsin soy agar were placed in 19 settings within the hospital. Locations included the OR with light and heavy traffic, with and without masks, jackets, and shoe covers; the substerile room; OR hallways; the sterile equipment processing center; preoperative areas; post-anesthesia care units; orthopedic floors; the emergency department; OR locker rooms and restrooms; a resident's home; and controls. The trypsin soy agar plates were incubated at 36 degrees C for 48 hours. Colony counts were performed for each plate. Average colony-forming units (CFUs) were calculated in each setting. The highest CFUs were in the OR locker room, at 28 CFUs per plate per hour. Preoperative and post-anesthesia care unit holding areas were 7.4 CFUs and 9.6 CFUs, respectively. The main orthopedic surgical ward had 10.0 CFUs per plate per hour, whereas the VIP hospital ward had 17.0 CFUs per plate per hour. All OR environments had low CFUs. A live OR had slightly higher CFUs than settings without OR personnel. In comparison with the local community household, the OR locker room, restrooms, hospital orthopedic wards, emergency department, preoperative holding, postanesthesia care unit, and OR hallway all had higher airborne contamination. On the basis of these results, the authors recommend environmental sampling as a simple, fast, inexpensive tool for monitoring airborne contamination.