Environmental bacteriology in the unidirectional (horizontal) operating room.

The continuing attempts to reduce bacterial contamination through clean air systems have been of special interest to surgeons dealing in joint replacement surgery. Although the definitive relationship between airborne contamination and surgical infections is not universally agreed on, there is little question that clean air systems reduce bacterial contamination of the surgical wound at the time of operation. This report reviews the history of surgical infections, presents statistical data that show the reduction of bacterial contamination by a clear air system, and suggests a pragmatic attitude regarding airborne bacterial contamination of surgical wounds.