ULTRAVIOLET LIGHT FOR THE CONTROL OF AIRBORNE BACTERIA IN THE OPERATING ROOM

In 1881 surgical asepsis was initiated by Semmelweis. who showed that improved personal hygiene could diminish contact contamination. Lister subsequently championed antiseptic techniques in the operating room and was a proponent of the “germ theory” of Koch as the cause of infection. Airborne infection was recognized as an entity but the application of aseptic techniques in operating on patients delayed the development of provisions for adequate ventilation in the operating In 1933, Meleney3 reemphasized the importance of airborne bacteria as a cause of wound sepsis. The first significant investigation of the relationship between airborne bacteria and sepsis in burns was completed in 1946 and 1948.4.5 This study showed that the use of “extract ventilation” brought bacteria contaminated air from outside into the operating room. The number of airborne bacteria was effected to the shedding from textiles. hair, skin and the upper respiratory tract of the operating room personnel.’ These observers influence the design of ventilation systems where clean air was brought in under positive pressure and the volume of air was sufficient to rapidly remove airborne microorganisms originating from operating room personnel. The aerospace industry introduced laminar flow with high-efficiency particulate air (HEPA] filters in the early 1960s. The unidirectional airflow (UAF) systems were used in the medical field in 1969.“‘ Charnley and others have indicated that reduction of wound infection was primarily related to UAF rooms even though UAF systems provided clean air relating to particles, but standards of hiologic clean air are not yet defined, nor has the actual effectiveness of UAF in the reduction of wound infection been documented by controlled clinical trials. The airborne spread of infection has been documented, but precise data as to the number of operative wound infections resulting from airborne transmission alone versus other endogenous and exogenous routes are still la~king.“’.~-’~ In the operating room, air is the only unsterile material with access to the wound and to other objects that may be placed in the wound.*’ Airborne bacteria do effect the incidence of wound infection as the number of individuals in the operating room at any given moment increases the chance of wound infection also increases. Traditional methods of reducing airborne bacteria are: (1) air conditioning systems that maintain 12 air exchanges per hour, air inflow near the ceiling with air exit near the floor, mechanical filtration of air prior to entering the operating room, regular cleaning of filters, humidity control at about 5070, and temperature control at approximately 21.1”C; (21 minimal number of personnel in the operating roam; (3) minimal personnel talking and movement; 14) detection and elimination of personnel with (5) adequate nose and face mask and head cover. Many systems have air conditioning now available for airflow control, for the entire room or for local control.