ZONED EXPONENTIAL, VERTICAL AND HORIZONTAL ULTRA-CLEAN LAMINAR AIR-FLOWS - NO DIFFERENCES IN BACTERIOLOGICAL EFFICIENCY

We compared the novel zoned exponential ultraclean operating room vent ilation, needing no extra side-walls with the traditionally used ultra -clean air systems having vertical or horizontal laminar airflow, but requiring extra side-walls. The three units were evaluated with regard to elimination of particles with focus on airborne and sedimenting ba cteria-carrying particles (colony forming units, cfu) during rigidly s tandardized sham operations. Although minor differences were recorded inside the ultra-clean airflows, the three systems were comparable wit h regard to bacteriological efficiency and ensured a low air and surfa ce contamination (0.05-4 cfu/m(3) and 7-72 cfu/m(2)/h, depending on th e site of sampling). We conclude that all three systems fulfilled well the criteria for ultra-clean air (< 10 cfu/m(3)), but that exponentia l airflow is the most versatile alternative, as additional side-walls around the operating area can be omitted.