Would a Titanium Dioxide Air Cleaner Reduce the Colony-Forming Unit Counts in Laminar Air Flow ORs?

INTRODUCTION: A previous study determined that titanium oxide filters added to standard air ventilation reduced the colony-forming units per cubic meter (CFU/m3) in the operating room. Laminar Air Flow has been shown to dramatically reduce CFU/m3 in various studies, however, its use depends on room size, configuration, and ventilation requirements to allow for maximum efficiency. From March through May 2003, air sampling was done to determine the performance of titanium dioxide filters as compared to Laminar Air Flow during orthopedic surgery in a 360-bed medical center in northwestern Pennsylvania. METHODS: In one operating suite, the Laminar Air Flow, titanium dioxide filters, and standard air flow were tested on separate days using microbiological air tests to determine viable airborne bacterial counts. Samples were obtained using an N-6 single stage air sampler with an Andersen high-volume air pump calibrated at 28.3 liters per minute and bacterial growth was expressed as colony-forming units (CFUs) per cubic meter of air (CFU/m3). The air samples collected at eight specific locations were allowed to run for 3-minute cycles and the potential contaminants deposited on Remel Sheep Blood Agar (SBA) culture plates. RESULTS: Using a Friedman Test, the Laminar Air Flow results showed a significant bacterial reduction (p<0.014) in mean counts for the three sampling times as compared to the titanium dioxide filters for the eight sites in the operating room, CONCLUSION: Laminar Air Flow significantly reduced CFUs per cubic meter compared to titanium dioxide filters.