Would a Titanium Dioxide Air Cleaner Reduce Colony-Forming Units in Standard Air Ventilation ORs?

Abstract

INTRODUCTION: Operating room air ventilation standards have been established to reduce the likelihood of contracting a surgical site infection (SSI) related to OR air ventilation. A question remains, however, regarding whether newer technology can further reduce the number of circulating airborne contaminants. From September through December 2002, air sampling was performed that compared standard air ventilation and titanium dioxide air filters during cardiovascular surgery at a 360-bed medical center in northwestern Pennsylvania. METHODS: On four separate days in one operating room, microbiological air tests were conducted to determine viable airborne bacterial counts, expressed as colony-forming units per cubic meter of air (CFU/m3). This was accomplished using an N-6 single stage air sampler with an Andersen high-volume air pump calibrated at 28.3 liters per minute. Air was sampled during 3-minute cycles at eight specific locations with the samples deposited on Remel Sheep Blood Agar (SBA) culture plates. Samples were taken at baseline (standard ventilation) and with the titanium filters turned on. RESULTS: For the eight sites in the operating room, an overall ANOVA revealed a significant difference in mean counts for the four sampling times (p=0.0014). Multiple comparison tests revealed that baseline standard air ventilation CFU/m3 values were consistently greater than the titanium dioxide filtered operational tests (p <0.0075). CONCLUSION: The use of titanium filters significantly reduced airborne contamination in the operating room. The fact that the baseline values were nearly identical with the filters off, indicated that good control existed and conditions were similar for each test.