Background: The objective of an operating room (OR) ultra-clean ventilation system is to eliminate or reduce the quantity of dust particles and colony-forming units per cubic meter of air (CFU/m3). To achieve this, ultra-clean goal high air change rates per hour are required to reduce the particle load and number of CFU/m3. Aim: To determine the air quality in an ultra-clean OR during surgery, in terms of the number and type of microorganism and quantity of dust particles in order to establish a benchmark. Methods: Number of CFUs and the quantity of dust particles were measured. For measuring the CFUs, sterile extraction hoses were positioned at the incision, the furthest away positioned instrument table, and the periphery. At these locations, air was extracted to determine the quantity of dust particles. Findings: The number of CFU/m3 and particles was on average at wound level ≤1 CFU/m3 resp. 852.679 particles, at instrument table ≤1 CFU/m3 resp. 3.797 particles and in the periphery ≤8 CFU/m3, resp. 4.355 particles. Conclusion: The number of CFUs in the ultra-clean area is below the defined ultra-clean level of ≤10 CFU/m3 for ultra-clean surgery. The quantity of dust particles measured during surgery was higher than the defined ISO 5.
Keywords: colony-forming units; infection prevention; instrument tables; operating room; surgical procedure; ultra clean ventilation systems.