Comparison of particle counting and microbiological sampling methods at-rest and during surgery

Abstract

Air quality monitoring in operating rooms is of prime importance because particles that carry microbiological contamination generate serious risks during surgical operations. Air quality monitoring is executed by two separate methods: Microbiological sampling and particle counting. The aim in this project is to investigate statistical correlation between these two methods. If so, particle counting technique could replace frequent microbiological sampling. Microbiological sampling and particle counting techniques are applied in ve operating rooms located at three di erent hospitals with a total number of 360 measurements taken before (at rest) and during surgery. Spearman's correlation coe cient is used for measuring the level of correlation between two methods. The bacteria counts are classi ed after their sizes and tested for size-by-size correlation. Then, the bacterial counts measured at the same site are cumulatively added together and correlated with the particle counts at each particle size-range. No correlation is found when size-by-size correlation is performed. When cumulative bacteria counts are considered in 'at-rest' conditions, the number of particles in 5.0-10.0 m and 10.0-25.0 m size ranges correlated with bacteria counts. Particles of 1.0-5.0 m size ranges and particles larger than 25.0 m correlated with bacteria counts during surgery.|Keywords : Particle Counting, Microbiological Sampling, Air Quality Monitoring, Operating Rooms, Surgery.