Validity of a photometric method of counting particles in air for control of operating rooms and clean rooms in hospitals
Uriel Latorre B, Seoane Mato D, Alves Pérez MT, Azuara García MJ, García García MJ, Blanco Rodríguez A, Fernández de Armas L, López Álvarez S, Méndez Diéguez MC
Servicio de Medicina Preventiva. Complexo Hospitalario Universitario de Ourense, Ourense, España.
Validate a photometric on-air particle measurement system in order to perform ambient bio-security checks in operating rooms and other clean rooms within hospitals.
Material and methods
A total of 144 coupled air samples were performed, 88 in 8 different operating rooms with conventional ventilation systems and 3-level filtering and 56 in 9 different rooms without specific ventilation systems. Particles were measured in size between 0,1 to 10 μm with the photometric system in mg/m3. Simultaneously in the rooms are performed the sampling air method with impact on culture media. Incubation period is 5 days and count is performed in colony-forming units (CFU/1000L). Finally, optimal cut-points in particles measure were calculated using ROC curves in order to discriminate the three different contamination levels.
Spearman’s correlation coefficient was 0,779 p<0,001. Sensitivity for cut-points in particle counting for the different contamination levels was 95,83% ,100% and 100% respectively, and the corresponding Kappa indexes were 0,51; 0,88 and 0,75.
Correlation among measurements is notable. Particle measurement can be a worthy alternative for some of the routine bio-security checks.
Air microbiology, environmental monitoring/methods, infection control/methods, operating room/standards, particulate matter/analysis.
Correspondencia: B Uriel Latorre e-mail: firstname.lastname@example.org