Inconsistent correlation between aerobic bacterial surface and air counts in operating rooms with ultra clean laminar air flows : proposal of a new bacteriological standard for surface contamination.
The relationship between surface contamination (cfus/m2/h) with particles carrying aerobic bacteria and corresponding air contamination rates (cfus/m3) was evaluated in operating rooms (OR) equipped with ultra clean vertical or horizontal laminar airflow (LAF).
For the evaluation we collected data during strictly standardized sham operations using non-woven disposable or cotton clothing.
Air contamination in the wound and instrument areas (Casella slit sampler) was related to the surface contamination rate (settle plates) in the same areas and in addition, on the patient chest.
Typically, the mean surface counts were 20-70 cfus/m2/h and the air counts 1-2 cfus/m3 in disposable clothing experiments hilst the use of cotton clothing resulted in higher counts of 100-200 cfus/m2/h (wound P>0.05, patient P>0.05, instruments P<0.01) and 4 cfus/m3 (P<0.02-0.001).
In the vertical LAF, taking both disposable and cotton clothing operations together, the surface and air contamination rates (surface/air ratio SAR) were highly correlated (P=0.02-0.004) and the ratio varied between 18 : 1 and 50 : 1 with a mean for wound air of 36 : 1. Using only disposable clothing in the vertical LAF, the number of significant correlations was reduced.
With cotton clothing experiments in vertical LAF and in the horizontal LAF using disposable clothing, no significant correlation between surface and air contamination was found. (...)
Mots-clés Pascal : Contamination, Air, Surface, Bloc opératoire, Norme, Bactérie, Aérobie, Ecoulement laminaire, Ecoulement air, Ventilation, Méthode mesure, Hygiène
Mots-clés Pascal anglais : Contamination, Air, Surface, Operating room, Standards, Bacteria, Aerobe, Laminar flow, Air flow, Ventilation, Measurement method, Hygiene
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0411609
Code Inist : 002B05A01. Création : 22/03/2000.