Berit Reinmüller

Single-use surgical clothing system for reduction of airborne bacteria in the operating room.

It is desirable to maintain a low bacterial count in the operating room air to prevent surgical site infection. This can be achieved by ventilation or by all staff in the operating room wearing clothes made from low-permeable material (i.e. clean air suits). We investigated whether there was a difference in protective efficacy between a single-use clothing system made of polypropylene and a reusable clothing system made of a mixed material (cotton/polyester) by testing both in a dispersal chamber and during surgical procedures. Counts of colony-forming units (cfu)/m(3) air were significantly lower when using the single-use clothing system in both settings.

Comparison of three distinct surgical clothing systems for protection from air-borne bacteria: A prospective observational study.

BackgroundTo prevent surgical site infection it is desirable to keep bacterial counts low in the operating room air during orthopaedic surgery, especially prosthetic surgery. As the air-borne bacteria are mainly derived from the skin flora of the personnel present in the operating room a reduction could be achieved by using a clothing system for staff made from a material fulfilling the requirements in the standard EN 13795. The aim of this study was to compare the protective capacity between three clothing systems made of different materials – one mixed cotton/polyester and two polyesters - which all had passed the tests according to EN 13795.MethodsMeasuring of CFU/m3 air was performed during 21 orthopaedic procedures performed in four operating rooms with turbulent, mixing ventilation with air flows of 755 – 1,050 L/s. All staff in the operating room wore clothes made from the same material during each surgical procedure.ResultsThe source strength (mean value of CFU emitted from one person per second) calculated for the three garments were 4.1, 2.4 and 0.6 respectively. In an operating room with an air flow of 755 L/s both clothing systems made of polyester reduced the amount of CFU/m3 significantly compared to the clothing system made from mixed material. In an operating room with air intake of 1,050 L/s a significant reduction was only achieved with the polyester that had the lowest source strength.ConclusionsPolyester has a better protective capacity than cotton/polyester. There is need for more discriminating tests of the protective efficacy of textile materials intended to use for operating garment.

Clothing Systems in Operating Rooms – A Comparative Study

The number of airborne bacteria-carrying particles in the operating room is considered an indicator of the risk of infections to the patient undergoing surgery. When the supply air in the operating room is HEPA-filtered, the main source of microorganisms is people (patient and staff). The filtration efficacy of the fabric in operating clothing systems plays an important role. The design of the clothing systems also affects the number of particles emitted from people into the air of the operating room. In ultraclean operating rooms, the selection of clothing systems for the operating team should be considered in terms of patient safety. Examples of clothing systems evaluated in operating rooms will be presented. The predicted influence of different clothing systems in the operating room will be discussed.

10 – LOCAL VENTILATION

This chapter describes the aerodynamic principles, models, and equations that govern the flow and the contaminant presence and transport in a designated volume of a workroom. Local ventilation is often a very important part of the ventilation system, both in function and in construction. By using a local ventilation system of good design less air is needed to reach a specific contaminant level than is possible with general ventilation. Proper design and construction of a local ventilation system must account for hood flow rate, contaminant generation process and rate, and the generated flow rate of contaminated air. Thus, knowledge about airflow mechanics, process performance, and the contaminant source is essential. The purpose of local ventilation is to control the transport of contaminants at or near the source of emission, thus minimizing the contaminants in the workplace air. All local ventilation systems can, in principle, be manufactured for use in one or more of three different modes: fixed, flexible, and mobile.

SOME OBSERVATIONS ON AIR MOVEMENTS IN CLEAN ROOMS WITH UNIDIRECTIONAL AIR FLOW

ABSTRACT To avoid particle contamination in clean process production, unidirectional air flow with HEPA-filtered air is used, either in the entire room or partly in the critical process region (clean air zones), the purpose of this presentation is to describe a number of observations in unidirectional air flow and to discuss the interaction between air movements and the dispersion of airborne contaminants, it has been shown, by using smoke photography technique, that wake regions and vortex streets can easily be formed behind the working operator and objects. If a contaminant is emitted in the region of a vortex an accumulation can occur. It is important for the user to investigate that such vortices do not occur in the clean working zone.