OPTIMIZATION OF ULTRACLEAN AIR - THE ROLE OF INSTRUMENT PREPARATION

The use of ultraclean air (UCA) in operating theatres reduces the infe ction rate after joint replacement but some cases of infection still o ccur, We investigated one possible source of contamination, namely the setting up of instruments in a conventional plenum-ventilated prepara tion room, We measured bacterial fallout using agar settle plates and compared instruments set up in the preparation room with those set up in the UCA theatre, assessed the effect of covering instruments after preparation and compared fallout during their preparation with total f allout throughout the operation, Our findings showed that covering the instruments reduced total bacterial fallout fourfold by reducing the exposure time, particularly during periods of increased activity and b acterial dispersal, Preparation in the UCA theatre and subsequent cove ring of the instruments reduced total fallout 28-fold, All measurable bacterial fallout occurred during the setting up and not during surger y.