BackgroundIntraoperative bacterial contamination is a major risk factor for postoperative wound infections. This study investigated the influence of type of ventilation system on intraoperative airborne bacterial burden before and after installation of unidirectional displacement air flow systems.Material/MethodsWe microbiologically monitored 1286 surgeries performed by a single surgical team that moved from operating rooms (ORs) equipped with turbulent mixing ventilation (TMV, according to standard DIN-1946-4 [1999], ORs 1, 2, and 3) to ORs with unidirectional displacement airflow (UDF, according to standard DIN-1946-4, annex D [2008], ORs 7 and 8). The airborne bacteria were collected intraoperatively with sedimentation plates. After incubation for 48 h, we analyzed the average number of bacteria per h, peak values, and correlation to surgery duration. In addition, we compared the last 138 surgeries in ORs 1–3 with the first 138 surgeries in ORs 7 and 8.ResultsIntraoperative airborne bacterial burden was 5.4 CFU/h, 5.5 CFU/h, and 6.1 CFU/h in ORs 1, 2, and 3, respectively. Peak values of burden were 10.7 CFU/h, 11.1 CFU/h, and 11.0 CFU/h in ORs 1, 2, and 3, respectively). With the UDF system, the intraoperative airborne bacterial burden was reduced to 0.21 CFU/h (OR 7) and 0.35 CFU/h (OR 8) on average (p<0.01). Accordingly, peak values decreased to 0.9 CFU/h and 1.0 CFU/h in ORs 7 and 8, respectively (p<0.01). Airborne bacterial burden increased linearly with surgery duration in ORs 1–3, but the UDF system in ORs 7 and 8 kept bacterial levels constantly low (<3 CFU/h). A comparison of the last 138 surgeries before with the first 138 surgeries after changing ORs revealed a 94% reduction in average airborne bacterial burden (5 CFU/h vs. 0.29 CFU/h, p<0.01).ConclusionsThe unidirectional displacement airflow, which fulfills the requirements of standard DIN-1946-4 annex D of 2008, is an effective ventilation system that reduces airborne bacterial burden under real clinical conditions by more than 90%. Although decreased postoperative wound infection incidence was not specifically assessed, it is clear that airborne microbiological burden contributes to surgical infections.

In nursing homes for the aged and hospitals the hygienic requirements should be formally identical. There are considerable differences in actual practice. The reasons for these differences are analysed below. Concrete ways of solution can be based on a variety of different reasons, which make it probable that sensible improvements of hygienic conditions in long-term nursing and nursing for the aged can be attained. Of special significance are the medical officers inspections and official education means to create representatives in hygienic nursing care for the aged.

For hospitals, the Directives for Hospital Hygiene and Prevention of Infection issued by the Robert Koch Institute represent clear and well formulated hygiene guidelines in terms of a set of rules. However, for long-term care facilities there are no standard hygiene procedures, and the above mentioned guideline recommendations are difficult to apply to geriatric and long-term care as well as to rehabilitation. It is left to the institutions themselves to determine the role of hygiene and prevention of infection. Framework guidelines are provided in the Protective Law on Infections and the hygiene requirements contained therein. However, there are no suggestions on how to actually implement the hygiene requirements. This article demonstrates one way in which the protective law might be transferred and used in practice based on the classic procedures of quality management. This is explained as a step-by-step, planned process. The appendix contains one possible structure and excerpts from a control checklist.