[Microbiological quality of hemodialysis water: what are the risk factors?]

ABSTRACT

BACKGROUND: A dialyzed patient weekly gets in touch with a large amount of water (on average 350 liters) through the dialysis bath. It is therefore essential that this solution would have a high quality and purity. The aim of our study was to monitor the microbiological quality of the hemodialysis water in order to identify possible factors that could affect it. METHODS: We conducted a cross-sectional study from January 2015 to October 2017 collecting the dialysis water in AOU Careggi. Samples were aseptically collected by specialized technicians and then transported under ice at 4° C to the Laboratory of Biological Hazards of USL Toscana Centro for laboratory analyses. RESULTS: 126 water samples were collected. Coliforms, E. coli, Staphylococcus aureus, enterococci were not detected. Pseudomonas aeruginosa was found in only one sample. Both for CFU at 37° C and at 22° C, the type of device represented the only statistically significant risk factor (OR 15.21 and OR 10.25 respectively) SDS devices had a significantly higher risk of being positive for CFU at 37° C and 22° C. CONCLUSIONS: As our study demonstrated, the system producing dialysis water must be constantly monitored, especially in cases of SDS devices which may be subjected more frequently to a higher contamination, due to their discontinuous use.