Competing interestsThe authors declare that they have no competing interests.Authors’ contributionsHMO selleck chemicals was involved in the concept and design of the study, in the analysis and interpretation of the data, and in the drafting and writing of the manuscript. MvS contributed to the biochemical measurements and the biochemical part of the database, the interpretation of the data and the writing of the manuscript. PJM performed the biochemical measurements and contributed to the interpretation of the data. JPJW contributed to the design of the study, the interpretation of the data and to the writing of the manuscript. AL contributed to the design of the study, in particular of the biochemical measurements, the interpretation of the data and the writing of the manuscript. All authors read and approved the final manuscript.

AcknowledgementsWe are grateful to Matty Koopmans (research nurse) for her efforts to collect the clinical data and the creation of the database.
The article by Bek and colleagues [1] in the previous issue of Critical Care raises an important and frequently unrecognised issue concerned with haemodialysis in a hospital setting. Renal services in hospitals frequently derive their water supply from the hospital water distribution network. Such networks are complex, can contain regions of low flow or stagnation, and frequently incorporate a storage tank to ensure adequate water pressure and availability of supply in times of peak demand. In common with any water distribution network, those in the hospital are subject to biofilm formation.

A number of pathogens (for example, Legionella, pseudomonas, and mycobacteria) thrive in the biofilm and may be up to 3,000 times more resistant to bacteriostats added to the public water supply than their free-floating counterparts [2,3].To minimise risk from nosocomial infections, hospitals employ a range of preventive strategies to control the formation of biofilm, including the use of chemical agents such as silver-stabilised hydrogen peroxide [4,5]. Hydrogen peroxide is an oxidising agent, which at concentrations used for disinfection is considered safe to drink, enabling it to be used in ‘live’ Drug_discovery buildings, and is eco-friendly since it breaks down to water and oxygen. Its effectiveness and stability can be enhanced by the addition of trace amounts of silver (silver-stabilized hydrogen peroxide).For dialysis applications, the unsuitability of drinking water has long been recognised and water for use in dialysis units undergoes additional treatment to reduce contaminant levels to below that specified in national or international standards dealing with water for use in dialysis [6].