Endotoxin and 'on line' production of substitution fluid in haemodiafiltration and haemofiltration.

In dialysis, machines intended for use in the treatment modes haemodiafiltration (HDF) and haemofiltration (HF) have been on the market about 10 years. These machines are equipped to be able to produce the substitution fluid to be used for direct infusion. In principle, this is done by using the reverse osmosis water of the clinic and mixing in concentrates as usual to form dialysis fluid. The dialysis fluid is then filtered in order to prepare it for use as substitution fluid. The volumes used when the substitution fluid is prepared on-line are usually 20-50 litres in HDF mode and 70-150 litres in HF mode. This means that a patient treated 3 times a week is exposed to a total volume of substitution fluid ranging from 3,000 litres to a maximum 23,000 litres a year. Where else in medicine do we see something coming close to this? Because of these large infusion volumes, the issue of endotoxin levels becomes as important as the issue of sterility.