Ultrafiltration of dialysis fluid for hemodialysis.

Since the quality of water in dialysis fluid varies considerably, and, in view of the fact that endotoxin or active derivatives can cause acute side effects in patients, the dialysis fluid must be sterile. The predialyzer fluid in 20 hemodialysis patients was investigated. Bacterial loading was between 5/ml and 5,000/ml, and the endotoxin concentration was high and extremely variable. After ultrafiltration of the dialysis fluid by a polyamide hollow fiber membrane, all samples were free of bacteria, and the concentration of endotoxin was lower than the detectable limit. With this procedure we can obtain sterile dialysis fluid, which is endotoxin free.