In vivo studies of dialysis-related endotoxemia and bacteremia

The transfer of bacteria and endotoxin and the development of fever was monitored during hemodialysis of dogs. Bacterial and endotoxin levels in dialysis fluids exceeded those reportedly associated with pyrogenic reactions, and bacteria-free dialysate filtrates administered intravenously were shown to be pyrogenic in 2 of 2 dogs. During 18 hollow-fiber dialyses, neither bacteria nor endotoxin, as measured in the Limulus lysate assay (LLA), was detected in venous and arterial blood samples. Body temperatures did not increase during or within 1/2 h after dialysis. In experiments with parallel dialyzers, contaminated dialysate was simultaneously ultrafiltered into the second blood compartment. Ultrafiltrates were unreactive in the LLA and the absence of pyrogens was confirmed with the pyrogen test, USP, in five of five experiments. This investigation suggests that the intact cellophane membrane of the hollow-fiber dialyzer is an effective barrier to endotoxin and bacteria.