Hemodiafiltration with endogenous reinfusion.

Hemodiafiltration (HDF) is well known to increase the solute convective clearance due to increased ultrafiltration but requires substantial amounts of high-quality reinfusion fluid. Initially in the early 90s, individual bags or containers of reinfusion fluid were used and caused many problems related to handling (storage, repeated connections) and costs. Additionally there was an increased risk of circuit contamination. The interest in HDF pushed technological research for online production of sterile and ultrapure reinfusion solutions. Using a 2-chamber filter, it is possible to produce reinfusion fluid from the ultrafiltrate of the patient, which has been 'regenerated' by a sorbent bed, in a closed circuit. This action eliminates any problems of sterility and apyrogenicity, while also providing the possibility of reinfusing physiologically important substances such as bicarbonates and essential and branched-chain amino acids. This HDF method, called hemofiltrate reinfusion (HFR), has been clinically demonstrated to reduce the loss of physiological components and is associated with decreased inflammation and oxidative stress. In addition to its ease of use, the technique is also highly biocompatible. Based on these observations, HFR appears to be a useful technique for patients with complex risk factors such as malnutrition, inflammation and atherosclerosis.