SEATTLE—Switching from five-hour hemodialysis (HD) to four-hour hemodiafiltration (HDF) does not significantly alter patient outcomes except for serum albumin levels, according to a new study by French researchers.

Despite a one-hour reduction in treatment time, ultrafiltration tolerance did not change and the average phosphate level did not increase, according to lead investigator Charles Chazot, MD, a nephrologist and the general manager of NephroCare, Tassin, France. B2 microglobulin plasma levels decreased significantly, however. He presented study findings here at the 30th Annual Dialysis Conference.

HDF has been growing in popularity in Europe. It combines conventional HD and hemofiltration (HF), which is exclusively convective (forcing blood through a filter under high pressure). This results in an ultrafiltrate (water and electrolytes). The quantity of ultrafiltrate lost in his process has to be compensated by a matching infusion of replacement fluid.

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HDF improves removal of uremic toxins and decreases the number of hospitalization days. In addition, HDF may result in fewer hypotensive episodes during treatment and may allow for correcting anemia at lowers doses of erythropoiesis-stimulating agents. HDF can increase middle-molecule clearance, so it may result in shorter times on dialysis while making the dialysis session more tolerant for the patient.

Dr. Chazot and his colleagues switched 86 patients from five-hour standard HD three times a week to four hours of HDF three times a week. Of these patients, 71 (43 men and 28 women) remained suitable for analysis with at least three months on both treatments. The subjects had a mean age of 70.4 years. Seven patients were switched back to five-hour standard HD program before three months because they could not tolerate higher ultrafiltration rate.

The switch to HDF resulted in no change in intradialytic hypotension, serum pre-albumin levels, serum phosphate levels, and predialytic systolic or diastolic pressure. Notable changes after the switch occurred with serum albumin, which dipped from a mean of 33.8 g/L on HD to 32.2 g/L on HDF, and B2-microglobulin, which dropped from 31.6 mg/L on HD to 23.4 mg/L on HDF. 

“The lower the level [of B2-microglobulin], the better the survival,” Dr. Chazot told Renal & Urology News.

Among the 86 patients, 60 were surveyed about how they liked or disliked the switch. Of these patients, 49% reported overall satisfaction before the switch compared with 62% after the switch.  In addition, 67% said they did not want to switch back to five-hour HD. After the switch, more patients reported that they were not as tired at the end of their dialysis session or the following day. They also indicated that they were less bothered by cramping.