Increased Frequency – Other Modalities
Although most reports of increased frequency regimens describe HD (both low and high flux) other dialysis modalities such as hemofiltration and hemodiafiltration have also been used. Maduell et al. recently reported the experience of 8 patients converted from standard thrice weekly 4-hours on-line hemodiafiltration (stdHDF) to daily HDF (DHDF) 2-2.5 hours 6 times weekly1. The patients were followed up for 6 months. Significant increases in weekly removal for large molecules (up to 23 kD) were reported but a consistent reduction in concentration was only identified for β2-microglobulin. No changes were identified for hemoglobin, EPO dose, serum lipids. There was an insignificant trend for lowering of C-reactive protein and fibrinogen. Despite unchanged BP, DHDF was associated with a large reduction in LVMI (97.9 ± 45 to 68.9 ± 22 g/m2).
Significant increase in the weekly percentage removal of solutes with daily HDF. Based on reference 1.
Fishbach et al. reported conversion of 5 unstable children with impaired cardiac function from stdHDF (4 hours thrice weekly) to DHDF (3 hours 6 times weekly)2. The results were encouraging. Anemia improved with a lower EPO dose. Serum phosphate and the calcium-phosphorus product fell, as did serum β2-microglobulin and homocysteine. In addition, significant improvements were seen for control of BP and in cardiac function. Catch-up growth occurred in one patient with severe growth retardation.
Daily hemofiltration can be applied using an on-line system or a system where replacement fluid is provided in PVC bags. There are theoretical issues regarding adequacy of small solute removal with hemofiltration, particularly where practiced in a short daily regimen. As yet, there is inadequate clinical information to assess this modality.
- Maduell F, Navarro V, Torregrosa E, Rius A, Dicenta F, Cruz MC, Ferrero A. Change from three times a week on-line hemodiafiltration to short daily on-line hemodiafiltration. Kidney Int 64:305-313, 2003
- Fischbach M, Terzic J, Laugel V, Dheu C, Menouer S, Helms P, Livolsi A. Daily on-line haemodiafiltration: a pilot trial in children. Nephrol Dial Transplant 19:2360-2367, 2004