Online-haemodiafiltration vs. conventional haemodialysis: a cross-over study

Abstract

BackgroundThe main short-term advantages of haemodiafiltration (HDF) are supposedly better removal of Beta2-microglobulin (ß2-m) and phosphate, and better haemodynamic stability. The main disadvantage is higher costs. The aim of the study was to compare the clinical and biological parameters associated with HDF and high-flux haemodialysis (HD), using a cross-over design, while maintaining the same dialysis parameters.MethodsAll patients on a 3 × 4 hours schedule were observed during 3 identical 6-months periods: HDF1 – HD – HDF2. The mean values for the 2 last months of each period were compared.ResultsA total of 51 patients (76 % males, 45 % diabetic) with a mean age of 74 ± 15 years, and who had been on dialysis for 49 ± 60 months were included. The mean blood flow (329 ± 27 ml/min), dialysate flow (500 ml/min), and convection volumes (21.6 ± 3.2 L) were recorded. Patient medications were not changed. Predialysis blood pressure, phosphataemia, calcaemia, iPTH, Kt/V, nPNA and intradialytic events were similar throughout the 3 periods. Only serum albumin (34. 4 ± 3.6, 35.9 ± 3.4, 34.1 ± 4 g/L, p < 0. 0001) and ß2-m serum levels (26.1 ± 5.4, 28 ± 6, 26.5 ± 5 mg/L, p < 0.001, values shown for HDF1, HD, HDF2, respectively) were significantly lower during the HDF periods. Factor associated with higher delta serum albumin levels between HD and HDF periods was mainly a lower convection volume.ConclusionComparing HDF and HD, we did not observe any differences in haemodynamic stability or in serum phosphate levels. Only serum ß2-m (−6 % vs. HD) and albumin (−5 % vs. HD) levels changed. The long-term clinical consequences of these biochemical differences should be prospectively assessed.

Comparison of intradialytic plasma volume change between online hemodiafiltration and standard hemodialysis

“…Intradialytic loss of albumin can decrease the vascular refilling, which increases IPVC. Thus, the possible loss of albumin, which is larger in ol-HDF than in std-HD, will overestimate IPVC in ol-HDF than in std-HD [20]. The present findings that post-dialysis Alb levels were similar while pre-dialysis Alb levels were generally lower in std-HD than in ol-HDFs would indicate difference in intradialytic albumin loss between std-HD and ol-HDFs.…”

Effects of online hemodiafiltration on anemia and nutritional status in chronic hemodialysis patients

“…Orasan et al [22] reported that albumin was significantly lower in patients on OL-HDF compared with those on HD after follow-up for 6 and 12 months and concluded that OL-HDF did not improve nutritional status as assessed by albumin. Jean et al [23] also showed that serum albumin level was significantly lower during HDF periods when they observed patients during 3 incidental 6-month periods of HDF1-HD-HDF2. However, similar decreases in serum albumin also occurred in the HD group.…”

Influence of Hemofiltration on Intradialytic Plasma Volume Decrease

“…In the present study, intradialytic Na change in ol-HDF did not differ from the change in HD. However, IPVD could be underestimated in ol-HDF because albumin loss is generally larger in HDF than in HD irrespective of the mode [18]. Nevertheless, recent data suggest that inward oncotic force has little effect on refilling [16].…”

“…While ultrafiltration is the primary determinant of IPVD, other factors could influence IPVD [16-18]. Vascular refilling from interstitial fluid is a major factor, and fluid excess relative to DW may facilitate refilling, and thus decrease IPVD.…”